This report presents the results of a study conducted at Picatinny Arsenal, Morris County, New Jersey, to (1) determine whether streambed sediments in Green Pond Brook and its tributaries are contaminated with inorganic or organic constituents, (2) determine the extent of contamination in those reaches, and (3) characterize the quality of water in the brook. Shallow auger samples and results of an electromagnetic-conductivity and natural-gamma-ray survey were used to describe the distribution of streambed and substreambed sediment types and particle sizes.

Forty-five streambed samples were analyzed for trace elements, base/neutral- and acid-extractable compounds, organochlorine and organophosphorus insecticides, polychlorinated biphenyls, and polychlorinated naphthalenes to determine whether contaminants have migrated to the brook from the surrounding area. Historical results of analyses of 63 surface-water and 27 streambed samples also are presented. Samples of streambed material collected from three areas in Green Pond Brook and its tributaries Green Pond Brook, from the area near the outflow of Picatinny Lake downstream to Parley Avenue; Bear Swamp Brook, from the area near building 241 downstream to the confluence with Green Pond Brook; and Green Pond Brook, from the open burning area downstream to the dam near building 1178 contained organic and (or) inorganic constituents in concentrations greater than those found under natural conditions and greater than those found in other areas sampled at the arsenal. Contaminants identified include trace elements, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine insecticides.

Surface-water samples from Green Pond Brook contained several volatile organic compounds, including trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene, at maximum concentrations of 3.8,4.6, and 11 micrograms per liter, respectively. Volatilization and dilution by surface- water and ground-water inflow reduce concentrations of volatile organic compounds from surface water in the steep, fast-flowing reaches of the brook at the southern end of the arsenal. No organic or inorganic constituents were detected in surface-water samples in concentrations greater than the U.S. Environmental Protection Agency primary drinking-water regulations. Only two constituents, iron and manganese, were detected in concentrations greater than the U.S. Environmental Protection Agency secondary drinking-water regulations.