North American Biofiltration Knowledge Base. Appendices A and B. Project #4459

Transcription

1 rth American Biofiltration Knowledge Base Appendices A and B Project #4459

2 rth American Biofiltration Knowledge Base Appendices A and B Prepared by: Jess Brown and Giridhar Upadhyaya Carollo Engineers, Inc., 3150 Bristol Street, Suite 500, Costa Mesa, CA Jason Carter and Trisha Brown Arcadis U.S., Inc., 2170 Highland Avenue South, Suite 250, Birmingham, AL and Chance Lauderdale HDR, Inc Park Tower Drive Suite 100, Vienna, VA Sponsored by: Water Research Foundation 6666 West Quincy Avenue, Denver, CO Published by:

3 APPENDIX A SUMMARY REPORTS FROM SURVEY RESPONSES 1

4 rth American Biofiltration Knowledge Base Summary Report- Large Facility 2

5 rth American Biofiltration Knowledge Base Summary Report- Large Facility (Cont.) 3

6 rth American Biofiltration Knowledge Base Summary Report- Large Facility (Cont.) - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - Plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 4

7 rth American Biofiltration Knowledge Base Planning Phase - Large Facility 5

8 rth American Biofiltration Knowledge Base Planning Phase - Large Facility (Cont.) Parameters Monitored of Facility Biofiltration Operational Objectives - Changed media type - DBP removal and Taste and Odor mitigation - ne Incidental Biofiltration - TOC removal - ne Designed for Biofiltration - TOC removal/tthm Precursers - TOC removal; DBP precursor removal; Taste and Odor Responses Unintended Consequences Experienced? 4 6

9 rth American Biofiltration Knowledge Base Evaluation Phase - Large Facility Regulatory Requirements - Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future Target Performance Criteria - Type of media for filters (GAC vs membranes). Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future. 7

10 rth American Biofiltration Knowledge Base Design Phase - Large Facility 8

11 rth American Biofiltration Knowledge Base Operation Phase - Large Facility Control Measures Used to Control Unwanted Biota - Manual cleaning - Previously chlorinated backwash water Level of Removal Achieved - 20% TOC; 24% BDOC; 74% AOC - T&O 100% How is the filter to waste and backwash water handled? - Recycled - Recycled to raw water, 5 min to sanitary water, remainder to recycle to raw water - Sent to quarry - filter to waste 9

12 rth American Biofiltration Knowledge Base Operation Phase - Large Facility (Cont.) How do biofilters perform when short term Chemicals Used process upsets occur? - Peroxide - Rare occurrence - Very well Type of training provided to operators? - ne - Backwashing Operational Impacts Observed - Filter run times change seasonally, summer 72 hrs, 120 hrs in winter (in design phase estimated <72 hrs) - Adjust backflow rates - Replace antracite with GAC - ne Modifications Made to Convert to Biofilters 10

13 rth American Biofiltration Knowledge Base Summary Report - Small Facility 11

14 rth American Biofiltration Knowledge Base Summary Report - Small Facility (Cont.) 12

15 rth American Biofiltration Knowledge Base Summary Report - Small Facility (Cont.) Parameters Monitored of Facility - Aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft2. - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 13

16 rth American Biofiltration Knowledge Base Planning Phase - Small Facility 14

17 rth American Biofiltration Knowledge Base Planning Phase - Small Facility (Cont.) Necessary Process Modifications - Changed media type - Moved chlorination point to post filtration - ne Incidental Biofiltration - ne Design for Biofiltration Responses 1 In planning Phase Biofiltration Operational Objectives - Mn removal, TOC reduction, reduce biological regrowth in distribution, DBP reduction - ne - reduce organic compounds - Remove organics prior to secondary disinfection - T&O - TOC removal/tthm Precursers - TOC, AOC - turbidity removal, AOCs - turbidity, filter run length, T&O - turbidity, filter run length Unintended Consequences Experienced? 1 Instrumentation fouling, unwanted bio growth in other processes 1 N/A 1 free chlorine zone prior to added ammonia 1 ne 1 On going 1 Shorter filter run times seasonally 6 Lessons learned encountered in the planning phase. - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspecation practice is needed to evaluate if media is being lost or broken down in size. - N/A - ne - Ozone piloting showed biofiltration removed T&O compounds Frequenty asked questions and responses for the planning phase. - N/A - NA 15

18 rth American Biofiltration Knowledge Base Evaluation Phase Small Facility Target Performance Criteria - Mn removal and aldehydes concentrations - ne - Turbidity, head loss, meeting finished water regulatory requirement - Turbidity, headloss, meeting finished water regulatory requirements - turbidity, filter run length Lessons Learned - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size 16

19 rth American Biofiltration Knowledge Base Design Phase Small Facility 17

20 rth American Biofiltration Knowledge Base Operation Phase Small Facility Control Measures Used to Control Unwanted Biota - add pre settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - Moved Ammonia Feed Downstream of Free Chlorine Addition - NONE - Pre Chlorination - Previously chlorinated backwash water Level of Removal Achieved - 10% (winter), 16% (summer) - 71% (Mn) - 90% % - unknown How is the filter to waste and backwash water handled? - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - filter to waste - NO, RECOVERY - not available on all filters and returned to head of plant - residuals lagoon NPDES permit - Sent to Sewer - Sent to lagoon and recycled 18

21 rth American Biofiltration Knowledge Base Operation Phase Small Facility (Cont.) Chemicals Used How do biofilters perform when short term process upsets occur? - Depends on type of upset often no issues or issues similar to normal filters - Depends on type of upset often no issues or issues similar to normal filters - MEMBRANE - observable differences have been noticed - overall excellent Mn removal except during extreme elevated levels - unknown Operational Impacts Observed - Adjust backflow rates - in planning phase/unknown - longer run times on media left in place - ne - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale Type of training provided to operators? - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - TBD - Overview training on principles of operating biofilters - ne Modifications Made to Convert to Biofilters - in planning phase/unknown - stopped replacing media - none 19

22 rth American Biofiltration Knowledge Base Summary Report Eastern/Mid-West US Chemicals Used 20

23 rth American Biofiltration Knowledge Base Summary Report Eastern/Mid-West US (Cont.) Parameters Monitored of Facility - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - Plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - Unknown 21

24 rth American Biofiltration Knowledge Base Planning Phase - rthwest/west US Report Necessary Process Modifications - Changed media type - ne Designed for Biofiltration - Moved chlorination point to post-filtration Biofiltration Operational Objectives - Plant effluent CBXA = 75 µg/l as carbon, or - ne - Plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - Plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. 22

25 Responses rth American Biofiltration Knowledge Base Planning Phase - rthwest/west US Report (Cont.) Unintended Consequences Experienced? 1 Instrumentation fouling, unwanted bio-growth in other processes 1 Manganese release 1 N/A 1 ne 1 Unwanted algae growth 3 Lessons learned encountered in the planning phase. - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control - N/A - N/A Frequently asked questions and responses for the planning phase. 23

26 rth American Biofiltration Knowledge Base Evaluation Phase - rthwest/west US Report Target Performance Criteria - Turbidity, head loss, meeting finished water regulatory requirement - Turbidity, headloss, meeting finished water regulatory requirements - Water quality and preservation of primary filtration objectives - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. Lessons Learned - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - In addition to all tests conducted, conduct pilot tests with existing plant media. 24

27 rth American Biofiltration Knowledge Base Design Phase - rthwest/west US Report Previous Process in Case of Retrofit 25

28 rth American Biofiltration Knowledge Base Design Phase - rthwest/west US Report (Cont.) 26

29 Level of Removal Achieved rth American Biofiltration Knowledge Base Operation Phase - rthwest/west US Report - 10% (winter), 16% (summer) % - plant effluent CBXA = 75 µg/l as carbon, or - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. How is the filter to waste and backwash water handled? - Sent to Sewer - Sent to lagoon and recycled Control Measures Used to Control Unwanted Biota - allowed for chlorinated backwash - design included capability to periodically use chlorinated backwash - capability for chlorinated backwash - capability to periodically backwash with chlorinated water - included capability to periodically backwash with chlorinated water - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - Pre Chlorination 27

30 rth American Biofiltration Knowledge Base Operation Phase - rthwest/west US Report (Cont.) Chemicals Used - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter Type of training provided to operators? How do biofilters perform when short-term process upsets occur? - Depends on type of upset often no issues or issues similar to normal filters - Depends on type of upset often no issues or issues similar to normal filters Operational Impacts Observed - ne except manganese release - ne - Overview training on principles of operating biofilters - Extensive training was provided for ozone system operations including the relocation of chlorine application from upstream to downstream of the filters, the need to conduct routine basin algae chlorination, additional monitoring samples, etc. specific training was conducted for biofilter operation. Modifications Made to Convert to Biofilters - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control. - Install/rehabilitate plant as needed such that the secondary chlorine application point is downstream of the filters, and add chlorination capacity for basin algae control and backwash chlorination. - The capability to chlorinate the backwash was provided for as part of the ozone retrofit at each treatment plant. Also, CBXA monitoring/sampling sites were established in the field. 28

31 rth American Biofiltration Knowledge Base Summary Report South/Southwest US Report Chemicals Used 29

32 rth American Biofiltration Knowledge Base Summary Report South/Southwest US Report (Cont.) Chemicals Used - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 30

33 rth American Biofiltration Knowledge Base Planning Phase - South/Southwest US Report Necessary Process Modifications - Retrofit filter boxes - Moved chlorination point to postfiltration - ne Incidental Biofiltration - Changed media type - ne Designed for Biofiltration Biofiltration Operational Objectives - Taste and odor removal - TOC reduction (below 5 mg/l), turbidity control and T&O Reduction - TOC reduction, turbidity reduction, and backwash with non chlorinated water. - reduce organic compounds - Remove organics prior to secondary disinfection - Remove turbidity and AOC - Mn removal, TOC reduction, reduce biological regrowth in distribution, DBP reduction - TOC, turbidity, TTHMs, chlorite - turbidity removal, AOCs - Minimize DBP Precursors 31

34 Responses rth American Biofiltration Knowledge Base Planning Phase - South/Southwest US Report (Cont.) Unintended Consequences Experienced? 1 free chlorine zone prior to adding ammonia 1 shorter filter run times seasonally 1 high chlorine demand 1 in planning phase 1 Learned that ferric chloride contained manganese and was adding manganese to the treatment process 1 unexplained short run times of around 24 hours 1 Yes. Problems maintaining total chlorine and ammonia residuals. 4 Lessons learned encountered in the planning phase. - ozone piloting showed biofiltration removed T&O compounds - run pilot evaluation using actual water source and not other source water. - All plants should try optimization; Started based on El Paso Texas doing bioenhanced and have excellent results; followed in their footsteps; maybe due to source water? Maybe due to feeding chlorine and chlorine dioxide upstream? Pretty much exhausted the options and did lots of testing - Using IMS Caps for media support instead of gravel - NONE Frequently asked questions and responses for the planning phase. - One of other Arizona municipalities installed GAC filters a few years ago and had online for a few years and put back in sand/anthracite think because didn't experiment with feeding chlorine upstream to form THMs, that then the 30 40% reduction in THMs; didn't see enough benefit of GAC; complaining that TOC removal exhaustion happened within a couple months - operational strategy - NA 32

35 rth American Biofiltration Knowledge Base Evaluation Phase - South/Southwest US Report Regulatory Requirements Target Performance Criteria - Turbidity reduction NTU and at least a 4 % TOC reduction - Biological activity - may be available in BODR - Mn removal and aldehydes concentrations - ne - There was a pilot study comparing oocyst removals during ripening and also DBP formation. 33

36 rth American Biofiltration Knowledge Base Evaluation Phase - South/Southwest US Report (Cont.) Lessons Learned - Adjusting wash water valves on main header - Early on, we wanted to find out if we could increase the GAC media's biological population by adding nutrients, and if so, would that increased population remove more TOC prior to reservoir chlorination for reduced TTHM's. During and after the Engineered Biofiltration Pilot, we didn't notice any significant increase in the biological population of the biofiltration pilot filters versus the control filter. significant TOC reductions. significant change in filter run times. Due to our findings, we decided to stop adding chemical nutrients and allow a natural biological process to occur. - Enhanced bio study underway - Unknown FAQ 34

37 rth American Biofiltration Knowledge Base Design Phase South/Southwest US Report Previous Process in Case of Retrofit 35

38 rth American Biofiltration Knowledge Base Design Phase South/Southwest US Report (Cont.) 36

39 rth American Biofiltration Knowledge Base Operation Phase South/Southwest US Report Control Measures Used to Control Unwanted Biota - NONE - add pre settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - Moved Ammonia Feed Downstream of Free Chlorine Addition - Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water. Level of Removal Achieved % % - 71% (Mn) - 80% TOC Removal total facility; about 1 mg/l across the filters, average effluent of 2 mg/l - 90% - Typically, 3 to 4 % TOC reduction. - unknown How is the filter to waste and backwash water handled? - NO, RECOVERY - BW water settled & FtW settled and water reused - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - not available on all filters and returned to head of plant - residuals lagoon NPDES permit - Sent to the reclaim basin and then pumped back to the head of the Plant. - Thickener, recycle back to the head - Recycled 37

40 rth American Biofiltration Knowledge Base Operation Phase - South/Southwest US Report (Cont.) Chemicals Used - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale Type of training provided to operators? How do biofilters perform when short-term process upsets occur? - observable differences have been noticed - MEMBRANE - overall excellent Mn removal except during extreme elevated levels - unknown - within 1 2 days (less than a week) after shutdowns, TOC removal is back to Steady State; growth returns within two weeks - turbidity increases - Typically, very well. - Poorly during lake turnover - backwashing - On the job training - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - SOPs for shutdown and backwashing - TBD - Vendor. - We spent a great deal of time with our operators ensuring they were very proficient with the dosage calculations of the Engineered Biofiltration chemicals. They were also able to contact a member of Carollo Engineering or a City Process Control Specialist 24/7 for any guidance needed. Chemical safety, dosage calculations, and chemical feed system training. They also received overall Engineered Biofiltration training regarding "why" and "how" it s supposed to work. - ne 38

41 rth American Biofiltration Knowledge Base Operation Phase - South/Southwest US Report (Cont.) Operational Impacts Observed - Backwash sequence, care not to backwash to rigorously to prevent damaging GAC - Following conversion there were no operational issues. During conversion was when we had issues. It was a nightmare trying to feed pre chlorine and ammonia on one side, while feeding post chlorine and ammonia on the other side. Plus, there were issues with air getting in the main wash water line and there were problems with the filter valves. - high chlorine demand - in planning phase/unknown - One thing that was changed going to GAC was the filter modes of operation from declining rate to constant rate. With declining rate filter, the water level low and would rise as the filter clogged up and with constant always the same; control logic to make that happen Modifications Made to Convert to Biofilters - Change media type - changed from anthracite to GAC - filter box modifications, changed media, moved chlorine downstream of filters - in planning phase/unknown - Raise filter troughs, replace sand with anthracite, and increase filter bed depth. - Disable pre chlorination 39

42 rth American Biofiltration Knowledge Base Summary Report Canadian Facilities Report Chemicals Usevd 40

43 rth American Biofiltration Knowledge Base Summary Report Canadian Facilities Report (Cont.) Chemicals Used - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 41

44 rth American Biofiltration Knowledge Base Planning Phase Canadian Facilities Report Necessary Process Modifications Biofiltration Operational Objectives - ne Designed for Biofiltration - ne - turbidity, reduce fouling of membranes, T&O control Responses 1 filter-clogging algae 1 Unintended Consequences Experienced? 42

45 rth American Biofiltration Knowledge Base Evaluation Phase Canadian Facilities Report Target Performance Criteria - reduce loading to membranes, produce biologically stable water FAQ - Why did we choose this advanced treatment train over conventional treatment? Robust and expandable, low risk (high performance, multiple barriers), primary pathogen barrier is non chemical based, exceeds current provincial regulations and has an eye on future regulatory changes. Secures increased consumer confidence on the potable water supply 43

