The Office of Water Resources is empowered by the federal Safe Drinking Water Act (SDWA), and the New York State and Suffolk County Sanitary Codes to enforce regulations controlling 39 Community Water Supplies (CWS) and 254 Non-Community Water Supplies (NCWS) in Suffolk County. The public water suppliers serve more than 90% of Suffolk County's 1.45 million residents. As a federally designated Sole Source Aquifer system, the quality and quantity of the county’s groundwater are monitored and the numerous hydrogeologic conditions that affect the water supply are studied. Special investigations are often conducted in cooperation with other government agencies and universities such as the Pesticide Monitoring Program and Long Island Breast Cancer Study. Recently completed was a major project, the Source Water Assessment Program (SWAP) for Long Island, an assessment of land use activities utilizing complex computer modeling that affect the watershed areas for all public water supply wells. Building on the SWAP findings, the Comprehensive Water Resource Management Plan for Suffolk County will be updated. The revised Plan will evaluate policies and practices for water resource management and possible new approaches for protection of our Sole Source Aquifer and surface waters and will assist in supporting “Smart Growth” and “Workforce Housing” initiatives.

Water Level Monitoring Wells Map

Protection of the quality of the public drinking water supply is accomplished through integrated activities that begin with reviewing plans for proposed water supplies, conducting inspections of wells and treatment facilities, certifying water supplier operators, and overseeing daily operations. Technical assistance and continuing education are provided to public water suppliers to keep them informed of regulatory changes and monitoring requirements of the SDWA.

There are more than 1,100 active public water supply wells in Suffolk County and sampling is routinely conducted for a wide range of potential contaminants. Monitoring is performed of both the raw water quality from the wells that feed the water supply to the distribution system, and of the finished treated water at the point-of-use. A single water sample may be examined utilizing a dozen analytical methods for more than 300 microbiological, chemical and radiological parameters. The extensive surveillance monitoring of the distributed water helps insure compliance with all water quality standards and reduces water quality complaints from customers. Oversight monitoring performed by the bureau is in addition to the self-monitoring mandated of all public water suppliers by the SDWA.

The office has been in the forefront nationally concerning the issues of new and emerging drinking water contaminants. Development of federal and state drinking water regulations often take years from the recognition of the problem implementation of compliance requirements for public water suppliers. Analytical methodologies are developed in response to evidence of unregulated contaminants in Suffolk County groundwater. The NYSDOH has provided an annual grant of $252,000 for enhanced drinking water monitoring.

Drinking water sources in Suffolk County are tested for many chemicals years before federal or state regulations require such monitoring. Examples of these emerging contaminants include: pesticides, and their degradates such as aldicarb metabolites, TCPA and DEET; herbicide metabolites such as the OA and ESA breakdown products of alachlor and metolachlor; metabolites of simazine and atrazine; the gasoline additives MTBE and TAME; perchlorate, which is a pesticide and fertilizer contaminant and used as an ingredient in fireworks; and, personal care products and medications such as ibuprofen and gemfribrozil.     

Individual on-site private wells provide water to approximately 50,000 year-round and seasonal homes in Suffolk County. In areas that lack a public water supply system, comprehensive water quality testing is conducted at all new realty subdivisions proposed with private wells. The bureau also has a testing program for existing homes with private wells that provides a comprehensive water quality analysis and recommendations as necessary. When this monitoring discovers significant water quality problems that may affect other nearby wells, the bureau conducts a survey by testing those adjacent wells. No government agency in New York State provides a similar level of commitment to private well water quality.     

Private wells in agricultural areas are particularly susceptible to impacts from agricultural chemicals including fertilizers and pesticides. Since 1979 the bureau has conducted private well surveys for many pesticides that have impacted drinking water supplies. Several chemical manufacturers provide granular activated carbon filtration or other remedial measures for affected private well owners based upon the bureau’s findings.

For more information regarding the Private Water Testing Program.

Groundwater investigations and studies are conducted by the bureau to determine factors affecting water quality. Groundwater flow directions are determined by monitoring of water table elevations in hundreds of monitoring wells. Additional monitoring wells to delineate contaminant plumes are installed utilizing auger-drilling equipment for wells up to 300 feet deep, while shallow plumes are investigated using a Geoprobe. Geophysical conditions are determined by gamma and induction logs of the boreholes.     

The NYS Pesticide Reporting Law (1996) mandated a monitoring program throughout the state. On Long Island this study is being conducted by the bureau. A key part of the program has been the establishment of a county wide monitoring well network consisting of over 200 wells to monitor pesticide and nitrogen use associated with various land uses. The sample results from the pesticide monitoring network have identified 109 pesticides in our groundwater since 1997 with agricultural areas being the most heavily impacted. The results provide valuable data for several management and regulatory programs including the Comprehensive Water Resource Management Plan and the NYSDEC Long Island Pesticide Use Management Plan. An annual report on the findings is submitted to the state. Since 1997 the state has provided over $1.5 million to the bureau to fund the study.   

The reuse of abandoned commercial and industrial properties are facilitated through the Brownfields program. The bureau performs groundwater investigations at county owned sites to help determine the extent of clean up required.

The Suffolk County Groundwater Model was developed under a program managed by the bureau. This powerful tool was instrumental for conducting the SWAP analyses for every public water supply well. In addition, the model is capable of particle tracking analysis, and dual density (fresh/salt water interface) evaluations.     

The last update of the County’s Plan was completed in 1987. A new $800,000 effort, jointly funded with the SCWA, began in 2005, with completion at the end of 2008. This plan will make extensive use of the SWAP analyses to update regulatory water protection and water resource management alternatives. In addition, this update’s pilot studies will facilitate access to new groundwater modeling techniques for municipalities incorporating Workforce Housing & Sustainable Growth concepts into their land use plans, while assuring protection of our Sole Source Aquifer and coastal marine environment.

For more information regarding the Comprehensive Water Resources Management Plan.

Groundwater Investigations are conducted in response to findings of significant well contamination, to delineate the aerial and vertical extent of the contaminant plume, and to ascertain potential sources. For example, since 2002, over 80 vertical profile wells were installed in Speonk for an investigation of VOC contamination found in private wells. A plume measuring 1,000 feet wide and 2,500 feet long was delineated and the data provided the basis for a Superfund application that resulted in public water being supplied to the affected homeowners. Similar investigations are underway in the Hauppauge, Lindenhurst, Calverton and Easthampton.

The bureau provides oversight and assistance for the investigation and clean up of 60 state and federal Superfund sites. Often the complexities of the investigations and remedial actions take many years to complete, such as the radiological and VOC groundwater plumes at Brookhaven National Laboratory. The bureau also managed the Peconic River Health and Environmental Assessment study authorized by the county legislature.

Special studies are conducted, often in cooperation with pesticide manufacturers, to help determine the leaching potential of new pesticides. An on-going study with Bayer Corporation is examining the leaching potential of the widely used insecticide imidacloprid. Methyl isothiocyanate was used by LILCO to treat 16,000 wood utility poles on Long Island to protect them from rot. The bureau’s investigation determined that the chemical does not appear to impact groundwater.