Aquifer Storage Recovery (ASR) for Reclaimed Water

Transcription

1 P R E S E N T A T I O N on Aquifer Storage Recovery (ASR) for Reclaimed Water Presented at the: St. Johns River Water Managment District Water Utility Advisory Board Sanford, Florida Presented by: Mark B. McNeal, P.G. CH2M HILL, Tampa FL Wednesday June 21, 2000

2 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 2

3 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 3

4 Crossbar Ranch Wellfield North Pasco Wellfield Cypress Creek Wellfield Water Clearwater and Dunedin Wellfields Starkey Wellfield Eldridge-Wilde Wellfield Cosme- Odessa Wellfield NW Hillsborough Regional Wellfield South Pasco Wellfield Section 21 Wellfield City of Tampa Aquifer Storage and Recovery Hillsborough River Reservoir Cypress Bridge Wellfield Morris Bridge Wellfield Cone Ranch Wellfield South Central Regional Wellfield Resources are Stressed in the Tampa Bay Area Alafia Northeast WRF Northwest WRF Albert Whitted WRF Southwest WRF Scale in Miles Little Manatee Regional Water Supply Facilities and the City of St. Petersburg s s Deep Injection Well System 4 0 9

5 A successful reclaimed water program can offset significant potable water usage, as demonstrated by the City of St. Petersburg s s system Potable Water Pumped (mgd) Reclaimed Water Pumped (mgd) 5 Water Use (mgd) Water Use (mgd)

6 Reuse is critical to water resource optimization in west-central Florida Urban Reuse-Irrigation Raw Sewage Pretreatment Secondary Treatment Filters High Level Disinfection Ground Storage and Pumps Confinement * Proposed projects in various stages of development Brackish Groundwater Zone Confinement Saline Groundwater Zone *Reclaimed Water ASR Deep Injection Wells * REWARD Project 6 City of St. Petersburg Treatment and Reclaimed Water Reuse Process

7 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 7

8 St. Petersburg is a recognized leader in reuse Large urban reuse system in service since 1977 More than 287 miles of reclaimed water pipeline 9,345 connections Elimination of surface water WWTP discharge More than 20 mgd of reclaimed water use Decreased potable water use over last 15 years Water Use (mgd) Northwest 0 WRF Southwest WRF Reclaimed Water Potable Water Central Ave INTERSTATE 275 Year 687 Northeast WRF 1978 Albert Whitted WRF

9 Mature reuse systems in West-Central Florida experience build-out at approximately 50 % without seasonal storage or supplemental sources Seasonal storage is needed to optimize use of the resource Flow Rate (mgd) Injection Reuse Date City of St. Petersburg Reuse Supplemental supplies are needed during peak demand periods

10 Seasonal reclaimed water demands can exceed available supply No surplus during extended drought periods Additional customers already identified MINIMUM DAILY INJECTION WELL FLOW (MAY JUNE 1992) FLOW (mgd) May 6-May 11-May 16-May 21-May 26-May 31-May 5-Jun 10-Jun 15-Jun 20-Jun 25-Jun 30-Jun No Surplus Available DATE 10

11 Reclaimed Water Benefits in Northwest Hillsborough County Total Reuse Demands by 2015 * Groundwater Pumping Offset * Commercial 3.0 mgd 16% Wetland/Wellfield 4.4 mgd 23% Golf Course 2.1 mgd 11% Total Reuse - 19 mgd Residential 9.5 mgd 50% Water Conservation Benefit (mgd) mgd Total Reduction 6.4 mgd Direct Groundwater 6.8 mgd Finished Potable Water (attributable to groundwater) *Contingent on Seasonal Storage Development 11

12 The County s s Program interconnects the four WWTPs,, allowing more efficient reuse Tarpon Springs Rd. Van Dyke WWTP Van Dyke Rd. Eagles WWTP Gunn Hwy. Expwy Veterans NWRWRF NW ASR Well No. 1 Fawn Ridge Gunn Hwy. Dale Mabry AWTP Dale Mabry 12 ID-5 ASR River Oaks WWTP Waters Ave.

