DISTRIBUTION SYSTEM WATER QUALITY CONTROL DEMONSTRATION WATER RESEARCH FOUNDATION PROJECT 4286

Transcription

1 DISTRIBUTION SYSTEM WATER QUALITY CONTROL DEMONSTRATION WATER RESEARCH FOUNDATION PROJECT 4286

2 PROJECT TEAM Abigail Cantor, P.E., Chemical Engineer; Process Research Solutions, LLC; Madison, WI Eric Kiefer, Manager; North Shore Water Commission; Glendale, WI Kevin Little, PhD, Statistician, Informing Ecological Design, LLC; Madison, WI Andrew Jacque, P.E., PhD, Environmental Engineer; University of Wisconsin-Platteville Archie Degnan, Microbiologist; WI State Laboratory of Hygiene; Madison, WI Barry Maynard, PhD, Geologist; University of Cincinnati David Mast, PhD, Physicist; University of Cincinnati Judith Cantor, Industrial Engineering Student; Acer Enterprises, Inc.; Raleigh, NC Project Advisory Committee: Frank Blaha, Project Manager; Water Research Foundation; Denver, CO Andrew Reid, P.E.; AECOM; Concord, MA Anne Spiesman, P.E.; Washington Aqueduct; Washington, D.C.

3 PROJECT FUNDING Tailored Collaboration with funding split between: North Shore Water Commission of Glendale, WI Water Research Foundation of Denver, CO

4 THE NEED FOR ENHANCED CONTROL OF WATER QUALITY IN WATER SYSTEMS

5 There are multiple opportunities, yet unrealized in many drinking water systems, to improve water quality and to save money in doing so.

6 3 WAYS TO MORE EFFECTIVELY USE MONITORING INFORMATION 1. Be Comprehensive 2. Be Consumer-centric 3. Be Proactive in Water Quality Control and Improvement

7 3 TOOLS FOR PROCESS CONTROL 1. A Comprehensive Monitoring Strategy 2. A Standardized Monitoring Station for Tracking the Quality of Water at the Consumers Taps 3. A Display Tool That Quickly Makes Sense of Complicated Data, Allowing Us to be Proactive

8 BENEFITS A lower possibility of falling out of compliance with drinking water regulations (including the Lead and Copper Rule) A lower frequency of consumer complaints A documented decision-making process leading to higher consumer confidence produces and giving confidence to managers and water commissioners More consistent water quality

9 WATER SYSTEM NORTH SHORE WATER COMMISSION OF GLENDALE, WI

10 NORTH SHORE WATER COMMISSION Photo courtesy of North Shore Water Commission

11 TREATMENT PROCESSES Lake Michigan Water: Potassium permanganate Alum and polymer Activated carbon Flocculation/sedimentation Anthracite carbon, sand and gravel filters UV disinfection Fluoride Orthophosphate Sodium hypochlorite Storage in a reservoir Ammonium hydroxide Diagram courtesy of North Shore Water Commission

12 PREVIOUS USE OF TECHNIQUES AT NSWC Before Disinfection and PO4 Change After Disinfection and PO4 Change

13 TOOL #1: STRATEGY OF MONITORING

14 WHAT IS WATER QUALITY? Scales and films on Pipe Wall Corrosion by-products Biofilms Precipitated chemicals from Source water contaminants Chemical addition for water treatment Water: Dissolved and entrained forms of pipe wall scales and films Pipe wall

15 COMPREHENSIVE MONITORING Parameters that describe the water type (This influences corrosion by-products formed and environmental conditions in the pipe.) Parameters that define the biostability of water, i.e. ability of microorganisms to grow in the water Parameters that track water treatment chemical addition Parameters that track source water and pipeline contaminants and debris Parameters that track metals released from piping material to the water

16 TOOL #2: CAPTURE OF WATER QUALITY EXPERIENCED BY THE CONSUMER

17 STANDARDIZED MONITORING STATION Similar to a AwwaRF Pipe Loop Less expensive More compact Standardized configuration for exposure of metal to water Can study metal plate scales like distribution system pipe Open-source technology Can purchase from a fabricator instead of building it yourself Can test any type of metal Can test chemical addition scenarios Alternative: Use Pipe Loops

18 SIMILITUDE Surface Area per foot of 1.5 ID pipe = 32 Volume per foot of 1.5 ID pipe Surface Area of 16 metal plates in test chamber= 32 Volume of test chamber Concentrations of metals in test chamber similar to those found in actual pipe of the pure metal. For example, lead concentrations from a lead test chamber are similar to concentrations of lead that would be found in a lead water service line in the water system being tested.

19 TOOL #3: INTERPRETATION OF WATER SYSTEM DATA

20 SHEWHART CONTROL CHARTS Plot of data over time Interplay with average New definition to variation of the data (sigma unit based on moving range) Interplay with +/- 1, 2, and 3 sigma units 3 sigma units = Upper and Lower Control Limits +3 σ +2 σ +1 σ -1 σ -2 σ -3 σ

21 SHEWHART CONTROL CHART RULES Troubleshoot if: Data fall outside the 3 sigma unit lines At least 2 out of 3 successive values fall on the same side of the average and are at least 2 sigma units from the average At least 4 out of 5 successive values fall on the same side of the average and are at least 1 sigma unit from the average 8 or more successive points fall on the same side of the average line +3 σ +2 σ +1 σ -1 σ -2 σ -3 σ

22 ADDITIONAL INFORMATION

23 ADDITIONAL INFORMATION Data from Previous Distribution System Monitoring Projects at NSWC and Other Systems Examination of Metal Plates from Monitoring Station Residential Sampling Lead and Copper Rule Sampling SCADA Data On-line Sensor Data Regulatory and Investigative Data (Disinfection and Turbidity at all Total Coliform Rule sampling sites)

