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Research about Suffolk County, New York

Source-linked reports with geographic coverage including Suffolk County, New York.

At least 19 recordsLinked to original sources
USGS2025

Characterization of stream water quality and groundwater levels in the Central Pine Barrens region, Suffolk County, New York, 2017–23

The area locally known as the “Central Pine Barrens” region, located in Suffolk County, New York, contains most of Long Island’s preserved and undeveloped land. This region overlays an aquifer system that provides potable groundwater for residents of Suffolk County. Between 2017 and 2023, the U.S. Geological Survey, in cooperation with the Central Pine Barrens Joint Planning & Policy Commission and the Town of Brookhaven, monitored groundwater levels and stream water quality in this region. Groundwater levels were measured monthly at five wells and continuously (15-minute intervals) at a sixth well. Water quality was monitored at five locations in the Carmans River and at two locations in the Peconic River, and samples were analyzed for major ions, trace elements, nutrients, pharmaceuticals, and pesticides. The major ion compositions at the sites were mainly sodium-chloride type waters, and compositions varied the most at the furthest upstream sites in both streams. Concentrations above aquatic-life criteria thresholds also occurred most frequently at the furthest upstream sites. The seasonal patterns of nutrient loads and concentrations varied between the Carmans and Peconic Rivers. Several organic compounds including pharmaceuticals, domestic use products, and pesticides were detected at low concentrations in both streams. Metformin was the most frequently detected pharmaceutical compound, and herbicides were the most frequently detected pesticide class. Water-quality conditions influenced by anthropogenic contributions are a result of current and historical land use, and these contributions include onsite wastewater disposal systems, commercial or domestic fertilizers and pesticides, and urban or industrial contaminants in road runoff. This study characterizes and improves understanding of the current hydrologic conditions in the Central Pine Barrens region and the study findings can help inform the development of plans to manage, protect, and restore water resources.

New York↗
USGS2024

Accuracy assessment of three-dimensional point cloud data collected with a scanning total station on Shinnecock Nation Tribal lands in Suffolk County, New York

A combined point cloud of about 85.6 million points was collected during 27 scans of a section of the western shoreline along the Shinnecock Peninsula of Suffolk County, New York, to document baseline geospatial conditions during July and October 2022 using a scanning total station. The three-dimensional accuracy of the combined point cloud is assessed to identify potential systematic error sources associated with the surveying equipment and the novel methodology used to collect and field-register (data are oriented and aligned in real time) point cloud data. The accuracy of the combined point cloud was assessed in terms of relative and absolute reference frames. Relative accuracy provides a measure of error within the local coordinate system and is determined by combining the uncertainty associated with the position of the scan station (the point being occupied by the scanning total station during the scan), the uncertainty associated with the position of the network control points, and the uncertainty associated with the laser of the scanning total station. Assessment of the absolute accuracy includes these three potential error sources combined with the uncertainty associated with the geodetic coordinates to which the local control network is referenced. The combined overall relative horizontal and vertical accuracy of the point cloud is 0.0156 and 0.0241 meter, respectively, at the 95 percent confidence level. The combined overall absolute horizontal and vertical accuracy of the point cloud is 0.0598 and 0.0733 meter, respectively, at the 95 percent confidence level.

New York↗
USGS2016

Hydrologic assessment of the shallow groundwater flow system beneath the Shinnecock Nation tribal lands, Suffolk County, New York

