Most of the freshwater inflow to the Barnegat Bay-Little Egg Harbor estuary is ground water that either discharges to streams that flow to the estuary or that seeps directly to the estuary. Consequently, the quality of shallow ground water is a potentially important determinant of the quality of freshwater inflow and water quality constituent loadings. The unconfined Kirkwood-Cohansey aquifer system is present throughout nearly all of the watershed area, and most of the ground water that flows to the streams and the estuary passes through this aquifer system. As a result, the quality of ground water in the Kirkwood-Cohansey aquifer system is most relevant to surface water quality in the watershed and the estuary.

The unconfined aquifer system generally is much more vulnerable to contamination than underlying confined aquifers. The quality of ground water in deeper, confined aquifers is important to water supplies that draw on them, but the quality of this water does not directly relate to surface water quality in the watershed or the estuary. The quality of ground water in the confined aquifers is less variable than water from the unconfined aquifer system (Harriman and Voronin, 1984).

Changes in land use, such as the conversion of farmland to residential housing development, can have major effects on ground water quality, because different substances are used in association with different types of land use. Chemicals and other substances used at the land surface can move to the ground water system through recharge from precipitation. These substances may eventually move into the estuary from ground water flows that enter streams and rivers, and then discharge into the estuary at the shoreline. Thus, an agricultural area that has been contributing nitrogen to the water system from fertilizers may at some later time after land conversion contribute residential fertilizers and pesticides and/or chemicals associated with gas stations or dry-cleaning operations prevalent in areas of residential development.

Many studies have been conducted to investigate the effects of land use on water quality in the Kirkwood-Cohansey aquifer system, the ground water resource directly beneath the Barnegat Bay watershed. These include studies of nitrates, pesticides, and volatile organic compounds in ground water of New Jersey Coastal Plain aquifer systems (Vowinkel, 1991), and an investigation of the relation of radium, nitrate, and pesticide occurrence in ground water to agricultural land use and depth in the Kirkwood-Cohansey aquifer system (Szabo et al., 1997). Major findings for select constituents and their relation to land use are summarized below.

Data sources include various data reports and interpretive reports, as well as databases maintained by the U. S. Geological Survey (USGS) and the Ocean County Health Department (OCHD). The USGS has conducted a number of studies of ground water quality of the Kirkwood-Cohansey aquifer system in recent years, resulting in a substantial database, which is part of the National Water Information System (NWIS) maintained by the USGS. Data contained in this database were used in the preparation of numerous interpretive reports that provide the basis for much of the summary of ground water quality presented here.

An evaluation of ground water quality in much of the Barnegat Bay watershed was conducted by the U. S. Geological Survey during the early 1980's, resulting in two summary reports. Harriman and Sargent (1985) evaluated inorganic chemistry using results of analysis of ground water samples from 209 wells screened in the Kirkwood-Cohansey aquifer system, in an area that closely approximates the Barnegat Bay watershed. Thirty chemical constituents, as well as physical characteristics, were statistically analyzed. A report by Harriman and Voronin (1984) includes results of analyses for selected volatile organic compounds. More recent studies of ground water quality in the Kirkwood-Cohansey aquifer system have focused on the relations between water quality and land use and on particular constituents, particularly pesticides, nitrate, mercury, and radionuclides (Vowinkel et al., 1994; Kozinski et al., 1995; Barringer et al., 1997; Szabo and DePaul, 1998).

In 1996, 22 shallow wells located close to streams within the Barnegat Bay watershed were sampled as part of a watershed-oriented monitoring network. Wells located near streams were selected so that the samples collected would be more representative of ground water discharging to the respective nearby streams than would be samples collected from wells selected randomly. Results of the analysis of these samples are included below.

Ocean County implemented a private well testing ordinance in 1986 to ensure that residents using private wells were receiving safe, potable water. The ensuing well testing program has resulted in tens of thousands of well tests and the accumulation of an extensive well-test database that is maintained by the OCHD. Analytical results from over 25,000 private (domestic) well tests conducted between 1986 and 1991 were statistically analyzed by Camp et al. (1993) and the U. S. Geological Survey. Results of these statistical analyses provide a basis for evaluating the frequency with which elevated levels of contaminants occur in shallow ground water in the watershed.

The following discussion describes the water-quality conditions in the Kirkwood-Cohansey aquifer system within the Barnegat Bay watershed. Figures 1-3 show nitrate plus nitrite, pH, and specific conductance, respectively, in samples of ground water from 22 shallow wells located near streams throughout the watershed. Table 1 shows the statistical summary of water analyses presented by Harriman and Sargent (1985).

Both human activities and natural resources contribute to increased nitrate in ground water. Some atmospheric deposition and organic matter in the soil are natural sources of nitrates, whereas sources from human activities vary by land-use type. Lawn fertilizers, septic system wastes, leaky sewer pipes, and industrial wastes contribute to increased nitrogen in ground water in urban/residential areas. Sources of nitrogen in agricultural areas include crop fertilizers, animal manure, and septic system wastes. Increased nitrogen can be attributed also to atmospheric deposition from automobile exhausts and industrial emissions (Clawges et al., 1999).

Nitrate is a common form of nitrogen that is mobile in the ground water system and usually exists at shallow depth. Results of studies show a strong relation between land use and nitrate concentrations in the unconfined Kirkwood-Cohansey aquifer system (Vowinkel and Siwiec, 1991; Stackelberg et al., 1997; Szabo et al., 1997; Clawges et al., 1999). Analysis of data from these studies indicates that concentrations of nitrate were significantly higher in water samples from wells in agricultural areas (where nitrogen fertilizer use is high) than in samples from wells in residential/urban or undeveloped areas. Szabo et al. (1997) reported that the greatest concentrations of nitrate occurred at shallow to medium depth (5 to 45 ft) below the water table. A study conducted in the coastal plain of Long Island, New York, showed that sewering practices, as well as land use, affect concentrations of nitrate in ground water (Leamond et al., 1992).

The concentrations of nitrogen and phosphorus are low in most shallow ground water areas within the Barnegat Bay watershed compared to levels observed in surface water. However, there are many potentially important exceptions. In summarizing ground water quality characteristics for the Kirkwood-Cohansey aquifer system in the area, Harriman and Sargent (1985) reported median concentrations of < 0.05, < 0.01, 0.14, and 0.08 mg/l for ammonia, nitrite, organic nitrogen and nitrite plus nitrate (all as nitrogen), respectively, and < 0.01 mg/l for both phosphorus and orthophosphate as P. The median concentration of organic carbon was 0.5 mg/l. Nitrate concentrations were as high as 10.5 mg/l, and ammonia concentrations were as high as 5.6 mg/l. Nitrate is a major constituent in ground water sampled in some residential areas (Watt et al., 1994), and a small percentage of analysis results contained in the OCHD Well Test database (51 tests out of 22,791, or 0.2%) revealed nitrate concentrations in excess of the 10 mg/l drinking water standard (Camp et al., 1993). Ground water sampled in 1996 from 22 wells located near streams in some areas contained elevated nitrate concentrations as high as 4.9 mg/l (Jones and DeLuca, 1996), but ammonia concentrations were less than 0.2 mg/l in samples from all but one of these wells. The distribution of nitrite plus nitrate concentrations in these 22 wells is shown in Figure 2. Orthophosphorus concentrations in samples from all but one of these wells were ≤ 0.02mg/l.

Volatile Organic Compounds (VOCs) are commonly used for household and industrial purposes, and are components of such materials as cleaning agents, solvent degreasers, refrigerants, and fumigants. VOCs are also components of gasoline, oil, and heating fuels. Ground water has been and continues to be contaminated by VOCs from sources such as industrial discharges, landfills, municipal wastewater discharges, leaks and spills from storage tanks, and domestic septic system effluent. Because VOCs are most often associated with urban land use, they are more frequently detected in aquifers beneath urban areas than in aquifers beneath non-urban areas.

Results presented by Harriman and Voronin (1984) indicated that 5% of the well-water samples (7 out of 142) from the Kirkwood-Cohansey aquifer system in the Barnegat Bay watershed had detectable concentrations of compounds that were included in limited scans for volatile organics. The detected compounds included xylenes, benzene, and toluene. Results from the statistical analysis of the OCHD Well Test database confirmed a widely scattered presence of VOCs at low levels (Camp et al., 1993). Two percent of the tests included in the analysis had concentrations above an established drinking water standard. This result suggests that, in areas where private wells are utilized, a small fraction of shallow ground water is contaminated by VOCs at levels of concern for human health.

In cases where well water analysis indicated that a standard (or standards) had been exceeded, water treatment or well replacement and/or retesting assured that results met drinking water standards. Statistical analysis of the OCHD Well Test database should not be construed to indicate that water delivered by private domestic water supplies was contaminated in excess of drinking water standards.

The frequency of occurrence provides a rough indication of the prevalence of a particular compound in shallow ground water. However, the OCHD data set includes retests in which not all compounds were evaluated; therefore, the true meaning of calculated frequencies is uncertain and must be evaluated with caution. The most frequently detected compound (7%) was methylene chloride, a compound commonly used in commercial and industrial applications as a solvent and aerosol propellant. This particular compound also can be introduced accidentally to water samples through laboratory contamination because it is a common laboratory solvent. The quality assurance information that would be needed in order to evaluate the likelihood of laboratory contamination is unavailable, and thus the meaning of the relatively high frequency of occurrence of methylene chloride is uncertain. The next most frequently detected compound (2%) was 1,1,1 trichloroethane, which is also used in industrial applications as a solvent. The third most frequently detected compound (1%) was tetrachloroethylene. The frequency of detection of the other 14 compounds was less than 1%.

