Mandatory Language for a Maximum Contaminant Level Violation
MCL, LRAA/ TTHM
The Texas Commission on Environmental Quality (TCEQ) has notified the City of Diboll water system
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 at 0.080 milligrams per liter (mg/L) based on a 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 for quarter
2 2014 of 0.093 mg/L at sample point 604 Neil Pickett & Pine Valley (DBP2-01) and for
quarter 32014 of 0.116 mg/L at sample point 604 Neil Pickett & Pine Valley (DBP2-01).
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 naturally-occurring organic matter in
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 systems, 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:
- Weekly flushing program initially, and will be adjusted as required, for S. Meadows and Neil Pickett area.
- Continue reducing chlorine residual levels (levels have been within regulated limits, but reducing to an acceptable limit will aid in lowering TTHM’s).
- Begin weekly testing of influent to Northside Water Plant for the following pre-cursors.
Please share this information with all people who drink this water, especially those who may not have
received this notice directly (i.e., people in apartments, nursing homes, schools, and businesses). You
can do this by posting this notice in a public place or distributing copies by hand or mail.
If you have questions regarding this matter, you may contact,
City of Diboll,
Water Superintendent at 936 829-3526
Posted / Delivered on: 10/23/2014
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