Defining the distribution and flow of shallow groundwater beneath the Shinnecock Nation tribal lands in Suffolk County, New York, is a crucial first step in identifying sources of potential contamination to the surficial aquifer and coastal ecosystems. The surficial or water table aquifer beneath the tribal lands is the primary source of potable water supply for at least 6 percent of the households on the tribal lands. Oyster fisheries and other marine ecosystems are critical to the livelihood of many residents living on the tribal lands, but are susceptible to contamination from groundwater entering the embayment from the surficial aquifer. Contamination of the surficial aquifer from flooding during intense coastal storms, nutrient loading from fertilizers, and septic effluent have been identified as potential sources of human and ecological health concerns on tribal lands. The U.S. Geological Survey (USGS) facilitated the installation of 17 water table wells on and adjacent to the tribal lands during March 2014. These wells were combined with other existing wells to create a 32-well water table monitoring network that was used to assess local hydrologic conditions. Survey-grade, global-navigation-satellite systems provided centimeter-level accuracy for positioning wellhead surveys. Water levels were measured by the USGS during May (spring) and November (fall) 2014 to evaluate seasonal effects on the water table. Water level measurements were made at high and low tide during May 2014 to identify potential effects on the water table caused by changes in tidal stage (tidal flux) in Shinnecock Bay. Water level contour maps indicate that the surficial aquifer is recharged by precipitation and upgradient groundwater flow that moves from the recharge zone located generally beneath Sunrise Highway, to the discharge zone beneath the tribal lands, and eventually discharges into the embayment, tidal creeks, and estuaries that bound the tribal lands to the east, south, and west. Water levels in many of the wells in the network fluctuated in response to precipitation, upgradient groundwater flow, and tidal flux in Shinnecock Bay. Water level altitudes ranged from 6.66 to 0.47 feet (ft) above the North American Vertical Datum of 1988 during the spring measurement period, and from 5.25 to -0.24 ft (NAVD 88) during fall 2014. Historically, annual and seasonal precipitation seem to indicate long-term water level trends in an index well located in the town of Southampton, correlates with changes in storage in the upper glacial aquifer, but does not necessarily indicate water level extremes in the shallow groundwater system. To place the study period in perspective, calendar year 2014 was the 32d wettest year on record, with precipitation for the year totaling 48.1 inches, a 2.6-percent increase from the annual average (46.9 inches per year), based on 81 years of complete record at the National Oceanographic and Atmospheric Administration, National Weather Service cooperative meteorological station at Bridgehampton, New York. Estimated recharge to the water table beneath the tribal lands from precipitation for 2014 is 25.4 inches. Tidal flux caused water levels in wells to fluctuate from 0.30 to -0.24 ft during May 2014. Water levels in wells located north of Old Fort Pond and beneath the southernmost extent of the tribal lands were most influenced by tidal flux. During June 2014, hydrographs indicate that tidal flux influenced water levels by 0.48 ft in a well located near the southernmost extent of the tribal lands approximately 0.3 miles north of Shinnecock Bay, and was zero at a well located approximately 0.5 miles south of Montauk Highway, and 0.4 miles west of Heady Creek, near the geographic center of the tribal lands. Tidal-influence delay time (time interval between peak high-tide stage and corresponding peak high-water level) ranged from 1.75 hours at the well located near the southernmost extent of the tribal lands, to more than 4 hours at a well located north of Old Fort Pond, near the northwestern part of the tribal lands. Estimated hydraulic-conductivity values derived from the results of specific-capacity tests that were completed at nine observation wells during March 2015 were used to calculate average linear velocity. Average linear velocity along conceptualized flow-path segments of the upper glacial aquifer located beneath the tribal lands was estimated using an assumed effective porosity value, and hydraulic-conductivity and hydraulic-head values that were interpolated from measured values. Groundwater travel times were estimated by dividing the length of the flow-path segment by the average linear velocity along the flow-path segment. Total estimated groundwater travel time along a conceptualized flow path, beginning near Sunrise Highway and terminating at Shinnecock Bay, is approximately 45 years using a porosity value of 30 percent. A surficial-silty unit was identified from approximately 0 to 10 ft below land surface at multiple locations beneath the tribal lands. The lithology of the surficial unit was verified by interpreted gamma log results obtained from select wells, and auger-rig drill cuttings from an observation well located near the geographic center of the tribal lands. The altitude of the unit varies with topography and was delineated along a cross section line that trends north-south along the approximate centerline (spine) of the tribal lands. The altitude of the hydrogeologic contact between the upper glacial and the Magothy aquifers generally decreases from northwest to southeast, occurs at a depth ranging from about 150 to 200 ft beneath the tribal lands, and was identified at two locations north of the tribal lands, near Sunrise Highway and Sebonac Road. Results of electrical geophysical surveys indicate that the depth to the freshwater/saltwater interface decreases from north to south with decreasing water level altitude, and the Magothy and upper glacial aquifers contain saltwater at varying depths along the north-south trending section. Results of the surveys also indicate that the Magothy aquifer beneath the tribal lands contains brackish and salty water and is not considered a source of potable water supply. In general, depth to the interface increases with increasing geographic distance from the coastline. Low water table altitudes can result in increased saltwater encroachment into the surficial aquifer beneath the tribal lands. This upward movement and shallow depth of the freshwater/saltwater interface can jeopardize water quality in wells that supply water for domestic use.

