Independent water testing confirms safe THM levels after 2007 boil notice

ull Page 1 of 8 EXECUTIVE SUMMARY Recent Drinking Water Testing Completed and the Results The City of West Palm Beach (City) treats surface waters at their downtown facility and produces drinking water for the residents of West Palm Beach. Residents of the Town of Palm Beach (Town) receive potable water from the City through a franchise agreement that expires in the year 2029. Due, in part, to the highly publicized " precautionary boil water" notice issued by the City in September of 2007, concerns arose regarding the overall safety of the drinking water supply being provided to the Town. Accordingly, HSA Engineers and Scientists was asked to collect and analyze additional samples from the water supply. These additional samples were collected by HSA personnel on November 14, 2008 and were submitted to a laboratory independent of the ones used by the City for their routine drinking water testing requirements mandated by the U.S. Environmental Protection Agency (USEPA) and the Florida Department of Environmental Protection (FDEP). There are more than 90 testing parameters that are required to be analyzed on drinking water supplies by the USEPA and the FDEP. HSA collected samples and tested for all of these drinking water parameters and the detailed results are supplied in the enclosed tabular summary. Also as shown in the attached detailed summary table, all of the testing results obtained from our recent sampling passed and all constituents were well below the allowable limits established by State and Federal regulations. What are Trihalomethanes (THMs) and Why Did We Receive a Notice That They Were Elevated? During the precautionary boil water notice that occurred during the latter part of 2007, the City added more chlorine to their finished drinking water to ensure adequate bacterial kill. Chlorine reacts with natural organics (that cause variations in the water’s color) producing a group of compounds called Trihalomethanes (THMs). Up to a point, the higher the chlorine dose added, the higher the THM concentrations produced. The USEPA has established a limit of 80 parts per billion (ppb) for drinking water supplies. In a few samples collected by the City during the ‘boil water notice’ time period, elevated THM test results were obtained due to the additional chlorine in the drinking water. This represented a one-time spike in THM results and the current level is well below the 80 parts per billion limit. During the special testing completed by HSA, the THM level was measured at slightly more than 50 parts per billion, well below the acceptable limit set by the regulators. HOUSE_OVERSIGHT_016681