Pesticides are substances or a mixture of substances used to control pests, such as insects (insecticide), weeds (herbicides), and molds and fungi (fungicides). Synthetic organic pesticides were introduced in the 1940's, and since then the manufacture and use of these pesticides have steadily increased (Barbash and Resek, 1996). Pesticides have long been used on agricultural crops; however, in the last few decades use in urban and undeveloped areas has increased. Pesticides have been used in residential areas to control insects, weeds and fungi on lawns, golf courses, cemeteries and parks, private and public gardens. They are also used and to control weeds on railroad, transmission-line, and roadway right-of-ways.

The potential of individual pesticides to contaminate ground water is controlled by the chemical characteristics of the compound, and the characteristics of the soil and aquifer material they penetrate. The chemical characteristics include, water solubility, soil adsorption, and persistence. Soil characteristics include texture, amount of organic matter, number and size of soil pores, and the depth to water from land surface. For example, sandy soil and low organic matter (characteristic of the Barnegat Bay watershed) will allow pesticides to move easily from land surface to the water table. A shallow depth to water from the land surface increases the probability that pesticides will reach the ground water.

The USGS began studies in 1992 to investigate the vulnerability of public supply wells to contamination by pesticides. The methods for determining vulnerability of a well are described by Vowinkel et al. (1994) and Vowinkel et al. (1996). Wells were rated as low, medium, and high vulnerability to pesticide contamination. Pesticide vulnerability ratings were determined for 115 public supply wells screened in the Kirkwood-Cohansey aquifer system in Ocean County, and six of these wells, or about 5%, were assigned a high rating. The remaining 95% of the wells were assigned a medium vulnerability rating, primarily because all public supply wells screened in the Kirkwood-Cohansey aquifer system are considered at least somewhat susceptible to pesticide contamination. Among 32 of the wells for which additional water quality information was available, the concentration of nitrite plus nitrate as nitrogen increased with increasing pesticide vulnerability rating (Eric Vowinkel, U.S. Geological Survey, personal communication, 1999). Pesticides were not detected in water samples drawn from 7 public supply wells screened in the Kirkwood-Cohansey aquifer system in Ocean County (Clawges et al., 1998). These data and pesticide vulnerability ratings provide some indication of the frequency with which pesticides may be present at detectable levels in shallow ground water in the Barnegat Bay watershed.

Although ground water is not considered a primary pathway for the transport of pathogenic organisms to surface water in the watershed, the available data on bacteria in ground water were evaluated. The possible presence of pathogenic organisms in water is indicated by the presence of indicator coliform bacteria. A statistical analysis of the OCHD Well Test database indicated that coliform bacteria were present in less than 2% of analyzed samples (Camp et al., 1993).

A statistical summary of the concentrations of various metals in shallow ground water in the watershed is reported by Harriman and Sargent (1985). Median concentrations of barium, beryllium, cadmium, chromium, lead, and silver were all below the respective detection limits. Median concentrations of manganese, strontium, and zinc were 0.014, 0.016, and 0.02 mg/l, respectively. The median iron concentration was 0.29 mg/l. Iron and manganese concentrations exceeded drinking water standards in some areas. Some slightly elevated concentrations in some of samples were possibly attributable to the leaching of metals from well-construction materials.

Among metals present in water, mercury is a primary health concern for both human and aquatic life. There is no single source, land use, or mode of transport that is responsible for the occurrence of elevated concentrations of mercury in ground water in the Kirkwood-Cohansey aquifer system (Barringer et al., 1997). Mercury concentrations in sediments of the Kirkwood-Cohansey aquifer system are low (~10 ng Hg/g). Elevated mercury levels (> 10 ng Hg/g) in area aquifers are probably ascribable to anthropogenic sources (Dooley, 1992).

Mercury attributable to human activities is largely derived from point sources of contamination such as landfills, industrial sites, military installations, and cemeteries, as well as from waste discharged from schools, hospitals, laboratories and dental offices. However, Barringer et al. (1997) could not conclusively link any of these sources with elevated concentrations of mercury in ground water found at 34 sites investigated in the Kirkwood-Cohansey aquifer system. Mercuric chloride (a form of mercury that is highly soluble in water) and phenyl mercuric acetate have been historically used as pesticides on agricultural crops in the New Jersey Coastal Plain. These pesticides have also been used in lawn care to control the growth of crabgrass and snow mold. Of the 34 sites in the study, 26 are located in or near past or present agricultural land (Barringer et al., 1997). In general, elevated mercury concentrations in ground water occur when there is a source and a chemical or physical process conducive to mercury mobilization and transport.

Concentrations of total mercury that exceed the Maximum Contaminant Level (MCL) of 2 µg/l have been reported in ground water samples from the Kirkwood-Cohansey aquifer system, including samples from the Barnegat Bay watershed. Elevated mercury concentrations in sampled ground water in the Kirkwood-Cohansey aquifer system appear to be spatially clustered, although this spatial pattern could be related, at least in part, to the non-random manner in which incidences of mercury contamination are typically investigated (Barringer et al., 1997). A statistical analysis of the OCHD Well Test database by the U. G. Geological Survey revealed that of the more than 12,000 samples analyzed for mercury, 106 (less than 1%) were found to contain mercury in concentrations in excess of the MCL (M. Ayers, U.S. Geological Survey, written communication, 1995). Investigations are currently underway to better understand the sources, transport, and fate of mercury in the Kirkwood-Cohansey aquifer system.

The main rivers and streams draining the Barnegat Bay-Little Egg Harbor watershed are the Metedeconk River, Kettle Creek, Toms River, Cedar Creek, Forked River, as well as Oyster, Mill, Westecunk, and Tuckerton Creeks. A part of Manasquan River flow enters the northern perimeter of Barnegat Bay through the Point Pleasant Canal Additional water discharge contributions to the bay are from islands and small basins via direct groundwater inputs. The relative contributions of nonpoint sources of contamination to streams in the coastal plain are likely influenced by ground water in this region of the state.

Much of the estuarine watershed lies within the state-designated Pinelands Area. The streams and shallow ground water in the Pinelands are acidic, with low alkalinities and generally low buffering capacities (Lord et al., 1990). Yuretich et al. (1981) describe the waters of the Pinelands as being atmospheric-controlled; that is, they receive a large part of their composition from precipitation. Such waters are also susceptible to changes in chemical composition due to nonpoint source contributions from various land-use activities .

The estuary receives constituents from point and nonpoint sources within the contributing drainage basin. Point sources are discrete, identifiable origins of constituents, such as permitted discharges from municipal and industrial wastewater treatment facilities that contribute water to a stream at a constant rate, independent of stream flow conditions. Constituents from more diffuse, nonpoint sources are transported to a stream or river by storm runoff from agricultural, residential, and urban areas including impervious surfaces (highways and parking lots), as well as ground water that percolates through soil, and effluent from leaking underground storage tanks, septic systems, and landfills. Ground water discharge to a stream is almost constant, varying slightly with season and precipitation rate. Storm runoff, composed of overland runoff and interflow, contributes to a stream intermittently, depending on storm intensity and frequency, and only during high flows at which time the ground water contributions to the stream are diluted (Chow, 1964; Novotny and Chesters, 1981). Instream concentrations of constituents are a summation of the contributions from constant (point sources and ground water discharge) and intermittent (storm runoff) sources.

The main contributors of water quality constituents to the estuary are nonpoint sources in the basin because there are few major permitted point source discharges to the major rivers draining the watershed. Nonpoint source contributions to a surface water body are greatly affected by the type and intensity of development and historical land use in the contributing drainage area. Concentrations of some constituents are typically associated with certain human activities, such as sediment from construction sites and nutrients from agricultural runoff and intensive lawn maintenance. Increased amounts of impervious surfaces reduce the infiltration rate of rainfall and enhance storm runoff. Soil compaction during building construction also reduces infiltration. Land cover consisting of forest and wetlands has greater water retention and less storm runoff than other land-use covers as a result of ponding and dense vegetation. The presence of some constituents in ground water can be attributed to historical land uses. For example, before the residential development of the early 1970's, several poultry farms were located within the Wrangel Brook basin. Nutrients from agricultural runoff, which infiltrated soils and deeper sediments may still be present in ground water. Because of the slow movement of ground water, the concentrations of these constituents in receiving streams may remain high for many years.

II. A. Data Sources

Available data on water and sediment quality data during water years 1960-98 at stream sites located within the Atlantic Coastal Plain were compiled for this Characterization Report. Most of the streams drain into the estuary; however, data from a few sites that drain into other estuaries and bays of the Atlantic Coastal Plain and the lower Delaware River basins were also included. This additional information was included because the streams drain areas with similar hydrology, geology, and water chemistry as streams within the Barnegat Bay watershed, and the information from these sites is transferable to streams located within the bay watershed.

The minimum criteria for data inclusion were as follows: (1) the data were for samples collected and analyzed with methods comparable to and consistent with those used by the U. S. Geological Survey (USGS); (2) the data were for samples collected and analyzed between October 1, 1959 and September 30, 1998; (3) the samples were collected throughout any consecutive three years; and (4) the data were available in digital format. If available, instantaneous stream flow - the stream discharge at the time of sampling - was retrieved and associated with each individual water quality sample. Remark codes pertaining to specific sample qualifiers are stored with the water quality data.

