Information and Frequently Asked Questions about Disinfection Byproducts
Archive – DBPs

January 2019 HAA5 Public Notification

April 2019 HAA5 Public Notification

July 2019 HAA5 Public Notification

October 2019 HAA5 Public Notification

January 2020 HAA5 Public Notification

April 2020 HAA5 Public Notification

July 2020 HAA5 Public Notification

October 2020 HAA5 Public Notification

December 2020 Sampling Results

The Commission conducts sampling for HAA5 quarterly, in accordance with MassDEP and EPA regulations. Test results from December 1, 2020, indicated that HAA5 levels were below regulatory limits at all eight sample locations.

While this is good news, it has been observed that HAA5 levels can fluctuate due to a variety of factors. Therefore it is possible that HAA5 levels could elevate above the regulatory limit again due to environmental conditions or other factors.

April 2021 HAA5 Public Notification

October 2021 HAA5 Public Notification

January 2022 HAA5 Public Notification

April 2022 DBP Notification

July 2022 DBP Notification

October 2022 DBP Notification

* Important:  The regulatory limit for DBPs is set as an annual average level (known as the “LRAA”) of 60 parts per billion (ppb) for HAA5 and 80 ppb for TTHMs. A single reading above 60 ppb for HAA5 or 80 ppb for TTHM does not constitute a regulatory violation or health hazard.