System Assessment Reports Information Sessions January 2013 Todays - - PowerPoint PPT Presentation

System Assessment Reports – Information Sessions January 2013

Today’s Presentation

• Updates to Nova Scotia’s

Municipal Drinking Water Treatment Standards

• Updates to Terms of

Reference for System Assessment Reports

• Questions

Nova Scotia’s Municipal Drinking Water Treatment Standards

• First introduced in 2002
• Updated in 2012 to include:

– Cryptosporidium as a target micro-

• rganism 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

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

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

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

System Assessment Reports (cont’d)

• Based on the multiple

barrier and source to tap concepts

– Source characterization – Treatment and distribution system – Operations and management

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

Microbial Risks – Section 2.2

• Surface Water – Section 2.2.1

– Summarize microbial risks – Summarize water quality variability

• Turbidity
• Colour
• TOC
• pH
• Alkalinity
• Temperature

– Provide raw water coliform and protozoa data if available

Microbial Risks – Section 2.2 (cont’d)

• Groundwater – Section 2.2.2

– 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

Chemical Risks – Section 2.3

• Disinfection by-products – Section 2.3.1

– 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

THMs and HAAs – Sampling Locations

• Identify sampling

locations on a map

• Verify sampling

locations are appropriate

Time (hours) Concentrations (ug/L) Free Chlorine (mg/L)

THMs HAAs

HAA formation

Chlorine

Lead and Corrosion Control – Section 2.3.2

• 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

Aluminum – Section 2.3.3

• For facilities using aluminum-based coagulants

– Compare average of 12 monthly samples at treatment facility to stipulated limit

• Exceedances require corrective action

Guidelines for Canadian Drinking Water Quality – Section 2.3.4

• 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

Guidelines for Monitoring Public Drinking Water Supplies – Section 2.3.5

• 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

Source Water Protection Plan Monitoring – Section 2.3.6

• Step 5 of the source water protection program
• Summarize parameters being monitored, sampling

frequency, concentrations

• Discuss water quality trends

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

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 m3 (not m3/d)

• Provide recommendations

– If actual withdrawals exceed approved limits – If growth is forecast to increase withdrawals beyond approved limits

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

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

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

Turbidity and Associated Criteria – Section 3.1.2

• Verify filtration meets turbidity limits

– Mandatory to be awarded log removal credits

• Surface Water – individual filter effluent turbidity

values

– Evaluating engineered filtration – 95th/99th percentile – If not achieved, recommend corrective action

• GUDI – individual well turbidity values

– Evaluating natural filtration – 1 NTU, 95th percentile – If not achieved, contact NSE

• Submission options

– Calculated or graphed values

Filter 2 Turbidity Measurements and Exceedances Readings /day # of Readings exceeding .15NTU # of Readings exceeding .20NTU %age of time below . 15 NTU %age of time below . 2NTU 1-Aug 708 100.00% 100.00% 2-Aug 1403 100.00% 100.00% 3-Aug 725 1 99.86% 100.00% 4-Aug 847 100.00% 100.00% 5-Aug 1241 100.00% 100.00% 6-Aug 702 2 99.72% 100.00% 7-Aug 1131 100.00% 100.00% 8-Aug 808 1 99.88% 100.00%

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 3.1.3

– Table B.1 – Integrity testing – Organics rejection rate (if applicable)

Non-GUDI Wells

• Evaluating turbidity spikes

– Daily grab or continuous measurement – 1 NTU, 95th 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

Primary Disinfection – Section 3.1.4

• 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

Primary Disinfection – Section 3.1.4

• 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

Secondary Disinfection – Section 3.1.5

• 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

Other Critical Processes – Section 3.1.6

• Evaluate and inspect other critical processes against

established standards and guidelines

Waste Streams – Section 3.1.7

• 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

Distribution System Water Quality – Section 3.2

• Chlorine residuals
• Microbiological water

quality

• Turbidity
• Other distribution system

monitoring/programs

On Site Inspection – Section 3.3

• Refer to pages 27-28 of Terms of Reference

– NSF approved chemicals

• If doing the report internally, consider using a third

party

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

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

Operations and Management – Section 4

• Monitoring and Reporting – Section 4.2

– Annual monitoring program – Labs used – Lab policy – Reporting

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

Conclusions and Recommendations – Section 4

• Refer to Terms of Reference – page 31

– Operations and maintenance – Monitoring and reporting – Management

• Carry forward to Section 5

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

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 32-33 of Terms of Reference

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

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

Questions?

Judy MacDonald Supervisor, Drinking Water Program tel: 902-424-2378 fax: 902-424-0501 email: macdonjx@gov.ns.ca