13 Seasonal supply and demand imbalances exist with Hillsborough County s s reuse system 30 NORTHWEST HILLSBOROUGH COUNTY RECLAIMED WATER SUPPLY AND DEMAND 25 FLOW (MGD) Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13 Jan-14 Jan-15 Jan-16 Jan-17 Jan-18 Jan-19 Jan-20 Jan-21 DATE TOTAL NW HILLSBOROUGH NON-POTABLE DEMAND TOTAL NW HILLSBOROUGH RECLAIMED WATER SUPPLY (with ASR) TOTAL NW HILLSBOROUGH RECLAIMED WATER SUPPLY (without ASR) 13

14 Regional interconnects will provide challenges for future reuse system optimization Water quality issues will be present (real and perceived) Varying water quality standards required for certain programs (principal vs. primary treatment) I don t want that stinky water in my system How to address the true cost of the water Seasonal storage requirements may not be available in all locations Political agendas will be different 14

15 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 15

16 GOOD LUCK!!!! , 610, FAC Rule Revisions Address Reclaimed Water ASR Native Water Quality Determines Effluent Quality Greater than 10k TDS - Limited restrictions 3k to 10k TDS -Principal treatment + Primary DWSs 1k to 3k TDS - Full Treatment with exceptions Less than 1k TDS - Full treatment, including primary/ secondary DWSs, total nitrogen, TOC, and TOX limitations Federal primary DWSs regulated as single sample exceedence, Secondary DWSs as annual average 16

17 New rules provide relief for secondary drinking water standards under some instances Greater than 3000 mg/l TDS aquifers, secondary drinking water standards requirements are waived Allows zone of recharge for aesthetic parameters such as color, odor, and iron Previously, water quality criteria exemption was required for anything less than 10,000 mg/l TDS 17

18 18 Water Quality Criteria Exemption ( (1) through (6), FAC) Granting the exemption is clearly in the public interest; compliance with such criteria is unnecessary for the protection of present and future potable water supplies; granting the exemption will not interfere with existing uses or the designated use of the waters or of contiguous water the economic, environmental, and social costs of compliance with the criteria outweigh the economic, environmental and social benefits of compliance; an adequate monitoring program approved by the Department is established to ascertain the location and approximate dimensions of the discharge plume, to detect any leakage of contaminants to other aquifers or surface waters, and to detect any adverse effect on underground geologic formation or waters; and the exemption will not present a danger to the public health, safety or welfare.

19 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 19

20 Non-potable ASR wells are regulated by FDEP s s Underground Injection Program Class I wells - municipal or industrial wastewater disposal Class II wells - oil and gas injection wells Class III wells - solution mining wells Class IV wells - hazardous waste (banned) Class V wells - all other injection wells (includes Group 3 for wells associated with a domestic wastewater facility and Group 7 for ASR wells associated with a WTP) 20

21 West/Central Florida Pioneering Reclaimed Water ASR Systems West Central Florida Reclaimed Water ASR Systems Feasibility FDEP System Cycle Site Study Permitting Constructed? Testing NW Hillsborough Done Done Yes ( ) Jul-2000 S/C Hillsborough Done Underway No ('00/'01) 2001 Englewood Done Done Yes (Apr-00) Aug-2000 SW Manatee Done Done No (2000) 2000 N. Manatee Done Initiated No ('00/'01) 2001 St. Petersburg Done Done No (2000) Dec-2000 Sarasota Done Underway No ('00/'01) 2000 Lehigh Acres Done Underway No (2000) Dec-2000 Marco Island Done Initiated No (2001)

22 CH2M HILL is Active in all Reclaimed Water ASR Projects Florida's Reclaimed Water ASR Systems No. of Planned No. Ultimate Capacity Site Consultants Sites of Wells (approx. mgd) NW Hills. Co. CH2M HILL South Hills. Co. CH2M HILL Central Hills. Co. CH2M HILL Englewood CH2M/PBS&J SW Manatee MW/CH2M N. Manatee CH2M/MW SW St. Petersburg CH2M HILL Sarasota PBS&J/CH2M Lehigh Acres CH2M HILL Marco Island CH2M HILL Over 70 mgd of Reclaimed Water ASR already Identified in Southwest Florida 22

23 23 Drivers for non-potable ASR development in west-central Florida Untreated or partially treated ASR Public water supply Agricultural use Ecological systems Reclaimed Water ASR Optimization of reuse systems Minimize wet weather disposal requirements Injection wells or surface water discharges

