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Patrick Tucci

Publications and source records attributed to Patrick Tucci.

26 records · Page 2Linked to original sources

Lithologic, geophysical, and well-construction data for observation wells in the Melton Valley area, Oak Ridge Reservation, Tennessee

Nineteen wells were installed at nine sites in the Melton Valley area. The wells are intended to provide information on water levels in both regolith and bedrock, aquifer characteristics, and subsurface lithology. Well depths range from 24 to 86 ft for shallow wells, and from 126 to 301 ft for deep wells. Four inch diameter cores were obtained from four of the deep wells. Caliper, gamma, neutron, and gamma-gamma density borehole geophysical logs were obtained for each deep well. Lithologic description of cores and analysis of geophysical logs indicate that one deep well (UA2) is completed entirely within the Nolichucky Shale; one deep well (UD2) is completely entirely within the Pumpkin Valley Shale; two deep wells (UB2, UE2) are completed entirely within the Maryville Limestone; four deep wells (UF2, UG2, UH2, UI2) penetrate both the Nolichucky Shale and the Maryville Limestone. Well UC2, located near the crest of Haw Ridge, penetrates an imbricate splay of the Copper Creek thrust fault, which places the older Rome Formation above the younger Chickamauga Limestone, at a depth of about 100 to 117 ft. (USGS)

Water-Resources Investigations Report↗

Surface-geophysical investigations in Melton Valley, Oak Ridge Reservation, Tennessee

Surface geophysical methods were found to be valuable for refining knowledge of the geohydrology of Melton Valley, an area used for burial of low-level radioactive waste at the Oak Ridge Reservation in Tennessee. The valley is characterized by locally complex geologic structures in lithologies of interbedded shale and limestone. Radionuclides have been transported away from the burial areas by groundwater along paths that are, in part, controlled by geologic structures and rock type. Direct current resistivity soundings were used to determine the depth to bedrock and to aid in the delineation of subsurface stratigraphy. Depth to bedrock, as indicated by an increase in resistivity in the interpreted geoelectric layering, was compared to auger-hole data at five sites, where bedrock depths ranged from 1 to 14 ft and were within 3 ft at four sites. The subsurface contact between shale and limestone was indicated by an increase in model calculated resistivity from < 100 to > 150 ohm-meters at four different sites. Terrain conductivity profiles were used to aid in mapping surficial geologic contacts between shale and limestone units. Terrain conductivity for shale at 33-ft coil separation was generally greater than 15 millimhos/m and ranged from about 10 to 40 millimhos/m. Conductivity for limestone was generally < 15 millimhos/m and ranged from 5 to 25 millimhos/m. Azimuthal conductivity surveys indicated that conductivity was generally greatest when the transmitter and receiver coils were oriented parallel to strike. This anisotropy in terrain conductivity shows the need to keep the coil orientation consistent throughout the length of a profile. (Author 's abstract)

Tennessee↗

Ground-water flow in Melton Valley, Oak Ridge reservation, Roane County, Tennessee; preliminary model analysis

Shallow land burial of low-level radioactive waste has been practiced since 1951 in Melton Valley. Groundwater flow modeling was used to better understand the geohydrology of the valley, and to provide a foundation for future contaminant transport modeling. The three-dimensional, finite difference model simulates the aquifer as a two layer system that represents the regolith and bedrock. Transmissivities, which were adjusted during model calibration, range from 8 to 16 sq ft/day for the regolith, and from 0.2 to 1.5 sq ft/day for bedrock. An anisotropy ratio of 1:3 for strike-normal to strike-parallel transmissivity values, in conjunction with recharge rate = 6% of precipitation that is uniformly distributed over the model area, produces the best match between simulated and observed water levels. Simulated water levels generally compare well to observed or estimated 1978 groundwater conditions. Simulated water levels for the regolith for 39 of 69 comparison points are within +/- 10 ft of average 1978 levels. Simulated vertical flow components are in the observed direction for 9 of 11 comparison points. Preliminary simulations indicate that nearly all groundwater flow is within the regolith and discharges to either the Clinch River or the White Oak Creek-Melton Branch drainage systems. Less than 3% of the flow is between the regolith and bedrock, and < 1% of total groundwater flow discharges to the Clinch River through bedrock. Additional data needed to refine and further calibrate the model, include: (1) quantity and areal distribution of recharge; (2) water levels in the regolith near the model boundaries and beyond the Clinch River; (3) water levels and aquifer characteristics for bedrock; and (4) additional surface water data. (Author 's abstract)

Tennessee↗

Use of a three-dimensional model for the analysis of the ground-water flow system in Parker Valley, Arizona and California

A three-dimensional, finite-difference model was used to simulate ground-water flow conditions in Parker Valley. The study evaluated present knowledge and concepts of the ground-water system and the ability of the model to represent the system. Modeling assumptions and generalized physical parameters that were used may have transfer value in the construction and calibration of models of other basins along the lower Colorado River. The aquifer was simulated in two layers to represent the three-dimensional system. Ground-water conditions were simulated for 1940-41, the mid-1960's, and 1980. Overall model results generally compared favorably with available field information. The model results showed that for 1940-41 the Colorado River was a losing stream through out Parker Valley. Infiltration of surface water from the river was the major source of recharge. The dominant mechanism of discharge was evapotranspiration by phreatophytes. Agricultural development between 1941 and the mid-1960 's resulted in significant changes to the ground-water system. Model results for conditions in the mid-1960 's showed that the Colorado River had become a gaining stream in the northern part of the valley as a result of higher water levels. The rise in water levels was caused by infiltration of applied irrigation water. Diminished water-level gradients from the river in the rest of the valley reduced the amount of infiltration of surface water from the river. Models results for conditions in 1980 showed that ground-water level rises of several feet caused further reduction in the amount of surface-water infiltration from the river. (USGS)

Open-File Report↗

Effects of seepage from fly-ash settling ponds and construction dewatering on ground-water levels in the Cowles unit, Indiana Dunes National Lakeshore, Indiana

Part of the Indiana Dunes National Lakeshore shares a common boundary with the Northern Indiana Public Service Company (NIPSCO). This area is underlain by unconsolidated deposits approximately 180 feet thick. NIPSCO accumulates fly ash from the burning of coal in electric-power generating units in settling ponds. Seepage from the ponds has raised ground-water levels above natural levels approximately 15 feet under the ponds and more than 10 feet within the Lakeshore. NIPSCO is presently (1977) constructing a nuclear powerplant, and construction activities include pumping ground water to dewater the construction site. The company has installed a slurry wall around the site to prevent lowering of ground-water levels within the Lakeshore. Plans call for continuous pumping through at least December 1979. A multilayered digital flow model was constructed to simulate the ground-water system. The model was used to demonstrate the effects of seepage from the fly-ash ponds on ground-water levels. Also, the model indicated a decline of 3 feet or less in the upper sand unit and 5 feet or less in the lower sand unit within the Lakeshore.

Indiana↗

Effects of pumping on ground-water levels near Taylorsville, Bartholomew County, Indiana

A two-dimensional digital flow model was used to estimate the effects of continuous pumping of a public-supply well field on the ground-water levels near Taylorsville, Indiana. Results of the modeling showed that the water levels would decline from less than 1 to about 4.5 feet within the study area and a maximum of 1 to 2 feet in Taylorsville in response to a pumping rate of 700 gallons per minute. Model results also show that the ground-water system would reach steady state in approximately 5 years after pumping begins. Corrections applied to water-level declines indicated by the model, to account for the effects of partial penetration of the aquifer by wells, showed that these effects, although substantial in the pumping wells, are negligible 200 feet from the wells.

Indiana↗