New York↗
USGS2006

Leachate plumes in a highly permeable aquifer

Two landfills, 27 and 41 years old, were studied and found to have plumes of leachate-contaminated ground water extending 10,600 and 5,000 ft (3,200 and 1,500 m), respectively, from the site of deposition in the upper glacial aquifer on Long Island, New York. The plumes sink to the bottom of the aquifer, which is 70 ft (21 m) below the water table at the 27-year old site and 170 ft (52 m) below at the 41-year old site. The aquifer has a hydraulic conductivity of 270 ft per day (80 m per day).

New York↗
USGS2006

Analysis of mid- and high-stage conditions for the Peconic River at the eastern boundary of Brookhaven National Laboratory, Suffolk County, New York

Brookhaven National Laboratory (BNL) has historically discharged sewage treatment plant (STP) effluent to the Peconic River, which runs through the BNL site in Suffolk County, N.Y. This effluent discharge has averaged about 700,000 gallons per day (about 1.1 cubic feet per second [ft 3 /s]) since 1962 and led to contamination of streambed sediments by radioactive and hazardous constituents. Large sections of the stream channel near BNL are dry during periods of relatively low water-table altitude referred to as low-stage conditions. During mid-stage conditions, the water table intersects the streambed and base flow commences and increases as the water table rises to the tops of the streambanks. Areas adjacent to the stream become flooded during high-stage conditions as the water table rises above the streambanks. Information on the long-term (1943-2003) percentages of time that discharges at two nearby streamflow-gaging stations exceeded thresholds associated with mid- and high-stage conditions is needed to provide a range of estimates of the prevalence and seasonal variability of these conditions during the same years for streamflow-gaging station HQ on the Peconic River at the eastern boundary of BNL. Analysis and correlation of discharge data from the three streamflow-gaging stations—BNL’s station HQ and the U.S. Geological Survey stations on the Peconic River at Riverhead, N.Y., and Carmans River at Yaphank, N.Y.—were performed to extend the 1995-2003 period of record for station HQ. Low-stage conditions occur when there is no flow at station HQ and, therefore, the start-of-flow for the Peconic River is downstream of BNL property. Mid-stage conditions occur when there is flow at station HQ but its daily mean value does not exceed 4.2 ft 3 /s; high-stage conditions occur when this discharge exceeds 4.2 ft 3 /s. Daily mean streamflows at station HQ were associated with low-stage conditions most of the time during 1995-2003 for all flow durations. Low-stage conditions predominated during January, March, and July through December of these years, whereas mid-stage conditions prevailed during parts of February and April through June. Mid-stage conditions generally appeared throughout the year during 1995-2003, except for mid-October, during which only low-stage conditions were observed. High-stage conditions were attained the least amount of time for all flow durations, and appeared only during parts of March through July and December of these years. The percentages of time during 1943-2003 that daily mean streamflows at the Riverhead and Yaphank stations were associated with low-, mid-, and high-stage conditions provide a range of estimates of the amounts of time that these conditions occurred during these years at station HQ. Daily mean streamflows were associated with low-stage conditions most of the time during 1943-2003 for durations of 30 and 60 days; with mid-stage conditions most of the time for durations of 1, 3, and 7 days; and with either of these conditions for a duration of 14 days. High-stage conditions were attained the least amount of time during these years for all durations, except perhaps that of 1 day, for which low-stage conditions could have occurred the least amount of time. Mid-stage conditions predominated during January through early March, June through early July, and late November through December of these years. These conditions typically appeared throughout the year during 1943-2003, and occurred most often during late February. High-stage conditions also generally appeared throughout the year, except perhaps for a few days during early September of these years, and occurred most often during April. These results indicate that streamflows observed during 1943-2003 at the Riverhead and Yaphank stations—used to estimate a longer record for station HQ—were considerably higher than those observed during 1995-2003 at the three stations, and provide information that can be used in future studies to better understand the long-term capacity of streams such as the Peconic River near BNL to supply continuous flow, flood adjacent low-lying areas, and sustain aquatic habitats.