46 rth American Biofiltration Knowledge Base Operation Phase Canadian Facilities Report Control Measures Used to Control Unwanted Biota Level of Removal Achieved How is the filter to waste and backwash water handled? - Backwash water treated, supernatant returned to lake - filter to waste is recycled for backwashing 44

47 rth American Biofiltration Knowledge Base Operation Phase - Canadian Facilities Report (Cont.) How do biofilters perform when short-term process upsets occur? - upsets - ATP declines quickly when ozone is off - ne - ozone training Type of training provided to operators? Operational Impacts Observed Modifications Made to Convert to Biofilters - ne - Removed chlorine from filters 45

48 rth American Biofiltration Knowledge Base Summary Report Planning Facilities Report 46

49 rth American Biofiltration Knowledge Base Summary Report Planning Facilities Report (Cont.) Chemicals Used - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 47

50 rth American Biofiltration Knowledge Base Planning Phase Planning Facilities Report Necessary Process Modifications - Retrofit filter boxes - ne Incidental Biofiltration - Changed media type - Moved chlorination point to post-filtration - ne Designed for Biofiltration 48

51 rth American Biofiltration Knowledge Base Planning Phase Planning Facilities Report (Cont.) Biofiltration Operational Objectives - ne - turbidity, reduce fouling of membranes, T&O control Responses Unintended Consequences Experienced? 1 filter-clogging algae 1 high chlorine demand 1 in planning phase 1 Instrumentation fouling, unwanted bio-growth in other processes 1 Learned that ferric chloride contained manganese and was adding manganese to the treatment process 1 manganese release 1 N/A 1 free chlorine zone prior to adding ammonia 1 shorter filter run times seasonally 1 on-going 1 unexplained short run times of around 24 hours 1 unwanted algae growth 1 Yes. Problems maintaining total chlorine and ammonia residuals. 2 ne 18 Lessons learned encountered in the planning phase. - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control - All plants should try optimization; Started based on El Paso Texas doing bioenhanced and have excellent results; followed in their footsteps; maybe due to source water? Maybe due to feeding chlorine and chlorine dioxide upstream? Pretty much exhausted the options and did lots of testing - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - run pilot evaluation using actual water source and not other source water. - ozone piloting showed biofiltration removed T&O compounds - Using IMS Caps for media support instead of gravel - NONE - N/A Frequently asked questions and responses for the planning phase. - One of other Arizona municipalities installed GAC filters a few years ago and had online for a few years and put back in sand/anthracite - think because didn't experiment with feeding chlorine upstream to form THMs, that then the 30-40% reduction in THMs; didn't see enough benefit of GAC; complaining that TOC removal exhaustion happened within a couple months - operational strategy - NA - n/a 49

52 rth American Biofiltration Knowledge Base Evaluation Phase Planning Facilities Report Regulatory Requirements - Turbidity reduction - Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future Target Performance Criteria - Turbidity, head loss, meeting finished water regulatory requirement - Turbidity, headloss, meeting finished water regulatory requirements - type of media for filters (GAC vs membranes). Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future. - Water quality and preservation of primary filtration objectives NTU and at least a 4 % TOC reduction - Biological activity - may be available in BODR - Mn removal and aldehydes concentrations - ne - reduce loading to membranes, produce biologically stable water - There was a pilot study comparing oocyst removals during ripening and also DBP formation. - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - turbidity, filter run length 50

53 rth American Biofiltration Knowledge Base Evaluation Phase Planning Facilities Report (Cont.) Lessons learned encountered in the planning phase. - Adjusting wash water valves on main header - better removal during warm water months; dechlorinated backwash helps but not that much - Early on, we wanted to find out if we could increase the GAC media's biological population by adding nutrients, and if so, would that increased population remove more TOC prior to reservoir chlorination for reduced TTHM's. During and after the Engineered Biofiltration Pilot, we didn't notice any significant increase in the biological population of the biofiltration pilot filters versus the control filter. significant TOC reductions. significant change in filter run times. Due to our findings, we decided to stop adding chemical nutrients and allow a natural biological process to occur. - Enhanced bio study underway - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - GAC was picked with the intent for biofiltration - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - In addition to all tests conducted, conduct pilot tests with existing plant media. FAQ - Unknown - Why did we choose this advanced treatment train over conventional treatment? Robust and expandable, low risk (high performance, multiple barriers), primary pathogen barrier is nonchemical based, exceeds current provincial regulations and has an eye on future regulatory changes. Secures increased consumer confidence on the potable water supply 51

54 rth American Biofiltration Knowledge Base Design Phase Planning Facilities Report Previous Process in Case of Retrofit 52

55 rth American Biofiltration Knowledge Base Operation Phase Planning Facilities Report Control Measures Used to Control Unwanted Biota Level of Removal Achieved - 10% (winter), 16% (summer) - 20% TOC; 24% BDOC; 74% AOC % % - 90% - Combined filter effluent turbidity < 0.3 NTU. Significant MIB and Geosmin reductions. 5-20% TOC removal % - 71% (Mn) - 80% TOC Removal total facility; about 1 mg/l across the filters, average effluent of 2 mg/l - plant effluent CBXA = 75 µg/l as carbon, or - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - T&O - 100% - Typically, 3 to 4 % TOC reduction. - unknown - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - add pre-settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - allowed for chlorinated backwash - capability for chlorinated backwash - capability to periodically backwash with chlorinated water - design included capability to periodically use chlorinated backwash - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - included capability to periodically backwash with chlorinated water - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - Manual cleaning - Moved Ammonia Feed Downstream of Free Chlorine Addition - NONE - Pre Chlorination - Previously chlorinated backwash water - Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water. 53

56 rth American Biofiltration Knowledge Base Operation Phase Planning Facilities Report (Cont.) How is the filter-to-waste and backwash water handled? - Backwash water treated, supernatant returned to lake - BW water settled & FtW settled and water reused - equalization basin and back to the head of the plant - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - filter to waste is recycled for backwashing - filter-to waste - NO, RECOVERY - not available on all filters and returned to head of plant - recycled to raw water; 5 mins to sanitary sewer, remainder to recycle to raw water - residuals lagoon - NPDES permit - Return to the head of the plant - sent to quarry - Sent to Sewer - Sent to the reclaim basin and then pumped back to the head of the Plant. - Thickener, recycle back to the head - Sent to lagoon and recycled - recycled 54

57 rth American Biofiltration Knowledge Base Operation Phase Planning Facilities Report (Cont.) Chemicals Used - peroxide - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale How do biofilters perform when short-term process upsets occur? - ATP declines quickly when ozone is off - Depends on type of upset - often no issues or issues similar to normal filters - Depends on type of upset - often no issues or issues similar to normal filters - MEMBRANE - observable differences have been noticed - upsets - overall excellent Mn removal except during extreme elevated levels - rare occurrence - Similar performance - turbidity increases - Typically, very well. - unknown - very well - within 1-2 days (less than a week) after shutdowns, TOC removal is back to Steady State; growth returns within two weeks - Poorly during lake turnover Type of training provided to operators? - On the job training - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - ozone training - Regular SOPs, OEPA class I license, water treatment class (annually) - SOPs for shutdown and backwashing - TBD - Vendor. - We spent a great deal of time with our operators ensuring they were very proficient with the dosage calculations of the Engineered Biofiltration chemicals. They were also able to contact a member of Carollo Engineering or a City Process Control Specialist 24/7 for any guidance needed. Chemical safety, dosage calculations, and chemical feed system training. They also received overall Engineered Biofiltration training regarding "why" and "how" it s supposed to work. - Overview training on principles of operating biofilters - backwashing - Extensive training was provided for ozone system operations including the relocation of chlorine application from upstream to downstream of the filters, the need to conduct routine basin algae chlorination, additional monitoring samples, etc. specific training was conducted for biofilter operation. - ne 55

58 rth American Biofiltration Knowledge Base Operation Phase Planning Facilities Report (Cont.) Operational Impacts Observed - Adjust backflow rates - Backwash sequence, care not to backwash to rigorously to prevent damaging GAC - Filter run times change seasonally; summer 72 hrs, 120 hrs in winter (in design phase estimated <72 hrs) - Following conversion there were no operational issues. During conversion was when we had issues. It was a nightmare trying to feed pre chlorine and ammonia on one side, while feeding post chlorine and ammonia on the other side. Plus, there were issues with air getting in the main wash water line and there were problems with the filter valves. - high chlorine demand - in planning phase/unknown - longer filter run times - longer run times on media left in place - ne except manganese release - One thing that was changed going to GAC was the filter modes of operation from declining rate to constant rate. With declining rate filter, the water level low and would rise as the filter clogged up and with constant always the same; control logic to make that happen - Possible slight reduction in filter run times - ne Modifications Made to Convert to Biofilters - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control. - Change media type - changed from anthracite to GAC - filter box modifications, changed media, moved chlorine downstream of filters - in planning phase/unknown - Install/rehabilitate plant as needed such that the secondary chlorine application point is downstream of the filters, and add chlorination capacity for basin algae control and backwash chlorination. - Raise filter troughs, replace sand with anthracite, and increase filter bed depth. - Removed chlorine from filters - replace anthracite w GAC - Stop prechlorination at filter influent - Disable pre-chlorination - Chlorine added mostly after filtration - stopped replacing media - The capability to chlorinate the backwash was provided for as part of the ozone retrofit at each treatment plant. Also, CBXA monitoring/sampling sites were established in the field. - none 56

59 rth American Biofiltration Knowledge Base Summary Report Design Facilities Report 57

60 rth American Biofiltration Knowledge Base Summary Report Design Facilities Report (Cont.) Chemicals Used - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 58

61 rth American Biofiltration Knowledge Base Planning Phase Design Facilities Report Necessary Process Modifications - Retrofit filter boxes - ne Incidental Biofiltration - Changed media type - Moved chlorination point to post-filtration - ne Designed for Biofiltration 59

62 rth American Biofiltration Knowledge Base Planning Phase Planning Facilities Report (Cont.) Biofiltration Operational Objectives - Currently no goal specific to biofiltration. Conventional filtration goals of filter effluent <0.3 ntu - DBP removal and taste and odor mitigation - Mn removal, TOC reduction, reduce biological regrowth in distribution, DBP reduction - Polishing post-ozone, reduction of hpc - reduce organic compounds - Remove organics prior to secondary disinfection - Remove turbidity and AOC - Solids removal and elimination of ozone disinfection byproducts - T&O - Taste and odor removal - TOC reduction (below 5 mg/l), turbidity control and T&O Reduction - TOC reduction, turbidity reduction, and backwash with non-chlorinated water. - TOC removal - TOC removal/tthm Precursers - TOC removal; DBP precursor removal; Taste and odor - TOC, AOC - TOC, turbidity, TTHMs, chlorite - turbidity removal, AOCs - turbidity removal, AOCs - plant effluent CBXA = 75 µg/l as carbon, or - turbidity, filter run length, T&O - turbidity, reduce fouling of membranes, T&O control - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft2 - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft2. - ne - Minimize DBP Precursors - turbidity, filter run length Responses Unintended Consequences Experienced? 1 filter-clogging algae 1 high chlorine demand 1 in planning phase 1 Instrumentation fouling, unwanted bio-growth in other processes 1 Learned that ferric chloride contained manganese and was adding manganese to the treatment process 1 manganese release 1 N/A 1 free chlorine zone prior to adding ammonia 1 shorter filter run times seasonally 1 on-going 1 unexplained short run times of around 24 hours 1 unwanted algae growth 1 Yes. Problems maintaining total chlorine and ammonia residuals. 2 ne 18 60

63 rth American Biofiltration Knowledge Base Planning Phase Planning Facilities Report (Cont.) Lessons learned encountered in the planning phase. - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control - All plants should try optimization; Started based on El Paso Texas doing bioenhanced and have excellent results; followed in their footsteps; maybe due to source water? Maybe due to feeding chlorine and chlorine dioxide upstream? Pretty much exhausted the options and did lots of testing - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - run pilot evaluation using actual water source and not other source water. - ozone piloting showed biofiltration removed T&O compounds - Using IMS Caps for media support instead of gravel - NONE - N/A Frequently asked questions and responses for the planning phase. - One of other Arizona municipalities installed GAC filters a few years ago and had online for a few years and put back in sand/anthracite - think because didn't experiment with feeding chlorine upstream to form THMs, that then the 30-40% reduction in THMs; didn't see enough benefit of GAC; complaining that TOC removal exhaustion happened within a couple months - operational strategy - NA - n/a 61

64 rth American Biofiltration Knowledge Base Evaluation Phase Design Facilities Report Regulatory Requirements - Turbidity reduction - Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future Target Performance Criteria - Turbidity, head loss, meeting finished water regulatory requirement - Turbidity, headloss, meeting finished water regulatory requirements - type of media for filters (GAC vs membranes). Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future. - Water quality and preservation of primary filtration objectives NTU and at least a 4 % TOC reduction - Biological activity - may be available in BODR - Mn removal and aldehydes concentrations - ne - reduce loading to membranes, produce biologically stable water - There was a pilot study comparing oocyst removals during ripening and also DBP formation. - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - turbidity, filter run length 62

65 rth American Biofiltration Knowledge Base Evaluation Phase Planning Facilities Report (Cont.) Lessons learned encountered in the planning phase. - Adjusting wash water valves on main header - better removal during warm water months; dechlorinated backwash helps but not that much - Early on, we wanted to find out if we could increase the GAC media's biological population by adding nutrients, and if so, would that increased population remove more TOC prior to reservoir chlorination for reduced TTHM's. During and after the Engineered Biofiltration Pilot, we didn't notice any significant increase in the biological population of the biofiltration pilot filters versus the control filter. significant TOC reductions. significant change in filter run times. Due to our findings, we decided to stop adding chemical nutrients and allow a natural biological process to occur. - Enhanced bio study underway - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - GAC was picked with the intent for biofiltration - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - In addition to all tests conducted, conduct pilot tests with existing plant media. FAQ - Unknown - Why did we choose this advanced treatment train over conventional treatment? Robust and expandable, low risk (high performance, multiple barriers), primary pathogen barrier is nonchemical based, exceeds current provincial regulations and has an eye on future regulatory changes. Secures increased consumer confidence on the potable water supply 63

66 rth American Biofiltration Knowledge Base Design Phase Design Facilities Report Previous Process in Case of Retrofit 64

67 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report Control Measures Used to Control Unwanted Biota Level of Removal Achieved - 10% (winter), 16% (summer) - 20% TOC; 24% BDOC; 74% AOC % % - 90% - Combined filter effluent turbidity < 0.3 NTU. Significant MIB and Geosmin reductions. 5-20% TOC removal % - 71% (Mn) - 80% TOC Removal total facility; about 1 mg/l across the filters, average effluent of 2 mg/l - plant effluent CBXA = 75 µg/l as carbon, or - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - T&O - 100% - Typically, 3 to 4 % TOC reduction. - unknown - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - add pre-settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - allowed for chlorinated backwash - capability for chlorinated backwash - capability to periodically backwash with chlorinated water - design included capability to periodically use chlorinated backwash - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - included capability to periodically backwash with chlorinated water - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - Manual cleaning - Moved Ammonia Feed Downstream of Free Chlorine Addition - NONE - Pre Chlorination - Previously chlorinated backwash water - Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water. 65

68 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) How is the filter-to-waste and backwash water handled? - Backwash water treated, supernatant returned to lake - BW water settled & FTW settled and water reused - equalization basin and back to the head of the plant - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - filter to waste is recycled for backwashing - filter-to waste - NO, RECOVERY - not available on all filters and returned to head of plant - recycled to raw water; 5 mins to sanitary sewer, remainder to recycle to raw water - residuals lagoon - NPDES permit - Return to the head of the plant - sent to quarry - Sent to Sewer - Sent to the reclaim basin and then pumped back to the head of the Plant. - Thickener, recycle back to the head - Sent to lagoon and recycled - recycled 66

