DELIVERING SAFE WATER FOR 60+ YEARS

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1 Regional Service Through Unity Meeting our Region s Needs Today and Tomorrow DELIVERING SAFE WATER FOR 60+ YEARS Tom Kula, Executive Director Billy George, Assistant Deputy Director of Water Frisco City Council Update on Water Quality April 3, 2018

2 CLICK TO EDIT MASTER TITLE STYLE REGIONAL WATER SYSTEM NTMWD has been delivering safe, quality water to cities for 60+ years Water industry is highly regulated; NTMWD meets or exceeds all standards of Safe Drinking Water Act NTMWD treatment, testing and maintenance are proven, industry practices optimized to our system NTMWD water supplies are from surface water (lakes) and requires treatment process specific to our region and system Test hundreds of samples each day; more than 250,000 annually to ensure compliance Monthly and annual water quality reports posted online at NTMWD.com TCEQ and EPA have confirmed NTMWD is in full compliance. 2

3 CLICK TO EDIT MASTER TITLE STYLE REGIONAL WATER SYSTEM Annual chlorine maintenance is preventive measure to protect water quality Conducted annually in late winter since 2007 not to correct problems but to ensure quality in system throughout hot summer months Industry-accepted practice used across U.S. Chlorine levels consistent with normal operations temporarily stopped ammonia for 28-day period (ended March 26) Minimizes formation and build up of harmful bacteria in pipes Those sensitive to taste and odor of chlorine may notice it more Chlorine remains at safe levels, tested daily Another safeguard to protect water quality and public health NTMWD staff has decades of experience operating our system and complying with state and federal standards 3

4 CLICK TO EDIT MASTER TITLE STYLE NTMWD AND CITIES PARTNER ON DELIVERING SAFE WATER 4

5 CLICK TO EDIT MASTER TITLE STYLE NTMWD TREATMENT PROCESS 5

6 Disinfectant Options Primary disinfection Ozone Chlorine Others Secondary disinfection Chloramine (Chlorine + Ammonia) Chlorine NTMWD uses ozone for primary disinfection which reduces disinfection by-products 6

7 Chloramines State and Federal regulations require utilities to maintain a chlorine residual throughout the distribution system. NTMWD and its Member Cities selected chloramine because it is: Longer lasting than free chlorine Creates fewer disinfection by-products Less impact on taste and odor than free chlorine The Centers for Disease Control and Prevention (CDC) ranks water chlorination and treatment as one of the top 10 greatest public health achievements of the 20 th century. 7

8 CLICK TO EDIT MASTER TITLE STYLE CHLORAMINES Chloramines have been used to treat drinking water since the 1930s 8

9 Preventive Maintenance Biofilm and sediment naturally occur in water distribution systems If not controlled, some of biofilm may convert ammonia into nitrate and nitrite and reduce disinfectant levels All chloraminated public water systems in Texas must have a nitrification action plan Primary activities to minimize nitrification: Treatment process control Preventive chlorine maintenance System flushing (hydrants) as needed Because of our warm climate and surface water characteristics, there is higher risk of nitrification occurring Left unchecked, high levels of nitrite and nitrate in water can cause public health issues chlorine maintenance minimizes risks TCEQ Letter Excerpt: All distribution systems harbor some biofilm TCEQ regulations require public water systems in Texas to maintain minimum disinfectant residual throughout their distribution systems 9

10 Annual Chlorine Maintenance Once per year Ammonia is turned off for 28-day period allowing free chlorine to move through the distribution system Chlorine levels are consistent with normal operations and regulatory limits NTMWD continuously tests to maintain safe levels (annual average of < 4.0 mg/l or parts per million) Levels may be higher closer to treatment plant and lower further out in distribution systems Other Major Water Systems Across U.S. Use Chloramines and Annual Chlorine Maintenance, including: Houston, Texas Arlington, Virginia Washington D.C. Because free chlorine is a stronger disinfectant than chloramine, it is more effective at curbing growth of biofilm Proactive measure to safeguard public health 10

11 TCEQ CONFIRMS CHLORINE MAINTENANCE COMMON PRACTICE From Texas Commission on Environmental Quality (TCEQ) letter received March 20, 2018: The American Water Works Association (AWWA) Nitrification Prevention and Control in Drinking Water guidance manual highlights temporary free chlorine conversions as a common practice for routine operational maintenance for nitrification prevention. Temporary conversion to free chlorine in conjunction with distribution line flushing has been shown to be an effective strategy to improve water quality. 11

12 Chlorine Levels Consistent with Year-Round Operations Total Chlorine Residuals (mg/l) at NTMWD Treated Water Storage Reservoir Sites During Maintenance Period During Maintenance Period 01/01/18-02/25/18 02/26/18-03/26/18 01/01/17-03/12/17 03/13/17-04/10/17 Sampling Locations Average Maximum Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Minimum Custer Pump Station Farmersville Forney Garland # Garland # McKinney Plano # Princeton Rockwall Royse City Shiloh Sunnyvale *NOTE: Water providers are required to maintain an annual average chlorine disinfection residual level of between 0.2 parts per million (ppm) and 4 parts per million (ppm). 1 mg/l = 1 ppm (parts per million) Above are chlorine residuals data from samples collected at designated NTMWD ground storage reservoirs before being delivered to city distribution systems. Sample sites approved by TCEQ for routine testing that is reported to TCEQ. NTMWD collects and analyzes a higher number of samples than required by TCEQ. The laboratory submits the results of the coliform testing and chlorine residuals of 40 samples each month to the TCEQ. These residuals are used for the annual Consumer Confidence Report. Cities are required to perform additional testing and reporting on their distribution systems. 12

13 Disinfection By-Products As chlorine and chloramine react with organic material in the water, disinfection by-products (DBPs) form Trihalomethanes (THM) are one form of DBPs The longer treated surface water stays in the distribution systems, the greater the potential for DBP formation The EPA and TCEQ maximum contaminant limit for THMs is an annual average of less than 80 parts per billion (ppb) rules written to prevent prolonged exposure to high levels Recent testing conducted confirms that NTMWD is in full compliance with Disinfection Byproduct Regulations Samples collected in Plano (northern system) and Forney (southern system) showed THM levels at 54 and 71 parts per billion (ppb) or (i.e and mg/l) 1 ppb is equivalent to 1 drop of water in an Olympic swimming pool 13

14 CLICK TO EDIT MASTER TITLE STYLE NTMWD SYSTEM The treatment and distribution systems have been optimized to remove organic material and other contaminants NTMWD is taking a number of steps to protect public health and lower the potential for the formation of disinfection by-products, including: Water quality monitoring Enhanced coagulation Ozone as a primary disinfectant ($127M) Biologically active filtration (BAF) Flow-paced chemical addition technology Free chlorine maintenance period is conducted as a preventive measure to protect the public water system 14

15 CLICK TO EDIT MASTER TITLE STYLE REGIONAL WATER SYSTEM Regional water system is safe and reliable The NTMWD treatment processes are state of the art and one of largest fully ozonated treatment facilities in the world Water quality data have far exceeded all state and federal requirements The NTMWD has been recognized by the TCEQ s Texas Optimization Program for superior performance in exceeding state standards 15