Rural Well Water and Sanitation—101

By Catherine Dalziel

City folk envy our freedom from water and sewer bills. Do we really get a free ride?

Hardly. Relying on well water for drinking, cooking, the toilet, the shower and laundry, among other household needs, and relying on a septic system for sewage, is not the bargain people with municipal services assume. For one, what happens when the electricity goes out!

NO WATER. In the blip of a watt you are out of luck and quickly out of the shower. And how about when you turn on the spigot and nothing comes out...and the electricity IS on?

Do you just turn on the tap and drink freely, trusting that someone is supervising your water’s potability? First off, what is “potable water”? Webster’s defines it as water suitable for drinking. That’s pretty ambiguous. Contaminants that may be in untreated water (our well water) include microorganisms such as viruses and bacteria, inorganic contaminants such as salts and metals, pesticides and herbicides, organic chemical contaminants from industrial processes and petroleum use, and radioactive contaminants.

Bacteria and Herbicides and Salts —Oh my! Yes, there are numerous contaminants lurking about, but to test for all of them is unrealistic. The good news is that small amounts of some contaminants are not threatening; testing for coliform bacteria and nitrates will provide you with a good idea of the overall condition of your water.

Coliform bacteria are carried in the feces of warm blooded animals, and can be present in water, soil, and on vegetation. Nitrates are water soluble salts that can enter aquatic systems through surface runoff from agricultural or landscaped land on which more nitrate fertilizer has been applied than can be taken up by plants (a common occurrence, as gardeners and farmers apply a bit extra “just for good measure.) Don’t use fertilizer and think you’re in the clear? Guess again. Nitrates are also a by-product of farming and of septic systems, remaining after the decomposition of animal or human waste.

So, just what is the connection between your well water and septic system? On the Ridge, most of us dispose of waste into a septic system. You flush your toilet and the contents, solid and liquid, leave the house and travel to an underground septic tank (Its size is generally determined by the number of bedrooms in the home.) for digestion.

In the septic tank, solids separate from liquids. The solids settle to the bottom where they gradually decompose by means of bacteria. Liquids flow into the drainfield (or leachfield). It takes about 24 hours for solid waste to break down. Some solids do not decompose, forming a sludge that must eventually be pumped out. Also, light solids, such as soap suds and fats, float to the top and form a scum layer; over time, it thickens and must also be pumped out. If solid wastes overwhelm the digestion process, the septic tank can become full, requiring pumping. The frequency of pumping depends on the size of your tank and the number of people in the home. Not pumping when necessary can cause contaminants to overflow and leach into the ground, and into the groundwater. Another problem occurs when the bacteria necessary for the digestion process are destroyed by paints, motor oil, pesticides, fertilizers or disinfectants or caustic drain cleaners. When this happens the tank fills with undecomposed waste.

The following is a quick primer to ensure the health of your well water:

  1. Know the location of your well, septic tank, and drain field.
  2. Be aware of old cisterns and shallow wells from earlier occupants of your land.
  3. Inspect your well every year. Ensure that the vent pipe is screened, the cap is secure, there are no cracks or holes in the casing, and surface water is not pooled at the base.
  4. Test your water every three years. “It tastes and looks okay” is not an accurate test. Some contaminants do not affect water’s color or taste. See below for testing sources.
  5. Keep contamination sources away from your well. Don’t store chemicals in your pump house. Keep fuel tanks, pesticides and manure piles at least 50 feet away and downhill from the well.
  6. Know how often your tank needs pumping. “Septic Tank Maintenance” published by the OSU Extension Department provides useful information on this.
  7. Keep heavy animals and vehicles off your drainfield, watching for wet spots/odor.
  8. Avoid planting anything but grass above the drainfield. Roots from trees and shrubbery above the drainfield may infiltrate and clog the holes in drainfield pipes.
  9. Playgrounds and storage buildings may damage a tank and drainage field. In addition, covering the drainfield with an impervious surface, such as a driveway or parking area, will seriously affect its efficiency.
  10. Excessive water entering the system will overload it. Check for plumbing leaks and practice water conservation.

What not to put into your septic system:

  1. Cooking oils and grease, which can fill the upper portion of the septic tank and cause the inlet drains to block, creating odor problems and difficulties with emptying.
  2. Non-biodegradable hygiene products such as sanitary towels and cotton buds, which will rapidly fill or clog a septic tank. Dispose of them elsewhere!
  3. Food; garbage disposals can cause a rapid overload of the system and early failure. Compost kitchen waste instead. If you do use a garbage disposal, your tank will need more frequent emptying.
  4. Certain chemicals, especially pesticides, herbicides, materials with high concentrations of bleach or caustic soda (lye), or any other inorganic materials such as paints or solvents.

You can test your water for free. Order a list of certified labs from the Oregon Health Division by calling 503-731-4317.

For a wealth of information about wells, septic systems and groundwater health, see the Oregon Well Water Program, or call 800-561-6719 or 541-737-2513 and ask for publications related to wells and septic systems.