System Assessment Reports Information Sessions. January 2013

Transcription

1 System Assessment Reports Information Sessions January 2013

2 Today s Presentation Updates to Nova Scotia s Municipal Drinking Water Treatment Standards Updates to Terms of Reference for System Assessment Reports Questions

3 Nova Scotia s Municipal Drinking Water Treatment Standards First introduced in 2002 Updated in 2012 to include: Cryptosporidium as a target microorganism for surface water and GUDI supplies Chlorine resistant Minimum requirements for alternate primary and secondary disinfectants Minimum requirements for membrane filtration Management of waste streams

4 Nova Scotia s Municipal Drinking Water Treatment Standards (cont d) Fundamentals: Based on 3-log reduction for protozoa (Giardia and Cryptosporidium) and 4-log reduction for viruses Filtration for all surface water and GUDI supplies Disinfection for all supplies Redundancy for critical processes Continuous monitoring for critical processes Management of waste streams

5 Log Reduction Components Log removal by physical treatment Filtration for surface water and GUDI supplies Performance indicator Turbidity Continuous monitoring Log inactivation by disinfection Applies to all supplies Performance indicators CT concept chemical disinfectants Continuous monitoring of chlorine residual IT concept UV disinfection Continuous monitoring of intensity

6 System Assessment Reports Due April 1, 2013 Last assessments were based on assumptions These assessments must demonstrate performance with turbidity criteria to be awarded log removal credits with disinfection criteria to meet CT/IT with continuous monitoring requirements with discharge criteria for waste streams Based on data from last calendar year can be 2011 no need to wait for 2012 data

7 System Assessment Reports (cont d) Based on the multiple barrier and source to tap concepts Source characterization Treatment and distribution system Operations and management

8 Source Characterization Section 2 Section 2.1 Source Description and Schematic Describe primary source(s) Describe any sources that are used as back-up supplies Identify sources on a map Document precautions for use of back-up supplies Municipalities that purchase water from an adjoining system Identify system connections on a map Document the name of the municipal system that water is purchased from Proceed to Section 2.3

9 Microbial Risks Section 2.2 Surface Water Section Summarize microbial risks Summarize water quality variability Turbidity Colour TOC ph Alkalinity Temperature Provide raw water coliform and protozoa data if available

10 Microbial Risks Section 2.2 (cont d) Groundwater Section Verify classified in accordance with GUDI protocol Summarize GUDI status by individual well Discuss wells that are no longer in use if applicable For GUDI wells Table A.1 MPA results Protozoa data if available Inspect the site to verify no changes to surrounding area Provide raw water coliform data Corrective action for wells Qualified hydrogeologist per GUDI Protocol

11 Chemical Risks Section 2.3 Disinfection by-products Section THMs HAAs Others Table 1 in Terms of Reference Summarize concentrations Tables A.2 and A.3 Calculate locational running annual average based on a minimum of four quarterly samples Exceedances require corrective action

12 Concentrations (ug/l) THMs and HAAs Sampling Locations Identify sampling locations on a map Verify sampling locations are appropriate HAA formation THMs HAAs Chlorine Time (hours) Free Chlorine (mg/l)

13 Lead and Corrosion Control Section Lead Verify sampling locations and frequency is appropriate Flushed samples Stagnant samples Identify sampling locations on a map Corrosion control Review the corrosion control program Langelier Index is not an adequate measure of corrosivity Summarize water quality results Exceedances require corrective action

14 Aluminum Section For facilities using aluminum-based coagulants Compare average of 12 monthly samples at treatment facility to stipulated limit Exceedances require corrective action

15 Guidelines for Canadian Drinking Water Quality Section Table A.4 Required every five years for raw and treated water Verify that sampling locations and frequencies are appropriate Detections require discussion and enhanced monitoring recommendations Include lab reports from last round of sampling; indicate date for next round of sampling Exceedances require corrective action

16 Guidelines for Monitoring Public Drinking Water Supplies Section Table A.5 Verify that sampling locations and frequencies are appropriate for raw and treated water Every year for surface water and GUDI Every two years for groundwater Discuss water quality trends Include lab reports from last round of sampling Exceedances require corrective action

17 Source Water Protection Plan Monitoring Section Step 5 of the source water protection program Summarize parameters being monitored, sampling frequency, concentrations Discuss water quality trends

18 Filter Backwash Water Section 2.4 If backwash water is discharged upstream of raw water intake, document the impact on the source If source is impacted, provide recommendations

19 Source Quantity Section 2.5 Compile water withdrawal approvals Include copy in Appendix Complete Table A.6 to compare actual withdrawals to approved limits Monthly withdrawal is m 3 (not m 3 /d) Provide recommendations If actual withdrawals exceed approved limits If growth is forecast to increase withdrawals beyond approved limits

20 Source Water Protection Plan Section 2.6 Identify protection zones on a map Submit zones in GIS format Summarize the status of the SWP plan and implementation schedule Document the dates of the last two SWP meetings Note the status of meeting actions and SWP plan deliverables Make recommendations to address concerns

