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Robert E. Faye

Publications and source records attributed to Robert E. Faye.

9 recordsLinked to original sources
USGS2013

Chapter A: Summary and findings

The Agency for Toxic Substances and Disease Registry (ATSDR) is conducting epidemiological studies to evaluate the potential for health effects from exposures to volatile organic compounds (VOCs) in finished water supplied to family housing units at U.S. Marine Corps Base Camp Lejeune, North Carolina (USMCB Camp Lejeune). The core period of interest for the epidemiological studies is 1968– 1985. VOCs of major interest to the epidemiological studies include tetrachloroethylene (PCE), trichloroethylene (TCE), trans -1,2-dichloroethylene (1,2-tDCE), vinyl chloride (VC), and benzene. Eight water-distribution systems have supplied or currently (2013) are supplying finished water to family housing and other facilities at USMCB Camp Lejeune. The three distribution systems of interest to this study—Tarawa Terrace, Hadnot Point, and Holcomb Boulevard—have historically supplied finished water to the majority of family housing units at the Base. Historical exposure data needed for the epidemiological studies are limited or unavailable. To obtain estimates of historical exposure, water-modeling methods are used to quantify concentrations of particular contaminants in finished water and to compute the level and duration of human expo- sure to contaminated finished water. During 2007–2009, ATSDR published historical reconstruction results for contaminants delivered in finished water to Tarawa Terrace family housing areas and vicinity. Corresponding results for Hadnot Point and Holcomb Boulevard family housing areas and vicinity are presented here as a series of reports supporting ATSDR’s health studies at USMCB Camp Lejeune. These reports and associated supplements provide comprehensive descriptions of information, data analyses and interpretations, and modeling results used to reconstruct historical contaminant concentration levels in finished water delivered within the service areas of the Hadnot Point and Holcomb Boulevard water treatment plants (WTPs) and vicinities. This report, Chapter A: Summary and Findings, summarizes analyses and results of reconstructed VOC concentrations in groundwater, in water-supply wells, and in finished water delivered by the Hadnot Point WTP (HPWTP) and Holcomb Boulevard WTP (HBWTP) to family housing areas and vicinities. Methods and approaches to complete the historical reconstruction process for the Hadnot Point–Holcomb Boulevard study area included (1) information discovery and data mining, (2) three-dimensional, steady-state (predevelopment) and transient groundwater-flow modeling using MODFLOW-2005 and objective parameter estimation using PEST-12, (3) deter- mining historical water-supply well scheduling and operations using TechWellOp, (4) three-dimensional contaminant fate and transport modeling for VOCs dissolved in groundwater using MT3DMS-5.3, (5) estimating the volume of light nonaqueous phase liquid (LNAPL) released to the subsurface at the Hadnot Point Industrial Area using TechNAPLVol, (6) analysis of LNAPL and dissolved phase fate and transport using TechFlowMP, (7) reconstruction of water-supply well concentrations at the Hadnot Point landfill using the linear control theory model (LCM) TechControl, (8) computation of flow-weighted average concentrations of VOCs assigned to finished water delivered by the HPWTP using a materials mass balance (simple mixing) model, (9) extended period simulation of hydraulics and water quality of the Holcomb Boulevard water-distribution system using EPANET 2, (10) sensitivity analysis of hydraulic, fate and transport, and numerical-model parameter values, (11) uncertainty analysis by coupling Kalman filtering with Monte Carlo simulation within the LCM methodology, and (12) probabilistic analysis of intermittent connections (1972–1985) of the Hadnot Point and Holcomb Boulevard water-distribution systems using the TechMarkov-Chain model. The end result of the historical reconstruction process was the estimation of monthly mean concentrations of selected VOCs in finished water distributed to housing areas served by the HPWTP and HBWTP. Historical reconstruction results summarized herein provide considerable evidence that concentrations of several contaminants of interest in finished water delivered by the HPWTP substantially exceeded current maximum contaminant levels (MCLs) during all or much of the epidemiological study period of 1968–1985. Reconstructed concentrations of TCE exceeded the current MCL of 5 micrograms per liter (μg/L) prior to and during the entire epidemiological study period and reached a maximum reconstructed concentration of 783 μg/L during November 1983. The most likely date that TCE first exceeded its current MCL is during August 1953; however, this exceedance could have been as early as November 1948. Corresponding finished-water concentrations of PCE exceeded the current MCL of 5 μg/L during most of the period 1975–1985 and also reached a maximum concentration of 39 μg/L during November 1983. Similar results for 1,2-tDCE and VC were also noted during the period 1975–1985. The maximum reconstructed concentrations of 1,2-tDCE and VC were 435 and 67 μg/L, respectively, and also occurred during November 1983. The respective current MCLs for these contaminants are 100 and 2.0 μg/L. Substantial volumes of liquid hydrocarbon fuels were lost due to leakage to the subsurface within the Hadnot Point Industrial Area. This area contained as many as 10 active water-supply wells. Despite the large volumes lost, finished- water concentrations of benzene only slightly exceeded the current MCL of 5 μg/L during the period 1980–1985. The maximum reconstructed concentration of 12 μg/L of benzene occurred during April 1984. Within the HBWTP service area, only TCE routinely exceeded its current MCL during intermittent periods (1972–1985). The TCE resulted from transfers of finished water from the Hadnot Point water-distribution system to the Holcomb Boulevard water-distribution system. The maximum reconstructed TCE concentration of 51 μg/L occurred during June 1978 at the Berkeley Manor housing area. During the 8-day period of January 28 through February 4, 1985, the HBWTP was out of service, and the HPWTP continuously supplied finished water to the Holcomb Boulevard housing area. During this period, the maximum reconstructed TCE concentration at the HPWTP was 324 μg/L, which resulted in a maximum reconstructed monthly mean concentration of 66 μg/L within the Paradise Point housing area.

