YOUR PRIVATE WATER WELL
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 20mg/L of sodium
should not be used for drinking by people on severely restricted
sodium diets. More than 270mg/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.