NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

April 8, 1999

Spring Tips to Keep Your Well Water Safe from Contamination

Spring rains and the resulting excess surface water can put well water at a higher risk for contamination, according to a North Dakota State University water quality expert.

"Farmers and other rural residents with private drinking wells should monitor their drinking water closely during springtime," says John Nowatzki, a water quality associate with the NDSU Extension Service. "A short assessment of rural well sites can identify steps that will help reduce the risk to drinking water."

Colors or off-tastes in the water often indicate contamination, Nowatzki notes. If you suspect your well water has been contaminated, you can have your water tested by the North Dakota Department of Health. Containers to use for submitting a sample and a list of procedures to follow are available at county extension offices.

A well site assessment checklist is available on the Internet at the home page for NDSU's Department of Agricultural & Biosystems Engineering (www.ageng.ndsu.nodak.edu/EXTEN/farmstead.html).

"Learning to recognize potential sources of contamination on farmsteads can be a first step in protecting well water, Nowatzki says. "People who live in areas with sandy soils or where the water table is within 20 feet of the surface should be particularly concerned. These conditions increase the risks of groundwater contamination."

Practices around the well also have an important effect on well contamination, he notes. For example, chemical and fuel storage, livestock enterprises and household waste disposal all have the potential to contaminate wells depending on proximity and management. Well depth also is an important factor to consider when assessing the potential for well contamination. Large diameter wells that were hand dug tend to be most easily contaminated. Driven wells also provide higher risk for groundwater contamination because they normally are not grouted around the casing. Older wells can be a higher contamination risk to groundwater because of structural problems such as collapsed casings or casings with holes.

Depressions around well casings can provide a sink for surface water to accumulate. Contaminants in the surface water can leak down around the casing or pass through cracks in the casing.

The well casing needs to project at least 12 inches above ground level, Nowatzki says. In areas subject to flooding, the top of the casing must be at least 2 feet above the highest known flood elevation.

Some specific potential contaminant sources must be at least 50 feet from a well in North Dakota. They include septic tanks and drainfields, barnyards, feedlots, lakes, streams, sloughs and ponds. Wells must be at least 30 feet from sewer lines, 20 feet from overhead power lines, and 10 feet from basements or pits.

Abandoned wells present a serious threat to drinking water wells, Nowatzki says. They provide a direct conduit for contaminants to enter the groundwater. These unused wells should be properly sealed to eliminate that risk.

For more information or technical assistance on assessing the risk to groundwater on your farmstead, contact your county office of the NDSU Extension Service.

###

Source: John Nowatzki (701) 231-8213

Editor: Tom Jirik (701) 231-9629