Steps were taken to ensure consistent data quality because of the long time period over which the data were collected. Water quality data for the period of record from each data source were reviewed separately to identify any obvious inconsistencies (i.e., extreme data outliers), because of changes in laboratory remark codes, reporting levels, analytical methods, project data entry protocols, project data quality review protocols, sample preservation, and sample processing. Breidt et al. (1991) found similar anomalies in USGS water quality data from this period of record. Some data sets had considerable data-quality concerns and are summarized separately and only qualitatively for this characterization. Extreme values were retained unless they were known to be errors of data entry.

On the basis of laboratory analytical procedure, constituent concentrations for total ammonia, total nitrite, and total nitrite plus nitrate at the USGS National Water Quality Laboratory were considered to be dissolved, regardless of how they were reported in the database. Data considered for this analysis were those collected for: (1) USGS cooperative programs and investigations; (2) USGS National Water Quality Assessment (NAQWA) Programs; (3) the Pinelands Commission; and (4) the Brick Township Municipal Utilities Authority.

USGS cooperative programs (i.e., USGS, with cooperating federal, state, and local agencies) maintain a network of water quality stations throughout New Jersey. The data are used to assess the water quality throughout the state and constitute a valuable database for developing an improved understanding of its water resources. Records of surface water quality ordinarily are obtained at or near stream gaging stations because the interpretation of records of surface water quality nearly always requires corresponding discharge data. Samples are collected and measurements are made at these sites, usually five times a year. In addition to the statewide routine network, smaller networks of water quality stations are established to provide data for specific studies. These sites are maintained for short durations, usually less than five years. Data collected by the USGS and cooperating agencies in New Jersey are maintained in the National Water Information System (NWIS) database. The NWIS is maintained by the USGS. Data maintained in NWIS are for samples collected and analyzed by methods of the USGS, which are consistent with nationally recognized standards. These data are collected as part of ongoing water quality monitoring and special investigations of New Jersey streams.

Data on surface water quality and bottom sediment quality for the period of record water years 1960-97 were retrieved from NWIS for 53 stations located within the estuarine watershed; 28 of these stations, including the USGS water quality station on the Toms River near the town of Toms River, had three or more years of surface water quality data. These stations are located within the Metedeconk River, Kettle Creek, Toms River (including Union and Ridgeway Branches, Wrangel Brook, and Jakes Branch), Cedar Creek, Forked River, Oyster Creek, Mill Creek, Cedar Run, Westecunk Creek, and Tuckerton Creek basins. Data were also retrieved for the McDonalds Branch in Lebanon State Forest, the hydrologic benchmark station located in the Delaware River drainage basin. Data for selected field parameters, major ions, nutrients, bacteria, sediment, and metals were available for these stations.

Since 1994, the water quality in several tributaries to the Toms River has been monitored as part of a cooperative study between the USGS and the New Jersey Department of Environmental Protection (NJDEP) to investigate nonpoint sources to the estuary. The sites are located on Long Swamp Creek, Wrangel Brook, Davenport Branch, and Jakes Branch; the drainage areas upstream from the sites are characterized as either highly, moderately, or slightly developed. Data for selected field parameters, nutrients, bacteria, and sediment were available for samples collected during a variety of seasonal and flow conditions.

USGS-NAWQA program studies are designed to assess the status of the nation's water quality, describe status and trends in water quality, and provide a sound scientific understanding of the primary natural and human factors that affect the quality of the nation's water reserves. As part of the Long Island-New Jersey (LINJ) coastal drainages investigations, intensive surface water monitoring at Great Egg Harbor River near Sicklerville occurred during 1996-98. In addition, synoptic sampling for VOCs, pesticides, and nutrients from 18 surface water sites within the New Jersey Atlantic Coastal Plain (including sites on the Toms, Great Egg Harbor, and Maurice Rivers) was conducted in 1997 and 1998.

The Pinelands Commission, in cooperation with the OCHD, monitored the water quality at 20 sites on 15 streams within the Barnegat Bay watershed from 1987 to 1996. Data for selected field parameters, major ions, and nutrients were available for these stations. A total of 13 Pinelands Commission sites and historic USGS water quality stations were co-located.

The Brick Township Municipal Utilities Authority (BTMUA) monitors water quality on a daily basis throughout the Metedeconk River Basin, upstream of the main intake near Forge Pond. Data for selected field parameters and bacteria have been collected since 1989 at a network of stations located throughout the watershed. Data for selected field parameters and bacteria were available for six sites on both the South and North Branches of the Metedeconk River for the time period 1989 to 1998. In 1996 the network was expanded to 30 sites, and samples were co-located for analysis of VOCs.

Data from the USGS, Pinelands Commission, and NJDEP sites were commingled and divided into three groups (water years 1959-72, 1973-86, and 1987-97) that correspond to available land cover data for 1972, 1984, and 1994/5, respectively. For the purposes of describing surface water quality within the bay watershed, the distribution of land cover in the area of contributing drainage to each water quality site was determined from 1972, 1986, and 1994/5 land cover data obtained from Rutgers University. These land-use percentages were determined, in part, by the use of a geographic information system and categories defined by Fegas et al. (1983).

The percentage of urban land ranged from 0 to 49% in the drainage basins of the 14 sites with water quality between water years 1959-72. In the drainage basins of the 18 sites with water quality between water years 1973-86, the percentage of urban land ranged from 0 to 39%. The percentage of urban land ranged from 0 to 55% in the drainage basins of the 25 sites with water quality between water years 1987-97.

From the 1994/5 data, sites draining more developed areas (that is, areas where the urban/residential and agricultural land plus grasslands land cover were greater than 10%) were located on the Metedeconk and Toms Rivers, the downstream reach of Ridgeway Branch, Wrangel Brook, Davenport Branch, Long Swamp Creek, and Mill Creek and its tributary Four Mile Branch. Sites draining less developed areas (i.e., areas where the urban/residential and agricultural land plus grasslands land cover were less than 10%) were located on tributaries to the upper reach of Toms River (Mapleroot, Union, and Old Hurricane Branches), the upstream reach of Ridgeway Branch, Jakes Branch, Cedar Creek and its tributary Factory Branch, North Branch of Forked River, and Oyster and Westecunk Creeks.

Table 2 lists the 43 stations with 3 years or more of surface water quality data during these time periods, and Figure 4 shows their locations. Data are available for selected field parameters and major ions at 14 USGS stations during the water years 1960-72. Data are available for selected field parameters, major ions, nutrients, bacteria, and metals at 19 USGS stations during the water years 1973-86. Surface water quality data for selected field parameters, major ions, and nutrients collected during the time period 1987-97 are available for 25 sites (2 USGS, 20 Pinelands Commission, and 4 NJDEP sites). A NJDEP and a Pinelands Commission site were co-located, and available data for both sites were commingled. Data from the BTMUA for selected field parameters, ammonia, bacteria, total organic carbon, and VOCs at 30 sites on the North and South Branches of the Metedeconk River for water years 1989-98 were analyzed separately. The sites of the BTMUA network are described in Table 3; the location of these sites is shown in Figure 5.

Table 4 gives the median values of surface water quality data for 43 sites within the bay watershed for the three aforementioned time periods. Figures 6-8 present box plots of the number of observations and distribution of the data in each of the time periods. Sites are arranged from left to right in order of increasing percentage of urban land cover. Box plots are used to indicate the range of data values and show a center line (median or 50th percentile) splitting a rectangle defined by the 25th and 75th percentiles. Whiskers are lines drawn from the ends of the box to the 10th and 90th percentiles. Box plots are not shown in cases where there are less than 9 data values. Comparisons between the sites during a time period and at an individual site over time are difficult to interpret for many reasons. The number of observations at individual sites during each time period varies greatly. At some sites, less than three measurements were made of some water quality characteristics, whereas at other sites, such as the long-term USGS water quality monitoring sites on Toms River and McDonalds Branch, data were collected several times a year, sometimes monthly, for decades. No concurrent flow data were available for the Pinelands Commission data. Data compiled for this analysis were not collected uniformly throughout the year/seasons or hydrologic conditions. For example, some data were collected specifically during summer low-flow conditions. For a more thorough interpretation of these data, the purpose of the data collection and the hydrologic conditions at the time of sample collection must be examined.

Because many factors (e.g., stream flow, season, sampling frequency) can affect observations of water quality, several years of data are needed to determine a trend in water quality at a station. Therefore, water quality trends can only be determined at sites where long-term records exist. Several USGS studies examined trends in selected water quality constituents in streams of the New Jersey Coastal Plain during various time periods and flow conditions. The results are summarized below. Trends were determined at the USGS water quality station on the Toms River near the town of Toms River during water years 1976-86 (Hay and Campbell, 1990) and 1986-95 (Hickman and Barringer, 1999) for all flow conditions. During water years 1976-86, the trends were positive for dissolved chloride and total nitrogen, and negative for dissolved magnesium, potassium, lead, chromium, and iron. The trends for specific conductance, pH, dissolved sodium, calcium, total ammonia, total phosphorus, were insignificant. During the same time period, the trend was insignificant for instantaneous stream flow. Robinson et al. (1996) reported on associations between water quality trends determined for water years 1976-86 and several drainage basin characteristics (i.e., population, effluent discharge, road-salt application, and agricultural activities). No statistically significant associations between water quality trends and drainage basin characteristics were determined at Toms River near the town of Toms River. During water years 1986-95, the trends were positive for pH, specific conductance, and total nitrite plus nitrate, ammonia, and negative for total organic nitrogen. The trends were insignificant for dissolved solids, sodium, potassium, calcium, and magnesium; total hardness, alkalinity, nitrogen, and phosphorus; and fecal coliform bacteria. During the same time period, the trend for instantaneous stream flow was also negative. In another study by the NJDEP, Carter (1996) reported no significant trend in summertime fecal coliform levels in the Toms River during the period of 1975-94.

