USGS CONN NAWQA

ABSTRACT

Inorganic and Organic Constituents and Grain-Size Distribution in Streambed Sediment and Ancillary Data for the Connecticut, Housatonic, and Thames River Basins Study Unit, 1992-94

Open-File Report 96-397

By Sandra L. Harris

Concentrations of inorganic and organic constituents, and grain-size distributions were analyzed for streambed-sediment samples collected at 43 sites in the Connectucut, Housatonic, and Thames River Basins study unit during 1992-94. These data were collected to define the occurrence and distribution of major and trace elements and hydrophobic organic chemicals in the study unit. Of the 45 elements analyzed for in these samples, 41 of them were detected at one or more of the sites, with 11 of the U.S. Environmental Protection Agency priority pollutants detected at nearly all sites. The most frequently detected chlorinated organic compounds included DDT, chlordane, and PCB. The most frequently detected semivolatile compounds were the polycyclic aromatic hydrocarbons chrysene, fluoranthene, and pyrene.

Ancillary data, including percentage by land-use class, percentage by bedrock type, number of permitted dischargers by class, and permitted volumes of discharge by class were tabulated for the drainage basin of each sample-site location. Most of the study unit is forested, with a few of the southern basins predominantly urban areas. In addition, most of the study unit is underlain by crystalline bedrock, however, the Connecticut River Valley of central Massachusetts and Connecticut is underlain by arkosic sedimentary bedrock; north-central Massachusetts and eastern Vermont is underlain by calcareous metamorphic rock; and the Housatonic River Valley in western Connecticut and Massachusetts and eastern New York is underlain by carbonate-rich bedrock. The largest number of permitted dischargers in the study unit are wastewater-treatment facilities and heavy industry, but the largest volumes of water are discharged from utilities as cooling water for thermoelectric power generation.