The Acid Rain Monitoring Project began at the University of Massachusetts Water Resources Research Center in 1983. The project's mission was initially to develop a comprehensive picture of the sensitivity of Massachusetts surface waters to acid deposition, and later evolved to determine long-term trends in this sensitivity.

In Phase I (1983-1984), citizen volunteers sampled 1000 streams and lakes monthly in the state and analyzed them for pH and alkalinity. Phase II (1985) studied 2500 lakes and streams twice a year (April and October) and expanded analysis to major cations and anions. Phase III covered 1986-1993, when a subsample of 860 lakes and streams were sampled 4 times a year (January, April, July and October).

After an eight-year hiatus, the project resumed in April 2001 (Phase IV), when samples were collected three times a year (April, July and October) at about 150 lakes and ponds (and a few streams) and run for the analysis of pH, alkalinity, total phosphorus, and major ions for two years. We have now switched emphasis to streams and are collecting in October and April from 26 sites on the long-term list of endangered water bodies (click here to see a Word document of this list, or here for a PDF document of the same list), and at least 100 streams from a list of randomly chosen sites sampled in Phase III.

Background Information on Acid Rain
Please read the booklet Acid Rain in Massachusetts 1988: the Massachusetts Acid Rain Research Program in Action (PDF)

Searchable Database
Search our database for full water chemistry records beginning with the start of the Project in March 1983. Samples were collected monthly from 1983 to 1984, semiannually from 1985 and 1986, and quarterly from 1986 to 1993. Current samples are collected semiannually. More than 40,000 records from nearly 5,600 lakes and streams are contained in the database.