The report reviews research carried out by the Rhode Island Water Resources Center. Methods were sought for removing high concentrations of iron and manganese from groundwater. Pollution of a water supply source by groundwater seepage from septic tanks, sewage lagoons and refuse fills has been followed. Social and economic problems of groundwater pollution were studied; groundwater in Rhode Island offers a least cost alternative to surface impoundment. Basic studies of the nature of pollutants in fresh water included the study of the correlation of structure to activity of pollutants using snails as detectors; the study of precipitation of trace elements by humic substances; a phase of the biochemical oxidation of hydrocarbons in natural waters using n-heptane; and the field detection of the changes in phytobenthon and periphton caused by pollution. (Author)