Protect Your Drinking Water – Simple Tips for Well Maintenance
Owning acreage often involves a few more chores than living in the city or suburbs. Many small acreage owners draw drinking water from a private well. Without some basic precautions, wells may allow pollutants into your water source. as the landowner, it is your responsibility to ensure your drinking water is safe. In order to ensure safe drinking water, landowners should regularly inspect and maintain their wells.
Locate Your Well
Wells may not be located near your pump or pressure tank. Start by looking for a four to eight inch wide metal casing, which may not reach the surface in older wells. Many well casings are enclosed in a concrete ring with a concrete lid. Unable to find the well? Try looking at well records posted online by the Washington Department of Ecology (see Resources at the end of this fact sheet). Be sure to locate all wells on a property since inactive wells, when improperly sealed, can lead to contamination of the groundwater supplying other nearby wells.
After you have located your well, check the distance between it and your septic tank and drainfield. If the distance is less than 100 feet, your septic system could contaminate the well water. Maintaining your septic system and having your tank pumped as needed extends the life of your drainfield and prevents septic effluent from tainting groundwater and other nearby water bodies.
Divert runoff, such as from gutters on homes, driveways, barns or other buildings away from your well since runoff may carry pollutants. Pesticides, fertilizers, gasoline and other chemicals should not be stored in your well or pump house. Locate manure piles, compost piles, and animal confinement areas at least 100 feet from your well; a greater distance may be required if you have sandy soils. Manure contains bacteria and nitrates which can contaminate drinking water on your property as well as your neighbor’s and even nearby streams and water bodies.
Regularly Inspect Your Well
Annually inspect key points on your well to prevent potential well contamination: vent pipe, the cap, the casing and the base (Figure 1). Ensure he vent pipe is screened to keep insects and rodents and replace worn screen that may have deteriorated over time. The well cap should be intact, with no large cracks or chips, and securely attached to the casing. The casing should be at least 6” above the ground, and also be free of cracks and holes. There should be no standing water around the base of the well. If needed, slope the ground away from the base to improve drainage.
It is too expensive for well owners to test all potential contaminants on a regular basis. Tests of a new well or a new home purchase should include a panel of all possible contaminants to establish an initial level for the well. Test your drinking water if you suspect a problem. Table 1 provides the most common pollutants in drinking water. Before sampling, contact the lab first to get sample procedures and containers. It is important to use the appropriate container for the type of sample you are collecting. Follow the laboratory’s instructions for collection and storage to avoid a contaminated sample. A list of certified labs is available online from Clark County Public Health, see the Resources section.
Results – What Do They Mean?
Once you receive the results back from the lab, check them against the drinking water standards set by the US Environmental Protection Agency (EPA). Table 2 shows the standards for some common contaminants. Always keep copies of all results to track changes in your well water over time. Three contaminants are described below:
While commonly found in the environment, these bacteria do not naturally occur in groundwater. Sources include surface water contaminated by human or animal waste leaking down into your well, a nearby shallow water source such as a stream or a pond, or objects such as deceased rodents entering an open well. A positive test result for coliform bacteria indicates the presence of bacteria in the water. It should not be consumed unless it has been boiled for at least three minutes to kill the bacteria.
Transported easily through the soil by water, nitrate can come from fertilizers, as well as human and animal wastes. If nitrate is found in your well water, look for potential sources in the vicinity, such as leaking septic systems, heavily fertilized lawns, or animal manures. Higher nitrate levels reduce the ability of red blood cells to carry oxygen throughout the body. Most adults and children red blood cells rapidly return to normal once the source is removed. However infants are more severely affected and may develop blue baby syndrome, a serious health condition caused by lack of oxygen. Boiling water will only increase the concentration of nitrate in the water. Nitrate cannot be removed through the use of filtration devices. More information on nitrate in drinking water is available from Washington Sate Department of Health; see Resources at the end of this fact sheet.
Adapted by Erin Harwood, WSU Clark County Extension (2008) – Updated 2020