Available pH, specific conductance, nitrite plus nitrate, and ammonia data for the long-term USGS water quality station on the Toms River near the town of Toms River are plotted versus time in Figures 9-12. Long-term trends are indicated by a computer generated smoothed line. The apparent trends from this large data set are similar to the combined findings of Hay and Campbell (1990) and Hickman and Barringer (1999) which show that pH, specific conductance, and nitrite plus nitrate appear to be increasing at this site.

Variations in concentration over time can indicate changes in certain drainage basin characteristics. Trends during high flows (stream flows greater than the 25th flow duration value) and low flows (stream flows less than the 75th flow duration value) were determined for selected constituents during water years 1976-93 at sites within the New Jersey Coastal Plain (Hunchak-Kariouk et al., 1999). Comparisons of trends in constituent concentrations during high and low flows can indicate changes over time in the contributions from constant (ground water and point sources) and intermittent (storm runoff) sources. Positive trends during low flows indicate an increase in the contributions from point sources and ground water or both over time, whereas negative trends indicate a decrease in the contributions from point sources and ground water. Positive trends during high flows indicate an increase in the storm runoff contributions, whereas negative trends indicate a decrease in the storm runoff contributions. Figures 9-15 provide examples of trends. During low flows, water years 1976-93, trends were positive for dissolved sodium and chloride, indicating an increase in the contributions from point sources and ground water over time. At this time, trends were negative for total phosphorus, indicating a decrease in the contributions from point sources and ground water over time. Trends were insignificant for dissolved solids, total hardness, total suspended solids, total nitrogen, dissolved nitrite plus nitrate, and total ammonia plus organic nitrogen. During high flows, the trend was positive for dissolved chloride, indicating an increase in the contribution of dissolved chloride from storm runoff over time, and negative for total hardness and phosphorus, indicating a decrease in the contributions of these constituents from storm runoff over time. Trends were insignificant for total suspended solids, dissolved solids and sodium, total nitrogen, dissolved nitrite plus nitrate, and total ammonia plus organic nitrogen.

Specific conductance and pH data were available for all three time periods (water years 1960-72, 1973-86, and 1987-97) at sites on the Toms River, Oyster Creek, Mill Creek, and McDonalds Branch. Figures 13 and 14 illustrate the median concentration values for the three time periods plotted as bar charts on a map of the watershed. Table 2 lists the site names, and Table 4, the median concentration values. The median concentration values are listed in Table 4; site names are listed in Table 2. The median values of pH and specific conductance are similar during each time period. Statistical significance was not determined because the number of observations during each time period varied greatly. The median pH at the Mill Creek site was larger than at any other site during each time period. The median specific conductance at the Toms River site was larger than at any other site during each time period.

Nitrite plus nitrate data were available for two time periods (water years 1973-86 and 1987-97) at 8 sites (5 sites in the Toms River watershed and one site on the Oyster Creek, Mill Creek, and McDonalds Branch.) Figure 15 shows the median concentration values for the two time periods plotted as bar charts on a map of the watershed. Table 2 lists the site names, and Table 4, the median concentration values. The median concentrations are higher at the 3 sites on the Toms River than at the other sites. In addition, the median concentration increased over time at each of these 3 sites. The median concentrations are low, and they did not vary much over time at sites on the Jakes Branch, Oyster Creek, Mill Creek, and McDonalds Branch.

Table 4 presents the median values of available nutrient data (total phosphorus, nitrogen, nitrite plus nitrate, ammonia plus organic nitrogen, and ammonia) for water years 1973-86 at 17 stream sites within the watershed and at a site on McDonalds Branch. Figure 7b shows the distributions of these data. Table 4 lists the median values of available nutrient data for water years 1987-97 at 24 stream sites and at the site on McDonalds Branch. Figure 8a and 8b illustrate the distributions of these data. Table 5 contains summary statistics for ammonia measurements at 30 sites on the North and South Branches of the Metedeconk River. The following paragraphs compare the concentrations for each of five nutrient species. Data from the Metedeconk River are discussed separately. The data were not suitable for rigorous statistical analysis because they originated from various sources (collecting agencies). The purpose of data collection was different for each site (i.e., frequency of sample collection, season of collection, hydrologic conditions, etc.), and the number of observations varied greatly between sites.

Concentrations of total phosphorus during water years 1987-97 were low in streams of the watershed. Concentrations were somewhat higher in streams draining more developed areas, although a direct increase in concentrations with increasing development (that is, increasing percentages of urban and agricultural plus grasslands land cover in the area of contributing drainage) is not obvious (Figure 8a). Median concentration values ranged from 0.01 to 0.07 mg/l, and the median value for all sites was 0.01 mg/l (Table 4 and Figure 16).

Concentrations of total nitrogen during water years 1987-97 were higher in streams draining more developed areas (Figure 8b). Median concentration values ranged from 0.18 to 0.99 mg/l, and the median value for all sites was 0.49 mg/l (Table 4 and Figure 17). Total nitrogen is a measure of several nitrogen species that can be dissolved (ammonia and nitrate plus nitrite) or associated with particles (organic nitrogen). Instream concentrations are dependent on the relative abundance of the dissolved and particulate species, contributions from groundwater and storm runoff, and modifications by instream biological and chemical processes.

Concentrations of total nitrite and nitrate plus nitrite during water years 1987-97 were strongly related to the amount of development in the area of contributing drainage to the specific stream (Figure 8b). Median concentration values ranged from 0.01 to 0.64 mg/l, and the median value for all sites was 0.07 mg/l (Table 4 and Figure 18). Median concentrations were 0.15 mg/l or greater at sites draining more developed areas except at one site on each the Davenport Branch and Mill Creek. Median values were 0.07 mg/l or less in streams draining less developed areas. Median concentrations increased in the downstream direction on the Toms River and were the highest (greater than 0.5 mg/l) at all three sites on Wrangel Brook.

Concentrations of total ammonia plus organic nitrogen during water years 1987-97 were somewhat related to the amount of development in the area of contributing drainage. Sites draining more developed areas had greater concentrations. The median concentration values ranged from 0.20 to 0.74 mg/l, and the median value for all sites was 0.30 mg/l. The median concentrations were less than 0.50 mg/l at all but one site with less than 10% development, and 0.50 mg/l or larger at five sites with greater than 10% development.

Values of total ammonia at the 25 sites not located on the Metedeconk River during water years 1987-97 were low. The median concentration values ranged from 0.02 to 0.39 mg/l and were 0.05 mg/l or less at all but four sites (Table 4 and Figure 19). The median value was 0.10 mg/l or greater at the two most downstream sites on the Toms River and the sites on Long Swamp Creek and Mill Creek. Concentrations were high on Mill Creek. The 25th percentile value was 0.30 mg/l. Concentrations of ammonia were fairly similar at the 30 sites on the Metedeconk River; median concentration values ranged from 0.10 to 0.30 mg/l, and the median value for all sites was 0.20 mg/l (Table 5). Ammonia concentrations were slightly lower at sites on the upper reaches of both branches, especially in the South Branch.

In-stream concentrations of nutrients appear to be related to the intensity of development (i.e., the percentages of urban/residential and agricultural plus grasslands land cover) in the areas of contributing drainage upstream of the surface water sites. Streams draining more developed areas have higher concentrations of nitrogen and phosphorus, although phosphorus concentrations throughout the bay watershed were small. Ammonia concentrations throughout the watershed were somewhat related to the intensity of development, but were also small. Ammonia concentrations in both branches of the Metedeconk River were similar to those measured in the Toms River. Mill Creek had very high ammonia concentrations (median value = 0.39 mg/). In most streams, especially those draining less developed areas such as the Mapleroot, Union, and Ridgeway Branches, and Old Hurricane Brook, the predominant nitrogen species was organic nitrogen. In more developed areas (i.e., Toms River, Davenport Branch, Long Swamp Creek, and Four Mile Branch), the median concentrations of nitrite plus nitrate and ammonia plus organic nitrogen were nearly equal. Nitrite plus nitrate was the predominant nitrogen species at all three sites on Wrangel Brook.

Figure 8a summarizes pH, specific conductance, and sulfate data measured at 24 stream sites within the bay watershed and a site on the McDonalds Branch during water years 1987-97. Table 4 lists the median values. Table 5 provides statistics for pH and specific conductance data measured at 30 sites on the North and South Branches of the Metedeconk River.

Values of pH were higher in streams draining more developed areas. Median values at the 25 sites not located on the Metedeconk River ranged from 3.9 to 5.7, and the median value for these sites was 4.5 (Table 4 and Figure 20). Median pH values were greater than 5.0 at three sites with 10% or greater development. Median values at the 30 sites on the South and North Branches of the Metedeconk River ranged from 4.4 to 6.6 (Table 5). Development is greater in the lower portions of the Metedeconk River watershed, and the pH was greater in the downstream than the upstream reaches of both branches. Median pH values at all downstream sites were 6.5 and 6.4 and at all upstream sites were 5.8 and 5.7 on the North and South Branches, respectively.

