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Research about Pennsylvania

Source-linked reports with geographic coverage including Pennsylvania.

At least 343 records · Page 19Linked to original sources
USGS1999

Evaluation of geophysical logs, Phase II, at Willow Grove Naval Air Station Joint Reserve Base, Montgomery County, Pennsylvania

Between March and April 1998, the U.S. Navy contracted Tetra Tech NUS Inc., to drill two monitor wells in the Stockton Formation at the Willow Grove Naval Air Station Joint Reserve Base, Horsham Township, Montgomery County, Pa. The wells MG-1634 and MG-1635 were installed to monitor water levels and sample contaminants in the shallow, intermediate, and deep water-producing zones of the fractured bedrock. Chemical analyses of the samples will help determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Wells were drilled near the Fire Training Area (Site 5). Depths of all boreholes range from 69 to 149 feet below land surface. The U.S. Geological Survey conducted borehole geophysical logging and video surveys to identify water-producing zones in newly drilled monitor wells MG-1634 and MG-1635 and in wells MG-1675 and MG-1676. The logging was conducted from March 5, 1998, to April 16, 1998. This work is a continuation of the Phase I work. Caliper logs and video surveys were used to locate fractures; inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-producing fractures. Heatpulse-flowmeter measurements were used to verify the locations of water-producing or water-receiving zones and to measure rates of flow between water-bearing fractures. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller's notes, wells MG-1634 and MG-1635 were screened such that water-levels fluctuations could be monitored and discrete water samples collected from one or more water-producing zones in each borehole.

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USGS1999

Water resources data, Pennsylvania, water year 1998. Volume 1. Delaware River Basin

Water resources data for the 1998 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 1 contains (1) discharge records for 76 continuous-record streamflow-gaging stations, 5 partial record stations and 16 special study and miscellaneous streamflow sites; (2) elevation and contents records for 14 lakes and reservoirs; (3) water-quality records for 23 gaging stations and 44 ungaged streamsites; and (4) water-level records for 38 network observation wells; and (5) water-quality analyses of groundwater from 5 special-study ground-water wells. Site locations are shown in figures 6-9. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 2 and 3, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

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USGS1999

Water resources data, Pennsylvania, water year 1998. Volume 2. Susquehanna and Potomac River basins

Water resources data for the 1998 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 2, contains (1) discharge records for 85 continuous-record streamflow-gaging stations and 16 partial-record stations, and 23 special study and miscellaneous streamflow sites; (2) elevation and contents records for 12 lakes and reservoirs; (3) water-quality records for 13 gaging stations and 80 ungaged streamsites; (4) water-level records for 30 ground-water network observation wells and water-quality analyses of ground water from 8 wells; and (5) water-quality analyses at 34 special study ground-water wells. Site locations are shown in figures throughout the report. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 1 and 3, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

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USGS1999

Water resources data, Pennsylvania, water year 1998. Volume 3. Ohio River and St. Lawrence River basins

Water resources data for the 1998 water year for Pennsylvania consists of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels of ground-water wells. This report, Volume 3, includes records from the Ohio and St. Lawrence River Basins. Specifically, it contains: (1) discharge records for 62 continuous record streamflow-gaging stations and 18 partial-record and miscellaneous streamflow stations; (2) elevation and contents records for 11 lakes and reservoirs; (3) water-quality records for 10 streamflow-gaging stations; and (4) water-level records for 15 network observations wells. Additional water data were collected at various sites not involved in the systematic data-collection program and are published as miscellaneous measurements and analyses. These data, together with the data in Volume 1 and 2, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, Municipal, Local, and Federal agencies in Pennsylvania.

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USGS1999

Hydrologic effects of the Pymatuning earthquake of September 25, 1998, in northwestern Pennsylvania

Within hours after the Pymatuning earthquake of September 25, 1998, in northwestern Pennsylvania, local residents reported wells becoming dry, wells beginning to flow, and the formation of new springs. About 120 household-supply wells reportedly went dry within 3 months after the earthquake. About 80 of these wells were on a ridge between Jamestown and Greenville, where water-level declines of as much as 100 feet were documented. Accompanying the decline in water levels beneath the ridge was an increase in water levels in valley wells of as much as 62 feet. One possible explanation of the observed hydrologic effects is that the earthquake increased the vertical hydraulic conductivity of shales beneath the ridge, which allowed ground water to drain from the hilltops. Computer simulations of ground-water flow beneath the ridge between Jamestown and Greenville indicate that increasing the vertical hydraulic conductivity of shale confining beds about 10 to 60 times from their pre-quake values could cause the general pattern of decreased water levels on hilltops and increased levels in valleys.

