U.S. Geological Survey |
New Jersey District |
U.S. Geological Survey |
New Jersey District | One of the long-term goals of the U. S. Geological Survey's (USGS) National Water Quality Assessment (NAWQA) Program is to document the presence and identify potential sources of contaminants in the Nation's water resources. The Long Island-New Jersey (LINJ) coastal drainages study is one of 59 planned investigations within the NAWQA program. Because the LINJ study area is one of the most densely populated and developed areas of the country, VOCs and other toxic chemicals are expected to be present in surface and ground waters. This fact sheet describes the presence of VOCs in Long Island and New Jersey streams on the basis of data obtained from three sources: the Suffolk County Department of Health Services (SCDHS), a synoptic study of one of the most urbanized river reaches in New Jersey, and reconnaissance sampling of other New Jersey streams.
More than 100 streams drain glacial deposits of sand, gravel, and clay that overlie all of Suffolk County. These glacial deposits also form the unconfined (water-table) aquifer. The drainage areas of most of the streams are less than 10 square miles. Streams are distributed throughout the county and in all types of land-use settings, but are more common on the south shore than on the north shore.
Water samples collected from 93 streams in Suffolk County were analyzed for 61 VOCs at least twice during 1993-95 by the SCDHS; 12 of these streams were sampled quarterly. Samples were collected during fair weather to minimize contamination by stormwater runoff.
Six VOCs were detected in more than 15 percent of all samples with a reporting level of 0.5 µg/L (micrograms per liter) (figure 2). 1,1,1-Trichloroethane (TCA); methyl tert-butyl ether (MTBE), a common fuel additive; and tetrachloroethene (PCE) were the most frequently detected compounds. They were present in 32, 29, and 21 percent of the samples, respectively. Median concentrations of TCA, MTBE, and PCE were estimated by use of a log-probability regression technique to be 0.41, 0.24, and 0.21 µg/L, respectively (Helsel and Cohn, 1988).
Total benzene, total toluene, ethylbenzene, and xylene (BTEX) compounds were detected infrequently in the Suffolk County streams sampled. Benzene and toluene were detected in less than 2 percent of all samples and ethylbenzene and xylene were not detected in any samples.
Detection frequencies of five of the six most frequently detected VOCs were slightly higher in samples collected during October through March than in samples collected during April through September. The cold-weather months coincide with the period of increased use of oxygenated fuels and increased solubility of VOCs in water (figure 2).
VOCs were detected more frequently and in larger concentrations in streams in the western, more heavily developed and populated part of Suffolk County than in streams in the eastern part (figure 3).
Maximum allowable concentrations of VOCs in surface waters established by the New York State Department of Conservation do not apply to streams in Suffolk County because they are not classified as sources of drinking water. However, guidance values have been established for streams that are classified for the protection of human and wildlife consumption of fish (table 1). Although maximum measured concentrations of PCE and TCE exceed these values (table 1), median concentrations do not.
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Table 1. Detection frequency and maximum concentration of volatile organic
compounds in stream samples collected during the three studies.