Values of specific conductance were slightly higher in streams draining more developed areas. Median values at the 25 sites not located on the Metedeconk River were generally low, ranging from 27 to 145 ms/cm. The median value for these sites was 52 ms/cm (Table 4 and Figure 21). Median specific conductance values increased in the downstream direction along the Toms River. Values were largest at the site on Long Swamp Creek, which drains an area with the greatest amount of development (greater than 50% urban land cover). Median specific conductance values at the 30 sites on the South and North Branches of the Metedeconk River ranged from 44 to 113 ms/cm (Table 5). Specific conductance was greater at sites on the North Branch than the South Branch Metedeconk River (median values = 94 ms/cm and 79 ms/cm, respectively) and greater in the downstream than the upstream reaches of both branches. Median specific conductance values at all downstream sites on the North and South Branches were 95 ms/cm and 83 ms/cm, respectively. At all upstream sites on these influent systems the specific conductance values were 62 ms/cm and 60 ms/cm, respectively.

Sulfate concentrations in surface water can be an indicator of the extent of acid deposition which is of great concern because much of the watershed lies within the Pinelands where the waters are acidic and have low alkalinity and buffering capacity. Sulfate concentrations were somewhat related to the amount of development in the area of contributing drainage. Sites draining more developed areas had slightly higher concentrations than sites draining less developed areas. Median concentration values of sulfate during water years 1987-97 ranged from 1.0 to 13.0 mg/l, and the median value for all sites was 6.0 mg/l (Table 4).

The 24 stream sites within the bay watershed were grouped into two major categories based on their water quality during water years 1987-97, in a manner similar to that reported by Windisch and Zampella (1989). These investigators summarized water quality data collected between 1983 and 1988 at over 40 sampling sites on Pinelands streams within Ocean County. Data from 20 of these sites were included in this data synthesis. The first group includes sites located on tributaries to the upper reach of the Toms River (i.e., Mapleroot, Union, and Old Hurricane Branches), the upstream reach of Ridgeway Branch, Jakes Branch, Cedar Creek and its tributary Factory Branch, North Branch Forked River, and Oyster and Westecunk Creeks, all of which drain less developed areas. Water quality at these sites is generally characterized by low nitrite plus nitrate, pH, specific conductance, and sulfate concentrations. Several of the sites on tributaries to the Toms River have somewhat lower pH and ammonia values compared to the other sites of this group.

The second major group of stream sites is comprised of sites located on the Metedeconk and Toms Rivers, the downstream reach of Ridgeway Branch, Wrangel Brook, Davenport Branch, Long Swamp Creek, and Mill Creek and its tributary Four Mile Branch, all of which drain more developed areas. At these sites, nitrite plus nitrate, pH, and specific conductance concentrations are higher than at the other sites. Nitrite plus nitrate concentrations are the highest at sites on Wrangel Brook, and ammonia concentrations are highest at the site on Mill Creek. Specific conductance, pH, and phosphorus, in turn, are highest at the site on Long Swamp Creek.

VOCs are not routinely measured in samples collected as part of the USGS/NJDEP water quality network. Few investigations of VOCs in surface waters of New Jersey have been conducted. However, since 1996, several reconnaissance and synoptic studies have been conducted in New Jersey as part of the USGS Long Island-New Jersey (LINJ) National Water Quality Assessment (NAQWA) coastal drainage program. The objective of this program is to understand the effects of toxic compounds in surface water and bed sediment on aquatic communities. While these studies have focused on northern New Jersey, some sampling has occurred at sites on Great Egg Harbor River and South Branch Big Timber and Mantua Creeks (tributaries to the Delaware River) in the coastal plain, and the results are transferable to the bay watershed. Land use within the area of contributing drainage to the Great Egg Harbor River at Sicklerville is similar to the land-use distribution within the bay watershed. Conditions at this Great Egg Harbor River site are most likely indicative of the more developed areas of the bay watershed.

Terracciano and O'Brien (1997) examined the occurrence of VOCs in streams on Long Island, New York, and New Jersey. Their work included data from a reconnaissance sampling in the winter and early spring of 1996 at nine streams located in a variety of land-use settings across New Jersey. The six most frequently detected compounds in samples collected from the New Jersey streams were (in order of decreasing detection frequency) MTBE, chloroform, cis-1,2, dichloroethene, tetrachloroethene, methylene chloride, and toluene - all by-products of and compounds used in gasoline, commercial and industrial processes, and the chlorination of drinking water.

In a study of the spatial variability of VOCs in streams on Long Island, New York, and in New Jersey, the number of VOCs detected and the concentration of MTBE were related to the land-use composition in the area of contributing drainage (O'Brien et al., 1997). Sites with higher percentages of residential and industrial land use had greater numbers of VOCs and higher concentrations of MTBE than sites with higher percentages of forests and wetlands. Generally, detection frequencies and concentrations were less in samples collected from the Great Egg Harbor River than in samples collected in other streams of New Jersey (Reiser and O'Brien, 1998). In this same study, greater detection frequencies were reported for this site during cooler months (October-March) than warmer months (April-September) for the six most frequently detected VOCs.

Since 1996, the Brick Township Municipal Utilities Authority (BTMUA) has measured VOCs in samples from its water quality network of 30 sites on the North and South Branches of the Metedeconk River. VOC data from these 30 sites and trip blanks collected between January and October, 1998, were suitable for this analysis after extensive data manipulation. Available data for trip blanks show considerable contamination, making the assessment of site data highly tenuous. These data quality concerns prevent a thorough assessment of the data, which can only be qualitatively summarized for this data synthesis.

Thirteen VOCs were detected in samples collected by BTMUA from the 30 river sites and in trip blanks. Four additional compounds were detected only in trip blanks (Table 6). Eleven of these 13 VOCs were detected at sites throughout New Jersey in a VOC synoptic study by the LINJ NAWQA (O'Brien et al., 1997). The four most frequently detected compounds in samples collected from the Metedeconk River were methyl tert-butyl ether (MTBE), tetrachloroethene (PCE), napthalene, and 1,1-dichloroethene. MTBE was detected at all sites and most frequently (50% or more of the time) at 10 sites. However, MTBE was also detected in 60% of the trip blanks, and the median concentration in the trip blanks was higher than that at all but two sites. 1,1-dichloroethene was detected at 4 sites on each of the North and South Branches. Six chlorinated compounds and toluene were detected only in samples collected at river sites and not in trip blanks.

In a synoptic investigation as part of the USGS National Water Quality Assessment Program during June 9-18, 1997, pesticides were detected in water samples collected from 50 New Jersey streams, including the Toms River. Six of 47 analyzed pesticide compounds were detected in samples from the Toms River near the town of Toms River, at concentrations of less than 0.05 mg/l (Reiser, 1999). These compounds included malathion, metalochlor, desethyl atrazine, DCPA, chlorpyrifos, and tebuthiuron. The concentrations of these detected compounds were within established criteria for both human health and aquatic life (Reiser and O’Brien, 1998). Additional short-term synoptic studies of pesticides are planned.

Concentrations of a narrower spectrum of 21 pesticides in base flow and storm flow of the adjacent Manasquan River were measured in 1990, and five of these pesticides were detected at concentrations of 0.05 mg/l or less (Ivahnenko and Buxton, 1994). As described earlier, reported pesticide application rates on agricultural lands of the Manasquan River and Metedeconk River basins are similar. However, the percentage of agricultural land in the Manasquan River basin above the sampling site is 30.7%, which is considerably higher than that of any Barnegat Bay tributary stream. Therefore, it is concluded that agricultural practices are unlikely to result in high pesticide concentrations in Barnegat Bay tributary streams. Because the percentage of developed land is higher than the percentage of agricultural land in the Barnegat Bay watershed, pesticides applied to residential lawns, other turfed areas, and along transportation and utility corridors may be a greater concern.

Fecal coliform bacteria data collected in the Toms River near the town of Toms River as part of the USGS/NJDEP water quality network are assessed every two years by the NJDEP. Examination of the water quality index values reported in 1988 and 1992 show an improvement in the water quality of the Toms River (New Jersey Department of Environmental Protection, 1995). Fecal coliform counts exceeded the state criterion of 200 MPN/100ml in 38% of the samples summarized in 1988 (N.J. Department of Environmental Protection, 1990) and in 14% of the samples summarized in 1992 (New Jersey Department of Environmental Protection, 1995).

Fecal coliform bacteria were measured as part of a nonpoint storm runoff study in the Toms River drainage basin (Hunchak-Kariouk, 1999). Concentrations were highest in those samples collected just before or at peak stream flow. Concentrations during the growing season were higher during storm flow than during base flow at all sites monitored. During base flow in the growing season, concentrations were highest at a site on Long Swamp Creek draining a highly developed area, and lowest at sites on Wrangel Brook draining moderately developed areas. During storm flow, concentrations in the growing season were similar to those at sites on Long Swamp Creek and Wrangel Brook and higher than those at a site on Davenport Branch draining a slightly developed area. During the nongrowing season, concentrations were highest at the site on Long Swamp Creek and lowest at the site on Davenport Branch. At sites on all three streams, concentrations were greater during the growing season than during the nongrowing season.

Metals can be transported from the watershed to the estuary in stream flow as dissolved species and associated with suspended sediment and colloids (insoluble chemical solids) in the water column. Metals readily form complexes with manganese and iron oxides and hydroxides, which are dissolved and associated with particulate surfaces. Metals associated with sediment in the stream bed can enter the water column as the sediment is resuspended during high stream flows. Metals can also enter the estuary from the atmosphere in the form of dry and wet deposition of metal-containing particulates. The concentration, predominant species, bioavailability, and toxicity of each metal depend on the chemical properties of the metal, water chemistry (as controlled by water acidity and the type and concentration of the major inorganic and organic compounds), and seasonal conditions such as temperature and stream flow (Meade, 1995).

