Publications

The hydrogeology of the 372-square-mile Pepacton Reservoir watershed (herein called the East Branch Delaware River Basin) in the southwestern Catskill Mountain region of Southeastern New York is described and depicted in a detailed surficial geologic map and two geologic sections. An analysis of stream discharge records and estimates of mean annual ground-water recharge and stream base...

Seven herbicides (2,4-D, 2,4-D methyl ester, bromacil, dicamba, diuron, imazaquin, and sulfometuron), four insecticides (carbaryl, diazinon, imidacloprid, and malathion), two fungicides (metalaxyl and myclobutanil), and caffeine (an indicator of wastewater) were detected in at least one sample from the Kisco River at concentrations above 0.1 ug/L (micrograms per liter). Four of these...

The Oyster Bay study area, in the northern part of Nassau County, N.Y., is underlain by unconsolidated deposits that form a sequence of aquifers and confining units. At least one production well has been affected by the intrusion of saltwater from Hempstead Harbor, Long Island Sound, and Cold Spring Harbor. Nineteen boreholes were drilled during 1995-98 for the collection of...

Estimates of the quantity and quality of ground-water discharge from valley-fill deposits were calculated for nine valley reaches within the Pepacton watershed in southeastern New York in July and August of 2001. Streamflow and water quality at the upstream and downstream end of each reach and at intervening tributaries were measured under base-flow conditions and used in mass-balance...

Baseflow samples were collected from 20 small streams in the Pepacton Reservoir watershed in Delaware County, N.Y., from December 2000 through November 2001 as part of an investigation to define the occurrence of pesticides in shallow ground water in watersheds containing either a recent (2001) corn crop, a previous (1993-94) corn crop, or no history of row-crop cultivation. Baseflow...

One normal episode of pump operation in domestic wells drilled into bedrock in New York typically lasts about 1 minute and lowers the water level about 1 meter. Measurement of water levels in the pumped well before and during pumping and recovery can be completed in 2 to 3 hours and requires negligible disturbance of the well, so can be easily arranged. Such a test involves less...

It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils...

Ground water is the sole source of freshwater on the North Fork of Long Island. Future demands for the limited freshwater supply during a prolonged drought could cause drawdowns that induce saltwater intrusion and render the supply unusable. The freshwater system on the North Fork contains several localized, hydraulically isolated aquifers bounded by salty water. The need for information...

Discharge and water-quality data collection at East Branch Allen Creek from 1990 through 2000 provide a basis for estimating the effect of the Jefferson Road detention basin on loads and concentrations of chemical constituents downstream from the basin. Mean monthly flow for the 5 years prior to construction of the detention basin (8.71 ft3/s) was slightly lower than after (9.08 ft3/s)...

Advanced borehole-geophysical techniques were used to assess the geohydrology of crystalline bedrock in 20 boreholes on the southern part of Manhattan Island, N.Y., in preparation for construction of a third water tunnel for New York City. The borehole-logging techniques included natural gamma, single-point resistance, short-normal resistivity, mechanical and acoustic caliper, magnetic

No abstract available.

Geophysical surveying techniques provide important information for ground-water investigations (Zohdy and others, 1974; Keys, 1997; Haeni and others, 2001). Subsurface-geophysical methods are used to delineate and characterize hydraulically active zones; the extent of contamination, and contaminant sources; identify geologic features; optimize monitoring well placement; and guide...