New York↗
USGS2005

Concentrations of Insecticides in Selected Surface Water Bodies in Suffolk County, New York, Before and After Mosquito Spraying, 2002-04

Concentrations of insecticides sprayed from truck or helicopter onto selected surface-water bodies in Suffolk County, N.Y., during the summers of 2002-04 decreased to below detection limits within 4 days after application. The U.S. Geological Survey (USGS), in cooperation with Suffolk County Department of Health Services (SCDHS), sampled surface waters from selected wetlands for insecticides that were sprayed seasonally from a truck or helicopter as part of the county’s West Nile Virus vector-control program. A total of 72 samples were collected from 27 sites and analyzed for 6 compunds—malathion, methoprene, methoprene acid, piperonyl butoxide (PBO), resmethrin, and sumithrin—that are typically used to help control mosquitoes. PBO was the most frequently detected analyte (33.3%), followed by resmethrin (11.1%), methoprene (9.7%), and methoprene acid (2.4%). Sumithrin and malathion were not applied and were not detected in any of the samples. Maximum recorded concentration of compounds in surface water were: PBO (59,800 ng/L), methoprene (9,030 ng/L), methoprene acid (1,710 ng/L), and resmethrin (293 ng/L). PBO and resmethrin were detected more often in samples when the compounds were applied by a helicopter rather than a truck. This report describes the 27 sampled locations, the sampling methods, and presents the initial results of the study. Detail is provided about concentrations of the applied compounds with respect to time as well as comparisons between the two application processes (truck versus helicopter). All data collected are presented in a table.

New York↗
USGS2004

Occurrence of arsenic in ground water of Suffolk County, New York, 1997-2002

Water-quality data from public and private drinking-water supply wells that were sampled from October 1997 through March 2001 in Suffolk County, New York were evaluated to define the occurrence and concentrations of arsenic throughout the county. The data bases of the Suffolk County Water Authority (SCWA) and the Suffolk County Department of Health Services (SCDHS) included 14 wells at which arsenic concentrations approached or exceeded the 2002 U.S. Environmental Protection Agency (USEPA) drinking-water guideline of 10 micrograms per liter (µg/L). As a followup, 19 wells were sampled from June through August 2002; 7 were wells previously reported to have had high arsenic concentrations; 7 were near other wells reported to have high concentrations, and the remaining 5 were in areas where detectable concentrations of arsenic were suspected. Arsenic concentrations near 10 µg/L were detected at only 2 of the 19 wells sampled; arsenic concentrations in samples from the remaining 17 wells were reported as less than the USGS Central Laboratory reporting limits of 2 µg/L or 4 µg/L. The elevated concentrations previously reported (1997 through 2001) for at least three of the wells were due to incompletely flushed carbon filters in the supply-well system or were typographical errors. A decrease in arsenic concentration was indicated at six of the seven resampled wells; no reasons are apparent. Arsenic concentrations in ground water that exceed drinking-water guidelines were found only at one site. On the basis of limited sampling data available for this study, the concentrations of arsenic above drinking-water standards (10 µg/L) do not appear to indicate a countywide problem with regards to arsenic concentrations in ground water.

New York↗
USGS1999

Ground-water flow paths and traveltime to three small embayments within the Peconic Estuary, eastern Suffolk County, New York