69 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) Chemicals Used - peroxide - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale How do biofilters perform when short-term process upsets occur? - ATP declines quickly when ozone is off - Depends on type of upset - often no issues or issues similar to normal filters - Depends on type of upset - often no issues or issues similar to normal filters - MEMBRANE - observable differences have been noticed - upsets - overall excellent Mn removal except during extreme elevated levels - rare occurrence - Similar performance - turbidity increases - Typically, very well. - unknown - very well - within 1-2 days (less than a week) after shutdowns, TOC removal is back to Steady State; growth returns within two weeks - Poorly during lake turnover Type of training provided to operators? - On the job training - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - ozone training - Regular SOPs, OEPA class I license, water treatment class (annually) - SOPs for shutdown and backwashing - TBD - Vendor. - We spent a great deal of time with our operators ensuring they were very proficient with the dosage calculations of the Engineered Biofiltration chemicals. They were also able to contact a member of Carollo Engineering or a City Process Control Specialist 24/7 for any guidance needed. Chemical safety, dosage calculations, and chemical feed system training. They also received overall Engineered Biofiltration training regarding "why" and "how" it s supposed to work. - Overview training on principles of operating biofilters - backwashing - Extensive training was provided for ozone system operations including the relocation of chlorine application from upstream to downstream of the filters, the need to conduct routine basin algae chlorination, additional monitoring samples, etc. specific training was conducted for biofilter operation. - ne 67

70 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) Operational Impacts Observed - Adjust backflow rates - Backwash sequence, care not to backwash to rigorously to prevent damaging GAC - Filter run times change seasonally; summer 72 hrs, 120 hrs in winter (in design phase estimated <72 hrs) - Following conversion there were no operational issues. During conversion was when we had issues. It was a nightmare trying to feed pre chlorine and ammonia on one side, while feeding post chlorine and ammonia on the other side. Plus, there were issues with air getting in the main wash water line and there were problems with the filter valves. - high chlorine demand - in planning phase/unknown - longer filter run times - longer run times on media left in place - ne except manganese release - One thing that was changed going to GAC was the filter modes of operation from declining rate to constant rate. With declining rate filter, the water level low and would rise as the filter clogged up and with constant always the same; control logic to make that happen - Possible slight reduction in filter run times - ne Modifications Made to Convert to Biofilters - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control. - Change media type - changed from anthracite to GAC - filter box modifications, changed media, moved chlorine downstream of filters - in planning phase/unknown - Install/rehabilitate plant as needed such that the secondary chlorine application point is downstream of the filters, and add chlorination capacity for basin algae control and backwash chlorination. - Raise filter troughs, replace sand with anthracite, and increase filter bed depth. - Removed chlorine from filters - replace anthracite w GAC - Stop prechlorination at filter influent - Disable pre-chlorination - Chlorine added mostly after filtration - stopped replacing media - The capability to chlorinate the backwash was provided for as part of the ozone retrofit at each treatment plant. Also, CBXA monitoring/sampling sites were established in the field. - none 68

71 rth American Biofiltration Knowledge Base Summary Report Operations Facilities Report 69

72 rth American Biofiltration Knowledge Base Summary Report Operations Facilities Report (Cont.) Chemicals Used - aldehydes - AOC - ATP on GAC, AOC - CBXA, TOC, AOC, ATP - CBXA, TOC, DOC, ATP - GROWTH IN MEDIA - N/A - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. Parameters Monitored of Facility - TOC - TOC reduction. - TOC, AOC - TOC, ATP - TOC, DOC, AOC, CBXA, ATP - TOC, P, N, ATP, DOC/AOC, UV254 - Turbidity, Headloss, MIB/GEOS and TOC - unknown 70

73 rth American Biofiltration Knowledge Base Planning Phase Operations Facilities Report Necessary Process Modifications - Retrofit filter boxes - ne Incidental Biofiltration - Changed media type - Moved chlorination point to post-filtration - ne Designed for Biofiltration 71

74 rth American Biofiltration Knowledge Base Planning Phase Operations Facilities Report (Cont.) Biofiltration Operational Objectives - Currently no goal specific to biofiltration. Conventional filtration goals of filter effluent <0.3 ntu - DBP removal and taste and odor mitigation - Mn removal, TOC reduction, reduce biological regrowth in distribution, DBP reduction - Polishing post-ozone, reduction of hpc - reduce organic compounds - Remove organics prior to secondary disinfection - Remove turbidity and AOC - Solids removal and elimination of ozone disinfection byproducts - T&O - Taste and odor removal - TOC reduction (below 5 mg/l), turbidity control and T&O Reduction - TOC reduction, turbidity reduction, and backwash with non-chlorinated water. - TOC removal - TOC removal/tthm Precursers - TOC removal; DBP precursor removal; Taste and odor - TOC, AOC - TOC, turbidity, TTHMs, chlorite - turbidity removal, AOCs - turbidity removal, AOCs - plant effluent CBXA = 75 µg/l as carbon, or - turbidity, filter run length, T&O - turbidity, reduce fouling of membranes, T&O control - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - ne - Minimize DBP Precursors - turbidity, filter run length Responses Unintended Consequences Experienced? 1 filter-clogging algae 1 high chlorine demand 1 in planning phase 1 Instrumentation fouling, unwanted bio-growth in other processes 1 Learned that ferric chloride contained manganese and was adding manganese to the treatment process 1 manganese release 1 N/A 1 free chlorine zone prior to adding ammonia 1 shorter filter run times seasonally 1 on-going 1 unexplained short run times of around 24 hours 1 unwanted algae growth 1 Yes. Problems maintaining total chlorine and ammonia residuals. 2 ne 18 72

75 rth American Biofiltration Knowledge Base Planning Phase Operations Facilities Report (Cont.) Lessons learned encountered in the planning phase. - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control - All plants should try optimization; Started based on El Paso Texas doing bioenhanced and have excellent results; followed in their footsteps; maybe due to source water? Maybe due to feeding chlorine and chlorine dioxide upstream? Pretty much exhausted the options and did lots of testing - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - run pilot evaluation using actual water source and not other source water. - ozone piloting showed biofiltration removed T&O compounds - Using IMS Caps for media support instead of gravel - NONE - N/A Frequently asked questions and responses for the planning phase. - One of other Arizona municipalities installed GAC filters a few years ago and had online for a few years and put back in sand/anthracite - think because didn't experiment with feeding chlorine upstream to form THMs, that then the 30-40% reduction in THMs; didn't see enough benefit of GAC; complaining that TOC removal exhaustion happened within a couple months - operational strategy - NA - n/a 73

76 rth American Biofiltration Knowledge Base Evaluation Phase Operations Facilities Report Regulatory Requirements - Turbidity reduction - Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future Target Performance Criteria - Turbidity, head loss, meeting finished water regulatory requirement - Turbidity, headloss, meeting finished water regulatory requirements - type of media for filters (GAC vs membranes). Were looking at THMs and HAAs and were anticipating lower regulatory levels in the future. - Water quality and preservation of primary filtration objectives NTU and at least a 4 % TOC reduction - Biological activity - may be available in BODR - Mn removal and aldehydes concentrations - ne - reduce loading to membranes, produce biologically stable water - There was a pilot study comparing oocyst removals during ripening and also DBP formation. - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - turbidity, filter run length 74

77 rth American Biofiltration Knowledge Base Evaluation Phase Operations Facilities Report (Cont.) Lessons learned encountered in the planning phase. - Adjusting wash water valves on main header - better removal during warm water months; dechlorinated backwash helps but not that much - Early on, we wanted to find out if we could increase the GAC media's biological population by adding nutrients, and if so, would that increased population remove more TOC prior to reservoir chlorination for reduced TTHM's. During and after the Engineered Biofiltration Pilot, we didn't notice any significant increase in the biological population of the biofiltration pilot filters versus the control filter. significant TOC reductions. significant change in filter run times. Due to our findings, we decided to stop adding chemical nutrients and allow a natural biological process to occur. - Enhanced bio study underway - For GAC filters, little is required to transition from a timed media replacement strategy to a performance based strategy. The filters are already biologically active, even with a disinfectant residual being applied. An inspection practice is needed to evaluate if media is being lost or broken down in size - GAC was picked with the intent for biofiltration - See Huck, P.M., Coffey, B.M., Amirtharajah, A., and Bouwer, E.J Optimizing Filtration in Biological Filters. Denver, Colorado. AwwaRF. - In addition to all tests conducted, conduct pilot tests with existing plant media. FAQ - Unknown - Why did we choose this advanced treatment train over conventional treatment? Robust and expandable, low risk (high performance, multiple barriers), primary pathogen barrier is nonchemical based, exceeds current provincial regulations and has an eye on future regulatory changes. Secures increased consumer confidence on the potable water supply 75

78 rth American Biofiltration Knowledge Base Design Phase Design Facilities Report Previous Process in Case of Retrofit 76

79 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report Control Measures Used to Control Unwanted Biota Level of Removal Achieved - 10% (winter), 16% (summer) - 20% TOC; 24% BDOC; 74% AOC % % - 90% - Combined filter effluent turbidity < 0.3 NTU. Significant MIB and Geosmin reductions. 5-20% TOC removal % - 71% (Mn) - 80% TOC Removal total facility; about 1 mg/l across the filters, average effluent of 2 mg/l - plant effluent CBXA = 75 µg/l as carbon, or - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - T&O - 100% - Typically, 3 to 4 % TOC reduction. - unknown - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - add pre-settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - allowed for chlorinated backwash - capability for chlorinated backwash - capability to periodically backwash with chlorinated water - design included capability to periodically use chlorinated backwash - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - included capability to periodically backwash with chlorinated water - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - Manual cleaning - Moved Ammonia Feed Downstream of Free Chlorine Addition - NONE - Pre Chlorination - Previously chlorinated backwash water - Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water. 77

80 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) How is the filter-to-waste and backwash water handled? - Backwash water treated, supernatant returned to lake - BW water settled & FTW settled and water reused - equalization basin and back to the head of the plant - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - filter to waste is recycled for backwashing - filter-to waste - NO, RECOVERY - not available on all filters and returned to head of plant - recycled to raw water; 5 mins to sanitary sewer, remainder to recycle to raw water - residuals lagoon - NPDES permit - Return to the head of the plant - sent to quarry - Sent to Sewer - Sent to the reclaim basin and then pumped back to the head of the Plant. - Thickener, recycle back to the head - Sent to lagoon and recycled - recycled 78

81 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) Chemicals Used - peroxide - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale How do biofilters perform when short-term process upsets occur? - ATP declines quickly when ozone is off - Depends on type of upset - often no issues or issues similar to normal filters - Depends on type of upset - often no issues or issues similar to normal filters - MEMBRANE - observable differences have been noticed - upsets - overall excellent Mn removal except during extreme elevated levels - rare occurrence - Similar performance - turbidity increases - Typically, very well. - unknown - very well - within 1-2 days (less than a week) after shutdowns, TOC removal is back to Steady State; growth returns within two weeks - Poorly during lake turnover Type of training provided to operators? - On the job training - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - ozone training - Regular SOPs, OEPA class I license, water treatment class (annually) - SOPs for shutdown and backwashing - TBD - Vendor. - We spent a great deal of time with our operators ensuring they were very proficient with the dosage calculations of the Engineered Biofiltration chemicals. They were also able to contact a member of Carollo Engineering or a City Process Control Specialist 24/7 for any guidance needed. Chemical safety, dosage calculations, and chemical feed system training. They also received overall Engineered Biofiltration training regarding "why" and "how" it s supposed to work. - Overview training on principles of operating biofilters - backwashing - Extensive training was provided for ozone system operations including the relocation of chlorine application from upstream to downstream of the filters, the need to conduct routine basin algae chlorination, additional monitoring samples, etc. specific training was conducted for biofilter operation. - ne 79

82 rth American Biofiltration Knowledge Base Operation Phase Design Facilities Report (Cont.) Operational Impacts Observed - Adjust backflow rates - Backwash sequence, care not to backwash to rigorously to prevent damaging GAC - Filter run times change seasonally; summer 72 hrs, 120 hrs in winter (in design phase estimated <72 hrs) - Following conversion there were no operational issues. During conversion was when we had issues. It was a nightmare trying to feed pre chlorine and ammonia on one side, while feeding post chlorine and ammonia on the other side. Plus, there were issues with air getting in the main wash water line and there were problems with the filter valves. - high chlorine demand - in planning phase/unknown - longer filter run times - longer run times on media left in place - ne except manganese release - One thing that was changed going to GAC was the filter modes of operation from declining rate to constant rate. With declining rate filter, the water level low and would rise as the filter clogged up and with constant always the same; control logic to make that happen - Possible slight reduction in filter run times - ne Modifications Made to Convert to Biofilters - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control. - Change media type - changed from anthracite to GAC - filter box modifications, changed media, moved chlorine downstream of filters - in planning phase/unknown - Install/rehabilitate plant as needed such that the secondary chlorine application point is downstream of the filters, and add chlorination capacity for basin algae control and backwash chlorination. - Raise filter troughs, replace sand with anthracite, and increase filter bed depth. - Removed chlorine from filters - replace anthracite w GAC - Stop prechlorination at filter influent - Disable pre-chlorination - Chlorine added mostly after filtration - stopped replacing media - The capability to chlorinate the backwash was provided for as part of the ozone retrofit at each treatment plant. Also, CBXA monitoring/sampling sites were established in the field. - none 80

83 rth American Biofiltration Knowledge Base Operation Phase Operations Facilities Report Control Measures Used to Control Unwanted Biota Level of Removal Achieved - 10% (winter), 16% (summer) - 20% TOC; 24% BDOC; 74% AOC % % - 90% - Combined filter effluent turbidity < 0.3 NTU. Significant MIB and Geosmin reductions. 5-20% TOC removal % - 71% (Mn) - 80% TOC Removal total facility; about 1 mg/l across the filters, average effluent of 2 mg/l - plant effluent CBXA = 75 µg/l as carbon, or - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2 - T&O - 100% - Typically, 3 to 4 % TOC reduction. - unknown - plant effluent CBXA = 75 µg/l as carbon, or greater than 70% CBXA removal through the filters, and UFRV = 5,000 gal/ft 2. - add pre-settling impoundment: 9 acres weekly (100 lbs) with copper sulfate when water temperature is above 18 de - allowed for chlorinated backwash - capability for chlorinated backwash - capability to periodically backwash with chlorinated water - design included capability to periodically use chlorinated backwash - H2O2 residual carried onto filter, sample panel flush, light blocking tiles on forebay lagoon - included capability to periodically backwash with chlorinated water - KMnO4 residual carried onton filter, sample panel flush, dark tubing used on sample panel - Manual cleaning - Moved Ammonia Feed Downstream of Free Chlorine Addition - NONE - Pre Chlorination - Previously chlorinated backwash water - Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water. 81

84 rth American Biofiltration Knowledge Base Operation Phase Operations Facilities Report (Cont.) How is the filter-to-waste and backwash water handled? - Backwash water treated, supernatant returned to lake - BW water settled & FTW settled and water reused - equalization basin and back to the head of the plant - Filter to Waste is pumped back to filter influent. Backwash water is returned to head of plant. - filter to waste is recycled for backwashing - filter-to waste - NO, RECOVERY - not available on all filters and returned to head of plant - recycled to raw water; 5 mins to sanitary sewer, remainder to recycle to raw water - residuals lagoon - NPDES permit - Return to the head of the plant - sent to quarry - Sent to Sewer - Sent to the reclaim basin and then pumped back to the head of the Plant. - Thickener, recycle back to the head - Sent to lagoon and recycled - recycled 82