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USGS1999

Hydrogeologic structure of the Newark Basin, Pennsylvania, from borehole geophysical logs

The Brunswick and the underlying Lockatong Formations are comprised of littrifled Mesozoic sediments that constitute part of the Newark Basin in southeastern Pennsylvania (USA). These fractured rocks form an important regional aquifer that consists of gmdational sequences of shale, siltstone, and sandstone, with fluid transport occurring primarily in fractures. An extensive suite of geophysical logs was obtained in seven wells located at the borough of Iamsdale, PA in order to characterize the areal hydrogeologic system. Analyses of these data indicate that the aquifer can be separated into two distinct structural domains which may, in turn, reflect different mechanical responses to basin bxtension: (1) In the shallow zone above 125 m, the dominant fmcucre population consists of gertfly dipping bedding-plane partings that strike N46°E and dip to the NW at about 11°. Fluid flow is concentrated within the upper 80 m and transmissivities rapidly diminish in magnitude with depth. (2) The zone below 125 m marks the appearance of numerous steeply dipping fractures that are orthogonal to the bedding plane features, striking subparallel at N227°E but dipping sharply to the SE at 77°. This secondary set of fractures is associated with a reasonably thick (= 60 m) high-resistivity, low- transmissivity sandstoned siltstone unit that is abruptly terminated by a thin shale bed at a depth of 190 m. This lower contact effectively delineates the aquifer's vertical extent and the observed lack of hydraulic productivity with increasing depth may be associated with the gradational transition into the Lockatong Formation.

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USGS1998

Faulting parameters of the January 16, 1994 Wyomissing Hills, Pennsylvania earthquakes

Two events dominated the January 1994, Wyomissing, PA earthquake sequence, an M w 4.0 foreshock, followed by an M w 4.6 mainshock. We modeled regional waveforms to estimate the event depth and the moment tensors for the two largest events in the sequence, and examine teleseismic waveforms recorded on the ARCESS short-period seismic array to estimate the depth and source time function of the mainshock. Our data constrain the depth of the events to be shallower than 5 km, and prefer a depth of 3–5 km. For an assumed depth of 3 km, the mainshock moment tensor is 75% double couple, with (the major double couple) planes striking at 135°N, 347°N, dips of 49°, 46°, and rakes of 68°, 114°. The estimated moment is 8.9 × 10 22 dyne-cm. The P axis strikes 241°N and plunges 2°, the Tension axis strikes 336°N and plunges 73°. The foreshock inversion results are virtually identical to the mainshock results; for a source depth of three km, we find a major double couple with a strike, dip, and rake of 121°N, 60°, and 66°, respectively. The seismic moment for the foreshock is 1.2 × 10 22 dyne-cm, which is approximately 13% of the mainshock moment release. These events did not excite high-frequency Lg waves as effectively as typical eastern North American events, and the mainshock had a stress drop in the range of 25–50 bars.

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USGS1998

U.S. Geological Survey cooperative water-resources programs in Chester County, Pennsylvania

Since 1969, the U.S. Geological Survey (USGS) has had a cooperative water-resources investigation program with Chester County to measure and describe the water resources of the County. Generally, the USGS provides one-half of the program funding, and local cooperators are required to provide matching funds. Cooperation has been primarily with the Chester County Water Resources Authority (CCWRA), with participation from the Chester County Health Department and funding from the Chester County Board of Commissioners. Municipalities and the Red Clay Valley Association also have provided part of the funding for several projects. This report describes how the long-term partnership between the USGS and Chester County, Pa., provides the County with the information that it needs for sound water-resources management. The CCWRA was created in 1961, primarily for land acquisition and planning for flood-control and water-supply projects. With the backing of the Brandywine Valley Association, the CCWRA started its first cooperative project with the USGS in 1969. It was a study of the water-quality condition of Chester County streams with an emphasis on benthic macroinvertebrates and stream chemistry. The kinds of projects and data collection conducted by the USGS have changed with the needs of Chester County and the mission of the CCWRA. Chester County is experiencing rapid population growth (it had the tenth-highest rate of growth in the nation from 1980 to 1990). This growth places considerable stress on water resources and has caused the CCWRA to broaden its focus from flood control to water-supply planning, water quality, and ground-water and surface-water management. The results of USGS studies are used by the CCWRA and other County agencies, including the Planning Commission, Health Department, and Parks and Recreation Department, for conducting day-to-day activities and planning for future growth. The results also are used by the CCWRA to provide guidance and technical assistance to municipalities, water suppliers, industrial dischargers, watershed and conservancy associations and other civic organizations, state and Federal agencies, river basin commissions, and the private sector. The cooperative water-resources program, which is described in the following sections, benefits not only the citizens of Chester County but also serves the interests of the Federal Government. Innovative studies conducted in Chester County provide methods and interpretations that often can be used nationwide, and the headwaters of several interstate drainages lie within the County. Major program thrusts include collection of surface-water, ground-water, and water-quality data and interpretive studies. The use of this information also is described.

