Geology Reports⌕ Search

Geology topics

Charles A. Pascale

Publications and source records attributed to Charles A. Pascale.

4 recordsLinked to original sources
USGS2006

Monitoring regional effects of high pressure injection of wastewater in a limestone aquifer

More than 10 billion gallons (38 × 10 6 m 3 ) of acid industrial liquid waste has been injected in about 11 years under high pressure into a saline-water-filled part of a limestone aquifer of low transmissivity between 1,400 and 1,700 feet (430 and 520 m) below land surface near Pensacola, Florida. A similar waste disposal system is planned for the same zone at a site about 8.5 miles (13.7 km) to the east. The injection zone is the lower limestone of the Floridan aquifer. The lower limestone is overlain by a confining layer of plastic clay about 220 feet (67 m) thick at the active injection site and underlain by another confining layer of shale and clay. The upper confining layer is overlain by the upper limestone of the Floridan aquifer. The active injection system consists of two injection wells about a quarter of a mile (0.4 km) apart and three monitor wells. Two of the monitor wells (deep monitors) are used to observe hydraulic and geochemical effects of waste injection in the injection zone at locations about 1.5 miles (2.4 km) south and 1.9 miles (3.1 km) north of the center of the injection site. The third well (shallow monitor), used to observe any effects in the upper limestone, is about 100 feet (30 m) from one of the injection wells. Since 1972 the injection zone has also been monitored at a test well at the planned new injection site. Three more monitor wells in the injection zone were activated in early 1974 at sites 17 miles (27 km) northeast, 22 miles (35 km) east and 33 miles (53 km) northeast of the injection site. The six deep monitors provide a system for evaluating the regional effects of injecting wastes. No change in pressure or water quality due to injection was, by mid-1974, evident in the upper limestone at the injection site, but static pressures in the lower limestone at the site had increased 8 fold since injection began in 1963. Chemical analyses indicated probable arrival of the diluted waste at the south monitor well in 1973. By mid-1974 waste evidently had not reached the north monitor well. Calculations indicate that by mid-1974 pressure effects from waste injection extended radially more than 40 miles (64 km) from the injection site. By mid-1974 pressure effects of injection were evident from water-level measurements made at the five deep monitor wells nearest the active injection site. No effects were recognized at the well 33 miles (53 km) away. Less than 20 miles (32 km) northeast of the active injection site, the lower limestone contains fresh water. Changes in the pressure regime due to injection indicate a tendency for northeastward movement of the fresh-water/salt-water interface in the lower limestone.

Groundwater↗
USGS1978

Hydrologic monitoring of waste-injection wells near Pensacola, Florida, March 1970 - December 1977

This report presents hydraulic and chemical data collected from March 1970 to December 1977 at a deep-well waste-injection system at the Monsanto Company's plant near Pensacola, Florida. The injection system presently consists of Injection Well A, Injection Well B, and two deep monitor wells all completed open hole in the lower limestone of the Floridan aquifer and one shallow monitor well completed in the upper limestone of the Floridan aquifer. The two deep monitor wells are used to observe hydraulic and geochemical effects of waste injection in the injection zone at locations 1.5 miles south-southeast and 1.9 miles north-northwest of the center of the injection site. The shallow monitor well, used to observe any effects in the first permeable zone above the 220-foot-thick confining bed, is 100 feet northeast of Injection Well A. Since injection began in July 1963, about 14.2 billion gallons of acidic industrial waste consisting of an aqueous solution of nitric acid, inorganic salts, and numerous organic compounds have been injected into a limestone aquifer containing saline water. From July 1963 to April 1968, the pH of the waste was raised to about 5.5 with aqueous ammonia prior to injection. Since 1968, no aqueous ammonia has been added and the waste has been injected at a pH of about 2.3. Wellhead injection pressures at both injection wells in December 1977 averaged 170 pounds per square inch and the hydraulic pressure gradient was 0.52 pound per square inch per foot of depth to the top of the injection zone. Increases in pressures since 1970 at the north and south monitor wells ranged from 21 to 31 pounds per square inch. The pressure in the shallow monitor well declined about 6 pounds per square inch. No changes were detected in the chemical characteristics of water from the shallow monitor and the north monitor wells. Since late 1973, concentrations of bicarbonate and dissolved organic carbon in water from the south monitor well have increased. These increases in bicarbonate and dissolved organic carbon have been accompanied by increases in gas content of water at the point of discharge from the well and a distinctive odor like that of the waste. In samples of water from the south monitor well, concentrations of nitrogen gas ranged from 5.1 to 12.7 milligrams per liter, methane from 24 to 70 milligrams per liter, and carbon dioxide from 14 to 56 milligrams per liter.

Florida↗
USGS1978

Hydrologic monitoring of a deep-well waste-injection system near Pensacola, Florida, March 1970 - March 1977

This report presents hydraulic and chemical data collected at a deep-well waste-injection system near Pensacola, Florida. Since injection began in July 1963, about 13.3 billion gallons of industrial acidic waste containing nitric acid, inorganic salts and numerous organic compounds have been injected into a saline-water-filled limestone aquifer. Wellhead pressure at two injection wells averaged 180 pounds per square inch in March 1977 and the hydraulic pressure gradient was 0.53 pound per square inch per foot of depth to the top of the injection zone. Increases in pressure since 1970 at two wells used to monitor the injection zone at sites located 1.9 miles north and 1.5 miles south of the injection site have been about 22 and 29 pounds per square inch. The pressure in a shallow monitor well, penetrating the first permeable zone above the 220-foot-thick confining bed, declined about 4 pounds per square inch. No changes were detected in the chemical character of water from the shallow monitor well and the north monitor well, but since late 1973, concentrations of bicarbonate and dissolved organic carbon in water from the south monitor well have increased. (Woodard-USGS)

Water-Resources Investigations Report↗