1. Locate your well
Your well may be somewhere other than where your pump or pressure tank is. Most wells have a 4- to 8-inch diameter metal pipe (called the “casing”) lining the hole. In some older wells, the casing doesn’t reach the surface and the wellhead is underground. If you have an underground wellhead or one that is less than 12 inches high, your well water may be at greater risk of contamination from surface runoff. To prevent contamination, a well professional can extend your wellhead to be 12 inches above the surface of the ground to ensure that runoff is diverted away from the well area.
Locate all wells around your home; inactive wells that have not been properly sealed are very risky. Order and install a free well identification number for each well from the Oregon Water Resources Department (WRD). For information on abandoning wells or to order well logs, contact the Oregon Water Resources Department.
2. Locate your septic tank
Your septic tank collects and begins processing human waste as it leaves your home. Use a map of your property to find your tank. If you don’t have a property map, your county building or health department or the Oregon Department of Environmental Quality may be able to provide one with the location of your septic tank. If you can’t find or get a property map, follow the discharge pipe from your house to locate your septic tank. A septic professional can also use tools to locate the tank and help determine its size.
3. Locate your drain field
The drain field is a set of underground pipes that distribute waste water from the septic tank through the soil (Figure 1). Drain field replacement is very expensive. Locate this area to avoid accidentally damaging it. Prevent damage to your drain field by keeping vehicles, heavy equipment and large animals away from it. Wet spots in this area could indicate failing systems that need professional attention. Do not irrigate, add to or remove surface soil in the drain-field area. Only grass should be grown over a drain field. During the dry times of the year, the green stripes of lawn over the field may be obvious.
4. Test your water
Water from household wells should be tested every year for coliform bacteria and nitrate. You can order additional tests if you suspect other contaminants. Check prices before ordering tests. A list of state-certified drinking water labs and information on water testing are available from your county health department, Oregon State University Extension Service or the Oregon Domestic Well Safety Program.
5. Pump your septic tank
Check online directories for septic tank pumping services. Pumping frequency depends on your household and septic tank size. Typically, a four-person household needs to pump about every three to four years. OSU Extension Service or your pumping company can provide additional guidelines. Regardless of a manufacturer’s claims, there is no evidence that septic system additives eliminate the need for regular pumping. Some additives may also be harmful to the beneficial microorganisms in your septic system or to groundwater. Neglecting septic system maintenance can result in backed-up sewage, expensive repairs and contaminated surface seepage that can pollute your well water.
6. Use water conservation measures
By using water-conservation measures, you reduce the need for constant recharge around the well’s pumping zone, which reduces the amount of time water is held and treated in the soil. Contrary to common assumptions, your septic system functions better if less water goes down your drain.
7. Clean out your well house
Store all potentially harmful products, such as fertilizer, pesticides and fuels, away from the wellhead. Spilled chemicals can reach your well water by entering through the top of the casing or by wicking through the soil down the outside of the casing. Well houses are great for storing nonhazardous items.
8. Ensure that your well is capped and has an adequate sanitary seal
The sanitary seal prevents foreign objects and surface water from entering your well. If the top of your well is not securely sealed or capped or both, a pump or well professional can provide parts and advise you how to proceed. In some cases, the sanitary seal supports the weight of the well pipe and pump replacement can be technically difficult. If your well is sealed, do not disturb it, just check that the vent screens are in place and the sanitary seal is not broken. See Figure 2 for inspection points. Vent screens prevent entry of insects, spiders and other foreign objects.
9. Install backflow prevention devices on all outdoor faucets
In some cases, water can siphon backwards through a hose and down the well. This is especially serious if a chemical sprayer is attached to the hose or if the hose end is under water, such as in a bucket. If you don’t have backflow protection on your water supply system, add an inexpensive, screw-on, brass atmospheric pressure breaker to each faucet. These are especially important for faucets used for irrigation, livestock trough water, chemical mixing and pressure washing.
10. Limit your use of lawn and garden chemicals
Excess fertilizer moves easily through the soil to the groundwater and contributes to excess nitrate levels in groundwater. Apply lawn fertilizer sparingly and follow the label directions. Remember: The label is the law. Don’t store or mix pesticides and fertilizers where spills can enter the soil and eventually reach the groundwater that supplies your drinking water.
11. Protect the soil from contamination from oil, gasoline and household chemicals
Contact your local waste-collection company about oil recycling and hazardous waste disposal programs. Dispose of motor oil, gasoline, furniture polish, cleaning fluids, paint thinners and other chemicals as advised. Never dump these items on your property and never pour them down the drain. Refuel equipment over an impermeable surface so spills do not reach the soil. Repair leaks. For information on removing underground fuel tanks, call the Oregon Department of Environmental Quality at (800) 452-4011.
12. Shield animal waste from rain
Animal pens and piles of composting manure are sources of bacteria and nitrate that can contaminate your drinking water. Take steps to prevent runoff and soil seepage. Ideally, manure piles should be on a covered concrete pad, but covering piles on the ground with a simple tarp during the rainy season helps reduce potential contamination of groundwater.
Resources
OSU Extension resources
- OSU Extension Service Well Water Program
- Keeping your well water well / Agua limpia en su pozo (EM 8752)
State and national well water resources
About the authors