The Peconic Estuary, at the eastern end of Long Island, has been plagued by a recurrent algal bloom that has caused the severe decline of local marine resources. Although the onset, duration, and cessation of the bloom remain unpredictable, ground-water discharge has been shown to affect surface-water quality in the western part of the estuary. Results from a study on the North Fork of Long Island indicate that local hydrogeologic factors cause differences in ground-water age and characteristics of discharge to the estuary. The need for information on the local patterns and rates of ground-water discharge to the Peconic Estuary prompted analysis of ground-water flow paths and traveltime to three small embayments within the estuary. Meetinghouse Creek, near the west end of the North Fork; Sag Harbor Cove, in the central part of the South Fork; and West Neck Bay, on Shelter Island. Ground-water-flow models were developed, and particle-tracking procedures were applied to the results of each model, to define the flow paths and traveltime of ground water to the three embayments. The steady-state flow models represent the two-dimensional ground-water-flow system along a vertical section through the uplands of each embayment and simulate long-term hydrologic conditions. The particle-tracking procedure used model-generated ground-water levels and flow rates to calculate the water-particle pathlines and times-of-travel through each flow system from the point of entry (recharge) to the point of exit at streams, the shore, or subsea-discharge areas. Results for the Meetinghouse Creek study area indicate that about 50 percent of the total recharge that enters the system flows southward to Meetinghouse Creek; half of this amount discharges as base flow to the fresh-water reach of the creek, and half as shoreline underflow to the estuarine reach. About 85 percent of the total discharge to Meetinghouse Creek has flowed entirely within the upper glacial aquifer, and about 15 percent has flowed through the Magothy aquifer. The average age of all ground water discharged to Meetinghouse Creek is about 60 years; the average age of base flow to the freshwater reach of the creek is about 7 years, and the average age of shoreline underflow to the estuarine reach is about 120 years. The results for the Sag Harbor Cove study area indicate that about 30 percent of the total recharge that enters the system flows northward to Sag Harbor Cove; about half of this amount discharges as shoreline underflow, and half as subsea underflow. About 40 percent of the total discharge to Sag Harbor Cove has flowed entirely within the upper glacial aquifer, and about 60 percent has flowed through the Pleistocene marine clay unit, Pleistocene(?) sand unit, or Magothy aquifer. The average age of all ground water discharged to Sag Harbor Cove is about 110 years; the average age of shoreline underflow is about 25 years, and the average age of subsea underflow is about 190 years. Results for the West Neck Bay study area indicate that about 65 percent of the total recharge that enters the system flows westward to West Neck Bay; virtually all of this amount discharges as shoreline underflow, but a negligible percentage discharges as subsea underflow. Virtually all discharge to West Neck Bay has flowed entirely within the upper glacial aquifer, although a minor amount has flowed through the Pleistocene marine clay unit. The average age of shoreline underflow to West Neck Bay is about 15 years, and the average age of subsea underflow is about 1,800 years. Ground water that discharges to streams and the shores represented in the models is mostly relatively young water that has flowed entirely within the shallow zones of the flow systems, whereas ground water that discharges to the subsea-discharge areas is mostly old water that has flowed through the deep zones. Data obtained from these models allows evaluation of each embayment.s vulnerability to contaminants introduced at the water table and can guide the development of source-area-protection strategies for the corresponding watersheds.

New York↗
USGS1999

Iron in the aquifer system of Suffolk County, New York, 1990-98

High concentrations of dissolved iron in ground water contribute to the biofouling of public-supply wells, and the treatment and remediation of biofouling are costly. Water companies on Long Island, N.Y., spend several million dollars annually to recondition, redevelop, and replace supply wells and distribution lines; treat dissolved iron with sequestering agents or by filtration; and respond to iron-related complaints by customers. This report summarizes the results of studies done by the U.S. Geological Survey, in cooperation with the Suffolk County Water Authority, to characterize the geochemistry and microbiology of iron in the aquifer system of Suffolk County. This information should be helpful for the siting and operation of supply wells. Concentrations of dissolved iron in Long Island's ground water, and the frequency of iron biofouling of wells, are highest in ground-water-discharge zones, particularly near the south shore. Ground water along a deep north-south flowpath of the Magothy aquifer in southwestern Suffolk County becomes anaerobic (oxygen deficient) and Fe(III) reducing at a distance of 8 to 10 kilometers south of the ground-water divide, and this change coincides with the downgradient increase in dissolved iron concentrations. The distribution of organic carbon, and the distribution and local variations in reactivity of Fe(III), in Magothy aquifer sediments have resulted in localized differences in redox microenvironments. For example, Fe(III)-reducing zones are associated with anaerobic conditions, where relatively large amounts of Fe(III) oxyhydroxide grain coatings are present, whereas sulfate-reducing zones are associated with lignite-rich lenses of silt and clay and appear to have developed in response to the depletion of available Fe(III) oxyhydroxides. The sulfate-reducing zones are characterized by relatively low concentrations of dissolved iron (resulting from iron-disulfide precipitation) and may be large enough to warrant water-supply development. Specific-capacity and water-quality data from wells screened in the Magothy aquifer indicate that water from biofouled wells contains higher median concentrations of total and dissolved iron and manganese, total phosphate, and dissolved sulfate, and lower median concentrations of dissolved oxygen and alkalinity, and lower pH, than does water from unaffected wells. Corresponding data from wells screened in the upper glacial aquifer indicate that water from biofouled wells contains higher median concentrations of total and dissolved manganese and dissolved sulfate, and lower pH, than does water from unaffected wells. Filamentous bacteria were detected in 31 (or 72 percent) of the 43 biofilm samples obtained from biofouled wells during reconditioning. The predominant filamentous organism was Gallionella ferruginea, a major biofouling agent in the upper glacial and Magothy aquifers throughout Suffolk County. Mineral-saturation indices indicate that most of the well-encrusting material is deposited when the wells are shut down. Furthermore, the use of treated water (which has a high pH and sometimes high concentrations of dissolved iron) for pump prelubrication when wells are shut down could greatly increase the rate of iron oxidation.