85 rth American Biofiltration Knowledge Base Operation Phase Operations Facilities Report (Cont.) Chemicals Used - peroxide - PO4 provided from GAC, carry H2O2 residual onton biofilter - PO4 provided from GAC, carry KMnO4 residual onto biofilter - will incorporate peroxide, caustic, and phosphorous feed when plant goes full scale How do biofilters perform when short-term process upsets occur? - ATP declines quickly when ozone is off - Depends on type of upset - often no issues or issues similar to normal filters - Depends on type of upset - often no issues or issues similar to normal filters - MEMBRANE - observable differences have been noticed - upsets - overall excellent Mn removal except during extreme elevated levels - rare occurrence - Similar performance - turbidity increases - Typically, very well. - unknown - very well - within 1-2 days (less than a week) after shutdowns, TOC removal is back to Steady State; growth returns within two weeks - Poorly during lake turnover Type of training provided to operators? - On the job training - Once we understood that the filters were biological we discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. - ozone training - Regular SOPs, OEPA class I license, water treatment class (annually) - SOPs for shutdown and backwashing - TBD - Vendor. - We spent a great deal of time with our operators ensuring they were very proficient with the dosage calculations of the Engineered Biofiltration chemicals. They were also able to contact a member of Carollo Engineering or a City Process Control Specialist 24/7 for any guidance needed. Chemical safety, dosage calculations, and chemical feed system training. They also received overall Engineered Biofiltration training regarding "why" and "how" it s supposed to work. - Overview training on principles of operating biofilters - backwashing - Extensive training was provided for ozone system operations including the relocation of chlorine application from upstream to downstream of the filters, the need to conduct routine basin algae chlorination, additional monitoring samples, etc. specific training was conducted for biofilter operation. - ne 83

86 rth American Biofiltration Knowledge Base Operation Phase Operations Facilities Report (Cont.) Operational Impacts Observed - Adjust backflow rates - Backwash sequence, care not to backwash to rigorously to prevent damaging GAC - Filter run times change seasonally; summer 72 hrs, 120 hrs in winter (in design phase estimated <72 hrs) - Following conversion there were no operational issues. During conversion was when we had issues. It was a nightmare trying to feed pre chlorine and ammonia on one side, while feeding post chlorine and ammonia on the other side. Plus, there were issues with air getting in the main wash water line and there were problems with the filter valves. - high chlorine demand - in planning phase/unknown - longer filter run times - longer run times on media left in place - ne except manganese release - One thing that was changed going to GAC was the filter modes of operation from declining rate to constant rate. With declining rate filter, the water level low and would rise as the filter clogged up and with constant always the same; control logic to make that happen - Possible slight reduction in filter run times - ne Modifications Made to Convert to Biofilters - Adjust backwash practices so that chlorine is added when deemed necessary for biogrowth control. - Change media type - changed from anthracite to GAC - filter box modifications, changed media, moved chlorine downstream of filters - in planning phase/unknown - Install/rehabilitate plant as needed such that the secondary chlorine application point is downstream of the filters, and add chlorination capacity for basin algae control and backwash chlorination. - Raise filter troughs, replace sand with anthracite, and increase filter bed depth. - Removed chlorine from filters - replace anthracite w GAC - Stop prechlorination at filter influent - Disable pre-chlorination - Chlorine added mostly after filtration - stopped replacing media - The capability to chlorinate the backwash was provided for as part of the ozone retrofit at each treatment plant. Also, CBXA monitoring/sampling sites were established in the field. - none 84

87 APPENDIX B CASE STUDIES 85

88 CASE STUDY LOCATION: EPA Region 8 CASE STUDY UTILITY: Aurora Water- City of Aurora, CO - Treatment Train. 1 &. 2 POPULATION SERVED: >100,000 CUSTOMER CONNECTIONS: 50, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation One facility currently utilizing biofilters In Operation for 3 Years since September 2010 BIOFILTRATION DRIVER: TOC Removal, Stabilization of AOC, T&O Removal FACILITY INFORMATION: Aurora Water currently has one facility that utilizes biofiltration via two separate treatment trains. The treatment trains vary in process and operation but are both combined and filtered via biofilters prior to the clearwells. Information for this facility as well as water quality data is presented below for each treatment train. Distribution water quality data is not presented due to the way the system blends water from multiple facilities, it would not be representative of biofiltration performance only. Treatment Train 1 Treatment Train 2 Plant Design Capacity (MGD) Average Production (MGD) 6 12 Maximum Production (MGD) 9 27 Source Water Type Blend Lake Plant process scheme Softening, UV/AOP, BAF, GAC Conventional - no Ozone Primary coagulant NaOH Ferric Chloride Primary coagulant dosage (mg/l) Polymer Type - - Polymer dosage (mg/l) 15 2 Settling basin residence time (hrs) - - Filter aid polymer type n/a n/a Filter aid dosage (mg/l) n/a n/a Number of filters 2 4 Primary disinfectant chlorine chlorine Primary disinfectant dosage - - Point of disinfection CCB (post filtration) CCB (post filtration) Secondary disinfectant type chloramine chloramine Secondary disinfectant dosage Point of disinfection CCB effluent CCB effluent 86

89 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Treatment Train 1 Treatment Train 2 TOC removal, Stabilize AOC, T&O Removal TOC removal and T&O removal Biofiltration Objectives - - Regulatory Requirements Process modification required N/A - New Installation N/A - New Installation Unintended Consequences Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters Instrumentation fouling and unwanted bio-growth in other processes Part of new water treatment plant - total cost 200 million n/a Instrumentation fouling and unwanted bio-growth in other processes Part of new water treatment plant - total cost 200 million n/a Lessons Learned: Currently being developed by the utility as operations continue Frequently Asked Questions: Currently being developed by the utility as operations continue EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Aurora Water conducted several evaluations prior to constructing the facility and utilizing biofilters. A 6-month bench-scale evaluation was conducted. There were no regulatory requirements mandated for this evaluation with regards to biofiltration. The total capital cost for biofiltration is not available as it was a part of the complete design of the facility in which the total was $200M. Pilot and demonstration scale evaluations were not conducted. A full-scale evaluation was only conducted a week prior to the plant coming online and commissioning water to the distribution system. The target performance criteria for the evaluating the efficacy of biofilters were turbidity performance and head loss as well as finished water regulatory requirements. Performance data for the evaluation periods are available upon request. 87

90 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Aurora Water as new construction following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Treatment Train 1 Treatment Train 2 Media Type GAC GAC Media Specification 1.4 mm/ 72 " 1.4 mm/ 72" Type of GAC bituminous bituminous Virgin or Reactivated virgin virgin Empty Bed Contact Time EBCT (mins) Total Filter Media Depth (inches) Filter Area per Filter Hydraulic Loading Rate (gpm/ft 2 ) Type of Underdrain System IMS IMS Backwash Water Type unchlorinated unchlorinated Backwash Rate high flow 22 gal/min/sq ft high flow 22 gal/min/sq ft Backwash Sequence Air scour 2 min, low rate BW 3 high rate BW 3 min Air scour 2 min, low rate BW 3 high rate BW 3 min Bed Expansion during backwash 20% 20% Backwash Frequency Avg. - 2 times per 7-8 gpm/sq foot Avg. - 2 times per 7-8 gpm/sq foot Average Headloss at Backwash Initiation 14 ft 14 ft Air Scour Utilization Yes Yes Surface Wash Utilization Media Extraction System Media not changed out Media not changed out Aurora Water has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including turbidity monitoring, particle counters, headloss indicators, and RSD. Lessons Learned: Currently being developed by the utility as operations continue. Frequently Asked Questions: Currently being developed by the utility as operations continue. 88

91 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects Target Contaminants experienced with biofilters. Biofilters were included in the design of the Turbidity Removal water treatment plant for Aurora Water to address several areas of concern including turbidity removal, TOC removal, contaminants of emerging TOC Removal concern (CEC) and biostability. Aurora water noted several areas in which CECs operational issues were experienced in the form of unwanted biological AOC Stabilization growth in sample panels, sample lines, on on-line equipment, as well as on the filters when n standby mode or shut down for a period of time. These issues were addressed by developing cleaning protocols for instrumentation and panels and conducting extensive filter backwashing prior to taking filters offline and prior to returning on-line. Additionally, adding light blocking tiles on the forebay lagoon and replacing clear tubing with dark tubing material on the sample panels reduced the occurrence of unwanted bio-growth. Bio-growth periodically occurred during production when insufficient concentrations of pre-oxidant were applied on top of the filters (i.e. potassium permanganate or hydrogen peroxide). Additional operations and maintenance information is below. Treatment Train 1 Treatment Train 2 Level of Contaminant Removal TOC: 10% in winter TOC: 14.9% 16% in summer Filter to waster and backwash Sent to lagoon and recycled Sent to lagoon and recycled handling Changes in filtered water quality after biofilter implementation T&O issues to date Additional TOC and CEC removal T&O issues to date Additional TOC removal Biofilters periodically shutdown? Yes Yes Reason for shutdown Source water conveyance issues, maintenance Shutdown process Depending on length of time: <2 weeks, backwash and then re-backwash before putting on-line, >2 weeks, backwash, drain and then backwash again prior to putting on-line Impacts after startup without precautions, unwanted bio-growth would occur; extended ripening times Monitoring tools for biofiltration effectiveness Turbidimeters, Particle Counters, Headloss monitoring Turbidimeters, Particle Counters, Headloss monitoring Programs used to interpret I-historian I-historian performance data Acclimation/Steadystate Period 6 months 6 months Parameters monitored for biological stability ATP on GAC AOC ATP on GAC AOC Method of evaluating new operational strategies Full scale trials Full scale trials Training for operators Overview training on principals of operating biofilters Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration Yes PO 4 provided from GAC Carry H 2 O 2 residual onto biofilters Longer filter runs unexpected headloss T&O to date Yes PO 4 provided from GAC Carry KMnO 4 residual onto biofilters Longer filter runs unexpected headloss T&O to date 89

92 Lessons Learned: Currently being developed by the utility as operations continue Frequently Asked Questions: Currently being developed by the utility as operations continue WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Yes Yes Yes Please specify time period for data provided below (mm/yy - mm/yy) Jan June 2013 Treatment Train 1 Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) <1.0 > E-Coli (cfu/100 ml) 30.8 < Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) < ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Turbidity (ntu) Temperature ( F) Bromide (mg/l)

93 Source Water Quality Data Average Minimum Maximum Total Iron (mg/l) < Dissolved Iron (mg/l) Total Manganese (mg/l) < Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) 4.6 < MIB (ng/l) Geosmin (ng/l) Treatment Train 2 Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) <1.0 > E-Coli (cfu/100 ml) 8.7 < Total Nitrogen as N (mg/l) Total Phosphorus as P (mg/l) Orthophosphate (mg/l) < Ammonia N as NH 3 (mg/l) <0.100 <0.001 <0.001 ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) < Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l)

94 Source Water Quality Data Average Minimum Maximum Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) Filter Effluent Data Combined Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) 0.01 < Dissolved Iron (mg/l) Total Manganese (mg/l) <0.005 <0.024 Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

95 CASE STUDY LOCATION: EPA Region 5 CASE STUDY UTILITY: Central Lake County Joint Action Water Agency, IL POPULATION SERVED: >100,000 CUSTOMER CONNECTIONS: 50, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation One facility currently in operation In Operation for 21 years BIOFILTRATION DRIVER: Particle Removal Achieve turbidity goals FACILITY INFORMATION: Central Lake County JAWA currently has one facility that utilizes biofiltration which has been in operation for 21 years. The information below is presented to provide a basic understanding of the facilities current processes. Facility Info Plant Design Capacity (MGD) 51.6 Average Production (MGD) Maximum Production (MGD) Source Water Type Lake Plant process scheme Direct Filtration - Ozone/BAF Primary coagulant DelPac 2020 Primary coagulant dosage (mg/l) 9.9 Polymer Type - Polymer dosage (mg/l) - Settling basin residence time (hrs) 0.5 Filter aid polymer type - Filter aid dosage (mg/l) - Number of filters 12 Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 0.66 Point of disinfection Raw Water Secondary disinfectant type UV Secondary disinfectant dosage 20 mj Point of disinfection Post Filtration 93

96 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Planning Biofiltration Driver Low turbidity (<0.5NTU) and maintaining phase IV Partnership award Biofiltration Objectives Solids removal and elimination of ozone disinfection byproducts Regulatory Requirements - Process modification required Unintended Consequences - Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters - ne EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Central Lake County JAWA did not provide information regarding evaluations performed prior to operations of the facility utilizing biofilters. The facility has been in operation for 21 years and therefore that information was not readily available. The target performance criteria for the evaluating the efficacy of biofilters were turbidity/particle removal to ensure maintaining phase IV Partnership award including solids removal and elimination of ozone disinfection byproducts. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Central Lake County JAWA as a new construction project following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Design Media Type GAC Media Specification 8x30 mesh reagglomerated Type of GAC Bituminous Virgin or Reactivated Virgin Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) 48 Filter Area per Filter - Hydraulic Loading Rate (gpm/ft 2 ) - Type of Underdrain System - Backwash Water Type chlorinated Chlorine/chloramine concentration in backwash water (mg/l)

97 Design Backwash Rate Backwash Sequence Bed Expansion during backwash Backwash Frequency Average Headloss at Backwash Initiation Air Scour Utilization Surface Wash Utilization Media Extraction System Air 3mm 4.4 ft 3 /min ft 2 Air/Water 3 min 5.2 gpm/ft 2 - High Wash 4 min 18 gpm/ft 2 Carbon + Sand 25 30% - 8 ft Yes Yes Media not changed out only topped off Low Wash 12 min 5.8 gpm/ft 2 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Information for this phase was not made readily available for this case study. WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) - Adenosine Triphosphate (ATP) - Phospholipid analysis on filter media - Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Yes Yes Yes Please specify time period for data provided below (mm/yy - mm/yy) Jan CASE STUDY FACILITY Source Water Quality Data Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l)

98 Source Water Quality Data Average Minimum Maximum UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) ADDITIONAL SOURCE WATER DATA FOR ENDOCRINE DISRUPTORS AND PPCPs Parameter Average Min Max Acetaminophen (µg/l) < Cotinine (µg/l) < DEET (µg/l) <0.005 < Diltiazem (µg/l) < < Gemfibrozil (µg/l) < <

99 Parameter Average Min Max Filter Effluent Water Quality Data Meprobamate (µg/l) <0.001 < Monensin (µg/l) <0.001 < Nicotine (µg/l) < < PFOS (ng/l) <2.24 < PFOA (ng/l) <3.47 < Progesterone (µg/l) <0.13 < Sulfamethoxazole (µg/l) <0.004 < Parameter Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) - - Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l)

100 Parameter Average Minimum Maximum Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l) Distribution System Water Quality Data Distribution System Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) < Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

101 CASE STUDY LOCATION: EPA Region 5 CASE STUDY UTILITY: Greater Cincinnati Water Works - Ohio - GCWW POPULATION SERVED: >100,000 CUSTOMER CONNECTIONS: >100,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation One facility currently utilizing biofilters BIOFILTRATION DRIVER: DBP Precursor Removal, Taste and Odor Removal, TOC Removal FACILITY INFORMATION: Greater Cincinnati Water Works (GCWW) currently has one facility that utilizes biofiltration which was implemented as a retrofit application. GCWW chose biofiltration because back in 1992 when they started up their GAC, they did not want to put chlorinated water onto the GAC. Chlorinated water could cause dioxin formation during GAC reactivation. GCWW also realized that they could reduce DBPs and reduce the chlorine dose around 66% if they added chlorine after the GAC contactor. The information below is presented to provide a basic understanding of the facilities current processes. Plant Design Capacity (MGD) 240 Average Production (MGD) 110 Maximum Production (MGD) 185 Source Water Type River Plant process scheme Conventional - no Ozone Primary coagulant Alum Sulfate Primary coagulant dosage (mg/l) 15 Polymer Type Cationic Polymer dosage (mg/l) 1.0 Settling basin residence time (hrs) 72 Filter aid polymer type ne Filter aid dosage (mg/l) - Number of filters 47 rapid sand filters Primary disinfectant Chlorine Gas Primary disinfectant dosage 1.6 mg/l Point of disinfection Clear well influent Secondary disinfectant type ne Secondary disinfectant dosage - Point of disinfection - 99