Water column and bottom sediment data were collected on six toxic trace metals (arsenic, chromium, copper, lead, nickel, and zinc), manganese, and iron at 28 sites throughout the bay watershed and at the McDonalds Branch in Lebanon State Forest during water years 1960-97. Although manganese and iron are not trace elements, they aid in the interpretation of trace element data because their concentrations reflect weathering, sedimentation, and the ambient chemistry in the water column. In addition, iron is an important agent in the onset of brown tide blooms (Cosper et al., 1996). Except at the long-term water quality sites on the Toms River near the town of Toms River and McDonalds Branch in Lebanon State Forest (a national benchmark site), samples for metal analysis were collected very infrequently (five or fewer samples during the sampling period). For analysis, the sites were grouped by amount of urban development into five groups: (A) McDonalds Branch in Lebanon State Forest; (B) all sites in the Forked River, Mill Branch, and Cedar, Oyster, Westecunk, and Tuckerton Creek Basins; (C) all sites in the Toms River Basin, excluding the Toms River at the town of Toms River site; (D) the Toms River at the town of Toms River; and (E) all sites in the Metedeconk River and Kettle Creek Basins (Table 7). Water column (total concentration) data for unfiltered, whole water samples were available for stations in all groups. Bottom sediment data, in turn, were available for stations in groups B, D, and E only. For this characterization, the total water metal concentration was used, which is the sum of the concentrations of the dissolved, colloidal, and suspended sediment metals.

Figure 22 shows the distributions of water column and bed sediment concentrations among the site groups for each metal. Table 8 provides a summary of these data. The site groups are arranged from left to right in order of increasing intensity of land development in the contributing drainage area of the sites in each site group. These data can only be compared qualitatively because of varying data available for each station and reporting limits, which differed for each medium and which changed over time. For the purpose of this characterization, censored values (data with less than remark codes) were considered equivalent to the reporting level at the time of sample analysis. The actual values are known to be less, but the exact value is indeterminate (Reed et al., 1998). The reporting limit is the minimum value for reporting a concentration measured by some standardized technique. The reporting limit for some metals changed during water years 1960-97 due to differences in sample collection and laboratory procedures.

The concentrations of metals in the water column and bed sediments of influent systems in the watershed are qualitatively related to the amount of development (urban/residential and agriculture/grasslands) in the sampled basin. The basins of the Metedeconk River and Toms River are more developed than the remainder of the bay watershed and the McDonalds Branch basin. The highest maximum and median concentrations of metals were at sites in either the Metedeconk River basin or at the Toms River at the town of Toms River. The lowest median concentrations were in the McDonalds Branch and in rivers other than the Metedeconk River and Toms River.

The utility of the data comparisons (e.g., the median concentrations) reported in this characterization to water quality regulations is uncertain for a several reasons. The purpose of the data collection and the hydrologic conditions at the time of sampling were not investigated for the characterization. The values reported here are for the total concentration of substances composited from several sites over very long time periods during which sampling and laboratory methods varied.

Stream bed sediments can be a source or sink of toxic chemicals such as trace elements and chlorinated organic chemicals depending on the physiochemical conditions in the water column and bottom sediments. Many trace elements in aquatic systems are strongly associated with iron and manganese oxide coatings on sediments. Chlorinated organic chemicals are extremely hydrophobic and therefore tend to sorb to organic matter, which is either dissolved in the water or associated with suspended and bottom sediments. As a result, sediments can provide a mechanism for these toxic chemicals to remain in surface water systems for many years after their input. When bed sediments are disturbed and transported downstream, re-equilibration with surrounding waters may release the chemicals to the water column.

The presence and distribution of trace elements and chlorinated organic compounds in stream bed sediments were determined for selected rivers of New Jersey (O'Brien, 1997; Stackelberg, 1997). The distribution of toxic chemicals was examined with respect to both physiographic province and major drainage areas with varying percentages of different land use. Bed sediment concentrations of toxic chemicals within the Barnegat Bay watershed were not analyzed in these studies; however, concentrations in other major drainage basins in the New Jersey Coastal Plain were examined. Land use in the Big Timber Creek and Cooper River (BTCR) basins is mostly urban. In the Salem River and Raccoon Creek (SRRC) basins, land use is mainly agriculture. Land use in the Great Egg Harbor and Mullica River (GEMU) basins is principally forest and wetland and that in the Toms River and elsewhere in the Barnegat Bay watershed is predominantly forest and wetland (similar to the GEMR basins). Results of these analyses are generally transferable to the Barnegat Bay watershed, although many river segments in the inner coastal plain that cross confining-unit outcrop areas may have different bed sediment compositions with correspondingly different adsorptive characteristics than those of the outer coastal plain.

Concentrations of arsenic and nickel in bed sediments are similar throughout the New Jersey Coastal Plain and do not appear to be related to land use because concentrations are similar among the urban (BTCR), agricultural (SRRC), and less-developed (GEMU) basins. Concentrations of copper and lead are higher in urban (BTCR) basins than in agricultural (SRRC) and less-developed (GEMU) basins, and concentrations of chromium, zinc, and iron are higher in urban (BTCR) and agricultural (SRRC) basins than in less-developed areas (GEMU) areas. Manganese concentrations are higher in agricultural (SRRC) basins than in urban (BTCR) and less-developed (GEMU) basins. Therefore, if the Barnegat Bay watershed is comparable to the GEMU basins with respect to factors affecting trace metals in bed sediments, then concentrations of trace metals in bed sediments of the Barnegat Bay watershed are likely to be low in relation to other, more developed basins in New Jersey.

Concentrations of DDT and DDE in bed sediments are similar throughout the New Jersey Coastal Plain and do not appear to be related to land use because the concentrations are similar among the urban (BTCR), agricultural (SRRC), and undeveloped (GEMU) basins. Concentrations of DDD, chlordane, dieldrin, and PCBs are higher in urban (BTCR) basins than in agricultural (SRRC) and undeveloped (GEMU) basins. Therefore, concentrations of chlorinated organic chemicals in bed sediments of the Barnegat Bay watershed are probably low.

Suspended sediment can be a transport mechanism for nutrients, organic chemicals, and metals to the estuary. Some hydrophobic organic chemicals and charged inorganic species such as phosphates, ammonium and organic nitrogen, as well as metals become associated with particle surfaces and are mobilized in the stream. Data on suspended sediment (quantity and quality) in streams of the bay watershed are limited. Historical data (prior to 1986) are available for sites on the North Branch of the Metedeconk River, Oyster Creek, and Westecunk Creek, and recent data (since 1994) are available for sites on the Wrangel Brook, Davenport Branch, and Long Swamp Creek. Suspended sediment has been measured at the long-term water quality stations on the McDonalds Branch in Lebanon State Forest and Toms River near the town of Toms River since 1969 and 1972, respectively. Table 9 lists sites where suspended sediment data have been collected.

Figure 23 shows the concentrations of suspended sediment, total phosphorus, ammonia plus organic nitrogen, and total organic carbon at sites within the bay watershed. Concentrations of total phosphorus, ammonia plus organic nitrogen, and total organic carbon are whole water measurements and represent the sum of the concentrations associated with suspended sediment and dissolved in the water column. The magnitude of these total water column concentrations is a qualitative measure of the amount of these nutrients associated with suspended sediment.

Concentrations of suspended sediment measured in streams of the bay watershed were low. Median values were less than 20 mg/l at all sampled sites (where data were available). Concentrations at sites on the North Branch of the Metedeconk River, Toms River, Wrangel Brook, and Long Swamp Creek were similar and higher than concentrations in Oyster Creek, Westecunk Creek, and McDonalds Branch, which were very low. Concentrations of phosphorus and total ammonia plus organic nitrogen were somewhat higher at sites on the North Branch of the Metedeconk River, Toms River, and Long Swamp Creek, where the concentrations of suspended sediment were also higher than at other sites in the watershed. Total concentrations of nutrients were lower at sites on Oyster Creek, Westecunk Creek, and McDonalds Branch, where the concentrations of suspended sediment were sampled than at other sites in the watershed.

Although human activities that directly affect water quality are usually assumed to be the dominant sources of estuarine pollutants, atmospheric deposition also can be a significant source of various contaminants to coastal waterways. Results of local studies of atmospheric deposition in the Barnegat Bay watershed are not yet available (Y. Gao, Rutgers University, written communication, 1999). However, investigations of other areas in, and adjacent to, New Jersey provide a reasonable indication of the likely magnitude of atmospheric deposition of various constituents.

In urban areas nationwide, atmospheric deposition generally is a less important source of VOCs than urban land surfaces (Lopes and Bender, 1998). Baehr et al. (1999) evaluated the atmosphere as a source of VOCs in shallow ground water in the Glassboro region of southern New Jersey and frequently found low-level concentrations of chloroform, methyl-tert butyl ether (MTBE), 1,1,1-trichloroethane, tetrachloroethylene (PCE), and carbon disulfide (not a VOC) in shallow ground water of the Kirkwood-Cohansey aquifer system. Atmospheric concentrations of MTBE (but not the other compounds) were found to be high enough (as high as 43.8 ug/l) to potentially explain its frequent detection in shallow ground water. In the Barnegat Bay watershed, the presence of MTBE in shallow ground water has not been investigated systematically, but this contaminant was the most frequently detected VOC in surface water samples from the Metedeconk River by the Brick Township Municipal Utilities Authority.

