What effects do they have in drinking water What are THM’s What effects do they have in drinking water

Trihalomethanes What are THMs? THMs are a group of chemicals that are created when water is chlorinated. When drinking water is disinfected with chlorine, the chlorine mixes with organic material, that is naturally present in the water (such as leaf debris and other organics, not coal ash), and creates other chemicals called “disinfection by-products (DBPs).” THMs are one of the by-products of chlorinating water. The amount of THMs in drinking water can change, depending on such things as water temperature, the amount of chlorine needed to disinfect the water, the time that the chlorine interacts with the organics, and even the amount of organic material.

Chlorination Chlorination is necessary for two reasons. First, almost all sources of surface water contain microbiological organisms, which have to be removed in order to prevent the outbreak of waterborne diseases such as typhoid fever and cholera. Second, once the treated water leaves the treatment plant, it may travel through water mains and pipes sometimes at significant distances, before it reaches it's destination. During this time, it is necessary to maintain a residual level of disinfectant in the water to ensure no possible regrowth of microorganisms. Without adequate disinfection, the health risks from microorganisms far outweigh the risks from THMs.

Is Our Water Safe To Consume Tap water provided by municipal governments is safe and regularly monitored by the government for physical, chemical and bacteriological quality. You do not need to stop drinking tap water unless you are have been advised to do so by the government. Notification MUST be sent to all customers in the event our drinking water is determined unfit to consume.

What Are The Standards For Trihalomethanes The EPA has established a Maximum Contaminant Level (MCL) for total THMs in public drinking water systems. MCLs are enforceable drinking water standards determined by balancing the adverse health effects of a particular chemical against the feasibility and costs of treating water, and in the case of THMs, a consideration of the benefits of chlorination in reducing the risk from acute gastrointestinal diseases. The MCL for total THMs is 80 parts per billion (ppb = micrograms per liter (ug/l).

New State Regulations As of October 2014, stage II DBP(disinfection byproducts) rules were enforced prior to this date. KLRWS went from sampling 4 sites quarterly and averaging 16 results in a running annual average. The new rule requires the sampling of 3 new sites plus an original site from the IDSE (Initial Distribution System Evaluation). Upon implementing the new testing rules KLRWS now has to average each location separately. This study showed KLRWS where the highest levels of THM’s in the distribution system were that need closer monitoring.

What Actions Are Being Taken Automatic flushers have been installed in high risk areas Dedicated personnel have been assigned for flushing program. On-line Total Organic Carbon analyzer installed at Kerr Lake Regional Water Facility. Constant monitoring of Chlorine levels leaving treatment facility. Algaecide is now online if needed.

Thank You From The Staff At Kerr Lake Regional Water System Phone: 252-438-2141 Fax: 252-438-7866 Christy Lipscomb: Director