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William F. Hardt

Publications and source records attributed to William F. Hardt.

6 recordsLinked to original sources
USGS2006

Model aids planners in predicting rising ground-water levels in San Bernardino, California

The city of San Bernardino is in a semiarid inland valley about 60 miles (100 kilometers) east of Los Angeles. The southern part of the city is traversed by the San Jacinto fault. Adjacent to the upgradient (northeast) side of the fault is a 10 square mile (26 square kilometers) area which contains a zone in the alluvial ground‐water basin that formerly was under artesian pressure and consisted of swampy lands with a history of flowing wells, springs, and ground‐water discharge to Warm Creek. Since about 1945, water levels have declined more than 100 feet (30 meters), and the swampy lands have dried up and are now highly urbanized. Basin replenishment by artificial recharge of imported northern California water at the base of the San Bernardino Mountains may cause ground‐water levels to rise again in the area that was formerly swampy land. If this should happen, building foundations and basements could be subjected to structural damage and flooding by renewed flowing of unplugged artesian wells. The U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, is developing a two‐layer digital model to aid in predicting the rate and extent of the rise in water levels. The solution to the mathematical equations used in the model was approximated numerically by the Galerkin finite‐element method. The water district desires to evaluate water management alternatives, such as varying location, distribution, amounts of recharge, and pumping centers, to avoid excessive water level rises that could indicate an overfilling of the basin and could cause damage.

California↗
USGS1980

Development and use of a mathematical model of the San Bernardino Valley ground-water basin, California

Part of the San Bernardino urbanized area in California overlies formerly swampy lands with a history of flowing wells. This area , upgradient from and adjacent to the San Jacinto fault, contains a zone in an alluvial ground-water basin that is under artesian pressure. Since 1945, withdrawals have exceeded recharge and caused head declines of more than 100 feet. Artificial recharge of imported water in the upgradient areas may cause ground-water levels to rise, which could cause abandoned but unplugged wells to resume flowing. If so, structures could be damaged. A two-layer Galerkin finite-element digital model was used for predicting the rate and extent of the rise in water levels from 1975 to 2000. Six hydrologic conditions were modeled for the basin. Artificial recharge of one-half entitlement and full entitlement from the California Aqueduct were each coupled with low, average, and high natural recharge to the basin. According to model predictions, the greatest water level rises will be along the San Bernardino front. This area encompasses the artificial recharge sites and also has a thick section of unsaturated sediments for storing ground water. The formerly swampy lands between Warm Creek and the Santa Ana River adjacent to the San Jacinto fault have little additional storage capacity, and water levels could rise to the land surface as early as 1983 under maximum recharge conditions and 1970-74 average pumping conditions. If pumping rates are reduced in the Warm Creek area, water levels may rise to land surface prior to the dates predicted by the model, regardless of the artificial-recharge program. (USGS)

Open-File Report↗
USGS1974

Oak Glen water-resources development study using modeling techniques, San Bernardino County, California

Hydrologic, digital-model, and economic analyses were made to determine the most efficient balance of conjunctive use of local ground water and surface water--specifically, whether additional ground-water supplies can be developed in the Oak Glen study area, San Bernardino County, Calif., for local use and also for export to the adjacent Yucaipa area, and what will be the effects of imported water available in 1980. The hydrologic analysis showed that transmissivity values of the aquifer in the Oak Glen study area ranged from 1,000 to 6,750 gallons per day per foot or their equivalent 134 to 902 feet squared per day (12 to 84 metres squared per day) and that net annual recharge in the area was about 1,940 acre-feet (2.39 cubic hectometres) per year. The volume of ground water in storage in 1970 was about 86,000 acre-feet (106 cubic hectometres). The digital-model analysis included building and verifying a steady-state and a non-steady-state model. The steady-state model was considered to be verified when the model-generated water levels approximated the measured 1949 water levels, which were assumed to represent steady-state water-level conditions. The non-steady-state model was verified for 1949-70, and the model satisfactorily reproduced the measured water-level changes for the study area during that period. Water-level changes in the ground-water basin were predicted from 1971 to 1980 using as representative average annual pumpage that from 1966 to 1970 and 1971. The model also predicted water-level changes from 1971 to 1980 using the maximum pumpage capacities of the wells under recharge conditions for average, wet, and dry periods. The predicted water-level changes in the Oak Glen study area were used to calculate the average costs of pumping water for 1980. The comparable average costs of importing water from an alternative supply and the capital costs of well construction were also determined. The economic evaluation suggests the following: (1) Increase ground-water pumping for local use, (2) reduce well-water import to the lower parts of the Oak Glen study area from adjacent areas to the west, (3) short term prior to 1980 overdevelopment appears to be feasible with export to Yucaipa, and (4) tunnel development or new shallow wells at the higher altitudes could help alleviate the water problem.

California↗
USGS1963

Public water supplies in Gloucester County, New Jersey

Gloucester County is in the southwestern part of New Jersey, below Camden, and is a part of the Lower Delaware River Valley. This area is attracting new industry and has shown a population increase of about 47 percent from 1950 to 1960, mostly urban. With the economic growth of the county, the availability and quality of water become increasingly important. The county is in the Coastal Plain of New Jersey. It is underlain by unconsolidated sands and clays of Quaternary, Tertiary, and Cretaceous age. The Raritan and Magothy Formations constitute the most important aquifers and yield more than 95 percent of the water pumped by the public water systems in the county. These formations are capable of yielding 1,400 gpm (gallons per minute) or more to large diameter wells. High yielding wells generally can be drilled anywhere in the county, although the formations are deeper toward the Atlantic Ocean. The Cohansey Sand, second most important aquifer, yields up to 800 gpm or more from large diameter wells. This aquifer is present only in the sparsely populated southeastern half of the county. The Wenonah Formation and Mount Laurel Sand are capable of yielding 100 to 200 gpm in certain areas. The overall chemical quality of the naturally occurring ground water is good. The water generally meets the U.S. Public Health Service's (1962) suggested limit for dissolved solids; however, in some areas, the water carries objectionable amounts of iron and nitrate in solution and has a low pH. Contamination of ground water by salt-water encroachment or by pollution from industrial activity or organic waste in densely populated areas should be prevented. The quality rather than the quantity of water may be the important factor in future ground-water developments. The 21 public water systems in Gloucester County pumped about 1.3 billion gallons of water during 1948 and some 2.7 billion gallons during 1959. This is slightly more than a hundred percent increase in pumpage in 12 year s. The average per capita public water supply consumption in 1959 was approximately 75 gallons per day. This report includes a summary of the history of the present installations, groundwater conditions, quality and availability of water, and potential future yield for the 2 public water systems in Gloucester County.

New Jersey↗