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Volatile organic compound Detection Maximum Surface-
frequency concentration water-quality
(percent) (ug/L) standard or
guideline
(ug/L)
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Suffolk County, Long Island
[Reporting limit= 0.5 micrograms per liter (ug/L); 297 samples from 93 streams;
--, no guideline concentration has been established]
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1,1,1-Trichloroethane 32 4 --
Methyl tert-butyl ether 29 20 --
Tetrachloroethene 21 18 1
Trichloroethene 17 670 11
cis-1,2-Dichloroethene 16 27 --
1,1-Dichloroethane 15 3 --
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Hackensack River, New Jersey
[Reporting limit = 0.2 micrograms per liter (g/L); 14 samples from 14 sites;
--, no standard concentration has been established]
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Methyl tert-butyl ether 100 30 --
Tetrachloroethene 100 5.9 .388
Chloroform 93 5.6 5.67
Trichloroethene 86 18 1.09
cis-1,2-Dichloroethene 86 15 --
Methylene chloride 86 2.5 2.49
Xylene, total 79 2.8 --
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Reconnaissance sampling, New Jersey
[Reporting limit=0.2 micrograms per liter (g/L); 11 samples from 9 streams;
--, no standard concentration has been established]
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Methyl tert-butyl ether 82 4.9 --
Chloroform 27 .794 5.67
cis-1,2-Dichloroethene 27 5 --
Tetrachloroethene 18 .7 .388
Methylene chloride 18 .3 2.49
Toluene 18 .289 6800
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A 14-site synoptic survey on the Hackensack River was conducted in the spring of 1994 as part of a cooperative effort by the USGS and the Hackensack Meadowlands Development Commission (figure 1). Samples were analyzed for 62 VOCs at the USGS National Water Quality Laboratory (NWQL). Industrial facilities, power plants, sewage-treatment plants, combined sewer and stormwater outfalls, landfills, and an extensive transportation network flank the 10-mile-long reach sampled in this study.
With a reporting limit of 0.2 µg/L, MTBE and PCE were detected in samples from all 14 sites with median concentrations of 7.75 and 1.3 µg/L, respectively. Chloroform, the next most frequently detected compound, was found in all but one sample. Total benzene, total toluene, ethylbenzene, and xylene were detected in 36, 57, 7, and 79 percent of the samples, respectively. The high detection frequencies and high median concentrations of several of these VOCs indicate that point sources of contamination have affected surface-water quality in this intensely urbanized basin.
As part of the LINJ NAWQA program, a reconnaissance sampling of nine streams located in a variety of land-use settings across New Jersey was conducted in the winter and early spring of 1996 (figure 1). Eleven samples were analyzed for 87 VOCs at the USGS NWQL. Three of the nine drainage basins are intensely developed, with urban land use occupying more than 60 percent of the basins; the remaining six basins contain smaller percentages of urban land and correspondingly greater percentages of agricultural and undeveloped land.
With a reporting level of 0.2 µg/L, MTBE, the most frequently detected VOC, was found in 10 of 11 samples at concentrations ranging from 0.2 to 4.9 µg/L. The largest concentrations (> 2.5 µg/L) were measured in samples from the three highly urbanized basins. Concentrations of MTBE in all samples from the other six basins were less than 1.0 µg/L. PCE and cis-1,2-dichloroethene were detected in samples from the three urban basins but not in those from the other six. BTEX compounds were detected only in two samples from rivers draining the largest basins.
Surface-water-quality standards established by the New Jersey Department of Environmental Protection (NJDEP) apply to all surface waters, regardless of designated use. The maximum measured concentrations of PCE exceed these standards in both New Jersey studies.
Helsel, D.R., and Cohn, T.A., 1988, Estimation of descriptive statistics for multiply censored water quality data: Water Resources Research, v.24, no.12, p. 1997-2004.
Squillace, P.J., Pope, D.A., and Price, C.V., 1995a, Occurrence of the gasoline additive MTBE in shallow ground water in urban and agricultural areas: U.S. Geological Survey Fact Sheet 114-95, 4 p.
Squillace, P.J., Zogorski, J.S., Wilber, W.G., and Price, C.V., 1995b, A preliminary assessment of the occurrence and possible sources of MTBE in ground water of the United States, 1993-94: U.S. Geological Survey Open-File Report 95-456, 16 p.
Wallace, L.A., 1993, VOCs and the environment and public health--exposure, in Bloemen, H.J.Th. and Burn J. eds., Volatile organic compounds in the environment: New York, Blackie Academic and Professional, p. 1.
For Additional Information, Contact:
Information related to NAWQA can be obtained from:
NAWQA Project Chief, USGS
810 Bear Tavern Road, Suite 206
West Trenton, New Jersey 08628
phone 609-771-3943
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