102 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Process modification required Unintended Consequences Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters DBP removal Currently no goal specific for biofiltration. As for conventional filtration, combined filter effluent turbidity shall be < 0.3 NTU ne Removed pre-chlorination at filter influent ne Minimal Minimal Lessons Learned: Currently being developed by the utility as operations continue Frequently Asked Questions: Currently being developed by the utility as operations continue EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. GCWW performed a multi-year biofiltration pilot study. The study focused on the biology and organics coming out of the pilot filters. Based on the study results, GCWW concluded that biofiltration is beneficial and did not pose a risk to the water system since they disinfect later in the process anyway. References for this pilot study: Hartman, D. J., DeMarco, J., Metz D.H., Himmelstein K.W, Miller, R. Disinfection Byproduct Precursor Removal by GAC and Alum Coagulation. Proc AWWA Annual Conf, Philadelphia, PA. Himmelstein, K. W., Hartman, D. J. & DeMarco, J. Water Quality Considerations of Implementing Full Scale Granular Activated Carbon. Proc AWWA WQTC San Diego, CA. 100

103 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at GCWW as a retrofit application following specified design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Design Media Type Media Specification Total Filter Media Depth (inches) Sand Sand effective size mm, Uniformity coefficient < Filter Area per Filter (ft 2 ) 1400 ft 2 Hydraulic Loading Rate (gpm/ft 2 ) 3 Type of Underdrain System (27) Leopold clay, (18) Leopold plastic and (2) AWI Stainless Backwash Water Type unchlorinated Backwash Rate gpm/ft2 Backwash Sequence Surface sweep for 1.5min@0.5 gpm/ft 2, back wash 3 min@15gpm/ft 2, wash gpm/ft 2 Bed Expansion during backwash 30% Backwash Frequency (hours) 40 Average Headloss at Backwash Initiation (ft) 6 Air Scour Utilization Surface Wash Utilization Yes Media Extraction System Vacuum truck GCWW has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including SCADA monitoring of flow meters at the combined filter influent, effluent and individual filter. Headloss measurements are read at each individual filter. Turbidimeters monitor turbidity at the combined filter influent, effluent and individual filter effluent. ph monitoring occurs at the combined filter influent. UVT is monitored at the filter effluent. Grab Samples are collected for TOC the combined filter influent and effluent. Lessons Learned: Currently being developed by the utility as operations continue. Frequently Asked Questions: Currently being developed by the utility as operations continue. 101

104 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Biofilters were implemented as a retrofit application to address several areas of concern including turbidity removal, TOC removal, and DBP precursor removal. GCWW water noted a slight reduction of filter run times after biofilters were put into operation however mitigation of this issues was not required. The only modifications required by GCWW to retrofit their filters for biofiltration was to stop chlorination at the filter influent and only chlorinate post filtration. GCWW reported that O&M costs were not significantly impacted by implementing biofiltration and operational costs for biofilters are approximately $850,000. Additional operations and maintenance information is below. Target Contaminants Turbidity Removal TOC Removal DBP Precursor Removal Operations Level of Contaminant Removal Filter to waste and backwash handling Combined filter effluent turbidity < 0.3 NTU Significant MIB and Geosmin reductions 5-20% TOC removal. Return to the head of the plant Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Reason for shutdown Shutdown process Impacts after startup Monitoring tools for biofiltration effectiveness Programs used to interpret performance data Increased reductions of TOC, MIB and Geosmin Yes Filter rotation based on system demand for finished water Filter cycle, backwash, idle, and back to cycle. Idle time depends on plant flow. rmal filter ripening time Headloss and turbidity monitoring through SCADA; MIB/GEOS monitoring through grab samples; TOC monitoring through grab samples. Excel data analysis of Turbidity, MIB/GEOS, TOC, UVT and filter run hours Acclimation/Steadystate Period About 2 20 C based on TOC removal Parameters monitored for biological stability Turbidity, Headloss, MIB/GEOS and TOC Method of evaluating new operational strategies Chemically enhanced biofiltration (in process) Training for operators $850,000 Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration Regular SOPs, OEPA class I license, water treatment class (annually) Drinking water treatment 102

105 WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Please specify time period for data provided below (mm/yy - mm/yy) July 2012 June 2013 Source Water Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Yes Yes Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l)

106 Source Water Quality Data Average Minimum Maximum Chlorophyll a (µg/l) MIB (ng/l) 2.17 < Geosmin (ng/l) 2.03 < Filter Effluent Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) <2 <2 <2 Geosmin (ng/l) <2 <2 <2 LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

107 Distribution System Water Quality Distribution System Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (mg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (mg/l) LRAA Haloacetic Acid (mg/l)

108 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of Denton, TX - Ray Roberts Water Production Plant POPULATION SERVED: 100, ,000 CUSTOMER CONNECTIONS: 30,000 50,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation One facility currently utilizing biofilters Case study facility in Operation for 11 years in 2014 BIOFILTRATION DRIVER: TOC Removal FACILITY INFORMATION: The City of Denton currently has one facility that utilizes biofiltration in their treatment processes. The facility represented in this case study has been in operation for eleven years. Information provided in the Knowledge Base is shown below in the following sections. Ray Roberts Water Production Plant Plant Design Capacity (MGD) 20 Average Production (MGD) 10 Maximum Production (MGD) 20 Source Water Type Lake Plant process scheme Conventional - Ozone/BAF Primary coagulant Ferric Sulfate Primary coagulant dosage (mg/l) 18.0 Polymer Type Cationic Polymer dosage (mg/l) 1.6 Settling basin residence time (hrs) 1 5 Filter aid polymer type ne Filter aid dosage (mg/l) - Number of filters - Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 1.5 Point of disinfection Post-sedimentation/Pre-filter Target disinfection residual (mg/l) - If ozone, where is it applied in the process scheme? Post-sedimentation Secondary disinfectant type Chloramines Secondary disinfectant dosage (mg/l) 5.2 Point of disinfection Post Filtration 106

109 Ray Roberts Water Production Plant If ozone, where is it applied in the process scheme? - Additional parameters monitored at this facility ATP Removal PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Ray Roberts Water Production Plant Biofiltration Driver Biofiltration Objectives Result of using ozone Removal of organics prior to secondary disinfection Regulatory Requirements Education of executive management or board of director (i.e., governance board) necessary prior - to decision to implement biofiltration Public Education Requirement - Process modification required ne Designed for Biofiltration Implementation and Acclimation Plan - Unintended Consequences during Startup/Conversion Unintended Consequences Mitigation Strategy Capital cost estimate for planning stage of biofiltration free chlorine zone prior to adding ammonia Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters Lessons Learned: ne Provided Frequently Asked Questions: ne Provided EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of Denton performed a bench scale evaluation for the duration of two years prior to designing the Ray Roberts Water Production Plant in which regulatory requirements were followed. The capital cost for these evaluations were approximately $10,000. performance data is available for this evaluation. Lessons Learned: ne Provided Frequently Asked Questions: ne Provided

110 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at City of Denton as new construction following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Media Type Outside Filters Covered Media Specification Type of GAC Ray Roberts Water Production Plant Sand/Anthracite Yes 6 in Sand; 44 in Anthracite - Virgin or Reactivated - Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) 50 Filter Area per Filter (ft 2 ) 464 Hydraulic Loading Rate (gpm/ft 2 ) 4.3 Type of Underdrain System Leopold S Block with IMS cap Backwash Water Type Unchlorinated Backwash Rate (gpm/ft 2 ) 15 Backwash Sequence Air scouring, low rate to high rate, back to low rate Bed Expansion during backwash 45 Backwash Frequency (hrs) 80 Average Headloss at Backwash Initiation (ft) 6.5 Average Filter Run Time (hrs) - Average Filter Run Time Summer (hrs) - Average Filter Run Time Winter (hrs) - Average Headloss Summer (ft) - Average Headloss Winter (ft) - Average unit filter run volume - Provisions for headloss across underdrains - Air Scour Utilization Surface Wash Utilization Media Extraction System Yes Media has not been replaced The City of Denton utilizes process monitoring tools for monitoring performance of biofilters consisting of rate of flow, headloss, water level, and turbidity. The sampling location for this monitoring is at the filter influent and effluent. 108

111 Lessons Learned: Filters were not designed for biofiltration but the design allowed the filters to go biological. t having a small free chlorine zone prior to adding ammonia allowed for growth in the distribution system. Frequently Asked Questions: ne Provided OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. At The City of Denton s Ray Roberts Production Plant, biofilters were implemented for removal of TOC. Target Contaminants Operational approaches were modified to move ammonia feed downstream of the free chlorine addition to address TOC Removal unwanted biological growth issues. Additional operations and maintenance information is below. Ray Roberts Water Production Plant Modification for Conversion to Biofilters ne Included in design Unwanted Biological Growth Yes, in DS Control Measures to Control Unwanted Moved ammonia feed downstream of free chlorine addition Biota Target Contaminants TOC Level of Contaminant Removal - Performance Changes - Filter to waste and backwash handling Filter to waste is pumped back to filter influent. Backwash water is returned to head of the plant Media Evaluation; frequency - Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Reason for shutdown Shutdown process - Yes t all filters are needed for average flow Same as putting a filter back in service when needed Impacts after startup ne Monitoring tools for biofiltration ne effectiveness Programs used to interpret performance - data Performance during short-term upsets observable differences at this time Acclimation/Steadystate Period - Parameters monitored for biological - stability Microbial evaluations; frequency - 109

112 Ray Roberts Water Production Plant Tool development - Method of evaluating new operational - strategies O&M Impacts from conversion ne O&M Costs for biofiltration 0 Training for operators Discussed with the staff what is going on in these filters versus what they were accustomed to at the other plant. Focus areas for training Proper backwash and monitoring of filter operations Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed - biofiltration Chlorine residual carried through filters Lessons Learned: way of periodic chlorination of filter and no instruments to measure biomass buildup on IMS cap Frequently Asked Questions: Are the filter biological? What is the biological activity in the filter? Do we need to clean the biomass off the filter and allow the biomass to regenerate? WATER QUALITY DATA: Ray Roberts Water Production Plant Source Water Quality Data Average Minimum Maximum AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Turbidity (ntu)

113 Source Water Quality Data Average Minimum Maximum Temperature ( C) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Distribution System Quality Data Average Minimum Maximum Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Turbidity (ntu) Temperature ( C) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l)

114 Distribution System Quality Data Average Minimum Maximum Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Total HAA5 (µg/l) Total TTHM (µg/l)

115 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of Fort Worth, TX Eagle Mountain Treatment Plant POPULATION SERVED: >1,000,000 CUSTOMER CONNECTIONS: 200, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Four facilities currently utilizing biofilters Case study facility in Operation for 21 years in 2014 BIOFILTRATION DRIVER: TOC Removal, DBP Precursor Removal, T&O Removal, Filter Performance, and Sustainable Treatment FACILITY INFORMATION: The City of Fort Worth currently has four facilities that utilize biofiltration in their treatment processes. The facility represented in this case study has been in operation for twenty-one years. Information provided in the Knowledge Base is shown below in the following sections. Eagle Mountain Treatment Plant Plant Design Capacity (MGD) 107 Average Production (MGD) - Maximum Production (MGD) 107 Source Water Type Lake Plant process scheme Conventional - Ozone/BAF Primary coagulant Ferric Sulfate Primary coagulant dosage (mg/l) 9 Polymer Type Cationic Polymer dosage (mg/l) 0.8 Settling basin residence time (hrs) 1 5 Filter aid polymer type Cationic Filter aid dosage (mg/l) 1.0 Number of filters 20 Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 3.0 Point of disinfection Raw Water/Pre-Coagulation Target disinfection residual (mg/l) 1.5 If ozone, where is it applied in the process scheme? Contact Basins Secondary disinfectant type Chloramines Secondary disinfectant dosage (mg/l) 3.5 Point of disinfection Post Filtration If ozone, where is it applied in the process scheme? - Additional parameters monitored at this facility UCMR3, Monitoring of Algal Toxins 113

116 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Education of executive management or board of director (i.e., governance board) necessary prior to decision to implement biofiltration Public Education Requirement Process modification required Implementation and Acclimation Plan Unintended Consequences during Start-up/Conversion Unintended Consequences Mitigation Strategy Capital cost estimate for planning stage of biofiltration Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters Eagle Mountain Treatment Plant TOC removal, DBP precursor removal, T&O, Metals, Inorganics, DS WQ Stability, Improving filter performance Turbidity removal, AOC Yes ne Designed for Biofiltration Lessons Learned: ne Provided Frequently Asked Questions: ne Provided EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of Fort Worth did not conduct evaluations prior to implementing biofiltration at this facility. Lessons Learned: ne Provided Frequently Asked Questions: ne Provided 114

117 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at City of Fort Worth as new construction following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Eagle Mountain Treatment Plant Media Type Sand/Anthracite Outside Filters Covered Media Specification Effective size 1.25 mm, Media porosity estimated 50% Type of GAC - Virgin or Reactivated - Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) 50 Filter Area per Filter (ft 2 ) - Hydraulic Loading Rate (gpm/ft 2 ) - Type of Underdrain System - Backwash Water Type Unchlorinated Backwash Rate (gpm) 2,600 Backwash Sequence - Bed Expansion during backwash - Backwash Frequency (hrs) 30 Average Headloss at Backwash Initiation (ft) 8 Average Filter Run Time (hrs) - Average Filter Run Time Summer (hrs) - Average Filter Run Time Winter (hrs) 30 Average Headloss Summer (ft) 8 Average Headloss Winter (ft) - Average unit filter run volume - Provisions for headloss across underdrains - Air Scour Utilization - Surface Wash Utilization - Media Extraction System - Lessons Learned: ne Provided Frequently Asked Questions: ne Provided 115

118 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. At The City of Fort Worth s Westside Treatment Plant, Target Contaminants biofilters were implemented for removal of TOC and taste TOC Removal and odor compounds such as MIB and geosmin. Taste and Odor Additional operations and maintenance information is below. Eagle Mountain Treatment Plant Modification for Conversion to Biofilters ne Included in design Unwanted Biological Growth Control Measures to Control Unwanted Biota ne Target Contaminants TOC, Taste and Odor (MIB/Geosmin) Level of Contaminant Removal - Performance Changes - Filter to waste and backwash handling - Media Evaluation; frequency - Changes in filtered water quality after biofilter - implementation Biofilters periodically shutdown? Reason for shutdown - Shutdown process - Impacts after startup - Monitoring tools for biofiltration effectiveness - Programs used to interpret performance data - Performance during short-term upsets - Acclimation/Steadystate Period - Parameters monitored for biological stability - Microbial evaluations; frequency - Tool development - Method of evaluating new operational strategies - O&M Impacts from conversion - O&M Costs for biofiltration - Training for operators - Focus areas for training - Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration - Chlorine residual carried through filters Lessons Learned: ne provided Frequently Asked Questions: ne provided Water Quality Data is not currently available for this case study. 116

