Resolving Drinking Water Non-compliance MCL Violations

KY Public Water System Violation Trends : Chlorine, TOC, Coliforms, CCR, MOR

KY Public Water System Violation Trends

Total Coliforms/E. coli

Total Coliform Positive total coliform/E.coli is almost always associated with problems with –Sample site –Sampling technique

Total Coliform—Sample Site Sample Site (or “Hey I had a good chlorine residual at that site!!) –No outdoor faucets!! The #1 reason for positives –No swing faucets –No dirty faucets –No hydrants No need to disinfect and most definitely don’t “flame” a faucet Good site and sample locations will reduce and even eliminate positive samples

Total Coliform—Sampling All samplers shall be trained in the proper sampling technique –No old bottles or bottles that have been rolling around in the bed or floorboard of a vehicle –No setting tops down or in pockets or held in the mouth –If removing strainers, do so carefully –Keep samples at 4 degrees C in a dedicated cooler

RTCR Assessment Impact In wine there is wisdom, in beer there is strength, in water there is bacteria (David Auerbach 2002) YearLevel 1Level 2Comment on Level All CWS (2 SW, 2 SWP) CWS, 1 TNC CWS (1 SW, 1 SWP), 1 TNC CWS (1 SWP)

Disinfection By-Products

DBPs—At the Source Start at the source –Pay attention to the source water total organic carbon (TOC) loading Actual TOC data or UV254 Is it related to algal blooms or rainfall or agricultural activity? Treat the source if needed –Be careful using copper sulfate for algal control as it will break up the algae, causing T&O, turbidity and possibly release microtoxins

DBPs and Plant Design It starts with good engineering –Design for the source water needs, not the “technology of the day” Or the technology should resolve the problem –There should be flexibility in chemical feed points and what chemicals can be applied This is a case of more is better –Too much design flow capacity (i.e., plant not operating) can create problems in the plant No flow through means more time for the chlorine to react in sedimentation basins and clearwells

DBPs and Coagulation Then move to the treatment process, starting with coagulation –Optimize coagulation You may find that the coagulation dosage needed for organics removal is different than that for turbidity removal—this is called “simultaneous compliance” –Try feeding PAC Although the dosages may be very high Avoid the pre-chlorine feed site –Look at Step 2 jars or permanent alternative TOC compliance Particularly if your system has TOC violations but not ones for DBPs

DBPs and Disinfection Once done with the coagulation process, examine plant disinfection practices –Minimize the amount of pre-chlorine added If chlorine usage is for oxidation as well as disinfection, evaluate other oxidants (KMnO4, H2O2) –Move the point of pre-chlorine addition to top-of- filter PWSs must request to move the point of chlorination –Watch the chlorine levels leaving the plant More is not always better

DBPs and Disinfection For disinfection, what if the plant needs to move the point of chlorination but can’t because of the “1 log” C-T inactivation requirement?? –2013 is a different drinking water world than 1998 –On a case-by-case basis, the DOW may reconsider the 1-log C-T inactivation but cannot lower it below 0.5-log –Back to “simultaneous compliance” Decreasing DBPs while avoiding TCR problems

DBPs and Distribution Systems And finally the distribution system –DOW data shows that the majority of the PWSs are forming the DBPs in the distribution system Plant tap levels are low –Good communication between plant, distribution and management personnel is critical No more “finger-pointing”

DBPs and Distribution Systems Again, it involves good engineering –As the operator(s)—BE INVOLVED! –The engineered project should not compound or create DBP problems More tanks, booster stations, long lines with minimal usage—not good More water movement, more tank mixing--good –Does your system have a hydraulic model and does it consider water quality impacts? In other words, water age

DBPs versus Booster Chlorination This is a real dilemma –Low chlorine in an area with maybe the occasional positive TCR sample (maybe you ought to figure out why…) –Flushing doesn’t seem to help and is expensive –Booster chlorination is considered Carefully examine where the booster station is placed (back to engineering and hydraulics) –If with a tank, after the tank is preferred –Automatic, SCADA control is preferred with an on-line chlorine analyzer –Seasonal booster chlorination is always when DBP formation is the highest

DBPs versus Water Age Water Age –The older the water, the more likely DBPs will be formed Chlorine + organics + time = DBPs

DBPs versus Storage Tanks Storage tanks –How many tanks are really needed? (and do regulations need to be reviewed to reflect the 2013 world?) –Too many tanks are being used for pressure and so the water in them cannot be adequately turned over –Is there a better way to avoid the tank-to-tank-to- tank movement of water? –Can you do more than monitor the water levels in the tanks—can you control it??

Multiple tanks in an area Multiple tanks & booster stations— Driven by terrain

DBPs versus Water Mains Water Mains –In an effort to provide water to all KY residents by 2020, KY drinking water infrastructure is now available to 93-95% of Kentuckians –Residential water usage is dropping Now estimated at 65 gallons per person per day Number of people in a residence is dropping –In 1990s it was 3.3, in 2006 it was 2.97 and in 2010 is was 2.49 –May have long mains with little usage –Or big mains to potential high usage areas that never developed

DBPs versus Flushing Flushing should be for more than “spot compliance” –KY regulations only recommend –But good distribution operation dictates that it should be routine practice –Scheduled, unilateral, from the plant out, water quality-based –Not just before compliance monitoring –Consider automatic flushers in areas that require more frequent turnover And what are you basing that on??

In Closing…..

DBP Formation and Compliance Chlorine is a good thing in water treatment –No acute, microbial-based public health concerns –So we can’t just stop chlorinating Other disinfectants also have by-product issues –Chlorine dioxide, chloramines, ozone Today’s source water is not getting any cleaner –And systems don’t always have another source water option

DBP Formation and Compliance Today’s operators are challenged with “simultaneous compliance” –How to stay in compliance with regulations that may not work together –Then there is the Clean Water Act impacts on source water and maybe how we treat water (a whole other story) Remember “ We are all downstream” (Ecologist’s Motto)

DBP Formation and Compliance We all have to work smarter not harder because we are all in this together: plant operators, distribution operators, management, engineers, regulators –Gather the data and look at it and stay ahead of the problems Once you get the NOV, it may be too late –What are the best overall option(s) for protecting public health—not just the cheapest or the newest technology, engineering or operations There may need to be multiple options –Communicate –Keep trying

Comments?? Questions?? KY Drinking Water Program Program Coordinator Compliance Technical Assistance Inspectors Capacity Development Engineering