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USGS1998

Radon in the ground water of Chester County, Pennsylvania

Introduction A study of the occurrence and distribution of dissolved radon in the ground water of Chester County was undertaken by the U.S. Geological Survey (USGS) in cooperation with the Chester County Water Resources Authority and the Chester County Health Depart-ment. The results of this study are published in a technical report by Senior (1998). This fact sheet summarizes the key findings pre-sented in the technical report. Much of the background information on radon was taken from Lindsey and Ator.

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USGS1998

Review of Aquifer Test Results for the Lansdale Area, Montgomery County, Pennsylvania, 1980–95

Aquifer and aquifer-isolation test results in and around North Penn Area 6 Superfund site, Lansdale, Montgomery County, Pennsylvania are reviewed to provide estimated aquifer properties for use in a numerical model of ground-water flow. This review was made to support of remedial action investigations by U.S. Environmental Protection Agency (USEPA), Region III, Philadelphia. The data reviewed are from files of the U.S. Geological Survey, USEPA, and water companies, and from unpublished consultant reports prepared for USEPA and corporations in the Lansdale area. Tested wells are in fractured sedimentary rocks of the Brunswick Formation, which are Triassic-aged, dipping shales and sandstones. Review procedures include, in some cases, new analyses of drawdown during pumping and recovery by use of analytical models of flow to wells. Estimated aquifer transmissivities (T) range from zero to about 1,300 m 2 /d (meters squared per day); most tests indicate T between 10 and 100 m 2 /d. Aquifer-isolation testing results indicate that most flow enters wells at a few discrete zones, probably fractures or bedding-plane openings. The vertical connection between the zones in a single borehole with multiple producing zones commonly is negligible. This suggests that the formation is vertically anisotropic; the hydraulic conductivity is much larger in the horizontal direction than in the vertical direction. Some evidence of well-field-scale horizontal anisotropy exists, with maximum transmissivity aligned with the regional northeast strike of bedding, but this evidence is weak because of the small number of observation wells, particularly wells screened in isolated depth intervals. Analysis of recovery data after constant-pumping-rate aquifer tests and of drawdown during step tests suggests that a significant fraction, perhaps as much as 85 percent, of the drawdown in some production wells is due to well loss or skin effects in or very near the pumped well and is not caused by resistance to flow in the surrounding formations.

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USGS1998

Evaluation of geophysical logs and video surveys in boreholes adjacent to the Berkley Products Superfund Site, West Cocalico Township, Lancaster County, Pennsylvania

Between February 1998 and April 1998, geophysical logs were collected in nine boreholes adjacent to the Berkley Products Superfund Site, West Cocalico Township, Lancaster County, Pa. Video surveys were conducted on four of the nine boreholes. The boreholes range in depth from 320 to 508 feet below land surface, are completed open holes, have ambient vertical flow of water, and penetrate a series of interbedded siltstone, sandstone, and conglomerate units. The purpose of collecting geophysical-log data was to help determine horizontal and vertical distribution of contaminated ground water migrating from known or suspected sources and to aid in the placement of permanent borehole packers. The primary contaminants were derived from paint waste that included pigment sludges and wash solvents. The chlorinated volatile organic compounds probably originated from the wash solvents. Caliper logs and video surveys were used to locate fractures; inflections on fluid-resistivity and fluid-temperature logs were used to locate possible water-bearing fractures. Heatpulse-flowmeter measurements were used to verify the locations of water-producing or water-receiving zones and to measure rates of flow between water-bearing fractures. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller's logs, permanent multiple-packer systems were installed in each borehole to obtain depth specific water samples from one or more water-bearing fractures in each borehole.

