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Walter Dawydiak



 360 Yaphank Avenue
Suite 2B
Yaphank, New York 11980

(631) 852-5800

Fax: (631) 852-5825

Environmental Quality

The Division of Environmental Quality (DEQ) conducts comprehensive programs that protect Suffolk County residents against adverse environmental factors. DEQ programs also preserve and enhance the generally high quality of the Suffolk County environment.

The major programs of the Division of Environmental Quality are groundwater and drinking water protection, wastewater management, toxic and hazardous materials pollution control, monitoring and laboratory analyses, enforcement of regulations, and environmental management studies and programs for groundwater and surface waters, including related ecological issues. These programs are managed through the five offices of the division: Water Resources, Pollution Control, Wastewater Management, Ecology, and the Public and Environmental Health Laboratory.

The Division’s Board of Review hears requests for variances and waivers, meeting on the third Thursday of every month, with the exception of December, when the meeting is on the second Thursday of the month. A listing of each month’s scheduled hearings may be obtained by contacting the division at 852-5800. On alternate Thursdays, voting for previous hearings may be recorded.

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In response to the growing water quality crisis facing our county, the Suffolk County Department of Health Services has developed an historic solution to address nitrogen pollution through the development of a countywide wastewater upgrade strategy. A Reclaim Our Water initiative, the strategy is documented in the Suffolk County Subwatersheds Wastewater Plan (SWP), which was developed in partnership with the Long Island Nitrogen Action Plan (LINAP) and in collaboration with numerous project partners, stakeholders, and technical experts. The SWP is the product of years of intensive research, documentation, modeling, and evaluation of all of Suffolk County’s water resources and provides a parcel-specific roadmap on how to address the nitrogen crisis through wastewater upgrades and other nitrogen pollution mitigation strategies. The plan seeks to arrest and reverse the existing trend of degrading water quality over a 10 year period by transitioning away from reliance on conventional cesspools and septic systems, which are the primary source of nitrogen pollution that has fouled local bays.

The Draft SWP was released in August 2019, along with a Draft Generic Environmental Impact Statement (DGEIS) for the actions proposed in the SWP, which was subject to a two month public comment period. A revised SWP and a Final Generic Environmental Impact Statement (FGEIS) incorporating public comments and comments received by the Suffolk County Council on Environmental Quality (CEQ) was posted in February 2020. The revised SWP, as well as the DGEIS, FGEIS and related State Environmental Quality Review (SEQRA) documents are available at the CEQ website here.

After minor revisions, the New York State Department of Environmental Conservation (NYSDEC) has also approved the Suffolk County SWP as a Nine Element (9E) Watershed Plan. The 9E program is designed to encourage municipalities to develop watershed based plans for improving water quality including nine key elements (refer to the NYSDEC website for more details on 9E plans). “The County’s 9E Plan is the first of its kind, as it addresses nitrogen pollution throughout an entire county.” said James M. Tierney, Deputy Commissioner of the NYSDEC. This historic first will open the County’s watersheds up for additional State and Federal funding opportunities to advance water quality improvement initiatives.

The final SWP incorporating minor revisions to satisfy the requirements of the 9E Watershed Plan program was published in July 2020. Please click on the following links to download the full July 2020 SWP and appendices, and obtain additional information on the SWP:

Click here to download the final July 2020 SWP.

Click here to download the final July 2020 SWP Appendices (> 600MB File).

For additional information, visit the SWP Page on the Reclaim Our Water website.

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The SCDHS has issued the final report on the Grand Canal Ecological and Public Health Assessment. For the document summary, full report, and appendices, please click on:

suffolk county comprehensive water resources management plan

Click here for the Suffolk Comprehensive Water Resources Management Plan

Click here for GIS Marine Water Quality Data


On December 29, 2017 the Suffolk County Department of Health Services adopted revised Standards for the management and approval of I/A OWTS along with significant revisions to the residential and commercial construction standards, which define the requirements for the design and construction of I/A OWTS. In addition, as of January 19, 2018 SCDHS has certified five (5) I/A OWTS technologies for Provisional Use. Copies of the Sanitary Code, Standards and other useful I/A OWTS documents can be found here:


Suffolk County Department of Health Services (SCDHS) has approved three (3) new sanitary technologies, the NitrexTM System, Aqua Point – Bioclere®, WesTech’s STM-AerotorsTM, as capable of attaining 10 mg/L for total nitrogen for systems between 1,000 gpd and 15,000 gpd.  These systems join the list of previously approved technologies which include, Cromaglass, Biologically Engineered Single Sludge Treatment (BESST), Sequencing Batch Reactor (SBR) and Membrane Biological Reactor (MBR) which qualify for a reduced separation distance of 75 feet under SCDHS standards for systems of 15,000 gallons per day (gpd) or less.    A new sanitary system study is currently in the planning phase to further examine small systems, under 1,000 gpd, with a 50% nitrogen removal criterion.

Please contact us for more information about the individual task summary reports.


In 2012 there were 195 sewage treatment plants (STP) operating in Suffolk County.  These plants are regulated under the terms and conditions of a State Pollution Discharge Elimination System (SPDES) Permit.  In 2012, Suffolk County Department of Health Services (SCDHS) performed inspections of all of the aforementioned STPs under its jurisdiction.    Out of 195 STPs, 168 plants are capable of reducing BOD5 (Biochemical Oxygen Demand), SS (Total Suspended Solids), and N (Total Nitrogen) and are categorized as tertiary plants and 27 plants are capable of reducing BOD5 and SS only and are categorized as secondary plants.

Please contact us for more information about complete 2012 Performance evaluation report.

Suffolk County Government

H. Lee Dennison Bldg

100 Veterans Memorial Hwy
P.O. Box 6100
Hauppauge, NY 11788

Riverhead County Center

County Road 51
Riverhead, NY 11901