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Private Well Water

Before the well is installed:

Establish a site for the well that will protect it from contamination:

  • Where possible, the well should be located uphill and a maximum possible distance from any potential sources of contaminants, such as pesticide or fertilizer storage areas, road salt storage, gasoline, and fuel oil tanks.
  • Surface water should drain away from the area of the well.
  • If possible, maintain the following minimum separation distances:
    • 10 ft to any building
    • 15 ft to property lines
    • 50 ft to septic tank
    • 100 ft to sewage system
    • 50 ft to stream, lake, or wetland

Use a well driller who is registered with the New York State Department of Environmental Conservation (DEC). A list of registered drillers can be obtained from the Tompkins County Health Department (TCHD).

Determine if there are any unused wells existing on the property. These wells should be properly abandoned to protect your ground water source from contamination. Please contact the TCHD for information on proper well abandonment procedures.

After installation:

The Tompkins County Health Department requires that a copy of the DEC well completion report (sometimes called the well log) be submitted to the above address. Please remind your well driller to do this.

  • The well casing should extend at least one foot above the ground surface (at least two feet above the 100 year flood elevation).
  • The ground surface immediately around the well should be graded to direct surface water away from the well.
  • The new well should be shock disinfected. This procedure is often performed by the well driller at the time of installation. The TCHD can also provide directions on how to shock disinfect the well.
  • Make sure the well is protected with a tight fitting, vermin-proof well cap or sanitary seal that is properly vented. The vent should face downward, be screened, and be at least 1 foot above the ground surface.
  • The water should be tested to establish safety of the new water source. This should be done after shock disinfection, when there is no longer any chlorine present in the water. Please refer to Table 1 for tests recommended by the TCHD.

Table 1: Individual Residential Well Water Supply Quality Testing

Test Maximum Contaminant Level (MCL)
Coliform bacteria Any positive result is unsatisfactory
Chloride 250.0
Lead 0.015 mg/L
Nitrates 10 mg/L as Nitrogen
Nitrites 1 mg/L as Nitrogen
Iron 0.3 mg/L
Manganese 0.3 mg/L
Sodium No designated limit **
pH No designated limit
Hardness No designated limit
Alkalinity No designated limit
Turbidity 5 NTU

– mg/L means milligrams per liter

– MCL defines the highest concentrations of contaminants allowed in public water supplies, as set by the New York State Health Department and the Environmental Protection Agency (EPA).

– NTU means Nephelometric Turbidity Units

**More than 20 mg/L of sodium should not be used for drinking by people on severely restricted sodium diets. More than 270 mg/L should not be consumed by people on moderately restricted sodium diets.

Also test for contaminants that might be located in your area. For example, test for volatile organic chemicals (VOCs) if oil, petroleum, or solvents are stored nearby or if there has been a spill, or for pesticides and herbicides if a well is located close to an area used for agriculture. Contact the TCHD if you have any questions.