119 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of Fort Worth, TX - rth/south Holly Treatment Plant POPULATION SERVED: >1,000,000 CUSTOMER CONNECTIONS: 200, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Four facilities currently utilizing biofilters Case study facility in Operation for 1 year in 2014 BIOFILTRATION DRIVER: TOC Removal, DBP Precursor Removal, T&O Removal, Filter Performance, and Sustainable Treatment FACILITY INFORMATION: The City of Fort Worth currently has four facilities that utilize biofiltration in their treatment processes. The facility represented in this case study has been in operation for one year. Information provided in the Knowledge Base is shown below in the following sections. rth/south Holly Treatment Plant Plant Design Capacity (MGD) 200 Average Production (MGD) 52 Maximum Production (MGD) 120 Source Water Type Lake Plant process scheme Conventional - Ozone/BAF Primary coagulant Ferric sulfate Primary coagulant dosage (mg/l) 6 8 Polymer Type Cationic Polymer dosage (mg/l) Settling basin residence time (hrs) 1.5 Filter aid polymer type n-ionic Filter aid dosage (mg/l) (as needed) Number of filters 22 Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 3 Point of disinfection Raw Water/Pre-Coagulation Target disinfection residual (mg/l) If ozone, where is it applied in the process scheme? Raw contact chamber Secondary disinfectant type Chloramines Secondary disinfectant dosage (mg/l) Point of disinfection Post Filtration If ozone, where is it applied in the process scheme? Additional parameters monitored at this facility UCMR3, Monitoring of Algal Toxins 117

120 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. rth/south Holly Treatment Plant TOC Removal, DBP removal, Taste and Odor, Biofiltration Driver Improving Filter Performance, Sustainable Water Treatment TOC reduction, turbidity reduction, and Biofiltration Objectives backwash with non-chlorinated water Regulatory Requirements - Education of executive management or board of director (i.e., governance board) necessary prior - to decision to implement biofiltration Public Education Requirement - Process modification required - Implementation and Acclimation Plan - Unintended Consequences during Start-up/Conversion - Unintended Consequences Mitigation Strategy - Capital cost estimate for planning stage of biofiltration - Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters - Lessons Learned: ne Provided Frequently Asked Questions: ne Provided EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of Fort Worth conducted several evaluations prior to converting the facility to utilize biofilters. A year long bench-scale evaluation was conducted in which regulatory requirements consisted of turbidity reduction. The total cost for conducting the study was approximately $100,000. A six-month pilot scale evaluation was conducted in which regulatory requirements consisted of turbidity and TOC reduction. Costs for this evaluation were not provided. A 30-day demonstration scale evaluation was conducted in which regulatory requirements consisted of turbidity (0.1 NTU) and TOC reduction (4 percent). Performance data is not available for these evaluations. Lessons Learned: Adjustment of wash water valves on main header Frequently Asked Questions: ne 118

121 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at City of Fort Worth as a retrofit installation converting from dual media filtration to biofiltration following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. rth/south Holly Treatment Plant Media Type Sand/Anthracite Outside Filters Covered - Media Specification - Type of GAC - Virgin or Reactivated - Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) - Filter Area per Filter (ft 2 ) - Hydraulic Loading Rate (gpm/ft 2 ) - Type of Underdrain System Gravel (South Filters) and Leopold Blocks (rth Filters) Backwash Water Type - Backwash Rate (gpm/ft 2 ) - Backwash Sequence - Bed Expansion during backwash - Backwash Frequency (hrs) - Average Headloss at Backwash Initiation (ft) - Average Filter Run Time (hrs) - Average Filter Run Time Summer (hrs) - Average Filter Run Time Winter (hrs) - Average Headloss Summer (ft) - Average Headloss Winter (ft) - Average unit filter run volume - Air Scour Utilization - Surface Wash Utilization - Media Extraction System - Lessons Learned: ne Provided Frequently Asked Questions: ne Provided OPERATION AND MAINTENANCE PHASE INFORMATION: Information was not provided for this phase. Water Quality Data is not currently available for this case study. 119

122 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of Fort Worth, TX - Rolling Hills Treatment Plant POPULATION SERVED: >1,000,000 CUSTOMER CONNECTIONS: 200, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Four facilities currently utilizing biofilters Case study facility in Operation for 10 Years in 2014 BIOFILTRATION DRIVER: TOC Removal, DBP Precursor Removal, T&O Removal, Filter Performance, and Sustainable Treatment FACILITY INFORMATION: The City of Fort Worth currently has four facilities that utilize biofiltration in their treatment processes. The facility represented in this case study has been in operation for ten years. Information provided in the Knowledge Base is shown below in the following sections. Rolling Hills Treatment Plant Plant Design Capacity (MGD) 200 Average Production (MGD) 100 Maximum Production (MGD) 200 Source Water Type Lake Plant process scheme Conventional - Ozone/BAF Primary coagulant PACl Primary coagulant dosage (mg/l) 7 Polymer Type Cationic Polymer dosage (mg/l) 0.4 Settling basin residence time (hrs) 5 10 Filter aid polymer type Cationic Filter aid dosage (mg/l) 1.0 Number of filters 20 Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 4 Point of disinfection Raw Water/Pre-Coagulation Target disinfection residual (mg/l) 1.5 If ozone, where is it applied in the process scheme? Contact Basins Secondary disinfectant type Chloramines Secondary disinfectant dosage (mg/l) 5 Point of disinfection Clearwell If ozone, where is it applied in the process scheme? 120

123 Rolling Hills Treatment Plant Additional parameters monitored at this facility UCMR3, Monitoring of Algal Toxins PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Education of executive management or board of director (i.e., governance board) necessary prior to decision to implement biofiltration Public Education Requirement Process modification required Implementation and Acclimation Plan Unintended Consequences during Start-up/ Conversion Unintended Consequences Mitigation Strategy Capital cost estimate for planning stage of biofiltration Rolling Hills Treatment Plant TOC Removal, DBP removal, Taste and Odor, Improving Filter Performance, Sustainable Water Treatment TOC reduction, turbidity reduction, and backwash with non-chlorinated water ne Yes ne Change media type ne Problems maintaining total chlorine and ammonia residuals Super-chlorination $4,000,000 Capital cost estimate for implementing biofilters $500,000 Operational cost estimate for implementing biofilters $250,000 Lessons Learned: Use IMS caps for media support instead of gravel Frequently Asked Questions: Operational strategy for biofilters EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of Fort Worth conducted several evaluations prior to converting the facility to utilize biofilters. A year long bench-scale evaluation was conducted in which regulatory requirements consisted of turbidity reduction. The total cost for conducting the study was approximately $100,000. A six-month pilot scale evaluation was conducted in which regulatory requirements consisted of turbidity and TOC reduction. Costs for this evaluation were not provided. A 30-day demonstration scale evaluation was conducted in which regulatory requirements consisted of turbidity (0.1 NTU) and TOC reduction (4 percent). Performance data is not available for these evaluations. Lessons Learned: Adjustment of wash water valves on main header Frequently Asked Questions: ne 121

124 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at City of Fort Worth as a retrofit installation converting from rapid sand to biofiltration following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Media Type Outside Filters Covered Media Specification Type of GAC Virgin or Reactivated Empty Bed Contact Time EBCT (mins) Total Filter Media Depth (inches) Filter Area per Filter (ft 2 ) Hydraulic Loading Rate (gpm/ft 2 ) Type of Underdrain System Backwash Water Type Backwash Rate (gpm/ft 2 ) Backwash Sequence Bed Expansion during backwash Backwash Frequency (hrs) Average Headloss at Backwash Initiation (ft) Average Filter Run Time (hrs) Average Filter Run Time Summer (hrs) Average Filter Run Time Winter (hrs) Average Headloss Summer (ft) Average Headloss Winter (ft) Average unit filter run volume Air Scour Utilization Surface Wash Utilization Media Extraction System Rolling Hills Treatment Plant Anthracite Leopold Type S Blocks with IMS Caps. IMS Caps have since been removed and replaced with layers of gravel in various sizes. Unchlorinated Air Scour, Air/Low Flow, High Flow, 2 nd Low Flow 50 percent MGD Yes Pump 122

125 City of Fort Worth has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including online turbidity, head loss, filter under drain pressure, and rate of flow. All are connected to the filter effluent pipe. Sampling locations are located at the filter as well as the filter effluent. Lessons Learned: Development of calculations required to retrofit the filters and achieve increased flow rates. Frequently Asked Questions: How to balance feeding both pre and post chloramines while one filter wing has the new filters and the other one is still using the old filters? Answer: Adjust dosages as needed to maintain finished water quality. OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Conversion to biofilters at The City of Fort Worth was to target removal of TOC and stabilization of AOC. The City of Fort Worth did not encounter issues following conversion. However, during conversion, managing chloramines feed on the filters that had been converted and those that had not was challenging due to feed pre-chloramines on one side and post chloramines on the other side. All other chemicals are fed in the rapid mix basin. Additionally, they experienced issues with air entering the main wash water line as well as filter valve problems. Resolution to these issues was accomplished by taking the filter of service and backwashing to relieve turbidity issues and super-chlorination for biological fouling issues. The lessons learned from these issues is when using IMS caps on the underdrains, install pressure transmitters to monitor the pressure on the underdrain during the high rate portion of the backwash and set alarm triggers to stop the backwash if the pressure gets too high. Have triggers that will alert operators that the IMS cap is getting clogged and needs to be either superchlorinated, cleaned with caustic, or some other method of cleaning them to prevent damage to the underdrain system. Additional operations and maintenance information is below. Target Contaminants TOC Removal AOC Stabilization Modification for Conversion to Biofilters Unwanted Biological Growth Control Measures to Control Unwanted Biota Target Contaminants Level of Contaminant Removal Performance Changes Filter to waste and backwash handling Media Evaluation; frequency Rolling Hills Treatment Plant Raise filter troughs, replace sand with anthracite, and increase filter bed depth Yes Super chlorination followed by backwash with chloraminated water, and then another backwash with unchlorinated water TOC 3 4 % TOC reduction Improved TOC reduction after filters became biologically active Sent to the reclaim basin and then pumped back to the head of the plant Core sample sent to a lab for biological analysis 123

126 Rolling Hills Treatment Plant Changes in filtered water quality after Lower TOC biofilter implementation Biofilters periodically shutdown? Reason for shutdown - Shutdown process - Impacts after startup Increase in turbidity Monitoring tools for biofiltration Turbidity and TOC reduction effectiveness Programs used to interpret performance Lab analysis, visual inspections, and experience data Performance during short-term upsets Very well Acclimation/Steadystate Period 3 6 months Parameters monitored for biological TOC reduction stability Microbial evaluations; frequency ne Tool development ne Method of evaluating new operational Constant monitoring strategies O&M Impacts from conversion ne O&M Costs for biofiltration $1,000 Training for operators Vendor training Focus areas for training Monitoring filter performance and backwash procedures Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed ne biofiltration Chlorine residual carried through filters Lessons Learned: Keeping normal operations and backwashes functioning when a valve fails Frequently Asked Questions: ne provided Water Quality Data is not currently available for this case study. 124

127 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of Fort Worth, TX - Westside Treatment Plant POPULATION SERVED: >1,000,000 CUSTOMER CONNECTIONS: 200, ,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Four facilities currently utilizing biofilters Case study facility in Operation for 1.5 years in 2014 BIOFILTRATION DRIVER: TOC Removal, DBP Precursor Removal, T&O Removal, Filter Performance, and Sustainable Treatment FACILITY INFORMATION: The City of Fort Worth currently has four facilities that utilize biofiltration in their treatment processes. The facility represented in this case study has been in operation for twenty-one years. Information provided in the Knowledge Base is shown below in the following sections. Westside Treatment Plant Plant Design Capacity (MGD) 12 Average Production (MGD) 10 Maximum Production (MGD) 11.5 Source Water Type Lake Plant process scheme Conventional - Ozone/BAF Primary coagulant PACl Primary coagulant dosage (mg/l) 8.0 Polymer Type ne Polymer dosage (mg/l) - Settling basin residence time (hrs) 1 5 Filter aid polymer type ne Filter aid dosage (mg/l) - Number of filters 3 Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 2.5 Point of disinfection Raw Water/Pre-Coagulation Target disinfection residual (mg/l) 0.1 If ozone, where is it applied in the process scheme? Injected in raw water pipe Secondary disinfectant type Chlorine Secondary disinfectant dosage (mg/l) 3.5 Point of disinfection Post Filtration If ozone, where is it applied in the process scheme? Pre-coagulation Additional parameters monitored at this facility UCMR3, Monitoring of Algal Toxins 125

128 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Education of executive management or board of director (i.e., governance board) necessary prior to decision to implement biofiltration Public Education Requirement Process modification required Westside Treatment Plant DS WQ Stability, Sustainable Water Treatment Turbidity removal, AOC Yes ne Designed for Biofiltration Implementation and Acclimation Plan Unintended Consequences during Startup/Conversion Unintended Consequences Mitigation Strategy - Capital cost estimate for planning stage of biofiltration - Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters - Lessons Learned: ne Provided Frequently Asked Questions: ne Provided EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of Fort Worth performed a year-long pilot evaluation prior to designing the Westside Treatment Plant in which regulatory requirements were followed consisting of TCEQ approvals. performance data is available for this evaluation. Lessons Learned: ne Provided Frequently Asked Questions: ne Provided 126

129 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at City of Fort Worth as new construction following the regulatory authority s specific design requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Westside Treatment Plant Media Type Sand/Anthracite Outside Filters Covered Yes Media Specification - Type of GAC - Virgin or Reactivated - Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) 50 Filter Area per Filter (ft 2 ) 420 Hydraulic Loading Rate (gpm/ft 2 ) 7.1 Type of Underdrain System Leopold Block Backwash Water Type Unchlorinated Backwash Rate (gpm/ft 2 ) 16 Backwash Sequence Air/Water Bed Expansion during backwash 30 Backwash Frequency (hrs) 60 Average Headloss at Backwash Initiation (ft) 9 Average Filter Run Time (hrs) 50 Average Filter Run Time Summer (hrs) 50 Average Filter Run Time Winter (hrs) 80 Average Headloss Summer (ft) 8 Average Headloss Winter (ft) 9 Average unit filter run volume 75,000 gallons Provisions for headloss across underdrains Yes Air Scour Utilization Yes Surface Wash Utilization Media Extraction System The City of Fort Worth Westside Treatment Plant utilizes process monitoring tools for monitoring performance of biofilters consisting of flow, headloss, and turbidity. The sampling location for this monitoring is at the filter effluent. Lessons Learned: ne Provided Frequently Asked Questions: ne Provided ne 127

130 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. At The City of Fort Worth s Westside Treatment Plant, Target Contaminants biofilters were implemented for removal of TOC and AOC removal. Operational approaches consist of maintaining chlorine residuals TOC Removal throughout the seasons. AOC Removal Additional operations and maintenance information is below. Modification for Conversion to Biofilters Unwanted Biological Growth Control Measures to Control Unwanted Biota Target Contaminants Level of Contaminant Removal Performance Changes Filter to waste and backwash handling Media Evaluation; frequency Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Westside Treatment Plant ne Included in design ne AOC 90 percent ne Recovery ne - Reason for shutdown - Shutdown process - Impacts after startup - Monitoring tools for biofiltration effectiveness Turbidity, headloss, and filter run time Programs used to interpret performance data - Performance during short-term upsets - Acclimation/Steadystate Period Parameters monitored for biological stability 3 6 months Growth in media Microbial evaluations; frequency - Tool development Method of evaluating new operational strategies Study of media O&M Impacts from conversion - O&M Costs for biofiltration - Training for operators - Focus areas for training - Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration - Chlorine residual carried through filters Lessons Learned: ne provided Frequently Asked Questions: ne provided 128

131 WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Yes Yes Please specify time period for data provided below (mm/yy - mm/yy) - Westside Treatment Plant Source Water Quality Data Average Minimum Maximum Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) 0-0 E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Turbidity (ntu) Temperature ( C) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l)

132 Source Water Quality Data Average Minimum Maximum Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Filtered Water Quality Data Average Minimum Maximum Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) <0.10 <0.10 <0.10 Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Turbidity (ntu) <0.10 <0.10 <0.10 Temperature ( C) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) <0.005 <0.005 <0.005 Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l)