24 Reclaimed Water ASR Benefits Source water costs pennies per 1000 gallons (pumping costs) Recovery to approximately twice the TDS of drinking water Additional aquifer treatment may enhance water quality Greater than 100 percent recovery in brackish aquifers could create water resources that would otherwise require expensive (membrane) treatment Inexpensive saltwater intrusion barrier or rehydration augmentation source 24 B-2-2

25 Reclaimed Water Characterization Important to evaluate each water reclamation facility for seasonal variations in parameters Bi-monthly sampling for 1 year for all parameters (62-550, FAC; pathogens; FDEP minimum criteria for effluent) More frequent (weekly/monthly) sampling for parameters of interest (exceedences) Less frequent sampling following initial year Anticipate quarterly to semi-annually for full scan 25

26 Hillsborough County Reclaimed Water Primary Drinking Water Standards Approx. 23 samples taken Inorganics All metals below MCLs Nitrate <2 mg/l (MCL=10) Nitrite <0.05 mg/l (MCL=1) Asbestos not required Radionuclides below MCL Coliforms Total Col - 4 of 153 >MCL Fecal Col - 2 of 174 >MCL Organics Di(2--ethylhexyl)phthalate 2 of 11 exceeded DWS MCL 6 ppb; <5 to 20 ppb THMs (MCL 100 ppb) High level disinfection Average of 4 samples 1 of 21 exceeded DWS 108 ppb maximum Increases in system All other organics below MCLs 26

27 Hillsborough County Reclaimed Water Characterization Update Di(2--ethylhexyl)phthalate Resampling at ASR well was required to confirm phthalates were a non-issue - lab or sampling interference suspected All 43 weekly samples supported this conclusion Total Trihalomethanes (TTHMs) Acceptable levels leaving the WWTP TTHM concentrations more or less double in transmission system, to approx. 150 ppb Proposed rules will be much more stringent Ammoniation will control TTHM formation Aquifer treatment confirmed at potable water sites 27

28 Hillsborough County Reclaimed Water Secondary Drinking Water Standards Approx. 22 samples taken Aesthetic Parameters For Secondary DWSs: allows annual averaging of monthly samples allows alternate standard based on native groundwater Fe/Mn well below MCLs Total Dissolved Solids 33/165>MCL of 500 mg/l Native water >1,000mg/L Color 21 of 22 <MCL of 15 PCU average well below MCL Odor 16 of 17<MCL of 3 TON average below MCL All other secondary DWSs below MCLs No exemptions needed 28

29 FDEP Minimum Criteria for Sewage Effluent - NWH County ASR Toluene Diethylphthalate Ammonia Chloroform 1,2 dichlorobenzene Aldrin Dimethylphthalate Organic Nitrogen TKN Chloroethane Napthalene Nitrite 1,2 dichloroethene Anthracene Total Nitrogen Dieldrin Phenanthracene Soluble Orthophosphate 2,4,6-Trichlorophenol Phenol Total Phosphorus 2-chlorophenol Butylbenzylphthalate Antimony Cryptosporidium and Giardia Lamblia monitoring also required 29

30 Sampling During Operational Testing Demonstrate recharge compliance at wellhead with all applicable water quality standards Monitor at storage zone observation well to evaluate water quality response during resident time Monitor shallow aquifers to evaluate confinement Monitor recovered water quality for reuse compliance (TSS, Coliforms, BOD, etc.) and customer satisfaction (TDS, Chlorides, etc.) 30

31 The City s s permitting and operating strategies link deep well injection to reuse optimization Surficial Sands Peace River Formation Tampa Member Upper Suwannee Limestone Lower Suwannee Limestone Base of USDW NW WRF SW WRF NE WRF AW WRF Ocala Limestone Avon Park Formation 31

32 200 Zone B ASR Well TDS Distribution After 90 Days of Operation (After 1st 180 mg Recharge) Southwest WRF - with Continuous Injection in Zone 3.2 mgd Zone HG Depth Below Land Surface in Feet A A/B B B/C C LEGEND TDS mg/l mg/l mg/l Modeled ASR Zone Feet from Center of Injection 10,000 TDS Concentration (mg/l) Historical Injection rate used through 12/31/95 Base of USDW

33 Blending of REWARD water with WRF reclaimed water will help meet City s s TDS standards mg/l TDS REWARD Well 2000 mg/l TDS Chlorine Contact Basin Water Reclamation Facility mg/l TDS mg/l TDS (350 mg/l chlorides) 33

