Health Services

Private Well Water Testing Program



To help residents with private wells determine the quality of their drinking water, the Suffolk County Department of Health Services operates an extensive water testing program. There are an estimated 40,000 to 45,000 individual private wells serving over 200,000 people in Suffolk County. Due to the large number of requests that the county receives for water analyses, there is a charge for the service.



In the past, the news media has provided volumes of coverage to incidents of groundwater contamination. Some people may have gotten the impression that our entire water supply is contaminated. In fact, the media coverage of well contaminations is news because most residents have high quality drinking water and want it to stay that way. There are many laws and programs designed to help preserve and protect the region’s groundwater supply.

Although testing by the department has discovered many instances of severe well water contamination, not every private well has a problem. Our analyses show that the majority of wells tested in Suffolk County meet drinking water standards that have been set for health-related reasons. Of course, natural waters sometimes contain constituents such as iron and manganese which can be objectionable aesthetically, but are not normally considered harmful to health.

The only way to determine the quality of a private well is to have the water tested. When a nearby well is found to be contaminated, it does not automatically mean that your well is similarly contaminated. The complexities of the hydrogeology of the area necessitate the sampling of each individual well to determine water quality.

On the request form, you are asked to supply your family physician’s name and address so that he or she can be informed of any problems with your water supply and can include this information in your medical records.





What will my well water be tested for?

Your water will be tested for basic potability including those chemical parameters that have been found to frequently occur in past testing by the department. Analyses usually performed are: microbiological quality, inorganic chemical content, volatile organic compounds and petroleum derivatives. If you live in an agricultural area your water can also be tested for carbamate pesticides.

How often can my water be tested?

Due to the great number of private wells in the county and the extensive analysis performed, the department reserves the right to limit the frequency of which your well can be tested. You can have your water tested by a commercial laboratory at any time. The county will test only your primary drinking water well, requests to test irrigation wells cannot be honored.

What if I have a water filter?

The county does not encourage the use of water filters which do not meet New York State or Suffolk County standards. Usually the raw or unfiltered water will be tested unless the department or applicant has requested otherwise.

Can I deliver a sample of my water to speed up the process?

No. The sample must be collected by department personnel according to proper sampling protocol in specially prepared containers and in accordance with procedures established for quality control.

What should I do until my water is tested?

If you are unsure if your water is safe for consumption, use bottled water or water from an approved public supply until the analysis is complete. It takes several weeks before you are notified of your results. A letter explaining the analysis will be mailed to the address indicated on the request form.

What if I am selling my home and need a water analysis right away?

For homes involved in a resale, it is suggested that a commercial laboratory be used. The department cannot ensure that you will receive test results in time to meet contract or closing dates.

I work during the day and cannot be home to wait for sample collection.

A sample can be collected from an outside tap or hose bib if one is available. Locked fences or loose dogs sometimes prevent sampling. Be sure the electric is on so that the water pump may be run for a few minutes to flush any stale water from the lines.

What can I do if my well water is contaminated?

The department will suggest some possible remedies depending on the type and amount of contaminants detected. However, the department cannot mandate any public agency to take corrective action, extend public water or supply bottled water to you. Generally, the owner of a private well is responsible for his own water supply. In severe cases of contamination financial aid may be available from federal (USEPA) or state (NYS DEC) programs. If you are a tenant, your landlord may be responsible for providing a potable water supply.


For more information, contact the Bureau of Drinking Water at (631) 852-5810