21 Conclusions and Recommendations Section 2 Refer to Terms of Reference pages 14 and 15 Microbial risks Chemical risks Filter backwash water risks Source quantity Source water protection plan Carry forward to Section 5

22 Treatment Processes Section 3 Compile existing Approval(s) to Operate Include copy in Appendix Provide a schematic of treatment process Source to treated water entering the distribution system

23 Turbidity and Associated Criteria Section Verify filtration meets turbidity limits Mandatory to be awarded log removal credits Surface Water individual filter effluent turbidity values Evaluating engineered filtration 95 th /99 th percentile If not achieved, recommend corrective action GUDI individual well turbidity values Evaluating natural filtration 1 NTU, 95 th percentile If not achieved, contact NSE Submission options Calculated or graphed values

24 Filter 2 Turbidity Measurements and Exceedances # of Readings exceeding.15ntu # of Readings exceeding.20ntu %age of time below. 15 NTU %age of time below. 2NTU Readings /day 1-Aug % % 2-Aug % % 3-Aug % % 4-Aug % % 5-Aug % % 6-Aug % % 7-Aug % % 8-Aug % %

25

26

27

28

29 Filtration Process Other Requirements Standard operating practices Continuous monitoring, alarms, alerting Inspect turbidimeter Range, accuracy, maintenance, QA/QC Redundancy Surface water Minimum of two filters Membrane filtration Section Table B.1 Integrity testing Organics rejection rate (if applicable)

30 Non-GUDI Wells Evaluating turbidity spikes Daily grab or continuous measurement 1 NTU, 95 th percentile If not achieved, contact NSE Submit turbidity values for individual wells or combined flow Option 1: Calculated values Option 2: Graphed values Inspect measurement method Continuous or grab

31 Primary Disinfection Section Document log inactivation required Discuss how disinfection is achieved Chemical disinfectant or UV Provide a process schematic Inspect the process and instrumentation Redundancy (minimum of two units) Continuous measurements, alarms, alerting Range and accuracy Maintenance, QA/calibration program Standard operating procedures

32 Primary Disinfection Section Chlorine Calculate CT Verify never out of design range otherwise provide daily calculations Ultraviolet light Verify IT Verify never outside of design range otherwise provide daily calculations See Appendix D of Treatment Standards for CT/IT sample calculations

33 Secondary Disinfection Section Describe the process Inspect the process On-line continuous measurement Maintenance, QA/calibration program Where UV is used for primary disinfection calculate CT for virus inactivation Verify never outside of design range otherwise provide daily calculations

34 Other Critical Processes Section Evaluate and inspect other critical processes against established standards and guidelines

35 Waste Streams Section Filter-to-waste Describe the process For chemically-assisted filtration, verify less than 0.2 NTU before returning a filter to service Filter Backwash Water Table B.2 to summarize location and quality of discharge If discharge criteria not met, identify recommendations Other Waste Streams Review other waste streams and Verify appropriately managed

36 Distribution System Water Quality Section 3.2 Chlorine residuals Microbiological water quality Turbidity Other distribution system monitoring/programs

37 On Site Inspection Section 3.3 Refer to pages of Terms of Reference NSF approved chemicals If doing the report internally, consider using a third party

38 Conclusions and Recommendations Section 3 Refer to Terms of Reference pages 14 and 15 Log removal credits Filtration Log inactivation credits Disinfection Secondary disinfection Other critical processes Distribution system water quality On site inspection Carry forward to Section 5

39 Operations and Management Section 4 Operations and Maintenance Section 4.1 Comprehensive operations manual Procedures to identify and correct problems Maintenance program for long term viability of system Including distribution system

40 Operations and Management Section 4 Monitoring and Reporting Section 4.2 Annual monitoring program Labs used Lab policy Reporting

41 Operations and Management Section 4 Management Section 4.3 Certified operators Back-up personnel ODRC Operator Table C. 1 Water quality goals Strategic plan Management plan Due diligence program

42 Conclusions and Recommendations Section 4 Refer to Terms of Reference page 31 Operations and maintenance Monitoring and reporting Management Carry forward to Section 5

43 Ability to Comply Section 5 Summarize conclusions and recommendations from Sections 2, 3 and 4 Include preliminary cost estimates and an implementation schedule prioritized with respect to health risks Obvious problems that jeopardize treated water quality are to be highlighted

44 Report Preparation Section 6 Three (3) copies to NSE Completed by Professional Engineer Corrective action for GUDI wells qualified hydrogeologist per GUDI Protocol Engineer s Declaration Report shall be acceptable to NSE Sample Table of Contents See pages of Terms of Reference

45 Summary of Updates Cryptosporidium added as a target organism for surface water and GUDI Alternate disinfectants Membrane technology Management of waste streams Balance disinfection with formation of by-products Lead and corrosion control

46 Summary of Updates (cont d) Demonstrate operational performance CT/IT Filtration Additional log removal credits for enhanced performance It is NOT acceptable to refer to the last system assessment report If you don t measure it, you can t manage it

47 Questions? Judy MacDonald Supervisor, Drinking Water Program tel: fax: