Site Selection for Private Drinking Water Wells

Several state administrative agencies have regulations, adopted under state law, which pertain to the on lot location of private water wells. The fact that these regulations are promulgated by more than one agency has created confusion in the past. This fact sheet outlines those applicable laws and rules to provide a reference document for water well contractors and the public.

The requirements in this document only pertain to private wells. Wells regulated as a public water supply as defined by RSA 485:1-a, XV must comply with additional requirements as specified in Env-Ws 372, Env-Ws 373, Env-Ws 378, and Env-Ws 379.

The New Hampshire Department of Environmental Services regulates site selection of private wells under RSA 485-A:30-b and associated rule Env-Ws 1008.05 through Env-Ws 1008.11. This law establishes a protective well radius for all wells, and is administered by the DES Subsurface Systems Bureau through the design and approval program for on-site wastewater disposal systems. The protective well radius is a uniform circle around the well, which establishes a setback distance from property lines and septic systems, and has a radius of 75 feet for design flows up to 750 gallons per day which is equivalent to a five-bedroom home. Protective well radii increase with design flows according to the following table:

A protective well radius is a uniform circle having the designated radius as specified above. For new wells, the protective area is required to be maintained wholly within the property boundaries of the lot to be served by the well. However, protective well radii may overlap onto other lands such as: land that is protected by a recorded easement, land that is permanently dedicated to a use that precludes development, or on land within a municipal property line septic system setback.

Examples of lands that are precluded from development include: wetlands, surface waters, roads, and protected conservation lands where the deed precludes development of buildings or subsurface waste disposal systems within the affected area.

Municipal property line septic system setbacks are minimum setback distances from septic systems to property lines established by local ordinance. Many towns in New Hampshire have setback criteria that differ from the 10-foot state requirement. These setback distances may vary from town to town.

All approved septic system site plans must indicate the location or proposed location of the well, or designated area within which the well will be located and the protective well radius. The property owner is required by law to provide the water well contractor with a copy of the approved site plan showing the location of the well, and the water well contractor must ensure, to the best of his ability, that the well is installed in accordance with the approved plan.

When a well cannot be installed as shown on the plan due to obstacles of a permanent nature, and the well radius cannot be maintained on-lot or in an area precluded from development on abutting property as described above, the water well contractor shall advise and consult with the property owner, or the owner’s agent, on the best possible alternative location. Using a standard release form the water well contractor shall alert the owner to the consequences of the alternate location and obtain a written acknowledgement that the consequences are understood prior to constructing the well.

Obstacles of a permanent nature include: buildings constructed prior to the installation of the well, or natural topography such as ledge outcrops or ravines, which prevents the well construction equipment from being brought to the designated location.

Standard release forms are available from the DES Subsurface Systems Bureau at (603) 271-3501 or the Public Information Center at (603) 271-2975.

Setbacks from Water Lines

DES requires separation distances from septic system components to water supply lines. These setbacks are found in Env-Ws 1008.04:

Where a water line must cross a sewer line, the sewer line is required to be at least 18 inches below the water line, unless the water line is encased in concrete or pipe having an SDR rating of 26 for a distance of 10 feet either side of the sewer line.

Stump Dumps

The burial of on-site tree stumps is not considered solid waste by DES under RSA 149-M:4, XXII, “provided that such burial locations are not located within 75 feet of a drinking water supply.” Therefore, on-site stump dumps are not regulated by DES as solid waste. The statutory language clearly contemplates, however, that wells be located at least 75 feet from stump burial sites.

Unfortunately, site clearing operations are usually complete at the time of well construction and site plans do not indicate where stumps are buried. This regulatory oversight is unfortunate and should be reviewed by state and local planners. Local planning boards may be the best avenue to pursue this problem.

Buried stumps in close proximity to wells can cause taste and odor problems and these problems will continue to worsen once the material starts to decay. These water quality problems are very difficult, if not impossible, to filter out once they have occurred. The best remedy in this case is prevention. Water well contractors should inquire about stump burial locations as a matter of good practice, and particularly if site conditions indicate that the drill site has been filled or disturbed.

New Hampshire Water Well Board

The New Hampshire Water Well Board regulates the construction of water wells and is the licensing authority for water well contractors and well pump installers. It is administratively attached to DES. The board is mandated under RSA 482-B to establish standards for the construction, maintenance, and abandonment of water wells, which includes well siting considerations. Regulations adopted by the Water Well Board include We 100 through We 1000.