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USGS1998

Water resources data, Pennsylvania, water year 1997. Volume 1: Delaware River basin

Water resources data for the 1997 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 1 contains (1) discharge records for 75 continuous-record streamflow-gaging stations, 7 partial-record stations and 16 special study and miscellaneous streamflow sites; (2) elevation and contents records for 14 lakes and reservoirs; (3) water-quality records for 21 gaging stations and 33 ungaged streamsites; and (4) water-level records for 37 network observation wells. Site locations are shown in figures 8-11. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 2 and 3, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

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USGS1998

Water resources data, Pennsylvania, water year 1997. Volume 2. Susquehanna and Potomac River basins

Water resources data for the 1997 water year for Pennsylvania consist of records of discharge and water quality of streams; contents and elevations of lakes and reservoirs; and water levels and water quality of ground-water wells. This report, Volume 2, contains (1) discharge records for 85 continuous-record streamflow-gaging stations and 17 partial-record stations, and 22 special study and miscellaneous streamflow sites; (2) elevation and contents records for 12 lakes and reservoirs; (3) water-quality records for 14 gaging stations and 63 ungaged streamsites; and (4) water-level records for 30 ground-water network observation wells and water-quality analyses of ground water from 8 wells. Site locations are shown in figures throughout the report. Additional water data collected at various sites not involved in the systematic data-collection program are also presented. These data together with the data in Volumes 1 and 3, represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Pennsylvania.

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USGS1998

Low-flow statistics of selected streams in Chester County, Pennsylvania

Low-flow statistics for many streams in Chester County, Pa., were determined on the basis of data from 14 continuous-record streamflow stations in Chester County and data from 1 station in Maryland and 1 station in Delaware. The stations in Maryland and Delaware are on streams that drain large areas within Chester County. Streamflow data through the 1994 water year were used in the analyses. The low-flow statistics summarized are the 1Q10, 7Q10, 30Q10, and harmonic mean. Low-flow statistics were estimated at 34 partial-record stream sites throughout Chester County.

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USGS1998

Radon-222 in the ground water of Chester County, Pennsylvania

Radon-222 concentrations in ground water in 31 geologic units in Chester County, Pa., were measured in 665 samples collected from 534 wells from 1986 to 1997. Chester County is underlain by schists, gneisses, quartzites, carbonates, sandstones, shales, and other rocks of the Piedmont Physiographic Province. On average, radon concentration was measured in water from one well per 1.4 square miles, throughout the 759 square-mile county, although the distribution of wells was not even areally or among geologic units. The median concentration of radon-222 in ground water from the 534 wells was 1,400 pCi/L (picocuries per liter). About 89 percent of the wells sampled contained radon-222 at concentrations greater than 300 pCi/L, and about 11 percent of the wells sampled contained radon-222 at concentrations greater than 5,000 pCi/L. The highest concentration measured was 53,000 pCi/L. Of the geologic units sampled, the median radon-222 concentration in ground water was greatest (4,400 pCi/L) in the Peters Creek Schist, the second most areally extensive formation in the county. Significant differences in the radon-222 concentrations in ground water among geologic units were observed. Generally, concentrations in ground water in schists, quartzites, and gneisses were greater than in ground water in anorthosite, carbonates, and ultramafic rocks. The distribution of radon-222 in ground water is related to the distribution of uranium in aquifer materials of the various rock types. Temporal variability in radon-222 concentrations in ground water does not appear to be greater than about a factor of two for most (75 percent) of wells sampled more than once but was observed to range up to almost a factor of three in water from one well. In water samples from this well, seasonal variations were observed; the maximum concentrations were measured in the fall and the minimum in the spring.

