Manganese is a common mineral that naturally occurs in rocks and soil, and is commonly found in ground and surface waters in New England. It may also be present due to underground pollution sources.  Manganese is an essential mineral for proper digestion, bone development, and immune function.  Primary sources in the diet include grains, beans, nuts and teas. At excessively high levels, however, manganese can have adverse neurological effects.  EPA has a secondary, aesthetic standard of 50 ppb.  Above the 50 ppb level, consumers may notice a gray or black coloring in their water and/or fixture staining. To be protective of public health MA DEP has a health guideline value of 300 ppb, and Consumer Confidence Report Notification Limit of 50 ppb. MWRA routinely samples for manganese in the source and finished water with results posted to MWRA’s web site on a monthly basis.  UCMR4 results are typical for results found through routine monitoring, and are well below the state and EPA health guidelines. Only two of 88 results were over the aesthetic standard of 50 ppb, likely due to local flushing or hydrant use.

1-Butanol is a naturally occurring alcohol, and also widely used in industry.  1-Butanol is not currently regulated by EPA, or by Massachusetts.  New York has a guidance value of 50 ppb.  There is an EPA Health Reference concentration of 700 ppb.  Only five of 185 samples had detectable concentrations, and all were well below the New York guidance and EPA Health Reference Levels.

Haloacetic acids (HAA) are a group of disinfection byproducts that form when chlorine compounds that are used to disinfect water react with other naturally occurring material in the water.  There are five significant HAAs potentially found in disinfected drinking water and their combined concentration is referred to as HAA5.  HAA5's are already regulated by the EPA and MassDEP and have a Maximum Contaminant Level (MCL) standard of 60 ppb as a locational running annual average.  MWRA’s HAA5 levels are always well below this 60 ppb standard with an average of about 10-15 ppb. HAA9 and HAA6Br include 4 more HAA compounds that are not currently regulated by EPA or MassDEP.  We detected 3 of the 4 new compounds, all at very low levels.  We did not detect tribromoacetic acid.  If you combined all 9 species in the HAA9 group, MWRA would still be well below the current HAA5 MCL of 60 ppb, with average of around 15 ppb.  

Only 6 of 185 samples taken at the required UCMR4 sample locations had any detections. The health effects of quinoline are uncertain, and thus EPA only provides a wide range for its health reference level (HRL), from 0.01 to 1 ppb. The average level detected is 10 to 1000 times lower than EPA HRLs.

Given the extremely sensitive test methods required and lack of published information on quinoline, MWRA conducted additional sampling beyond that required by UCMR4. This included field blanks to rule out any potential environmental contamination at the sample location, and samples before and after treatment and at other key locations. One of these 15 additional samples was positive with a value of 0.071 ppb.