Geology topics

H. F. Ku

Publications and source records attributed to H. F. Ku.

3 recordsLinked to original sources

USGS1997

Urbanization and recharge in the vicinity of East Meadow Brook, Nassau County, New York: Part 4 — Water quality in the headwaters area, 1988-93

Surface-water and ground-water quality in the East Meadow Brook headwaters area was monitored during 1988-93 to determine the effects of urban stormwater on water quality before, and for 1 year after, the construction of a stormwater-detention basin in 1992. Stormwater samples were collected from the stream during storms. Between storms, water samples were collected from the stream and from a network of monitoring wells in the headwaters area. The detention basin was constructed as part of a pilot project to increase aquifer recharge while decreasing the discharge of contaminated stormwater to coastal waters. Bacteria and road salt were the major contaminants detected in stormwater samples, and the concentrations of organic compounds and nutrients in the samples rarely exceeded New York State drinking-water standards. Lead and chromium were detected in only a few of the stormwater samples, and cadmium was not detected in any of the samples. Loads of most inorganic constituents in stormwater reflected the season and the magnitude of the storm and were proportional to the total stormwater volume measured at the headwaters area. Stormwater during the nonwinter (non-road-salting) season had a diluting effect on shallow ground water adjacent to the stream. Large amounts of sodium and chloride that entered the stream and ground water after road-salt applications to the Westbury drainage area affected the ground-water quality beneath and adjacent to the stream for several months. Concentrations of sodium and chloride in streamwater on March 6, 1989, reached 1,700 mg/L (milligrams per liter) and 2,700 mg/L, respectively, as a result of road salt washed in by stormwater. Median concentrations of sodium and chloride in wells in an area affected by road salt were generally several times higher than concentrations in shallow wells in unaffected suburban areas. Bromide-to-chloride ratios were used to distinguish road salt from atmospherically derived sea salt within the shallow aquifer and indicated that ground water was affected by road salt to a depth of 14 meters.

New York↗

USGS1987

Hydrologic effects of artificial-recharge experiments with reclaimed water at East Meadow, Long Island, New York

Artificial recharge experiments were conducted at East Meadow, Long Island, New York, from October 1982 through January 1984 to evaluate the degree of groundwater mounding and the chemical effects of artificially replenishing the groundwater system with tertiary-treated wastewater. More than 800 million gallons of treated effluent was returned to the upper glacial aquifer through recharge basins and injection wells in the 15-month period. Reclaimed water was provided by the Cedar Creek advanced wastewater treatment facility in Wantagh, 6 miles away. The chlorinated effluent was pumped to the recharge facility, where it was fed to basins by gravity flow and to injection wells by pumps. Observations during the recharge tests indicate that the two most significant factors in limiting the rate of infiltration through the basin floor were the recharge test duration and quality of reclaimed water. Head buildup in the aquifer beneath the basins ranged from 4.3 to 6.7 ft, depending on the quantity and duration of water application. Head buildup near the injection wells within the aquifer ranged from 0.3 to 1.2 ft. Recharge basins provided a more effective means of moving large quantities of reclaimed water into the aquifer than injection wells. Results of 3-day and 176-day ponding tests in two basins indicate that reclaimed water is relatively unchanged chemically by percolation through the unsaturated zone because: (1) the sand and gravel of the upper glacial aquifer is unreactive, (2) the water moves to the water table rapidly, and (3) the water is highly treated before recharge. The quality of water in the aquifer zones affected by recharge improved, on the whole. Groundwater concentrations of nitrate nitrogen and several low molecular weight hydrocarbons, decreased to well within drinking water standards as a direct result of recharge. Sodium and chloride concentrations increased above background levels as a result of recharge but remained well within drinking water standards and the New York State effluent standards established for this groundwater recharge study. (Lantz-PTT)

Water-Resources Investigations Report↗

USGS1986

Effect of urban stormwater runoff on ground water beneath recharge basins on Long Island, New York

Urban stormwater runoff was monitored during 1980-82 to investigate the source, type, quantity, and fate of contaminants routed to the more than 3,000 recharge basins on Long Island and to determine whether this runoff might be a significant source of contamination to the groundwater reservoir. Forty-six storms were monitored at five recharge basins in representative land use areas (strip commercial, shopping-mall parking lot, major highway, low-density residential, and medium-density residential). Runoff:precipitation ratios indicate that all storm runoff is derived from precipitation on impervious surfaces in the drainage area, except during storms of high intensity or long duration, when additional runoff can be derived from precipitation on permeable surfaces. Lead was present in highway runoff in concentrations up to 3300 micrograms/L, and chloride was found in parking lot runoff concentrations up to 1,100 mg/L during winter, when salt is used for deicing. In the five composite stormwater samples and nine groundwater grab samples that were analyzed for 113 EPA-designated ' priority pollutants, ' four constituents were detected in concentrations exceeding New York State guidelines of 50 micrograms/L for an individual organic compound in drinking water: p-chloro-m-cresol (79 micrograms/L); 2 ,4-dimethylphenol (96 micrograms/L); 4-nitrophenol (58 micrograms/L); and methylene chloride (230 micrograms/L in either groundwater or stormwater at the highway basin). One stormwater sample and two groundwater samples exceeded New York State guidelines for total organic compounds in drinking water (100 micrograms/L). The presence of these constituents is attributed to contamination from point sources rather than to the quality of runoff from urban areas. The median number of indicator bacteria in stormwater ranged from 0.1 to 10 billion MPN/100 ml. Fecal coliforms and fecal streptococci increased by 1 to 2 orders of magnitude during the warm season. The use of recharge basins to dispose of storm runoff does not appear to have significant adverse effects on groundwater quality in terms of the chemical and microbiological stormwater constituents studied. (Author 's abstract)

Water-Resources Investigations Report↗