Contaminants Detected in Rivers in the Boston Area

Because these two rivers are not used for drinking water, there is no direct effect on human health. However, the chemicals were detected much more frequently than in other similar rivers in the United States.

The gasoline additive methyl tert-butyl ether (MTBE); chloroform, a by-product of drinking water chlorination; and commonly used solvents such as trichloroethylene (TCE) and tetrachloroethylene (PCE) were found in all 23 water samples from the Aberjona River and in all but 1 of the 29 water samples from the Charles River.

Seasonal trends were evident in MTBE concentrations in the Aberjona and the Charles Rivers.

“The Aberjona River had the highest concentrations of MTBE in the winter, but the Charles River had the highest MTBE concentrations in the summer—perhaps as a result of the gasoline-powered recreation boats that use the river,” said Kimberly Campo, USGS hydrologist researcher and lead scientist for the study.

In all, nearly 30 different chemicals or volatile organic compounds (VOCs) were detected in at least one sample from the two rivers, but generally at concentrations well below U.S. Environmental Protection Agency (USEPA) standards for the protection of freshwater aquatic life.

Household pesticides, such as the herbicides prometon and atrazine and the insecticides diazinon and carbaryl, were detected in more than half of the 70 water samples collected in the Aberjona and Charles Rivers.

“With the small amount of agricultural land in these watersheds, which is where these pesticides would be applied, it is surprising to find the pesticides in so many of the water samples,” said Campo.

Pesticide levels were the highest during the spring and summer when pesticides are typically applied. In most of the water samples, pesticides were detected at levels well below the current standards for the protection of freshwater fish and aquatic plants and insects, although carbaryl was detected in two samples from the Aberjona River at levels (0.5 parts per billion) greater than what Canada considers safe for freshwater aquatic life.

“The most likely explanation for the presence of pesticides in the rivers is from runoff in urban areas where these chemicals are used to control weed growth and grubs and other insects on lawns and gardens," said Campo.

The USGS also compared the results from this study to a similar study done in two other rivers in the New York City area. Nearly 100 percent of the samples from the rivers in the New York and Boston areas contained some concentration of MTBE, which was twice the national average of 44 percent seen in rivers in other urban areas across the country.

“This difference,” explained Campo, “is perhaps a reflection of the high use of MTBE in reformulated gasoline sold in the northeastern United States."

Details of this investigation can be found in USGS Water-Resources Investigations Report 03-4210 Water Quality of Selected Rivers in the New England Coastal Basins in Maine, Massachusetts, New Hampshire, and Rhode Island, 1998-2000 by K.W. Campo and others. It is available online at http://pubs.water.usgs.gov/wri034210. Paper copies can be obtained by contacting the USGS office in Northborough, MA, at 508-490-5058 or calling 1-888-ASK-USGS (275-8747).

The USGS serves the nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy and mineral resources; and enhance and protect our quality of life.

Note to Editors: For additional information on other water-quality studies in New England, visit the Web site http://nh.water.usgs.gov/CurrentProjects/nawqa/nawqaweb.htm
 

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