North Carolina↗
USGS2013

Descriptions and characterizations of water-level data and groundwater flow for the Brewster Boulevard and Castle Hayne Aquifer Systems and the Tarawa Terrace Aquifer

This supplement of Chapter A (Supplement 3) summarizes results of analyses of groundwater-level data and describes corresponding elements of groundwater flow such as vertical hydraulic gradients useful for groundwater-flow model calibration. Field data as well as theoretical concepts indicate that potentiometric surfaces within the study area are shown to resemble to a large degree a subdued replica of surface topography. Consequently, precipitation that infiltrates to the water table flows laterally from highland to lowland areas and eventually discharges to streams such as Northeast and Wallace Creeks and New River. Vertically downward hydraulic gradients occur in highland areas resulting in the transfer of groundwater from shallow relatively unconfined aquifers to underlying confined or semi-confined aquifers. Conversely, in the vicinity of large streams such as Wallace and Frenchs Creeks, diffuse upward leakage occurs from underlying confined or semi-confined aquifers. Point water-level data indicating water-table altitudes, water-table altitudes estimated using a regression equation, and estimates of stream levels determined from a digital elevation model (DEM) and topographic maps were used to estimate a predevelopment water-table surface in the study area. Approximate flow lines along hydraulic gradients are shown on a predevelopment potentiometric surface map and extend from highland areas where potentiometric levels are greatest toward streams such as Wallace Creek and Northeast Creek. The distribution of potentiometric levels and corresponding groundwater-flow directions conform closely to related descriptions of the conceptual model.

North Carolina↗
USGS1986

Hydraulic characteristics of Upper Cretaceous and Lower Tertiary clastic aquifers: Eastern Alabama, Georgia, and western South Carolina

Transmissivity and storativity data for the clastic sediments of the northern Coastal Plain of eastern Alabama, Georgia, and western South Carolina were compiled and evaluated. Transmissivity values ranged from less than 100 to about 35,000 ft sq/day; storativity ranged from about 0.00002 to 0.0002. Data for lower Tertiary sediments represented by the Clayton and Tallahatta Formations and equivalent Midwayan and Claibornian sediments are listed for 17 sites. Transmissivity values of these sediments range from about 500 to 10,000 ft sq/day. Transmissivity values for the Cretaceous Providence Sand and Cusseta Sand and equivalent Navarroan-Tayloran sediments are listed for 10 sites and range from about 500 to 34,000 ft sq/day. Transmissivity values for the Blufftown and Eutaw Formations and equivalent Cretaceous Tayloran-Austinian sediments are listed for 16 sites and range from about 3000 to 35,000 ft sq/day. Transmissivity of the Cretaceous Tuscaloosa Formation and equivalent Eaglefordian sediments is listed for 5 sites and ranges from about 30 to 500 ft sq/day. Estimates of transmissivity based on well specific capacity were computed by using the modified nonequilibrium formula and linear regression analysis. The regression analysis was based on log-transformed paired transmissivity and specific-capacity data at 48 pumping wells. The regression model provided better estimates of transmissivity than the modified nonequilibrium formula. (Author 's abstract)

Alabama, Georgia, South Carolina↗
USGS1985

Approximate potentiometric surface for the aquifer unit A4, southeastern coastal plain aquifer system of the United States, prior to development

A generalized potentiometric surface map prepared as part of a regional analysis of sand aquifer system defines the altitude of water levels under pre-development conditions for aquifer unit A4, the lowermost group of aquifers in the sand aquifer system. Aquifer unit A4, consisting of Upper and Lower Cretaceous sands, is under artesian conditions except locally in the recharge areas. The regional flow direction is to the rivers in the area where the unit outcrops and southward to the Gulf of Mexico in Mississippi, Alabama, and West Georgia. In coastal Georgia and South Carolina, the direction of flow is east northeast parallel to the coast and into North Carolina. (USGS)

