County LogoClallam County, Washington

Maintaining Your Septic System

Over 50% of the residents in Clallam County live in homes that are not served by public sewers, but by a septic tank and drainfield system known as an On-site Septic System (OSS) because it treats sewage at the location it is generated. Maintenance of these systems is important if they are to continue to work properly over a long period of time, and in order to protect our health and environment.  Scroll down or select the topics below for more details.Septic Care Begins with You

The 2005 on-site septic system regulations (WAC 246-272A) state that septic system owners shall “assure a complete evaluation of the system components to determine functionality, maintenance needs, and compliance with regulations and any permits.” Those State regulations require that homeowners inspect and maintain their septic system regularly (meaning annually for those with pumps and every three years for gravity fed systems) to ensure it is functioning properly. Please go to the Summary of Septic System Inspection Requirements page for more details. Visit the septic system Operation and Maintenance (O&M) page for more information on professional septic system inspections.  To learn more about the different types of septic system inspections see the System Status Report page.

Take of Your Septic TabloidClallam County Environmental Health Services (CCEH) has published an artistic and informative tabloid titled `Take Care of your Septic´(2.1MB PDF) available online.  It is full of information about how systems work, the do's and don'ts of septic system use, and tips to follow to help your system last as long as possible. 

How a Septic System Works

The typical septic system consists of a septic tank and some type of a disposal drainfield. The septic tank collects all the waste water from the kitchen, bathroom and laundry and then separates the solids from the liquids. The septic tank is designed to use naturally occurring bacteria to digest organic matter and separate floatable materials like oils and grease while the solids settle out from the wastewater. Diagram of a two compartment septic tank

Modern septic tanks are divided into two chambers. In the first chamber, heavy solids settle to the bottom to form a sludge layer; greases and soaps float to the top to form the scum layer. Bacteria begin to work on the solids and partially digest them. The liquid portion between the two layers, called effluent, then flows into the second chamber where additional settling and digestion occurs. The outlet baffle prevents the sludge and scum from leaving the tank. The addition of an outlet screen can further help extend the life of your septic system by preventing even finer waste particles from escaping the septic tank to clog soil pores in the drainfield. Septic System Drainfield Diagram

The liquid effluent flows out into a drainfield for treatment, which in conventional gravity systems typically consists of a series of perforated pipes in trenches designed to slowly release the effluent into the soil. Bacteria and viruses are removed from the effluent as it filters through the soil ultimately discharging back into the groundwater. 

Alternative systems use pumps to help septic tank effluent trickle through sand, organic matter or other media to remove or neutralize pollutants like disease-causing pathogens, nitrogen, and other contaminants. Some alternative systems are designed to evaporate wastewater or disinfect it before it is discharged to the soil. If the drainfield is overloaded with too much water, it will flood, causing sewage to pond at the surface or create backups in toilets and sinks.

Why Maintenance is Necessary

Septic systems need proper care and maintenance just like your car. A failed or malfunctioning septic system is a risk to human and animal health and can pollute the environment. A responsible septic owner is alert to the signs of a possible failure and with a quick response may save money in repairs and may prevent illness and negative impacts on the environment. 

Regular septic system maintenance:

  • Money down the drainSaves You Money – Maintenance fees of a few hundred dollars every few years is a bargain compared to the cost of repairing or replacing a malfunctioning septic system, which can cost thousands.
  • Keeps You and Your Neighbors Healthy – Household wastewater is loaded with disease-causing bacteria and viruses, as well as high levels of nitrogen and phosphorus. A properly functioning septic system helps remove these pollutants so well water and nearby surface water does not get contaminated.
  • Protects the Environment – Malfunctioning septic systems release bacteria, viruses, and chemicals that eventually enter streams, rivers, lakes, Puget Sound, and the ocean. The pollutants harm local ecosystems by killing native plants, fish, and shellfish.
  • Protects Your Property Value – An unusable septic system or one in disrepair will lower your property value and poses a potentially costly legal liability.
  • It is the Law! If you own a septic system anywhere in Washington State, you are required by state law to check your septic system on a regular basis to make sure it is working properly.

