Starting in the Fall 2016 PKWSC is to begin construction to replace the existing sand and gravel pre-filters with a new micro-filtration system. This equipment will provide better quality water to send to the reverse osmosis (R/O) systems and reduce the amount of water that is returned to the lake. Additionally, the filters in the R/O's will not have to be replaced as often due to the cleaner water thus reducing the overall cost of production.
Communications have been sent to members regarding a notification from theTexas Commission on Environmental Quality regarding Trihalomethanes. The following is mandatory language and notification regarding a Trihalomethanes (THM) violation:
The Texas Commission on Environmental Quality (TCEQ) has notified the Possum Kingdom Water Supply Corporation TX1820076 that the drinking water being supplied to customers had exceeded the Maximum Contaminant Level (MCL) for total Trihalomethanes. The U.S. Environmental Protection Agency (U.S.EPA) has established the MCL for total Trihalomethanes to be .080 milligrams per liter (mg/L) based on locational running annual average (LRAA) and has determined that it is a health concern at levels above the MCL. Analysis of drinking water in your community for total Trihalomethanes indicates a compliance value in quarter two 2016 of 0.100 mg/L for DBP2-01 and 0.108 mg/L for DBP2-02.
Trihalomethanes are a group of volatile organic compounds that are formed when chlorine, added to the water during the treatment process for disinfection, reacts with the naturally-occurring organic matter in the water.
Some people who drink water containing Trihalomethanes in excess of the MCL over many years may experience problems with their liver, kidney, or central nervous system, and may have an increased risk of getting cancer.
You do not need to use an alternative water supply. However, if you have health concerns, you may want to talk to your doctor to get more information about how this may affect you.
We are taking the following actions to address this issue: This is explained in the next to the last paragraph below.
The following is additional information to better explain this violation and the steps being taken to remedy the problem.
Chlorination has made the U.S. water supply safe from illness produced by bacteria, viruses, and parasites. Fortunately, chlorine disinfection has almost completely eliminated risks of deadly waterborne diseases such as typhoid fever, cholera, and dysentery. However, the chlorination process has also produced byproducts. These disinfection byproducts include a group of chemicals known as Trihalomethanes (THMs). THMs include four chemicals:
The low lake levels at Possum Kingdom Lake for a few years allowed vegetation to grow in areas normally under water. With the lake filling up, the decaying plant matter now produces acids that when mixed with chlorine produce THM's as a byproduct.
The U.S. Environmental Protection Agency (EPA) has mandated public water systems check for THM's on a regular basis and that the level of THM's in the water should be less than 80 parts per BILLION (ppb). EPA has set standards for THMs in water because there is a slight possibility of an increased risk of bladder or colorectal cancer over a lifetime of drinking water with THMs above 80 ppb. This agency estimates that drinking 2 liters of water containing 100 ppb THMs every day for 70 years could result in 3 extra cases of cancer for every 10,000 people. The slight risk of increased cancer occurs only after decades of drinking water with elevated THMs. There is no immediate risk from the water with THMs above 80 ppb. THMs do not pose a high health risk compared to waterborne diseases, but they are among important water quality issues faced by public water supply systems.
What is the remedy?
There are several ways to reduce THMs in drinking water including changing the disinfection process or filtration. Every solution does involve some cost and time to implement. PK Water Supply has chosen a preferred disinfection method to control THMs and has accepted bids for construction. Construction is anticipated to begin in September and will take approximately 3 to 4 months to complete at a cost of $400,000. This will reduce THM levels well below the standards set by TCEQ and EPA.
What happens between now and construction completion?
PKWSC will continue to test and monitor THM levels. However, violation reporting by TCEQ is based on a yearly running quarterly average. Members may continue to receive notices of violation in the next two quarters as required by TCEQ.
BRA's website www.brazos.org provides current drought information and conservation suggestions. We appreciate your cooperation.