Drinking Water Notice

Public Notice


The City of Brockton’s water system was recently in violation of an Environmental Protection Agency (EPA) drinking water standard.

Although this is not an emergency, you have a right to know what has happened, what you should do and what the City is doing to correct the situation.

Brockton’s drinking water is disinfected with chlorine.  In addition to testing for any bacteria in the distribution system weekly, the water is also routinely tested quarterly, at various sites in the distribution system, for the presence of byproducts related to the disinfection process.  The EPA sets standards for the maximum levels of both disinfectants and disinfection byproducts (DBP’s) in drinking water.  This includes substances known as trihalomethanes, collectively called total trihalomethanes or TTHMs.

The EPA Stage 2 DBP Rule, which went into effect in 2012, requires water systems to meet “locational” running annual averages (LRAA) for total TTHM at each of 8 sampling locations.  In the past the City had to report a combined annual average (RAA) of all samples collected throughout the distribution system and was able to meet EPA requirements.   With the more stringent Stage 2 DBP requirements, the City added an automatic mixing system to help meet these requirements.

The compliance limits for TTHMs are calculated by averaging the results over the last 4 quarters at each location.  In Brockton the LRAA results for the last 4 quarters show that our system exceeded the maximum contaminant level for TTHMs at two locations.  The EPA standard for TTHMs is 80 parts per billion (ppb).  Brockton’s 2014, Quarter 3, LRAA for the two locations was as follows:  Thorney Lea – 81.4 ppb and Walgreens –- 85.8 ppb

What does this mean?

This is not an emergency, nor is there an imminent risk.  It if had been, you would have been notified immediately through local media outlets.  Some people who drink water containing trihalomethanes in excess of the maximum contaminant level over many years may experience problems with their liver, kidneys or central nervous system and may have an increased risk of getting cancer.

What should I do?

You do not need to use an alternate water supply such as bottled water, However, if you have specific health concerns, please consult your doctor.

What happened?   What is being done?

TTHMs form when free chlorine reacts with naturally occurring organic matter (NOM) in water.  Lowering TTHM levels may be achieved by removing NOM by upgrading the treatment process, changing from using free chlorine in the water distribution system to using monochloramine to prevent reaction with NOM, by flushing or removing TTHMs from the water.

The risk of illness from TTHMs is much lower than the risk of illness from drinking water that has not been disinfected.  Regardless, the City is committed to addressing the violation of the TTHM limit.  The City is currently flushing the area with automatic flushing units; the City is currently working with the DEP and our consultant on a longer term corrective action plan that will ensure continued compliance with the TTHM standards.

How do I find out more information?

For more information, please contact Brian Creedon, Water Systems Manager at the Water Commission Office at 508.580.7825.

This public notice is sent to you by the City of Brockton

PWS ID# 40444000-01S & 02S

Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses).  You can do this by posting this notice in a public place of distributing copies by hand or mail.