Pesticides can be transported into the atmosphere by various processes, dispersed by air currents, and then re-deposited on land and water surfaces. More than 24 agricultural pesticides have been reported in fog and rainfall in the United States, Canada, and Europe. Although atrazine and alachlor concentrations of 0.2-0.4 ug/l were typically measured in precipitation sampled in midwestern cornbelt states during 1990-91, concentrations of these compounds measured in precipitation across the northeastern United States at this time were generally less than 0.05 ug/l (Goolsby et al., 1997). In the Glassboro area in southern New Jersey, pesticide concentrations in precipitation were less than 0.05 ug/l during most of the year, but were higher during the spring application period (A. Baehr, U. S. Geological Survey, written communication, 1999).

Atmospheric deposition of nitrogen is generally recognized by east coast estuarine programs as either a significant factor in eutrophication or a mechanism of possible concern (Valigura et al., 1996). A strong linkage between increasing rates of nitrogen oxide emissions and increasing cultural eutrophication of coastal waters of the northeast United States has been suggested (Jaworski et al., 1997). However, trends in nitrate ion concentration in precipitation sampled nationwide during 1983-94 did not exhibit a consistent spatial pattern, and trends in the coastal mid-Atlantic region during this period were not statistically significant (p > 0.05) (Lynch et al., 1996). Johnsson and Barringer (1993) described inorganic precipitation chemistry in the McDonalds Branch subwatershed, situated close to the Barnegat Bay watershed. They showed that ammonium and nitrate were substantial carriers of ionic charge in precipitation sampled during 1984-88, and that concentrations of most major ions, including nitrate, were higher in throughfall (sampled under the forest canopy) than in precipitation. This finding suggests that dry deposition of nitrogen on vegetative surfaces in the Barnegat Bay watershed could be significant, as suggested by Wang (1984).

Atmospheric deposition can increase the nitrogen load of streams if nitrogen inputs to a watershed exceeds vegetative uptake or if soils are particularly permeable and unable to retain nitrogen. Jaworski et al. (1997) observed that for large watersheds in the northeastern U. S., riverine nitrogen fluxes were highly correlated with nitrogen deposition onto their landscapes and also with nitrogen oxide emissions from fossil fuel combustion into their airsheds.

For the purposes of relating precipitation chemistry with that of surface and ground water in the Barnegat Bay watershed, and estimating the contribution of nitrogen load from atmospheric deposition, inorganic chemical data for precipitation sampled at selected sites as part of the National Atmospheric Deposition Program (NADP), were examined. Two NADP sites proximal to the Barnegat Bay watershed for which data are available for the past 10 years are located at Washington Crossing, New Jersey, and on the eastern shore of Maryland at Wye. NADP summary reports indicate that inorganic precipitation chemistry is similar at these and surrounding sites (NADP, 1995, 1997), and similar to that observed in the McDonalds Branch basin by Johnsson and Barringer (1993). Therefore, these two NADP sites provide a reasonable indication of the chemistry of precipitation occurring over the Barnegat Bay watershed. A factor that may possibly limit the applicability of these sites is their relatively inland location with respect to sources of marine aerosols. Monthly mean values for nitrate-N, ammonia-N, sulfate, specific conductance, and pH for these two sites were analyzed for the 1987-97 period. Figure 24 shows statistical distributions of these values for the two respective sites. These distributions can be used to summarize the recent history of precipitation chemistry for the Barnegat Bay watershed.

Concentrations of the five inorganic constituents in shallow ground water located near streams were similarly analyzed. Water from 22 shallow wells located near surface water was sampled during September and October of 1996, and respective constituent values for the wells were commingled and statistically analyzed (Jones and DeLuca, 1997). These synoptic data can be thought of as a "snapshot" in time with fairly wide spatial coverage.

The 25 surface water sampling sites with constituent data for the 1987-97 period were selected, and respective constituent medians for these sites were commingled and statistically analyzed. Some streams were sampled more frequently than others; therefore, an uneven statistical reliability is present among the median values analyzed. Whereas ground water samples provide an indication of the chemistry along discrete flow paths that intersect a small fraction of the aquifer system resource, the samples from the 22-25 surface water sites integrate all surface water inputs upstream (covering most of the watershed land mass). In this sense, the available surface water quality data set represents the surface water resource more completely than the available ground water data set represents the ground water resource.

In spite of fundamental differences between the data sets for these hydrologic compartments (spatial coverage vs. temporal coverage), a qualitative comparison of statistical distributions can provide a meaningful first step in understanding the relations between precipitation, ground water, and surface water. Relative distributions provide some indication of the extent to which precipitation can be expected to represent a potential source of these constituents in ground water and surface water.

Baehr, A., P. E. Stackelberg, and R. J. Baker. 1999. Evaluation of the atmosphere as a source of volatile organic compounds in shallow ground water. Water Resour. Res., 35:127-136.

Barbash, J. E. and E. A. Resek. 1996. Pesticides and Ground Water Distribution: Trends and Governing Factors. Ann Arbor Press, Chelsea, Michigan. 588 p.

Barringer, J. L., C. L. MacLeod, and R. A. Gallagher. 1997. Mercury in ground water, soils, and sediments of the Kirkwood-Cohansey aquifer system in the New Jersey Coastal Plain. USGS Water-Resources Investigation Report 95-475, U. S. Geological Survey, West Trenton, New Jersey. 260 p.

Breidt, F. J., D. C. Boes, J. I. Wagner, and M. D. Flora. 1991. Antidegradation water quality criteria for the Delaware River: A distribution-free statistical approach. Wat. Resourc. Bull., 27: 849-858.

Camp, Dresser & McKee. 1993. Evaluation of the Ocean County Health Department Domestic Well Test Database. Unpublished Consultant's Report, Edison, New Jersey.

Carter, G. P. 1997. Eight characterizing trends in the Barnegat Bay watershed, Ocean County, New Jersey. Pp. 1-16 in Flimlin, G. E. and M. J. Kennish, M.J. (eds.), Proceedings of the Barnegat Bay Ecosystem Workshop. Rutgers Cooperative Extension of Ocean County, Toms River, New Jersey.

Chow, V.T. 1964. Handbook of Applied Hydrology. McGraw Hill, New York. 1418 p.

Clawges, R. M., T. D. Oden, and E. J. Vowinkel. 1998. Water quality data for 90 community water supply wells in New Jersey, 1994-95. USGS Open-File Report 97-625, West Trenton, New Jersey. 31 p.

Clawges, R. M., P. E. Stackelberg, M. A. Ayers, and E. F. Vowinkel. 1999. Nitrate, volatile organic compounds, and pesticides in ground water - A summary of selected studies from New Jersey and Long Island, New York. U. S. Geological Survey Water Resources Investigations Report 99-4027, West Trenton, New Jersey. 32 p.

Dooley, J. H. 1992. Natural sources of mercury in the Kirkwood Cohansey aquifer system of the New Jersey Coastal Plain. New Jersey Geological Survey Report 27, West Trenton, New Jersey. 16 p.

Cosper, E. M., M. D. Gastrich, O. R. Anderson, and S. S. Benmayor. 1997. Viral infection and brown tide. Pp. 233-242 in Flimlin, G.E. and M. J. Kennish, (eds.), Proceedings of the Barnegat Bay Ecosystem Workshop. Rutgers Cooperative Extension of Ocean County, Toms River, New Jersey.

Fegeas, R. G., R. W. Claire, S. C. Guptill, K. E. Anderson, and C. A. Hallam. 1983. Land use and land cover digital data. U. S. Geological Survey Circular 895-E, Reston, Virginia. 21 p.

Goolsby, D. A., E. M. Thurman, M. L. Pomes, M. T. Meyer, and W. A. Battaglin. 1997. Herbicides and their metabolites in rainfall: origin, transport, and deposition patterns across the midwestern and northeastern United States, 1990-91. Environ. Sci. Technol., 31:1325-1333.

Harriman, D. A. and B. P. Sargent. 1985. Ground water quality in east-central New Jersey, and a plan for sampling networks. U. S. Geological Survey Water Resources Investigations Report 85-4243, Trenton, New Jersey. 114 p.

Harriman, D. A., and L. M. Voronin. 1984. Water quality data for aquifers in east-central New Jersey, 1981-82. U. S. Geological Survey Open-File Report 84-821, Trenton, New Jersey. 39 p.

Hay, L. E. and J. P. Campbell. 1990. Water quality trends in New Jersey streams. U. S. Geological Survey Water Resources Investigations Report 90-4046, West Trenton, New Jersey. 297 p.

Hickman, R. E. and T. H. Barringer. 1999. Trends in water quality of New Jersey streams, water years 1986 - 95. U.S. Geological Survey Water Resources Investigation Report 98-4204, West Trenton, New Jersey. 174 p.

Hunchak-Kariouk, K. 1999. Relation of water quality to land use in the drainage basins of four tributaries to the Toms River, New Jersey, 1994-5. U. S. Geological Survey Water Resources Investigation Report 99-4001, West Trenton, New Jersey. 120 p.

Hunchak-Kariouk, K., D. E. Buxton, and R. E. Hickman. 1999. Relations of surface water quality to stream flow in the Atlantic Coastal, Lower Delaware River, and Delaware Bay Basins. U. S. Geological Survey Water Resources Investigation Report 98-4244, West Trenton, New Jersey. 146 p.

Ivahnenko, T. and D. E. Buxton. 1994. Agricultural pesticides in six drainage basins used for public water supply in New Jersey: 1990. U. S. Geological Survey Water-Resources Investigation Report 93-4101, West Trenton, New Jersey. 56 p.

Jaworski, N. A., R. W. Howarth, and L. J. Hetling. 1997. Atmospheric deposition of nitrogen oxides onto the landscape contributes to coastal eutrophication in the Northeast United States. Environ. Sci. Technol., 31:1995-2004.

