Reconnaissance of the effect of landfill leachate on the water quality of Marshall Brook, Southwest Harbor, Hancock County, Maine

A small stream (2.2 square miles drainage area) receiving leachate from a landfill was studied from August through November 1979 to determine the impact of the leachate on water quality. The presence of un-ionized ammonia, considered toxic to some aquatic vertebrates, was indicated in samples taken from sections of the stream affected by leachate. Some dissolved oxygen values did not meet the criteria for the protection of aquatic life. Many other dissolved constituents were present in elevated concentrations in the leachate-influenced reaches of the stream. Flow-data comparisons indicate that streamflow less than that observed will occur approximately 20 percent of the time. Leachate-affected stream conditions may deteriorate further during such low streamflow. Several areas with the potential for large sediment yields are present in the basin.