We 602.05 establishes setback distances from wells to sources of contamination:

Septic systems – Wells are required to be located with a minimum separation distance of 75 feet from septic tanks and septic system leach fields. The setback distance to septic tanks may be reduced to 50 feet, however, if the sewer pipe has a minimum rating of SDR 26 and the tank is sealed and grouted.

Livestock pens – The setback distance from wells to livestock pens is dependent on the type of construction. Shallow wells constructed in unconsolidated materials by excavation must not be located closer than 100 feet from a livestock pen, and should be constructed upslope wherever possible. The standard setback for drilled wells is 75 feet. However, drilled wells may be located up to 20 feet from a livestock pen, provided that the water well contractor obtains a written acknowledgement from the property owner using a non-conforming well location form, and utilizes special methods of construction to provide additional protection from contamination.

Areas Subject to Standing Water – Shallow wells constructed by excavation, commonly known as dug wells, must not be constructed in areas that are subject to standing water during parts of the year.

Surface Waters of the State – For private wells, there are no required setback distances to lakes, ponds, rivers, or streams. However, for wells constructed as a supply source for a public water system, setback distances do apply. See Env-Ws 372, Env-Ws 373, and Env-Ws 378.

Non-Conforming Well Location Form – Where site conditions prevent compliance with the setback requirements of the Water Well Board or where a well is located closer than 75 feet from any observed source of contamination, water well contractors are required to take the following steps:

1. Alert the property owner of the potential for contamination at the proposed location.
2. Obtain a written acknowledgement from the property owner, prior to construction of the well, using the non-conforming well location form, that the potential consequences of the location are understood.
3. Utilize special methods of construction to provide additional protection from potential pollution.

Special methods of construction usually includes one or more of the following applications:

1. The installation of additional well casing, than would normally be used, into the bedrock formation to provide added insurance against surface water leakage into the well.
2. Installing no less than 40 feet of casing where the depth to bedrock is less than 20 feet from the ground surface.
3. Sealing the space outside the well casing, between the casing and the larger diameter hole in the ground, with grout material.

Non-conforming well location forms must be signed by both the water well contractor and the property owner and are available from our web page at www.des.nh.gov/wwb or from the Public Information Center at (603) 271-2975 or from the NH Water Well Board office at (603) 271-1973.

Please note: This form should not be confused with the standard release form previously referenced, which is used when a well encroaches on a property line.

Standard Release Forms are used in accordance with RSA 485-A:30-b and DES rule Env-Ws 1008.09. The form is signed by, and is the responsibility of, the property owner.

Non-conforming Well Location Forms are used in accordance with NH Water Well Board rule We 602.05. The form is the responsibility of the licensed water well contractor and is signed by the property owner and the water well contractor.

New Hampshire Department of Transportation

Setback from Roadways

The Department of Transportation administers a private well program to replace, repair or pay damages for water supplies that have been destroyed or rendered unfit for use as a water supply resulting from construction or maintenance operations on the state highway system. Many of the wells that qualify under this program have been contaminated by the application of road deicing chemicals.

RSA 228:34 mandates that the Commissioner of the DOT may not authorize the use of state highway funds when it is determined that the well is located closer than 50 feet to a highway right-of-way or drainage ditch or where the location does not allow or provide for adequate surface drainage.

This statute does not prohibit the construction of a well closer than 50 feet from a state highway right-of-way or drainage ditch, but it certainly does limit the rights of property owners to receive compensation for damages from road salt contamination if it occurs. Therefore, it is recommended that wells be located at least 75 feet from all property lines, including the boundary abutting the road. Furthermore, wells should not be located in areas subject to road drainage or in areas designed to accept accumulating road runoff.

Local Regulations

In addition to State regulations, some municipalities in New Hampshire have adopted local regulations pertaining to on lot setback distances for private wells. Contractors and property owners should contact the local building code official to inquire if additional well siting criteria apply.

Planning for the Future

Many existing homes and cottages in New Hampshire have older or outdated septic systems, which may need to be replaced in the future. When considering options for selecting the location for a new water well, contractors and property owners should also consider the likelihood of having to replace the on site waste disposal system in the future, and where that system would have to be located. This area should then be eliminated from consideration as a possible site for the well. Planning for the future in this way could prevent major headaches and expense down the road.

For Additional Information

Please contact the Drinking Water and Groundwater Bureau at (603) 271-2513 or dwgbinfo@des.state.nh.us or visit our website at www.des.nh.gov/dwgb. All of the bureau’s fact sheets are on-line at www.des.nh.gov/dwg.htm.

Note: This fact sheet is accurate as of January 2007. Statutory or regulatory changes, or the availability of additional information after this date may render this information inaccurate or incomplete.