Maintaining Your Septic SystemSeptic system diagram

Follow these important to tips to keep you septic system functioning properly and help extend its life:

Perform Regular Inspections

Conventional gravity septic systems should be inspected at least every three years and pumped when necessary. Alternative systems (those with electronic components/pumps) should be inspected annually. If you own a septic system anywhere in Washington State, you are required by state law (WAC 246-272A-0270) to check your septic system on a regular basis to make sure it is working properly. You can hire a professional Septic System Maintenance Provider or Designer to inspect your system for you, or you can do it yourself with proper training. Clallam County Environmental Health (CCEH) has developed a Homeowner Do-It-Yourself Septic System Inspection certification program called Septics 201 that details how to inspect your septic system and collects a record of your homeowner inspections.  Not all system types are eligible for Homeowner DIY inspection.  Please see the Summary of Septic System Inspection Requirements for more details.

Cleaning Outlet FilterTo inspect the tank, uncover both the inlet and outlet access covers. Use a stick to measure the thickness of the scum and sludge layers. It is time to pump the tank if the sludge is more than 12 inches thick, or if the scum is more than 6 inches deep or within 3 inches of the bottom or top of the outlet baffle. Only pump the septic tank when it is needed, excessive pumping can be expensive and hard on the tank ecosystem. Inspect the inlet and outlet baffles and replace them if they are broken or missing and clean the baffle screens. The baffles help keep the liquids from being stirred up. They also keep scum and sludge from leaving the tank and clogging the drain lines. Review the Basics of Septic Systems Septics 101 general information video at the Department of Health for more details and then become certified to inspect your septic system (if eligible) through the Septics 201 DIY Program to submit a record of your inspection to CCEH.

Septic Tank RiserInstall inspection access risers, which are basically extension tubes from the top of the septic tank or distribution box to the ground surface that make it easier to access your system for inspection or pumping.

The drainfield generally requires little maintenance by a homeowner. It should be checked routinely to make sure there is no surfacing sewage. Vegetation should be kept to a minimum and be well maintained. Roof drains should be directed away from the drainfield. A thick growth of very lush grass, spongy ground or a strong odor may indicate a potential failure.

Keep Septic System Records

  • Request or locate online a copy of your septic system’s ‘as-built’ record drawing if you do not already have one. This drawing should show the location of your septic tank, drainfield, reserve drainfield and all septic components.
  • Keep records of any pumping, inspections or repairs.  Search available septic information online for past inspection records.

Be Aware of What Goes Down the Drain

A variety of household products can clog and potentially damage septic system components.Not in my Septic ListSeptic Sign

Do not flush:

            • Cat Litter
            • Cigarette butts
            • Coffee grounds
            • Condoms
            • Diapers
            • Feminine hygiene products
            • Prescription Medication
            • Wipes

Your septic system contains a collection of living organisms that digest and treat household waste. Pouring toxins down your drain can kill these organisms or disrupt the natural bacterial action necessary for wastewater treatment. Moderate amounts of household cleansers and detergents should not pose a problem; however, dispose of solvents, pesticides, herbicides, motor oil, antifreeze, and paint through a household hazardous waste collection facility rather than down the drain.

Ways to improve drain use:

  • Avoid chemical drain openers for a clogged drain. Instead, use boiling water or a drain snake. See also other Alternatives to Hazardous Products.
  • Limit the use of chlorine bleach to less than ½ cup per laundry load. Bleach kills the “good” bacteria in the tank and drainfield.Soil Microbes Cartoon image
  • Never pour cooking oil or grease down the drain. Instead let it cool, harden, and then throw it away in the trash. Kitchen grease does not break down in the tank – it accumulates, filling the tank quicker, and ultimately shortening the time until it will need to be pumped.
  • Eliminate or limit the use of a garbage disposal. Food waste from garbage disposals fill the septic tank and can clog the drainfield. Rinse or dust off dirt from vegetables or clothes outside on the grass before introducing extra soils into your system.
  • Consider installing sink strainers, hair traps in drains, lint traps on washing machines, and an effluent filter at the outlet of the septic tank. These devices reduce the possibility of solids moving out of the tank and clogging the drainfield prematurely.
  • Use liquid laundry detergent and no more than the recommended amount. Powdered laundry detergents use clay as a ‘carrier’. This clay can hasten the buildup of solids in the septic tank and potentially plug the disposal area.
  • Be aware that medications used in the household can have adverse effects on your septic system.  Long term use of antibiotics and chemotherapy drugs kill bacteria in the septic tank.  Have the septic tank pumped more frequently while taking such medications and work with your maintenance provider to monitor the situation.  Dispose of unwanted medication properly at Jim's Pharmacy and some law enforcement offices. For information on permanent disposal information and laws, go to the Take Back Your Meds web page.
  • Keep kitty litter and all pet waste out of the toilet even when connected to sewer! These do not break down the same as human waste and should be bagged and placed in the trash for proper disposal.  There can be pathogens in pet waste harmful to marine life that cannot be treated properly by soil or waste water facilities.
  • Never pour oil-based paints, solvents, or large volumes of toxic cleaners down the drain. Even latex paint waste should be minimized. Rinse latex paint off of brushes and application devices on the gravel or cardboard and allow to dry to dispose.
  • Avoid septic tank additives; a product that is sold with the claim that using it will improve the performance or aesthetics of your septic system. Septic tank additives sold in stores are not necessary to keep your septic tank working properly and they don't reduce or eliminate the need for routine pumping and can sometimes even be harmful to your system. The Washington State Department of Health (DOH) reviews and approves septic tank additives to provide consumer protection. DOH product approval merely indicates that the ingredients are unlikely to cause harm.

Use Water Efficiently

The more wastewater you produce, the more wastewater the soil must treat and dispose of. By reducing and balancing your use, you can extend the life of your drainfield, decrease the possibility of system failure, and avoid costly repairs.

Septic System Water Inputs Pie ChartTo reduce your water use:

  • Use water-saving devices such as faucet aerators and high-efficiency toilets, shower heads, dishwashers, and washing machines.
  • Repair leaky faucets and plumbing fixtures. A leaky toilet can waste hundreds of gallons of water a day.
  • Take shorter showers.  Strive for less than 5 and do the shower jive.
  • Take baths with a partially-filled tub and do not leave the faucet running when doing other tasks.
  • Wash only full loads of dishes and laundry. If your washing machine has load settings, make sure you select the proper load size. Don't select the large-load cycle if you're washing a small amount of laundry.

Hydraulic overloading occurs when too much water enters the septic system at one time, resulting in wastewater backing into drains or effluent surfacing in your yard. Being conservative with water use by following the tips above can prevent hydraulic overloading.

Additional ways to prevent hydraulic overloading:

  • Adequately space showers, laundry, dish washing, and other high-volume water uses throughout the week so they do not coincide with one another, which may flood the septic tank and push solids into the drainfield.
  • Higher-than-normal usage from occupants or visitors can overload the system so make sure household guests are aware of water use recommendations or consider temporarily renting a port-a-potty to avoid putting excessive stress on your system.
  • Avoid using a water softener since backwash in the septic tank can cause hydraulic overloading and do not drain hot tubs into your septic system.
  • If heavy rains cause water to sit around your septic system, avoid putting any extra water down your drains until it dries out.

If too much water has saturated the drainfield (from large amounts of water going down the drain or through flood water on the drainfield), it is possible that the drainfield can be dried out and rehabilitated. Contact a professional maintenance provider to assess the situation.  To learn more about precautions to take when your septic system floods visit the EPA’s page on “What to do After the Flood”.Healthy Soil Composition

Maintain the Area Around Your System

To protect the lifespan of your drainfield and reserve area, you should:

  •  Avoid building structures on the drainfield, including tool or garden sheds, decks, sport courts, patios, swing sets, sand boxes, or compost bins as they can prevent air from getting into the soil.
  • Keep vehicles, heavy equipment, and livestock off your septic tank, drainfield, and drainfield replacement area. Pipes can get broken and compacted soil may no longer be able to absorb the liquid wastewater or effluent.
  • Do not put concrete or plastic over your septic system, the soil needs to breathe to be most effective at treating effluent.
  • Do not over irrigate in the drainfield area since that can saturate the soil and decrease the ability of the system to function properly.
  • Keep water runoff away from your system. Regulations stipulate minimum separation distances between a septic system and any surface water, ground water, and foundation drains to prevent flooding your drainfield. Water from roof drains, driveways, patios, or sump pumps should be diverted away from the septic tank and drainfield area. Soil over your system should be slightly mounded to help surface water run off.
  • Do not use a roto tiller over drainfield components which could damage any parts close to the surface.
  • Avoid burning piles of leaves or branches over the drainfield, as the heat could damage the plastic pipes below.
  • sewer pipe filled with tree rootsLimit the addition of topsoil or compost to no more than two to three inches over the drainfield. A good rule of thumb for landscaping over drainfields is to use shallow rooted plants that do not need additional topsoil to thrive.
  • Landscape your system properly. Grass is the best cover. Avoid trees, shrubs, and water-loving plants with deep roots. Grasses, mixed wildflowers, and ground covers with shallow roots are good alternatives. Plant trees and shrubs at least 30 feet away from your septic tank and drainfield to keep roots from getting into and breaking or clogging the drainfield pipes. If large trees that cannot be removed are nearby you can try digging a ditch to cut off the source of any infiltrating roots. For more information please visit the landscaping your drainfield page.