133 CASE STUDY LOCATION: EPA Region 6 CASE STUDY UTILITY: City of rman rman, OK POPULATION SERVED: 50, ,000 CUSTOMER CONNECTIONS: 30,000-50,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Planning and Design One facility BIOFILTRATION DRIVER: Taste and Odor Removal FACILITY INFORMATION: The City of rman currently has one facility that in the planning and design phase of utilizing biofilters. Information for this facility is presented based on planning and evaluation level data and how the filters are intended to operate in the future. Facility Info Plant Design Capacity (MGD) 17 Average Production (MGD) 8.4 Maximum Production (MGD) 17 Source Water Type Lake Plant process scheme - Primary coagulant Ferric Sulfate Primary coagulant dosage (mg/l) 25 Polymer Type - Polymer dosage (mg/l) - Settling basin residence time (hrs) Filter aid polymer type none Filter aid dosage (mg/l) - Number of filters 8 Primary disinfectant UV Primary disinfectant dosage - Point of disinfection Post Filtration/Clearwell Secondary disinfectant type chloramine Secondary disinfectant dosage (mg/l) 3.0 Point of disinfection - PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. 131

134 Planning Biofiltration Driver Biofiltration Objectives Taste & Odor Removal TOC removal Regulatory Requirements Process modification required Unintended Consequences ne change disinfection type, move secondary disinfection to post-filter, de-chlorinate backwash water, add air scour for filters Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters Lessons Learned: Ozone piloting showed biofiltration as effective at removing T&O compounds. Frequently Asked Questions: Currently being developed by the utility. EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. The City of rman conducted several evaluations prior to designing the facility and utilization of biofilters. A 3-month bench-scale evaluation was conducted. There were no regulatory requirements mandated for this evaluation with regards to biofiltration. There was not a capital cost associated with this evaluation as a facility was rented to perform the bench-scale analysis. However, there was a $20,000 cost for conducting the bench-scale study. A pilot study was conducted for a period of 7 months in which there were no regulatory requirements for conducting this study. The capital cost for the pilot evaluation was approximately $350,000 with an additional $640,000 for conducting the study. Demonstration and full-scale studies have not been performed to-date. Performance data for the evaluation periods are available upon request. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters will be implemented at the City of rman as retrofit application following the regulatory authority s specific design requirements for biofiltration. Site limitations specific to the City of rman were that filters are limited with regards to hydraulics therefore, filter troughs will need to be raised to accommodate air scour. Additionally, electrical limitations will require modification of controls for the use of air scour. The following table provides the filter configurations and backwash schemes that are currently in the design plans for the City of rman. n/a - Design Media Type GAC/sand 132

135 Media Specification Type of GAC Virgin or Reactivated not yet determined bituminous Virgin Empty Bed Contact Time EBCT (mins) 10 Total Filter Media Depth (inches) 30 Filter Area per Filter (ft 2 ) Filters. 1-4: 586 ft 2 Filters. 6-8: 464 ft 2 Hydraulic Loading Rate (gpm/ft 2 ) 3.4 Type of Underdrain System Backwash Water Type Leopold plastic unchlorinated Backwash Rate gpm/ft 2 Backwash Sequence Air Alone 2.5 scfm/ft 2 2 min, 1 min rest, collapsed pulse, air 2.0 scfm/water 6 gpm/ft 2 to 1 ft below trough, high rate for 15 min Bed Expansion during backwash (in) Backwash Frequency not yet determined Average Headloss at Backwash Initiation (ft) 6-8 Air Scour Utilization Surface Wash Utilization Media Extraction System Yes Manual The City of rman has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including turbidity monitoring, flow monitoring, and headloss monitoring at each filter. Lessons Learned: Will be developed at a later time post-operation Frequently Asked Questions: Will be developed at a later time post-operation 133

136 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Biofilters will be implemented at the City of rman as a retrofit Target Contaminants application. At this time operation and maintenance information is not available for full-scale operations. However, the information Taste and Odor Removal below outlines the anticipated operation of the plant post-retrofit. TOC Removal Filter to waster and backwash handling Biofilters periodically shutdown? Reason for shutdown Shutdown process Utilization of supplemental chemicals to manage biofiltration Filter to waste is not available on all filters; where available the water will be returned to the head of the plant The filters will be shutdown/idle periodically once in operation Filters not needed for operation periodically Currently unknown Lessons Learned: Will be developed at a later time post-operation Frequently Asked Questions: Will be developed at a later time post-operation WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 0 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Please specify time period for data provided below (mm/yy - mm/yy) Yes Yes Yes Yes Yes t Specified 134

137 Treatment Train 1 Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) >2419 E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l)

138 FILTER EFFLUENT DATA Combined Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) <0.001 <0.001 <0.001 Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

139 CASE STUDY LOCATION: EPA Region 2 CASE STUDY UTILITY: Fairfax Water - Virginia Facility 1 POPULATION SERVED: 1,700,000 CUSTOMER CONNECTIONS: >230,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Two facilities currently utilizing biofilters BIOFILTRATION DRIVER: TOC Removal, DBP Removal, Taste and Odor, Filter Performance, Sustainable Water Treatment FACILITY INFORMATION: Fairfax Water currently has two facilities that utilize Biofiltration. The facility information in this case study represents the retrofit application at one of their plants which has been in operation for approximately 14 years as of The information below is presented to provide a basic understanding of the facilities current processes. Plant Design Capacity (MGD) 225 Average Production (MGD) 90 Maximum Production (MGD) 160 Source Water Type River Plant process scheme Conventional Ozone/BAF Primary coagulant PACl Primary coagulant dosage (mg/l) 30 Polymer Type - Polymer dosage (mg/l) - Settling basin residence time (hrs) 5-10 Filter aid polymer type ne Filter aid dosage (mg/l) - Number of filters 24 Primary disinfectant Chloramines Primary disinfectant dosage 4.0 mg/l Point of disinfection Post Filtration/Clearwell Target Disinfectant Residual 3.3 mg/l Secondary disinfectant type Ozone Secondary disinfectant dosage 2.5 mg/l Point of disinfection - If ozone, where is it applied in process? Pre-filter 137

140 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Education of executive management or board of directors required? Public education required? Process modification required Unintended Consequences after startup TOC Removal, DBP removal, Taste and Odor, Improving Filter Performance, Sustainable Water Treatment TOC removal ne Changed media type ne Capital cost estimate for implementing biofilters $1,000,000 Operational cost estimate for implementing biofilters - Lessons Learned: ne were provided at this time Frequently Asked Questions: ne were provided at this time EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Fairfax Water performed a bench scale evaluation prior to retrofitting filters at their plant. Regulatory requirements specifically for biofiltration were not required. Costs for this effort were not provided for this case study. 138

141 DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Fairfax Water as a retrofit application following specified design and electrical requirements for biofiltration. The following table provides the filter configurations and backwash schemes. Design Media Type GAC/Sand Media Specification Effective size ; Iodine #>900 Total Filter Media Depth (inches) 24 GAC 12 Sand Type of GAC Bituminous Virgin or Reactivated Virgin Empty Bed Contact Time (EBCT) 2.5 mins Filter Area per Filter (ft 2 ) 1240 ft 2 Hydraulic Loading Rate (gpm/ft 2 ) 6.0 Type of Underdrain System Leopold blocks Backwash Water Type chlorinated Chlorine or chloramine concentration in backwash? 3.8 mg/l Backwash Rate 17 gpm/ft 2 Backwash Sequence Surface wash Bed Expansion during backwash 20-50% Backwash Frequency (hours) 96 Average Headloss at Backwash Initiation (ft) 3 Average filter run time 96 Average filter run time in summer 72 Average filter run time in winter 120 Average headloss measurement at backwash 3 Average headloss at backwash in summer 6 Average headloss at backwash in winter 5 Average unit filter run volume Did you include design provisions to address headloss across underdrains? Air Scour Utilization Surface Wash Utilization Media Extraction System Primary disinfection CT with chlorine before filtration? 11 MG Yes Vacuum 139

142 Fairfax Water has multiple online monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including filter levels, head loss, effluent turbidity, flow rates, particle counters, and backwash turbidity. Lessons Learned: ne provided as part of this case study. Frequently Asked Questions: ne provided as part of this case study. OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Biofilters were implemented as a retrofit application with the purpose of addressing the removal of DBP precursors. Fairfax Water did not Target Contaminants note any unexpected operational impacts after converting to biofilters. The modifications required by Fairfax Water to retrofit their filters DBP Precursor Removal for biofiltration was to change the media type from anthracite to GAC and sand. Additional operations and maintenance information is below. Operations Level of Contaminant Removal -. Filter to waste and backwash handling Recycled Media evaluation steps Media change-out Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Measure level and inspect annually change-out to-date Reduction in TOC and DBPs Reason for shutdown - Shutdown process - Impacts after startup - Monitoring tools for biofiltration effectiveness - Programs used to interpret performance data - Acclimation/Steadystate Period 6-12 months Parameters monitored for biological stability - Method of evaluating new operational strategies - Training for operators Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration Backwashing 140

143 WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Yes Yes Yes Please specify time period for data provided below (mm/yy - mm/yy) Jan 2012 Dec 2013 Source Water Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l)

144 Source Water Quality Data Average Minimum Maximum Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Minimum Filter Effluent Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) 142

145 Filtered Water Quality Data Average Minimum Maximum LRAA Haloacetic Acid (µg/l) Settled Water Quality Settled Water Average Minimum Maximum TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) Distribution System Water Quality Distribution System Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (mg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l)

146 Distribution System Average Minimum Maximum Geosmin (ng/l) LRAA Total Trihalomethanes (mg/l) LRAA Haloacetic Acid (mg/l)

147 CASE STUDY LOCATION: EPA Region 2 CASE STUDY UTILITY: Fairfax Water - Virginia Facility 2 POPULATION SERVED: 1,700,000 CUSTOMER CONNECTIONS: >230,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Two facilities currently utilizing biofilters BIOFILTRATION DRIVER: TOC Removal, DBP Removal, Taste and Odor, Filter Performance, Sustainable Water Treatment FACILITY INFORMATION: Fairfax Water currently has two facilities that utilize biofiltration. The facility information in this case study represents one of their plants which was designed for Biofiltration and has been in operation for approximately 7 years as of The information below is presented to provide a basic understanding of the facilities current processes. Plant Design Capacity (MGD) 120 Average Production (MGD) 80 Maximum Production (MGD) 110 Source Water Type Lake Plant process scheme Conventional Ozone/BAF Primary coagulant PACl Primary coagulant dosage (mg/l) 60 Polymer Type Cationic Polymer dosage (mg/l) 1 Settling basin residence time (hrs) 1-5 Filter aid polymer type PACl Filter aid dosage (mg/l) mg/l Number of filters 14 Primary disinfectant Chlorine Primary disinfectant dosage 4.2 mg/l Point of disinfection Post Filtration/Clearwell Target Disinfectant Residual 3.4 mg/l Secondary disinfectant type Ozone Secondary disinfectant dosage 1.0 mg/l Point of disinfection - If ozone, where is it applied in process? Pre-filter 145

148 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver Biofiltration Objectives Regulatory Requirements Education of executive management or board of directors required? Public education required? Process modification required Unintended Consequences after startup TOC Removal, DBP removal, Taste and Odor, Improving Filter Performance, Sustainable Water Treatment TOC removal, DBP precursor removal, taste and odor ne Designed for biofiltration Biofilm in post ozone channel Capital cost estimate for implementing biofilters - Operational cost estimate for implementing biofilters - Lessons Learned: ne were provided at this time Frequently Asked Questions: ne were provided at this time EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Fairfax Water performed a three-month bench scale evaluation prior to designing the filters at their plant to evaluate GAC and membranes. Regulatory requirements specifically for biofiltration were not required. Evaluations covered performance related to DBPs. Costs for this effort were not provided for this case study. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Fairfax Water as new construction following specified design and electrical requirements for biofiltration. The following table provides the filter configurations and backwash schemes. 146

149 Design Media Type Media Specification GAC/Sand GAC mm/sand mm Total Filter Media Depth (inches) 82 Type of GAC Virgin or Reactivated Empty Bed Contact Time (EBCT) Bituminous Virgin 7 mins Filter Area per Filter (ft 2 ) 1156 ft 2 Hydraulic Loading Rate (gpm/ft 2 ) 6.3 Type of Underdrain System Backwash Water Type Leopold/IMS cap Unchlorinated Chlorine or chloramine concentration in backwash? - Backwash Rate 17 gpm/ft 2 Backwash Sequence 8000 gpm + air 100 scfm Bed Expansion during backwash 20-50% Backwash Frequency (hours) 60 Average Headloss at Backwash Initiation (ft) 5 Average filter run time 60 Average filter run time in summer 48 Average filter run time in winter 72 Average headloss measurement at backwash - Average headloss at backwash in summer - Average headloss at backwash in winter - Average unit filter run volume Did you include design provisions to address headloss across underdrains? Air Scour Utilization Surface Wash Utilization Media Extraction System Primary disinfection CT with chlorine before filtration? 12 MG Yes Have not replaced to-date Fairfax Water has multiple online monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including head loss, effluent turbidity, and TOC. Lessons Learned: Problems with sand in the underdrains. Frequently Asked Questions: ne provided as part of this case study. 147

150 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Target Contaminants Biofilters were designed for at this plant with the purpose of addressing removal of TOC, DBP precursors, taste and odor compounds, and for TOC Removal turbidity and particle counts. Fairfax Water noted that manual cleaning DBP Precursor Removal of pre-filter channels was needed to remove biofilm. Shorter filter run times and increased headloss have resulted since startup. Taste and Odor Turbidity/Particle Counts Additional operations and maintenance information is below. Operations Level of Contaminant Removal Filter to waste and backwash handling Media evaluation steps Media change-out Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? 20% TOC; 24% BDOC; 74% AOC Sent to quarry Measure level and inspect annually change-out to-date Reduction in TOC and DBPs Reason for shutdown - Shutdown process - Impacts after startup - Monitoring tools for biofiltration effectiveness - Programs used to interpret performance data - Acclimation/Steadystate Period <3 months Perform microbial evaluation on influent, filter media, and effluent? Only to diagnose biofilm problem Parameters monitored for biological stability - Method of evaluating new operational strategies Any pre-filter chemical changes are evaluated for effect on biofiltration Training for operators Backwashing Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration 148

151 WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Yes Yes Yes Please specify time period for data provided below (mm/yy - mm/yy) Jan 2012 Dec 2013 Source Water Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) 35 TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) 0.83 Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (µg/l) Dissolved Iron (mg/l) Total Manganese (µg/l)

152 Source Water Quality Data Average Minimum Maximum Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Filter Effluent Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) 150

153 Filtered Water Quality Data Average Minimum Maximum LRAA Haloacetic Acid (µg/l) Distribution System Water Quality Distribution System Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (mg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (mg/l) LRAA Haloacetic Acid (mg/l) CASE STUDY LOCATION: EPA Region 4 CASE STUDY UTILITY: Greenville Utilities Commission Greenville, NC

154 POPULATION SERVED: 50, ,000 CUSTOMER CONNECTIONS: 30,000-50,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Planning/Evaluation One facility currently in planning/ evaluation stages for retrofit BIOFILTRATION DRIVER: Distribution System Water Quality Stability, Manganese Removal TOC Removal, DBP Precursor Removal FACILITY INFORMATION: The Greenville Utilities Commission currently has one facility that in the planning and design phase of utilizing biofilters with a retrofit application. Information for this facility is presented based on planning and evaluation level data and how the filters are intended to operate in the future. Plant Design Capacity (MGD) 22.5 Average Production (MGD) Maximum Production (MGD) 17.5 Source Water Type River Plant process scheme Conventional - Ozone/BAF Primary coagulant Aluminum Sulfate Primary coagulant dosage (mg/l) 40.5 Polymer Type Cationic Polymer dosage (mg/l) 0.09 Settling basin residence time (hrs) 3.5 Filter aid polymer type Cationic Filter aid dosage (mg/l) occasional avg 0.03 ppm Number of filters 7 filters total 2 biofilters currently Primary disinfectant Ozone Primary disinfectant dosage (mg/l) 2.6 Point of disinfection Post sedimentation/prior filtration Secondary disinfectant type Chloramines Secondary disinfectant dosage 4.5 Point of disinfection Post Filtration-Clearwell PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Biofiltration Driver DS WQ Stability 152