Water-Resources Investigations Report↗
USGS1978

Impact of flow regulation and power plant effluents on the flow and temperature regimes of the Chattahoochee River - Atlanta to Whitesburg, Georgia

A calibrated and verified transient flow temperature model was used to evaluate the effects of flow regulation and powerplant loadings on the natural temperature regime of the Chattahoochee River in northeast Georgia. Estimates were made of both instantaneous and average natural temperatures in the river during an eight-day period in August 1976. Differences between the computed average natural temperature and an independent estimate of natural temperature based on observed equilibrium temperatures were less than 0.5°C. The combined thermal effects of flow regulation and powerplant effluents resulted in mean daily river temperatures downstream of the powerplants about equal to or less than computed mean natural temperatures during the period of interest. An independent analysis of historical river and air-temperature data, although considerably less accurate than model computations, provided substantially the same result. The range and rates of change of computed natural diurnal temperature fluctuations were considerably less than those presently observed (1976) in the river. The models also were used to simulate summer river temperatures using estimated year 2000 flow conditions and meteorologic data collected during 1976. Except during periods of peak water-supply demand, differences between computed year 2000 river temperatures and observed present-day temperatures were less than 2°C.

Georgia↗
USGS1976

Mathematical model of the West Bolsa Ground-water Basin, San Benito County, California

Simulation of the West Bolsa ground-water basin hydrology in California had provided values of basin recharge and discharge and nodally distributed values of transmissivity and storage coefficient. Average net recharge from April 1945 to March 1969 was 6.2 cubic feet per second and occurred as subsurace recharge and infiltration of rain and minor streamflow. Discharge from the basin during the same period was 8.1 cubic feet per second and occurred as pumping and leakage from confined parts of the basin. Values of transmissivity used in the model generally range from 3,300 to 20,000 feet squared per day. Values of storage coefficient used in the model range from 0.0005 to 0.10. (Woodard-USGS)

California↗
USGS1974

Mathematical model of San Juan Valley ground-water basin, San Benito County, California

A mathematical model study of the San Juan Valley ground-water basin in San Benito County, Calif., has quantitatively described the ground-water hydrology of the basin under past, present, and future conditions of development. An analysis of conditions in the basin prior to large-scale ground-water development indicates that net recharge equaled 9.23 cubic feet per second and occurred as subsurface flow to the eastern part of the basin and infiltration of rain, direct runoff, and minor streamflows. Net predevelopment discharge equaled 9.23 cubic feet per second and occurred as aquifer discharge to the San Benito River. The 9.23 cubic feet per second of predevelopment recharge is considered to be perennial recharge to the basin. Large-scale ground-water development occurred in the area during the period 1945-68 and caused water levels to decline throughout most of the basin. Progressive depletion of aquifer storage during this period changed the San Benito River from a gaining (perennial) stream to a losing stream along most of its reach in the basin area. Net discharge from the basin during the period 1945-68 averaged 18.10 cubic feet per second. Of this amount 17.82 cubic feet per second occurred as pumpage from wells, and 0.28 cubic foot per second occurred as basin discharge to the San Benito River. Net recharge to the basin during the same period averaged 13.57 cubic feet per second. Of this amount 4.34 cubic feet per second occurred as infiltration from the San Benito River and 9.23 cubic feet per second occurred as perennial recharge. Use of the calibrated mathematical model to simulate quantities of imported water entering the basin from the San Benito River indicates that water levels in San Juan Valley will stabilize or recover when additional recharge equals or exceeds 3,000 acre-feet per year.

California↗
USGS1973

Ground-water hydrology of northern Napa Valley, California

The alluvium of northern Napa Valley is the principal aquifer of the area and is capable of yielding as much as 3,000 gallons per minute to wells. Generally the larger-yielding wells are along the Napa River where the alluvium is thickest and most permeable. Recharge to the alluvium is chiefly by percolation from streams and infiltration of precipitation. Discharge is chiefly flow to the Napa River, evapotranspiration, and pumpage from wells. Both recharge to, and discharge from, the alluvial aquifer are sensitively influenced by rainfall. About 190,000 acre-feet of water is presently (1972) stored in the alluvium of northern Napa Valley. Future annual water use in the project area will probably vary between 12,000 and 35,000 acre-feet and, for most purposes, can be supplied by the alluvial aquifer even during extended periods of limited rainfall. Generally low transmissivities in the alluvium, however, limit the opportunity for obtaining sustained, large yields from wells in much of the valley and require that large-scale development and operation of wells in much of the area be planned and synchronized. Sustained drought conditions in the Napa Valley accompanied by expected increases in the use of ground water will probably cause significant reductions in the base flow of the Napa River and cause many shallow wells in the area to dry up. Sodium chloride ground water occurs near Calistoga and in the vicinity of Oakville and in some places is not suitable for irrigation. Model studies indicate that limited migration of sodium chloride water into intensively pumped parts of the aquifer probably will not be a serious problem.

California↗