New York↗
USGS1983

Altitude of the top of the Matawan Group-Magothy Formation, Suffolk County, Long Island, New York

The Magothy aquifer, with its irregular surface and deeply eroded buried valleys, has become the major source of fresh water in most of Suffolk Country. With the availability of recent data from deep wells and test holes, refinement of the surface-altitude contours has been possible and resulted in substantial revision in some areas. This 1-sheet map delineates the surface altitude of the Magothy aquifer (Matawan Group-Magothy Formation) and includes a brief text and bibliography.

New York↗
USGS1981

Hydrogeologic data from selected wells and test holes in Suffolk County, Long Island, New York, 1972-80

The population of Suffolk County, New York, an area of 922 square miles, has increased rapidly, from less than 200,000 in 1940 to about 1.3 million in 1978. Ground-water pumpage has increased from an average of 42 million gallons per day in 1950 to about 257 million gallons per day in 1978. To help supply the hydrologic information needed to anticipate and prevent shortages, this report presents hydrogeologic and well-completion data on over 700 wells and test holes.

New York↗
USGS1976

Change in methylene blue active substances and chloride levels in streams in Suffolk County, New York, 1961-1976

Since 1961, concentrations of methylene blue active substances and chloride were measured in samples collected at 67 sampling stations on 44 streams in Suffolk County, Long Island, New York. Changes in the concentrations of these constituents and calculated chloride/methylene blue active substances ratios are reported. Although many factors--the 1962 to 1966 drought, urbanization, change in detergent formulation, and the 1971 Suffolk County detergent ban--make specific interpretation of the data difficult, it appears that the quality of water in streams and, consequently, that part of the upper glacial aquifer supplying water to the streams, is improving in terms of the concentration of methylene blue active substances.

New York↗
USGS1974

Preliminary findings of a leachate study on two landfills in Suffolk County, New York

Plumes of leachate-enriched ground water extend 10,600 and 5,000 ft (3,200 and 1,500 m) downgradient from landfills in the towns of Babylon and Islip, respectively, and extend vertically beneath the landfills to the base of the upper glacial aquifer, whose thickness ranges from 71 to 77 ft (22-24 m) at the Babylon site and is 170 ft (52 m) at the Islip site. The Babylon and Islip landfills were started in 1947 and 1933, respectively. The quantities of ground water in the plumes are 2X10 9 gal (8X10 6 m 3 ) at Babylon and 1X10 9 gal (4X10 6 m 3 ) at Islip. Differences in quantity of water in the plumes and length of the plumes may result partly from a slower rate of refuse accumulation at Islip than at Babylon; however, the rate of travel for the front of the Islip plume is considerably less than the prevailing groundwater velocity would indicate. Distance traveled by the front of the Islip plume was roughly one-third the distance indicated by the calculated minimum ground-water velocity and may result from greater vertical travel distance in the upper glacial aquifer at Islip. Concentrations of HCO 3 - , Cl - , and SO 4 - 2 in the leachate-enriched ground water are higher than those in ambient ground water. Concentrations of Fe and Mn in the plumes are as much as 400,000 μ g/1 and 200,000 μ g/1, but concentrations of other metals, including Zn (220 μ g/1), do not exceed the U.S. Public Health Service drinking-water standards. The concentration of NH 4 + , the predominant nitrogen species in plume water, is usually more than 10 percent of the total cations in plume water and is greater than NH 4 + concentrations in ambient ground water; concentrations of NO 3 - in plume water are less than those in ambient ground water at Babylon and at some locations in Islip.

New York↗