155 Biofiltration Objectives Regulatory Requirements Process modification required Unintended Consequences Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters Mn removal, TOC reduction, reduce biological regrowth in distribution, DBP reduction Covering filters, peroxide, caustic, and phosphorus feed for enhanced biofiltration when going full scale Reduced filter run times seasonally $1.5 Million estimated N/A Lessons Learned: Will be developed after implementation Frequently Asked Questions: Will be developed after implementation EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Greenville Utilities Commission performed several evaluations to determine the efficacy of biofilters at their facility. Bench scale analysis was performed for which there were no regulatory requirements associated with this evaluation. Pilot and Demonstration scale evaluations were not performed. A full-scale evaluation is currently under with a project total duration of two years. There were no regulatory requirements associated with the full-scale evaluation. The target performance criteria for this evaluation was manganese removal as well as monitoring aldehyde concentrations. Performance data is available for the evaluation phases upon request. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters will be implemented at Greenville Utilities Commission as a retrofit of a nonbiological dual media anthracite filter plant. regulatory requirements will have to be required with specific regard to biofiltration. Structural design requirements required by Greenville Utilities Commission consist of specific underdrain and filter covering design. The following table provides the filter configurations and backwash schemes. 153

156 Design Media Type GAC/Sand Media Specification - Type of GAC - Virgin or Reactivated Empty Bed Contact Time EBCT (mins) - Total Filter Media Depth (inches) Virgin Filter Area per Filter (ft 2 ) 544 Hydraulic Loading Rate (gpm/ft 2 ) 4 Type of Underdrain System Backwash Water Type Backwash Rate Backwash Sequence Bed Expansion during backwash Backwash Frequency (hours) 48 IMS Caps -lateral block underdrain with porous plate Chloraminated 10,417 gpm for 10 minutes average air scour/backwash/filter to waste up to 50 percent up to 96 hours Average Headloss at Backwash Initiation (ft) 5.98 Air Scour Utilization Surface Wash Utilization Media Extraction System Greenville Utilities Commission has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including headloss monitoring, turbidimeters, and ph meters on the filter effluent. Lessons Learned: Currently being developed. Frequently Asked Questions: Currently being developed. Yes N/A 154

157 OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Biofilters will be implemented as a retrofit application to address Target Contaminants several areas of concern including manganese and TOC removal. Greenville Utilities Commission has not yet implemented biofiltration Manganese Removal and therefore the information provided below is based on how the filters are intended to be operated once the retrofit is complete. TOC Removal Currently, during the full-scale evaluation, unwanted biological growth has occurred on the biological filters. To mitigate these issues copper sulfate is applied during pre-settling when the water temperature increases above 18 o C. Below are additional operational criteria that expected in the full-scale implementation based on the full-scale evaluation currently underway. Operations Level of Contaminant Removal Total Manganese removed from settled channel (71%) Filter to waste and backwash handling Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Residuals Lagoon-NPDES permit Lower aldehydes, Greater Manganese removal Reason for shutdown - Shutdown process - Impacts after startup - Monitoring tools for biofiltration effectiveness Headloss, Turbidity, Filter Run Time, Manganese data, Aldehydes Programs used to interpret performance data Spectrophotometer Acclimation/Steady-state Period - Parameters monitored for biological stability Aldehydes Method of evaluating new operational strategies - Training for operators - Utilization of supplemental chemicals to manage biofiltration Operational impacts from managed biofiltration N/A 155

158 WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Please specify time period for data provided below (mm/yy - mm/yy) January 2011 Dec 2011 Source Water Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (mg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l)

159 Source Water Quality Data Average Minimum Maximum Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) Filter Effluent Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (mg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) <0.01 Dissolved Manganese (mg/l) <0.01 Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (mg/l)

160 Filtered Water Quality Data Average Minimum Maximum LRAA Haloacetic Acid (mg/l) Distribution System Water Quality t Available as full-scale biological filter effluent is combined with non-biological filter effluents. 158

161 CASE STUDY LOCATION: EPA Region 4 CASE STUDY UTILITY: Gwinnett County DWR Lawrenceville, GA Lanier Filter Plant POPULATION SERVED: >100,000 CUSTOMER CONNECTIONS: >100,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Two facilities currently utilizing biofilters BIOFILTRATION DRIVER: Improving Filter Performance FACILITY INFORMATION: Gwinnett County DWR currently has two facilities that utilizes biofiltration; Lanier Filter Plant and Shoal Creek Filter Plant. The treatment plants do not vary in process and operation. Information for Lanier Filter Plant as well as water quality data is presented below. Lanier Filter Plant Plant Design Capacity (MGD) 150 Average Production (MGD) 40 Maximum Production (MGD) 75 Source Water Type Lake Plant process scheme Direct Filtration Ozone/BAF Primary coagulant Ferric Chloride Primary coagulant dosage (mg/l) 0.65 Polymer Type Cationic Polymer dosage (mg/l) 1.2 Settling basin residence time (hrs) Filter aid polymer type N/A Filter aid dosage (mg/l) N/A Number of filters 12 Primary disinfectant Ozone Primary disinfectant dosage 0.5 Point of disinfection Ozone Contactor Secondary disinfectant type Gaseous Chlorine Secondary disinfectant dosage 3.2 Point of disinfection Filter Effluent Channel N/A PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. 159

162 Lanier Filter Plant Biofiltration Driver Biofiltration Objectives Regulatory Requirements Process modification required Unintended Consequences Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters Improving Filter Performance Minimize DBP Precursors ne - Incidental Biofiltration ne Unknown, Incidental Biofiltration Unknown, Incidental Biofiltration EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Gwinnett County DWR conducted one evaluation for Lanier Filter Plant s biofilters. A 7-month pilot evaluation was conducted. There were no regulatory requirements mandated for this evaluation with regards to biofiltration. Bench-scale, demonstration scale, and full-scale evaluations were not conducted. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Gwinnett County DWR as incidental biofiltration. The regulatory authority did not have any specific design requirements/standards, nor did they have site design, electrical design, or structural design requirements. The following table provides the filter configurations and backwash schemes. Media Type Lanier Filter Plant Sand/Anthracite Total Filter Media Depth (inches) 60 Hydraulic Loading Rate (gpm/ft 2 ) 7.5 Type of Underdrain System Backwash Water Type Backwash Rate Backwash Sequence Backwash Frequency Average Headloss at Backwash Initiation Air Scour Utilization Surface Wash Utilization Media Extraction System Primary Disinfection CT achieved with chlorine prior to filtration? IMS Cap Chlorinated 10,000 gpm Air, low/air, low, high 65 hours average 7.5 ft Yes Vacuum Truck 160

163 Gwinnett County DWR has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including level and flow transmitters, headloss monitoring, turbidity monitoring, and flow monitoring. OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Drivers for the biofilters at the Lanier Filter Plant for Gwinnett County DWR are to address TOC removal. Gwinnett County Target Contaminants DWR noted that they do not experience any unwanted biological growth at Lanier Filter Plant due to biofiltration. TOC Removal Additional operations and maintenance information is below. Lanier Filter Plant Modifications to convert conventional filters to biofilters Turned Off Pre-chlorination Level of Contaminant Removal 15-20% Filter to waster and backwash handling Recycled Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Monitoring tools for biofiltration effectiveness Programs used to interpret performance data Biofilter performance during short-term process upsets Acclimation/Steadystate Period Parameters monitored for biological stability O&M costs impacted by conversion? Training for Operators Utilization of supplemental chemicals to manage biofiltration Unknown TOC, HPC, Turbidity Data Reports Poorly during lake turnover t Observed ne ne WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water 161

164 Data Availability Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Please specify time period for data provided below (mm/yy - mm/yy) August 2012 July 2013 Lanier Filter Plant Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (mpn/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (µg/l) MIB (ng/l) Geosmin (ng/l) Filter Water Quality Data Average Minimum Maximum Turbidity (ntu)

165 Source Water Quality Data Average Minimum Maximum Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (cfu/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

166 CASE STUDY LOCATION: EPA Region 4 CASE STUDY UTILITY: Gwinnett County DWR Lawrenceville, GA Shoal Creek Filter Plant POPULATION SERVED: >100,000 CUSTOMER CONNECTIONS: >100,000 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation Two facilities currently utilizing biofilters BIOFILTRATION DRIVER: Improving Filter Performance FACILITY INFORMATION: Gwinnett County DWR currently has two facilities that utilizes biofiltration; Lanier Filter Plant and Shoal Creek Filter Plant. The treatment plants do not vary in process and operation. Information for Shoal Creek Filter Plant as well as water quality data is presented below. Shoal Creek Filter Plant Plant Design Capacity (MGD) 98 Average Production (MGD) 47 Maximum Production (MGD) 50 Source Water Type Lake Plant process scheme Direct Filtration Ozone/BAF Primary coagulant Ferric Chloride Primary coagulant dosage (mg/l) 0.65 Polymer Type Cationic Polymer dosage (mg/l) 1.2 Settling basin residence time (hrs) Filter aid polymer type N/A Filter aid dosage (mg/l) N/A Number of filters 6 Primary disinfectant Ozone Primary disinfectant dosage 0.5 Point of disinfection Ozone Contactor Secondary disinfectant type Gaseous Chlorine Secondary disinfectant dosage 3.2 Point of disinfection Filter Effluent Channel N/A 164

167 PLANNING LEVEL INFORMATION: Information below was provided for planning level expectations and experiences. Shoal Creek Filter Plant Biofiltration Driver Biofiltration Objectives Regulatory Requirements Process modification required Unintended Consequences Capital cost estimate for implementing biofilters Operational cost estimate for implementing biofilters Improving Filter Performance Minimize DBP Precursors ne Incidental Biofiltration ne Unknown, Incidental Biofiltration Unknown, Incidental Biofiltration EVALUATION LEVEL INFORMATION: Information below was provided for evaluation level expectations and experiences. Gwinnett County DWR conducted one evaluation for Shoal Creek Filter Plant s biofilters. A 7- month pilot evaluation was conducted. There were no regulatory requirements mandated for this evaluation with regards to biofiltration. Bench-scale, demonstration scale, and full-scale evaluations were not conducted. DESIGN LEVEL INFORMATION: Information below describes the design requirements and details. The biofilters were implemented at Gwinnett County DWR as incidental biofiltration. The regulatory authority did not have any specific design requirements/standards, nor did they have site design, electrical design, or structural design requirements. The following table provides the filter configurations and backwash schemes. Shoal Creek Filter Plant Media Type Sand/Anthracite Total Filter Media Depth (inches) 72 Hydraulic Loading Rate (gpm/ft 2 ) 7.5 Type of Underdrain System IMS Cap Backwash Water Type Backwash water dosed with 0.50 mg/l chlorine Backwash Rate 18,900 gpm Backwash Sequence Air, low/air, low, high Backwash Frequency 65 hours average Average Headloss at Backwash Initiation 8 ft Air Scour Utilization Yes Surface Wash Utilization Media Extraction System Primary Disinfection CT achieved with chlorine prior to filtration? Vacuum Truck 165

168 Gwinnett County DWR has multiple monitoring tools that are utilized to monitor and evaluate the performance of their biofilters including level and flow transmitters, headloss monitor, turbidity monitor, and flow monitor. OPERATION AND MAINTENANCE PHASE INFORMATION: Information below describes the operation and maintenance aspects experienced with biofilters. Drivers for biofilters at the Shoal Creek Filter Plant for Gwinnett County DWR were to address TOC removal. Gwinnett County Target Contaminants DWR noted that they did not experience any unwanted biological TOC Removal growth at Shoal Creek Filter Plant. Additional operations and maintenance information is below. Shoal Creek Filter Plant Modifications to convert conventional filters to biofilters Turned Off Pre-chlorination Level of Contaminant Removal 15-20% Filter to waster and backwash handling Recycled Changes in filtered water quality after biofilter implementation Biofilters periodically shutdown? Monitoring tools for biofiltration effectiveness Programs used to interpret performance data Biofilter performance during short-term process upsets Acclimation/Steadystate Period Parameters monitored for biological stability O&M costs impacted by conversion? Training for Operators Utilization of supplemental chemicals to manage biofiltration Unknown TOC, HPC, Turbidity Data Reports Poorly during lake turnover t Observed ne ne WATER QUALITY DATA: Data Availability LT2ESWTR Bin Classification (Bin 1, 2,3, or 4) 1 UCMR3 Microbial community structure (e.g. TRFLP) Adenosine Triphosphate (ATP) Phospholipid analysis on filter media Endocrine disruptors in the source water Data Availability 166

169 Pharmaceuticals and personal care products in the source water Algal toxins in raw water source (blue-green algae, cyanotoxins) Please specify time period for data provided below (mm/yy - mm/yy) August 2012 July 2013 Shoal Creek Filter Plant Source Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphorus as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l)

170 Filtered Water Quality Data Average Minimum Maximum Turbidity (ntu) Temperature ( C) Color (c.u.) AOC (µg/l) TOC (mg/l) DOC (mg/l) UV-254 (cm -1 ) BDOC (mg/l) Heterotrophic Plate Counts (mpn/100 ml) Total Coliform (cfu/100 ml) E-Coli (cfu/100 ml) Total Nitrogen as N (mg/l) Total Phosphate as P (mg/l) Orthophosphate (mg/l) Ammonia N as NH 3 (mg/l) ph (s.u.) Dissolved Oxygen (mg/l) Alkalinity (mg/l CaCO 3 ) Hardness (mg/l CaCO 3 ) Bromide (mg/l) Total Iron (mg/l) Dissolved Iron (mg/l) Total Manganese (mg/l) Dissolved Manganese (mg/l) Total Dissolved Solids (mg/l) Chlorophyll a (mg/l) MIB (ng/l) Geosmin (ng/l) LRAA Total Trihalomethanes (µg/l) LRAA Haloacetic Acid (µg/l)

171 CASE STUDY LOCATION: EPA Region 3 CASE STUDY UTILITY: Henrico County - Virginia POPULATION SERVED: 300,000 CUSTOMER CONNECTIONS: >95,700 PHASE OF BIOFILTRATION IMPLEMENTATION: Operation One plant in operation BIOFILTRATION DRIVER: DBP Removal and Taste and Odor FACILITY INFORMATION: Henrico County currently has one facility that utilizes biofiltration. The facility information in this case study represents their plant which was designed for Biofiltration and has been in operation for approximately 11 years as of The information below is presented to provide a basic understanding of the facilities current processes. Plant Design Capacity (MGD) 80 Average Production (MGD) 22.7 Maximum Production (MGD) 50.9 Source Water Type River Plant process scheme Conventional Ozone/BAF Primary coagulant Alum Sulfate Primary coagulant dosage (mg/l) 35 Polymer Type Cationic Polymer dosage (mg/l) 0.30 Settling basin residence time (hrs) 1 5 Filter aid polymer type Cationic Filter aid dosage (mg/l) 0.1 Number of filters 12 Primary disinfectant Ozone Primary disinfectant dosage 0.5 Point of disinfection Post-sedimentation/Pre-filter Target Disinfectant Residual 0 Secondary disinfectant type Chloramines Secondary disinfectant dosage 4 Point of disinfection Post-Filtration If ozone, where is it applied in process? - 169