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USGS1998

Hydrogeology and groundwater quality of the glaciated valleys of Bradford, Tioga, and Potter Counties, Pennsylvania

The most important sources of groundwater in Bradford, Tioga, and Potter Counties are the stratified-drift aquifers. Saturated sand and gravel primarily of outwash origin forms extensive unconfined aquifers in the valleys. Outwash is underlain in most major valleys by silt, clay, and very fine sand of lacustrine origin that comprise extensive confining units. The lacustrine confining units locally exceed 100 feet in thickness. Confined aquifers of ice-contact sand and gravel are buried locally beneath the lacustrine deposits. Bedrock and till are the basal confining units of the stratifies-drift aquifer systems. Recharge to the stratified-drift aquifers if by direct infiltration of precipitation, tributary-stream infiltration, infiltration of unchanneled runoff at the valley walls, and groundwater inflow from the bedrock and till uplands. Valley areas underlain by superficial sand and gravel contribute about 1 million gallons per day per square mile of water from precipitation to the aquifers. Tributary streams provide recharge of nearly 590 gallons per day per foot of stream reach. Water is added at the rate of 1 million gallons per day per square mile of bordering uplands not drained by tributary streams to the stratified-drift aquifers from unchanneled runoff and groundwater inflow. Induced infiltration can be a major source of recharge to well fields completed in unconfined stratified-drift aquifers that are in good hydraulic connection with surface water. The well fields of an industrial site in North Towanda, a public-water supplier at Tioga Point, and the U.S. Fish and Wildlife Service at Asaph accounted for 75 percent of the 10.8 million gallons per day pf groundwater withdrawn by public suppliers and other selected users in 1985. The well fields tap stratified-drift aquifers that are substantially recharged by induced infiltration or tributary-stream infiltration. Specific-capacity data from 95 wells indicate that most wells completed in stratified-drift aquifers have specific capacities an order of magnitude greater than those completed in till and bedrock, Wells completed in unconfined stratified-drift aquifers and in bedrock aquifers have the highest and lowest median specific capacities -- 24 and 0.80 gallons per minute per foot of drawdown, respectively. Wells completed in confined stratified-drift aquifers and in till have median specific capacties of 11 and 0.87 gallons per minute per foot of drawdown, respectively. The results of 223 groundwater-quality analyses indicate two major hydrogeochemical zones: (1) a zone of unrestricted groundwater flow that contains water of the calcium bicarbonate type (this zone is found in almost all of the stratified-drift aquifers, till, and shallow bedrock systems); and (2) a zone of restricted groundwater slow that contains water of the sodium chloride type (this zone is found in the bedrock, and, in some areas, in till and confined stratified-drift aquifers). Samples pumped from wells that penetrate restricted-flow zones have median concentrations of total dissolved solids, dissolved chloride, and dissolved barium of 840 and 350 milligrams per liter, and 2,100 micrograms per liter, respectively. Excessive concentrations of iron and manganese are common in the groundwater of the study area; about 50 percent of the wells sampled contain water that has iron and manganese concentrations that exceed the U.S. Environmental Protection Agency secondary maximum contaminant levels of 300 and 50 micrograms per liter, respectively. Only water in the unconfined stratified-drift aquifers and the Catskill Formation has median concentrations lower than these limits.

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USGS1997

Food resource partitioning by nine sympatric darter species

We compared the diets among members of the diverse darter community of French Creek, Pennsylvania, in relation to seasonal prey availability, feeding ontogeny, and sex. Prey taxa and size attributes were characterized for nine syntopic darter species; taxon, size, and availability of macroinvertebrate prey were also analyzed from Surber samples. In general, darters fed opportunistically on immature insects; few taxa were consumed in greater proportions than they were found in the environment. Some variation in diet composition was expressed, however, among different life stages and species. Juvenile darters consumed smaller prey and more chironomids than did adults. Etheostoma blennioides and E. zonale consumed the fewest taxa (2–3), whereas E. maculatum , E. variatum , and Percina evides had the most diverse diets (7–10 taxa). Etheostoma maculatum , E. flabellare , E. variatum , and P. evides consumed larger prey (1–13 mm in standard length), whereas E. blennioides , E. caeruleum , E. camurum , E. tippecanoe , and E. zonale rarely consumed prey longer than 6 mm. Percina evides fed on larger prey, fewer chironomids, and more fish eggs than Etheostoma species. Females consumed more prey than males and overlapped less in diet composition with males during the spawning season than afterwards. Fish diets did not seem related to habitat use. Greater trophic partitioning was observed in April, when prey resources were scarce, than in July, when prey were abundant. Darter species fed opportunistically when prey were dense, whereas they partitioned food resources mainly through the prey size dimension when prey were less abundant. The divergence of darter diets during a period of low food availability may be attributed to interspecific competition. Alternatively, the greater abundance of large prey in April may have facilitated better prey size selectivity, resulting in less overlap among darter species.

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