Materials collected from workshop on Septic Tanks and Private Wells
Intro:
We attended a special workshop for homeowners on how to properly maintain septic systems and private wells on their property, how to prevent costly repairs, and how to protect drinking water from contamination. This workshop was presentd by the Washington State University Cooperative Extension and Clark County Health Department, and it was sponsored by Clark County Clean Water Program, and Clark Conservation District.
If you have questions or concerns about inspecting, servicing, or maintaining your septic tank or drinking well, please contact Reuel F. Emery, Clark County Health Department: 360-397-8084, or remery@swwhd.wa.gov
Materials include:
- Homeowner Septic System Checklist to record you septic system maintenance (click here to view – printable size)
- A Homeowner’s Guide to Septic Systems — EPA pamphlet on Septic maintenance (click here to view)
- Information on Clark Conservation District’s Manure Exchange Program for organic fertilizer (click here to view)
- Class notes taken during this workshop (below)
Class Notes:
Septic Tanks
A bulletin listed E.coli monitoring results for 12 Salmon Creek Checkpoints. Results ranged from only 2.0 to 131.7 E.Coli per 100 mls of creek water. (126 E.coli per 100 mls is the maximum standard for E.Coli concentration for safe human contact.) Only one of these Salmon Creek checkpoints was slightly above the standard, and the remaining counts were all less than 67.0. The stormwater outfall from Rosemere into Burnt Bridge Creek is 2400 E.Coli per 100 mls, a concentration that is far worse.
The workshop was funded by County residents who pay their Clean Water Fund fees.
Checklists are also available to evaluate private well water, water testing, and Septic System components, managing livestock to protect the water table, Roof Water Diversion to prevent flooding of septic systems, and other conservation materials.
The Health Department recommends the installation of protective collars for septic tank access points and private well heads.
To measure the depth of septic sludge in the tank, a 7-8′ stick is required, the bottom of which is wrapped in a white towel. It the sludge is mesured to be more than 1′ thick at the bottom of tank, it needs to be pumped. If it is less than a foot, then the tank is good for another four years.
During septic inspections, make sure all baffles are in place and are without cracks or breaks.
Septic solids can get into the drainfield and cause spillage.
10% of septic systems owners do not inspect their systems, and are therefore not in compliance.
If older systems fail, they can be replaced with a sand filter system.
Some septic systems have screens that get plugged up. These screens need to be cleaned at least every six months. They can become clogged with human hair in this time period, even from only two occupants.
There are approximately 40,000 septic tanks in Clark County.
Indicators of a failing septic tank:
- Slow draining toilets, sinks, tubs
- Sewage backs up into house
- Sewage is leaking from septic components
- Sewage is surfacing onto ground or in surface water
- Broken transport lines resulting from tree roots, blockages from foreign objects, or from driving over buried components with vehicles
An average septic tank system will last only 25-30 years. A new drainfield may be required during this time, or a pumping chamber may need to be added. A new septic tank can cost between $3000 and $10,000.
When inspecting the septic system, always were gloves and protective eye gear. Wash your hands throroughly after finishing inspection or service. Avoid breathing fumes or having direct contact with septic effluent, or illness can occur.
To inspect your system, you must first find the tank, open the lids, measure sludge depth, check and clean screens, check and replace baffles if needed, find the drainfield, and maintain inspection records (records to be filed with the County Health Department).
Make sure your home’s downspouts are not connected to the septic system. This does happen, and it can flood the septic tank.
An average septic tank will process 300 pounds of septic waste per day from toilets, showers, tubs, washing machines and dishwashers.
Septic tanks must now be set back 100′ from well heads.
A drain field averages 30′x70′, and a reserve area must be set aside if the drain field needs to be moved after 30 years of service.
Conserve water from overusing the system.
Do not build or drive over the drain field.
The Health Depeartment requires septic inspections every 4 years. A certified inspector can be referred by the Health Department (State law WAC 246-272 mandates septic inspections every 3 years)
Do not build a sprinkler system over the drainfield.
RNA asked why people are unaware they are even on a septic system until it malfunctions and spills septic sludge into the home? This has happened a lot all over town.
The Health Department answered by saying that there are many homes in Clark County that pay sewage bills, who think they are on the sewer system, but they are not. It is important to check title company records and health department records to know for sure.
Wells
Our drinking water comes from rain. It soaks down into the water table at the saturation point under ground.
Wells can be 25-700′ deep. They are drilled through the soil, into solid rock. They are set with a steel casing that is 6-8″ in diameter. There is an electric pump at the bottom of the well hole. Some pumps have lower water level shut offs to prevent the punp from burning out when the water level is depleated.
The seal around the well head must be sloped to prevent contaminants from leaching into the well (animal waste). Well heads can have cement collars placed around them to keep them safe.
Well heads are connected to pressure tanks, located in the garage of the house. During cold weather, keep the garage door closed to prevent the tank from freezing.
Clorox can be used to treat water contaminated with bacteria. There is a formula based on how deep the well is and how high the water column is. Contact the health department for directions. Do not over use Clorox. The well must run for several hours to expel the Clorox from the well.
Some well heads have GPS units that can be tracked by satellite.
Some Well heads are sealed with a bentonite casing that is water activated.
Some well set-ups have UV filters to kill bacteria.
The well head must be above the water line and all flood plains in order to prevent contamination. Some well heads are several feet above the ground level due to potential flooding.
Keep the well house clean and free of debris (especially chemicals). Note that mice consume insullation (around pipes). Mice can contaminate the well with their droppings.
Abandoned wells should be filled with chlorinated sand to prevent contamination of the water table.
There is a concern over arsenic contamination in North Clark County.
Private wells are at high risk for contamination if they are near gas stations, gravel pits or mines, landfills, dry cleaners, industrial sites, livestock pastures or oil or gas lines or drilling sites.
RNA asked if industrial spills like Boomsnub can threaten well water on private property.
Boomsnub, a Superfund Site, spilled toxic hexavalent chromium into the ground water. There are 11 Superfund Sites in the Vancouver/Clark County area.
The Health Department answered that such spills can cause serious contamination to wells, and costly repairs. It can even cause wells to be abandoned and make the water unsafe to drink. The Health Department and the Department of Ecology can help you determine if a toxic plume has contaminated your well water. They monitor such spills, and they also manage cleanup operations for spills that endanger the environment and the publics health. It can take many years to clean up such a spill.