24 RESULTS: QUICK UNDERSTANDING OF DATA WITH SHEWHART CONTROL CHARTS

25 CONTROL CHARTS AND MONITORING DATA

26 CONTROL CHARTS AND MONITORING DATA ENTRY POINT MONITORING STATION LEAD RELEASE HIGH WATER AGE MONITORING STATION LEAD RELEASE +3 σ Average -3 σ

27 RESULTS: WATER QUALITY EXPERIENCED BY THE CONSUMER CAPTURED

28 WATER QUALITY SAME BETWEEN MONITORING STATION AND RESIDENCES

29 WATER QUALITY SAME BETWEEN MONITORING STATION AND RESIDENCES

30 WATER QUALITY SAME BETWEEN MONITORING STATION AND RESIDENCES

31 WATER REACTIONS SAME BETWEEN MONITORING STATION AND RESIDENCES

32 RESULTS: COMPREHENSIVE, CONSUMER-CENTRIC PROCESS CONTROL DEMONSTRATED

33 CONCEPTS OF WATER SYSTEM PROCESS CONTROL There are many interrelated factors that create the existing water quality. Monitoring strategy should capture as many factors as possible based on knowledge, time, and budget. Must try to monitor the water that the consumer receives. Must relate the consumers water to the water from the source through the treatment through the distribution system. Must view the data in a quick and meaningful way. Don t jump to conclusions about cause and effect: measure, observe, theorize, experiment, monitor. Iterate: Monitor, observe, theorize, experiment, monitor, You ll be surprised how the essence of the water system will reveal itself to you over time.

34 EXAMPLE: WHAT CAUSED THE LEAD INCREASE? No change in lead at entry point Increase in lead at high water age location Summer pattern seen in water produced and other characteristics PO4 dose change coincided with summer pattern

35 EXAMPLE: WHAT CAUSED THE LEAD INCREASE? Interesting pattern of lower iron in summer Turbidity matches iron pattern Summer pattern of higher water usage and characteristics brought higher dissolved lead and copper, higher aluminum, lower dissolved and particulate iron. Seems unlikely that a small change in PO4 dose could cause this.

36 GETTING STARTED WITH SHEWHART CONTROL CHARTS

37 SHEWHART CONTROL CHART FOR MONITORING DATA Insert Tab Create Data Sheet for Control Chart Create Control Chart Help Excel Spreadsheet

38 CLICK ON CREATE A DATA SHEET [Title] [Results] in [Units] Date Results

39 DATA SHEET FILLED IN Example Control Chart Measured Value, e.g. Chloride in mg/l Date Results 6/22/ Etc.

40 CLICK CREATE A CONTROL CHART

41 CLICK HELP Rules of interpreting a Shewhart Control Chart are summarized.

42 GETTING STARTED WITH A COMPREHENSIVE CONSUMER- CENTRIC PROCESS CONTROL METHODOLOGY

43 GET STARTED RIGHT AWAY 1. Graph disinfection data from Total Coliform Rule sampling sites. (For each site, create a graph of disinfection over time.) 2. Study the charts, understand past trends per site, and take action where disinfection is low currently. If you just continue to do this, your water quality at the consumers taps will improve.

44 IF YOU WANT TO DO MORE 1. Take turbidity reading s at Total Coliform Rule sites, and graph and study that data. Take action where turbidity is high. 2. Now, turn your disinfection and turbidity data graphs into Shewhart Control Charts using the Excel add-in. 3. Graph any water system data you can get your hands on with a Shewhart Control Chart, study to determine the normal events and the unusual events, take action when data are out of a desired range.

45 IF YOU WANT TO DO EVEN MORE 1. Use a standardized monitoring station (or pipe loop) of lead, copper, brass, iron, or any metal of interest to track the status of metal transfer into the water routinely 2. Use a standardized monitoring station to track the ability of microorganisms to grow in the water and on metal surfaces 3. Use all water system and monitoring data with control charts to: Observe, Theorize, Experiment or Make Improvements, Monitor. ITERATE it s a way of life and a philosophy of water system operation!

46 SUMMARY OF BENEFITS

47 BENEFITS THAT HAVE ALREADY BEEN EXPERIENCED BY WATER SYSTEMS USING THESE TECHNIQUES System Operation Triggering the need to troubleshoot equipment or other system operations Saving money on treatment chemicals Minimizing temporary water quality degradation Evaluating system operations routinely Lead and Copper Rule Issues Study lead and copper release in the context of multiple influencing factors Serve as a surrogate for residential sampling to know transfer status routinely Aid in determining mechanisms of lead and copper transfer specific to system Establish key water quality parameters relevant to lead or copper release Monitor and control the key water quality parameters Monitor and control system transitions (simultaneous compliance) Determine need for corrosion control chemicals Compare and select corrosion control chemicals

48 BENEFITS THAT HAVE ALREADY BEEN EXPERIENCED BY WATER SYSTEMS USING THESE TECHNIQUES Beyond Lead and Copper Rule Issues Assess and control biostability of water, aid in setting disinfection level, stay in compliance with Total Coliform Rule Assess cleanliness of pipeline and effects of water main flushing Develop hypotheses for further research on a system level and a national level A Comprehensive Consumer-centric Process Control Methodology Establish water quality control methods Establish water system process improvement methods

49 QUESTIONS? CONTACT: Abigail Cantor, P.E. Process Research Solutions, LLC Photo courtesy of Process Research Solutions, LLC