MWRA online - home
Home
About MWRA
Water System
Sewer System
Harbor and Bay
School Program
Doing Business with MWRA
Contact MWRA

UCMR Page for Wilmington: 2014
Massachusetts Water Resources Authority

Research for New Regulations

The US Environmental Protection Agency (EPA) periodically requires water systems across the country to conduct monitoring for substances that may be present in drinking water to help understand their national occurrence as part of the process of deciding whether to regulate them.  Under the Safe Drinking Water Act Amendments, EPA is required once every five years to develop a list of up to 30 new contaminants that must be monitored by public water systems. 

Wilmington collected samples during 2014 at locations throughout the community.  Even with the extremely sensitive test methods used capable of detecting some substances at parts per trillion levels, Wilmington expected to find very few of the substances that we were required to test for due to well protected watershed and reservoirs. Only 6 of the 28 tested for in 2014 were detected, and all were at extremely low levels.

2014 UCMR Test Results for Wilmington

Here is the complete list of 21 substances plus 7 hormones:

Substances (21)
1,2,3-trichloropropane  strontium
bromomethane  total chromium
chloromethane hexavalent chromium
bromochloromethane chlorate
chlorodifluoromethane perfluorooctanesulfonic acid
1,3-butadiene perfluorooctanoic acid
1,1-dichloroethane perfluorobutanesulfonic acid
1,4-dioxane perfluorohexanesulfonic acid
vanadium perfluoroheptanoic acid
molybdenum perfluorononanoic acid
cobalt


More information on these substances and UCMR3 can be found at at on the US EPA web site.

Only the substances discussed below were detected.  All other substances listed in the UCMR3 were not detected.   

Substance Measurement Units Average Range
Total Chromium  parts per billion (ppb)   0.66 ND - 1.1
EPA already regulates total chromium with a Maximum Contaminant Level (MCL) of 100 ppb and a Maximum Contaminant Level Goal of 0.  It is found at low levels in most water as it is an abundant element in the Earth’s crust.  MWRA regularly tests for it and does not detect it with the normally required detection limit of 1 ppb.  Total chromium was included in the UCMR3 testing with a more sensitive detection level to help understand hexavalent chromium occurrence data.  Results for total chromium were all below the normal detection limit, and far below the MCL of 100 ppb. 

Substance Measurement Units Average Range
Hexavalent Chromium  ppb 0.44 ND - 0.9
Hexavalent chromium is one form of chromium.  It is not currently regulated by EPA, by Massachusetts, or any other state other than California.  In June 2014, California issued a maximum contaminant level standard of 10 ppb.  It is commonly found in the environment, from both natural and human-made sources.  MWRA levels are well below this California standard. 

Substance Measurement Units Average Range
Chlorate  ppb

36.2

ND - 227
Chlorate is a byproduct of disinfection with chlorine, and is commonly found in most waters in the US that use chlorine.  EPA and Massachusetts do regulate a number of disinfection by-products, and MWRA is well below those standards, but chlorate is not regulated at this time.  The World Health Organization has a provisional guideline value of 700 ppb, Health Canada has a guideline value of 1,000 ppb, and several years ago California proposed a standard (which was never finalized) of 500 ppb. EPA has not set a standard but has a provisional safe daily reference dose of 210 ppb for lifetime exposure.  MWRA levels are below all of these proposed or finalized standards. 

Substance Measurement Units Average Range
Strontium    parts per million (ppm) 0.14 0.03 - 0.25
Strontium is a metal that is common in nature, and small amounts are found in air, dust, soil, foods, and drinking water, though it is more commonly found at higher levels in ground water.   EPA has developed a non-regulatory lifetime health advisory of 4 ppm for strontium levels in drinking water.  MWRA levels are well below this health advisory. 

Substance Measurement Units Average Range
Vanadium   ppb     1.4 ND - 12
Vanadium is a naturally occurring “rare earth” element that is found ubiquitously in the earth's crust. Vanadium compounds are found in fossil fuels and exist in over 50 different mineral ores. There are no federal or state standards, though California has proposed a Notification Level of 15 ppb. Wilmington’s levels were well below this level.

Substance Measurement Units Average Range
1,4-Dioxane ppb    

0.01

ND - 0.08

1,4-Dioxane is a clear liquid used  as a solvent in the manufacture of chemicals. It has historically been used as a stabilizer in chlorinated solvents.  It can be found in paint, adhesives, pesticides and some consumer products such as household cleaners, detergents, shampoos, deodorants, and cosmetics.  1,4 Dioxane does not have a federal Maximum Contaminant Level or Maximum Contaminant Level Goal.  The World Health Organization has a guideline value of 50 ppb.  Massachusetts DEP has recently introduced a drinking water guideline of 0.3 ppb.   In 2014, California adopted a drinking water notification level of 1 ppb.  Wilmington’s levels were well below all these guideline values.    

           
How will this data be used?

   
EPA will collect and analyze data for all three years and from systems all across the country to develop an understanding of the occurrence, level and distribution of these substances in drinking water.  That data, along with information on potential health effects and water treatment effectiveness will be used by EPA to determine if any new regulations are needed. 

Posted May 26, 2015

 
Historic Withdrawls Reservoir Levels