Geology topics

Gary L. Pederson

Publications and source records attributed to Gary L. Pederson.

3 recordsLinked to original sources

USGS1998

A workbook for preparing a district quality- assurance plan for water-quality activities

APPEARS TO BE A REPORT ON HOW TO WRITE REPORTS --THE 'ABSTRACT' THAT FOLLOWS IS JUST THE GENERIC ABSTRACT TO BE USED FOR WATER USE REPORTS: In accordance with guidelines set forth by the Office of Water Quality in the Water Resources Division of the U.S. Geological Survey, a quality-assurance plan has been created for use by the [State name] District in conducting water-quality activities. This quality-assurance plan documents the standards, policies, and procedures used by the [State name] District for activities related to the collection, processing, storage, analysis, and publication of water-quality data. The policies and procedures that are documented in this quality-assurance plan for water-quality activities are meant to complement the District quality-assurance plans for surface-water and ground-water activities and to supplement the [State name] District quality-assurance plan.

Open-File Report↗

USGS1985

Distribution and transport of trace substances in the Schuylkill River basin from Berne to Philadelphia, Pennsylvania

During the period from October 1978 to March 1981, the U.S. Geological Survey assessed the river quality of the Schuylkill River basin in Pennsylvania from the headwaters to the Fairmount Dam at Philadelphia (river mile 8.4). The assessment focused on the distribution and transport of trace metals and organic substances (trace substances). Trace metals included were arsenic, beryllium, cadmium, copper, lead, mercury, nickel, and zinc; trace organic substances included organochlorine insecticides and polychlorinated biphenyls. In general, concentrations of trace substances in the streambed sediments were greater in the main stem of the Schuylkill River than in its tributaries and exceeded the background concentrations in the study area. Concentrations of most trace metals in the sediments were lowest in the Berne area (river mile 95) and highest in the urban-industrial area of Reading (river mile 76). Concentrations generally decreased from Reading downstream to Philadelphia (river mile 10.2). Concentrations of the organochlorine insecticides chlordane, DDT and its metabolites, and dieldrin generally increased gradually from Berne to Philadelphia. Average concentrations of trace metals in the main stem of the Schuylkill River in the sediment-sized fraction, less than 0.063 millimeters, were: zinc, 603 ?g/g (micrograms per gram); lead, 284 ?g/g; copper, 252 ?g/g; nickel, 119 ?g/g; chromium, 96 ?g/g; beryllium, 8.2 ?g/g; arsenic, 0.64 ?g/g; and mercury, 0.002 ?g/g. Average concentrations of trace organic substances in sediments of the main stem of the river were: polychlorinated biphenyls, 152 ?g/kg (micrograms per kilogram); chlordane, 24 ?g/kg; DDT and its metabolites, 18 ?g/kg; and dieldrin, 1.8 ?g/kg. The average annual transport of trace substances by the river was computed for chromium, copper, lead, nickel, and zinc. Concentrations of other trace substances in the sediment-water mixtures were generally undetectable. Of the trace metals, average annual transport of zinc was the greatest, and that of nickel was the least. Transport of trace metals in the river is closely associated with and related to suspended-sediment transport. About 71 percent of the average annual total metal transport is particulate material. Yields, in tons per square mile per year, of copper, lead, zinc, and total organic carbon in the Schuylkill River basin were compared with yields in the Chattahoochee River basin (Georgia). The comparison indicates that yields, by constituent, were of the same order of magnitude. Both basins lie in the Piedmont province, and both have about the same percentage of urban land use. The frequency of occurrence of concentrations of copper, lead, and zinc in the sediment-water mixture at Manayunk in Philadelphia were compared with domestic water-supply criteria of the U.S. Environmental Protection Agency. The criteria are exceeded less than 1 percent of the time, or about 4 days per year.

Schuylkill River basin↗

USGS1985

Effects of low-level dams on the distribution of sediment, trace metals, and organic substances in the lower Schuylkill River basin, Pennsylvania

Heavy use of the Schuylkill River for municipal water supplies and a history of accidental spills and discharges of trace metals and organic substances have been a concern of State and local officials for many years. The U.S. Geological Survey, as part of their River Quality Assessment Program, developed a study to assess the occurrence and distribution of trace substances that pose a threat to human health and aquatic life. This report presents the results of the part of the study that evaluates the effects of low-level dams in the lower basin on the distribution and transport of sediment and trace substances. A combination of historical and current data were used in the assessment. Suspended-sediment data collected at several mainstem and tributary sites from 1954 to 1979 and sedimentation surveys of the six pools in the lower basin were used to define the sediment-transport characteristics of the river. These data provided a base for assessing the transport of trace substances, which are associated closely with riverbed sediments and suspended particles. Water and riverbed samples were collected for analyses of trace substances at numerous sites in the lower basin from 1978 to 1980. The six dams on the river between Pottstown and Philadelphia have had a significant effect on the transport of sediment and trace substances. Between 1954 and 1970, more than 4.7 million cubic yards of sediment accumulated in the pools formed by the dams. The quantity of sediment deposited in the pools ranged from 150,000 cubic yards in Plymouth Pool to 1.6 million cubic yards in Fairmount Pool. The rate of accumulation in the pools was a function of pool size and geometry and the frequency of storms. About 35 percent of the total sediment discharged by the river was stored in the six pools from 1954 to 1970. Since 1970, the net change in sediment accumulation has been minimal. More than 24 percent of the sediment in Fairmount Pool in 1970 was scoured from the pool during Hurricane Agnes in 1972; however, total sediment accumulation returned to the 1970 level within 2 years. Analyses of water samples showed that some trace substances are associated closely with particulate material transported by the river. The concentration of suspended and total cadmium, chromium, copper, lead, nickel, and zinc correlated well with the concentration of suspended sediment and suspended organic carbon. The average annual discharge of metals in suspension as a percentage of total average annual discharge ranged from 46 percent for nickel to 94 percent for lead for the Schuylkill River at Manayunk. The average annual discharge of each metal remained about the same or decreased between Pottstown and Philadelphia. Synoptic sampling of the inflow and outflow of several pools during storm runoff showed that the pools limit the transport of trace metals. More than 50 percent of the suspended copper transported by the river at Pottstown was deposited in Vincent Pool during the storm of May 12-15, 1980. Similar reductions were observed between Port Kennedy and Manayunk as the storm runoff passed through Norristown, Plymouth, and Flat Rock Pools. Analyses of riverbed sediments showed that concentrations of trace substances were higher in sediments that included all particles finer than 0.062 millimeter than in sediments that included only particles finer than 0.016 millimeter. This suggests that medium and coarse silt particles or conglomerates of finer particles sorb as much or more trace constituents as the individual fine silts and clay particles. Concentrations of trace metals were as much as 90 percent higher in the sediments that included coarse silt. Concentrations of trace organic substances were several times higher in the sediments that included coarse silt than in sediments consisting of only fine silt or clay. Surficial and core samples of riverbed sediments were used to define the present and historical distribution of trace substances in

Pennsylvania↗