Massachusetts Water Resources Authority
Updated May 8, 2012
Posted October 21, 2008

Ria Convery
(617) 788-1105, <>


UPDATE May 8 2012 -- Since this was first posted in 2008, MWRA has improved its testing capabilities and can now detect lower levels of substances. The detection limits for perchlorate were reduced twenty-fold from the required sensitivity of 1 part per billion to 0.05 parts per billion.  In 2011, perchlorate was detected at 0.07 parts per billion, much lower than the maximum contaminant level of 2 parts per billion.


You may have seen recent media reports about perchlorate, a chemical that can be found in drinking water.

MWRA has never found perchlorate in its water supply.

The Massachusetts Department of Environmental Protection requires all water suppliers to monitor for perchlorate. MWRA will report results annually.

Since 2007, has tested for perchlorate annually. Tests are performed with highly-sensitive equipment that can now detect levels of perchlorate to less than 1 part per billion. Before perchlorate was regulated by DEP, MWRA tested for perchlorate quarterly in 2001 and 2004 at three locations, with the last samples in November 2004.

MWRA tests the water supply each year for over 120 contaminants to ensure the water supplied is of the
highest quality. For more information, please read MWRA's Water Quality Report.

The Massachusetts Water Resources Authority provides water and sewer services to 2.5 million people
in 61 metropolitan Boston communities.  


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Updated May 8, 2012
Posted October 24, 2008