Johnsson, P. A. and J. L. Barringer. 1993. Water quality and hydrogeochemical processes in McDonalds Branch basin, New Jersey Pinelands, 1984-88. U. S. Geological Survey Water Resources Investigation Report 91-4081, West Trenton, New Jersey. 111 p.

Jones, W. D. and M. J. DeLuca. 1997. Water resources data New Jersey water year 1996. U.S. Geological Survey Water-Data Report NJ-96-2, West Trenton, New Jersey. 207 p.

Kozinski, J., Z. Szabo, O. S. Zapecza, and T. H. Barringer. 1995. Natural radioactivity in, and inorganic chemistry of, ground water in the Kirkwood-Cohansey aquifer system, southern New Jersey, 1983-89. U. S. Geological Survey Water Resources Investigations Report 92-4144, West Trenton, New Jersey. 130 p.

Leamond, C. E., R. J. Haefner, S. J. Cauller, and P. E. Stackelberg. 1992. Groundwater quality in five areas of differing land use in Nassau and Suffolk Counties, Long Island, New York. U. S. Geological Survey Open-File Report 91-180, Syosset, New York. 67 pp.

Lopes, T. J. and D. A. Bender. 1998. Nonpoint sources of volatile organic compounds in urban areas - relative importance of land surfaces and air. Environ. Pollut., pp. 221-230.

Lord, D. G., J. L. Barringer, P. A. Johnsson, P. F. Schuster, R. L. Walker, J. E. Fairchild, B. N. Sroka, and E. Jacobson. 1990. Hydrogeochemical data from an acidic deposition study at McDonalds Branch basin in the New Jersey Pinelands, 1983-86. U. S. Geological Survey Open-File Report 88-500, West Trenton, New Jersey. 132 p.

Lynch, J. A., V. C. Bowersox, J. W. Grimm. 1996. Trends in precipitation chemistry in the United States, 1983-94: an analysis of the effects in 1995 of Phase I of the Clean Air Act Amendments of 1990, Title IV. U. S. Geological Survey Open-File Report 96-0346, Reston, Virginia. 100 p.

Meade, R. H. (ed.). 1995. Contaminants in the Mississippi River: U. S. Geological Survey Circular 1133, Reston, Virginia. 140 p.

Moser, F. C. 1997 Sources and sinks of nitrogen and trace metals, and benthic macrofauna assemblages in Barnegat Bay, New Jersey. Ph.D. Thesis, Rutgers University, New Brunswick, New Jersey. 135 p.

Moser, F. C. and R. F. Bopp. 1996. A comparison of trace metals in bay and marina sediments in Barnegat Bay. Pp. 95-108 in Flimlin, G. E. and M. J. Kennish (eds.), Proceedings of the Barnegat Bay Ecosystem Workshop. Rutgers Cooperative Extension of Ocean County, Toms River, New Jersey.

National Atmospheric Deposition Program. 1997. National Atmospheric Deposition Program 1997 Wet Deposition. Illinois State Water Survey, Champaign, Illinois. 16 p.

National Atmospheric Deposition Program. 1995. NADP/NTN Wet Deposition in the United States 1995. Illinois State Water Survey, Champaign, Illinois. 12 p.

New Jersey Department of Environmental Protection. 1995. New Jersey 1994 State Water Quality Inventory Report. New Jersey Department of Environmental Protection, Office of Environmental Planning, Trenton, New Jersey. 176 p.

New Jersey Department of Environmental Protection. 1990. New Jersey 1990 State Water Quality Inventory Report. New Jersey Department of Environmental Protection, Division of Water Resources, Trenton, New Jersey. 471 p.

Novotny, V. and G. Chesters. 1981. Handbook of Nonpoint Pollution Sources and Management. Van Nostrand Reinhold Company, New York. 555 p.

O'Brien, A. K., R. G. Reiser, and H. Gylling. 1997. Spatial variability of volatile organic compounds in streams on Long Island, New York, and in New Jersey. U. S. Geological Survey Fact Sheet FS-194-97, West Trenton, New Jersey. 6 p.

O'Brien, A. K. 1997. Presence and distribution of trace elements in New Jersey streambed sediments. J. Am. Wat. Resour. Assoc., 33, No. 2.

Preston, S. D. 1996. Study of nonpoint source nutrient loading in the Patuxent River Basin, Maryland. U. S. Geological Survey Water Resources Investigation Report 96-4273, Baltimore, Maryland. 6 p.

Reed, T. J., G. L. Centinaro, M. J. DeLuca, and J. H. Oden. 1998. Water Resource Data, New Jersey, Water Year 1997. U. S. Geological Survey Water-Data Report NJ-97-1, West Trenton, New Jersey. 608 p.

Reiser, R. G. 1999 Relation of pesticide concentrations to season, stream flow, and land use in seven New Jersey streams. U. S. Geological Survey Water Resources Investigations Report 99-4154, West Trenton, New Jersey. 19 p.

Reiser, R. G. and A. K. O'Brien. 1998. Occurrence and seasonal variability of volatile organic compounds in seven New Jersey streams. U. S. Geological Survey Water Resources Investigations Report 98-4074, West Trenton, New Jersey. 11 p.

Robinson, K. W., T. R. Lazaro, C. Pak. 1996. Associations between water quality trends in New Jersey streams and drainage-basin characteristics, 1975-86. U. S. Geological Survey Water Resources Investigation Report 96-4119, West Trenton, New Jersey. 148 p.

Stackelberg, P. E. 1997. Presence and distribution of chlorinated organic compounds in stream bed sediments, New Jersey. J. Am. Wat. Resour. Assoc., 33:271-284.

Stackelberg, P. E., J. A. Hopple, and L. J. Kauffman. 1997. Occurrence of nitrate, pesticides, and volatile organic compounds in the Kirkwood-Cohansey aquifer system, southern New Jersey. U. S. Geological Survey Water Resources Investigation Report 97- 4241, West Trenton, New Jersey. 8 p.

Szabo, Z. and V. DePaul. 1998. Radium-226 and radium-228 in shallow ground water, southern New Jersey. U. S. Geological Survey Fact Sheet FS-062-98, West Trenton, New Jersey.

6 p.

Szabo, Z., D. E. Rice, C. L. McLeod, and T. H. Barringer. 1997. Relation of distribution of radium, nitrate, and pesticides to agricultural land use and depth, Kirkwood Cohansey aquifer system, New Jersey Coastal Plain, 1990-91. U. S. Geological Survey Water Resources Investigations Report 96-4165A, West Trenton, New Jersey. 107 p.

Terracciano, S. A. and A. K. O'Brien. 1997. Occurrence and distributions of VOCs in streams on Long Island, New York, and in New Jersey--A review of existing and reconnaissance data. U. S. Geological Survey Fact Sheet FS-063-97, West Trenton, New Jersey. 4 p.

Valigura, R. A., W. T. Luke, R. S. Artz, and B. B. Hicks. 1996. Atmospheric nutrient input to coastal areas--reducing the uncertainties. National Oceanic and Atmospheric Administration, NOAA Coastal Ocean Program, Decision Analysis Series No. 9, NOAA Coastal Ocean Office, Silver Springs, Maryland. 24 p,.

Vowinkel, E. F. and W. A. Battaglin. in press. Analysis of nonpoint source ground water contamination in relation to land use: Chapter D, Relation of ground water quality to hydrogeology and land use in the Coastal Plain of New Jersey. U. S. Geological Survey Water Supply Paper 2381-D, Reston, Virginia. 110 pp.

Vowinkel, E. F., R. M. Clawges, D. E. Buxton, and D. A. Stedfast. 1996. Vulnerability of public drinking water supplies in New Jersey to pesticides. U.S. Geological Survey Fact Sheet FS-165-96, West Trenton, New Jersey. 3 p.

Vowinkel E. F., R. M. Clawges, and C. G. Uchrin. 1994. Evaluation of the vulnerability of water from public supply wells in New Jersey to contamination by pesticides. Pp. 495-510 in Weigmann, D. L. (ed.), New Directions in Pesticide Research, Management, and Policy. Virginia Water Resources Research Center, Nov. 1-3, 1993, Blacksburg, Virginia.

Vowinkel, E. F. and S. F. Siwiec. 1991. Plan to evaluate the effects of hydrogeologic conditions and human activities on water quality in the Coastal Plain of New York and New Jersey. U. S. Geological Survey Water Resources Investigations Report 91-4091, West Trenton, New Jersey. 42 pp.

Wang, D. 1984. Fire and nutrient dynamics in a pine-oak forest ecosystem in the New Jersey Pine Barrens. Ph.D. Thesis, Yale University, New Haven, Connecticut. 217 p.

Watt, M. K., M. L. Johnnson, and P. J. Lacombe. 1994. Hydrology of the unconfined aquifer system Toms River, Metedeconk River, and Kettle Creek basins, New Jersey, 1987-90. U. S. Geological Survey Water Resources Investigation Report 93-411, West Trenton, New Jersey. 5 plates.

Windisch, M. A, and R. A. Zampella. 1989. New Jersey Pinelands surface water quality data, 1983-88. Tech. Rept. Prepared by the New Jersey Pinelands Commission in cooperation with the Cape May County, Burlington County, and Ocean County Health Departments, 515 p.

Yuretich, R. F., D. A. Crerar, D. J. J. Kinsman, J. L. Means, M. P. Borscsik. 1981. Hydrogeochemistry of the New Jersey Coastal Plain. 1: Major element cycles in precipitation and river water. Chem. Geol., 33:1-21.