Septic Information

Care for your Septic System Inside and Out

Learn how your system works and the signs of failure in a system. Below is a listing of the most frequently asked questions that we receive.

Should I use My Garbage Disposal?

No. Food does not easily break down in the septic tank. Find out how to compost food by calling 360.786.5445, ext. 7908.

What About "Miracle Additives"?

Avoid additives. They're not necessary. Don't be fooled by the ads that state "you'll never have to pump again!" Some chemical "cleaners" may contain harmful chemicals that can pollute ground and surface water.

Does It Matter Whether I Use a Liquid or Powdered Detergent?

No, but if you use powdered, choose a concentrate. Bulk, economy-size powders may have fillers made of clay that can clog the septic tank inlet.

How Can I Clean My Drains Safely?

Use gentle drain cleaners if drains get sluggish. Try pouring 1/4-cup baking soda and 1/4-cup vinegar down the drain, followed by a kettle of boiling water. Some strong concentrated drain-clog removers, in large amounts, can harm septic systems by killing the bacteria needed to break down human waste.

Why Should I Conserve Water?

Conserving water extends the life of your septic system. The less water you use the better. Try these tips:

• Install low-flush toilets and water-saving faucets and showerheads.
• Repair leaky fixtures promptly.
• Wash only full loads of dishes and laundry.
• Divert water away from the drainfield.
• Make sure downspouts, surface water, and sump pumps are not soaking your drainfield. If it gets too soaked, the drainfield loses its ability to remove pollutants from wastewater.

What Can I Plant on My Drainfield?

The best plants for over the drainfield are shallow-rooted ground covers, such as grass and wildflowers. Keep trees at least 30 feet away from the drainfield. For a list of appropriate plants, call 360.754.4111 and ask for the "Landscaping Your Drainfield" brochure.

Can I Make it Easier to Inspect My Tank?

Yes! Installing risers makes it easier to inspect and pump your tank. This not only makes it easier to find your tank opening, it saves the time (and expense) of digging.

How Can I Protect My Drainfield?

Install an effluent filter to protect your drainfield. This keeps sludge and scum from moving into the drainfield. A pumper can install it. Expect to pay around $200 to $300 for installation of a high-quality filter.

How Does Pumping My Tank Save Me Money?

Over time, sludge builds up and needs to be pumped out. If sludge isn't pumped out, the buildup can cause your drainfield to clog, and the system to malfunction. It's easy to see below that an investment in pumping your system will save you money.

• Inspecting a tank usually costs less than $100.
• Pumping typically costs between $185 and $375.
• Replacing a drainfield can cost between $2,000 and $10,000.
• If you can't dig down to the tank yourself, you can pay the pumper to uncover the tank. This costs between $75 and $200, depending on the depth of your tank.
• Pumping out a chamber usually costs between $10 and $250. Prices vary. Get estimates from several pumpers and check with friends and neighbors for recommendations.

What Should I Know About Pumping?

Consider the following tips when having your septic system pumped:

• The pumper should pump both compartments. All tanks installed after the mid-1970s should have two chambers.
• The contents should be pumped out through the main lids, not the baffle (the pipe that goes down into the liquid).
• The tank should be thoroughly emptied from both compartments and rinsed out; there is no need to leave "starter" material behind.
• On the outlet of newer systems (since 1995), there should be an effluent filter to protect the drainfield. During pumping, the filter should be removed and rinsed over the tank. Regularly inspect and clean effluent filters as needed.
• If you have a pressurized system, have the pump and the pump chamber inspected and pumped (to the pump truck, not drainfield) if there is even a little sludge in it. Pumpers should not change the arrangement of float switches or control panel switches.
• While pumping or inspecting your septic system, pumpers may identify other problems. Pumpers can do minor repairs, such as repairing or replacing a broken baffle. We recommend you get a second opinion for any repair estimated at more than $200. It takes several days to refill the tank, so you should have time to get estimates.
• Get a signed and dated receipt with the company name. Ask the pumper to recommend when your tank should be pumped next and ask if you waited too long or could have waited longer. Keep records.

Resources Available

Brochures - for copies of brochures e-mail us at Publicworks@ci.olympia.wa.us.

 Available brochures include:

• "Understand Your System"
• "Prolong Your System's Life"

Onsite septic system installation within Olympia's Urban Growth Area:

• Download our printer-friendly information on where septic systems are permitted to be installed within Olympia's urban growth area.

Permits, low-interest loans, and pumping records: Call 360.754.4111.

Free advice and brochures: Call 360.357.2490.

Educational materials: Go to Thurston County Public Health & Social Services.

Have questions? Call the Septic Help Line at 360.357.2490.

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Contacting Public Works:

• Mailing Address: PO Box 1967, Olympia, WA 98507
• Physical Address: 924 7th Ave. SE, Suite A (directions)
• Hours: Monday - Friday from 8:00 a.m. to 5:00 p.m.
• 360.753.8588, TTY 360.753.8270
• publicworks@ci.olympia.wa.us
• Visit the Public Works homepage