34 Storage in subsurface can enhance select water quality parameters as demonstrated by St. Petersburg s s DIW system Albert Whitted MW-1 Phosphorus Data Albert Whitted MW-2 Phosphorus Data Average Reclaimed Water Phosphorus Concentration Average Reclaimed Water Phosphorus Concentration Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 TOT-P (mg/l) TOT-P (mg/l) 34

35 Comparison of reclaimed water ASR to other storage options suggests ASR is preferred Three possible options identified for storing an additional 640 mg seasonally Reclaimed water ASR Cost effective/regulatory issues Above ground storage tanks High cost/aesthetics/siting constraints Surface reservoir High cost/siting constraints/water quality issues/ Evapotranspiration 35

36 ASR more practical than above ground storage for seasonal quantities 36 ID-4 6 ASR Wells $4 to 5 million cost 3 acres of land Storage = 640 MG 128-5MG Storage Tanks >$100 million cost 100s of acres of land

37 ASR is more practical than open reservoir systems for reuse storage 37 ID-4 6 ASR Wells $4 to 5 million cost 3 acres of land Storage = 640 MG 640 million gallon Reservoir >$100 million cost 100s of acres of land

38 ASR Site Selected at NW WRF Discharge Hillsborough County Northwest Dechlorination Facility and ASR Phase I Facilities To Northwest Regional WRF River Oaks AWTP To Dale Mabry AWTP Hillsborough County Project Location HILLSBOROUGH COUNTY 38

39 Initial Class V, Group 3 System Installed 0 WCRWSA Well 14-D Shallow Rehabilitation Monitoring Well (r = 900 feet) Geologic Unit Undifferentiated 12 Test Production Well TPW-1 30 Steel Shallow Monitoring Well SMW-1 (radius = 340 feet) 6 Steel ASR Storage Zone Monitoring Well SZMW-1 (radius = 370 feet) 18 Steel Depth Below Land Surface (Feet) Arcadia Formation Tampa Member Suwannee Limestone 6 TD 150 Pilot Hole Backplugged with Neat Cement to TD to 2 mgd Steel 16 Steel TD 170 Pilot Hole TD 460 (Backplugged with Neat Cement) mg/l TDS TD Steel 6 Steel Ocala Limestone mg/l TDS 39

40 Existing and Proposed Land Use and Conceptual ASR Layout ASR #1 SMW-1 SZMW-1 24 Jacor Broadcasting Old Memorial Hwy ASR #6 12 ASR #5 SZMW-2 SMW-2 WTMW-2 16 SZMW-3 SMW-3 WTMW-3 Channel A ASR #4 ASR # S 14-D 24 ASR #2 24 LEGEND Existing ASR Well Existing Monitoring Well Proposed Monitoring Well Proposed ASR Well Wetlands School Board Site (Proposed) Mitigation Area Upland Area Montague Road (Proposed) Utilities 40

41 NW Hillsborough County ASR Cycle Testing Plan of Action Weekly water quality sampling during recharge events for parameters of interest Composite sample for full scan at completion of cycle test recharge event Contingency for water quality excursions - Cease recharge and initiate recovery Recover 100 to 120 percent initially Comprehensive testing at monitoring wells 41

42 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 42

43 Future rule revisions will be necessary to expand the use of this technology Still operating under state and federal regulations that were developed prior to ASR technology UIC rules and WUP rules are antiquated The regulators should consider aquifer degradation on a more holistic approach, not on a single parameter basis Treatability of the recovered water should be a key part of the decision process Aquifer treatment benefits should be realized Zones of discharge should be allowable, even for select primary drinking water standards (e.g., THMs, coliform) under certain situations 43

44 Presentation Overview Introduction Reclaimed Water Management Challenges Recent Rule Revisions Affecting Reclaimed Water Management New Reclaimed Water Opportunities Reclaimed Water ASR Overview Reclaimed Water ASR case studies Future Rules Needed to Optimize Reclaimed Water Use Summary 44

45 Summary and Conclusions Reclaimed water use is increasing rapidly in Florida and nationwide West-central Florida is a Hot Spot for reclaimed water programs Reclaimed Water Systems are faced with seasonal imbalances in supply and demand Reclaimed water ASR is in its infancy but expanding rapidly in west-central Florida Recent Florida rule revisions will help reclaimed water utilities optimize their systems - Great start! Future rule revisions are needed to further optimize reclaimed water systems 45