Know the Signs of Septic System Failure or Malfunction

A septic system failure causes untreated sewage to be released and transported to where it should not be. This may cause sewage to come to the surface of the ground around the tank or the drainfield or to back up in pipes in the building. The sewage could also find its way into groundwater, surface water, or marine water without anyone ever seeing it. Untreated sewage carries pathogens and other dangerous contaminants. Exposure to these pathogens and contaminants can make people and animals sick. It can also contaminate water sources and make them unsafe for drinking, swimming, shellfish harvesting, and agricultural uses.

Some signs of septic system failure include:

  • Smelly DrainfieldWater and sewage from toilets, drains, and sinks backing up into the home.
  • Bathtubs, showers, and sinks draining very slowly.
  • Gurgling sounds in the plumbing system.
  • Standing water or damp spots near the septic tank or drainfield.
  • Bad odors around the septic tank or drainfield.
  • Bright green, spongy lush grass over the septic tank or drainfield, even during dry weather.
  • Algal blooms in nearby ponds or lakes.
  • High levels of nitrates or coliform bacteria in well water.

Drainline cross-section compared over time

Like most components of your home, septic systems require routine maintenance. If maintained, the septic system should provide reliable service for many years. If the septic system isn't maintained, owners run the risk of dangerous and costly failures. Most types of septic systems have a standard expected operational lifetime and eventually the soil around the drainfield will become clogged with organic material, making the system unusable which is why you must also protect your "reserve area" for a possible future replacement system.

If you have sewage on the ground, take immediate action to protect yourself and your family from contamination:

  • Cover the breakout with sand, lye and/or bark chips
  • Place a rope or barricade around the area to prevent contamination
  • Keep children and pets away
  • Call a professional maintenance provider as soon as possible
  • Practice extreme water conservation measures to avoid making the problem worse

Ponded drainfieldLocal codes and regulations ensure proper installation practices and protect public health. A poorly installed system will not work effectively and will fail early. A properly installed septic system will be designed according to your specific site conditions (soil types, bedrock, groundwater, and slope). Local regulations also protect surface and ground water quality. A septic system that does not conform to regulations can potentially affect the health and safety of you and your neighbors. Test your household well water regularly!

Septic Tank Lid Safety

People do accidently fall into septic tanks. In most cases, the person who falls in gets out without serious injury. But a child's tragic death is a reminder to inspect your septic system for damaged or missing lids. Owners of septic systems are responsible for ensuring the systems are safe and function properly, including having a secure lid on the tanks.Septic Tank Lid

Take these precautions to make sure no one accidently falls into your septic tank:

  • Know where your septic system lids or covers are located.
  • Routinely inspect the condition of the lids for hazards or problems.
  • Keep the lids secure by repairing or replacing all damaged or missing parts.
  • Use bolts, screws, or other locks to secure the lids and prevent easy access.
  • Never drive or park vehicles on top of septic systems– it can damage or dislodge the cover.
  • Never leave an open lid unattended when inspecting or having your septic system pumped. Make sure the lids are secured after working on your septic system.
  • Teach children that the septic tank lids are not to be played on or opened.
  • Have septic systems that are no longer in use properly decommissioned.

For other general safe practices around septic systems please review the Septics 201 DIY Program Septic Safety Tips.

More Resources

Clallam County Environmental Health (CCEH) has printed literature available with more Septic Smart Week 2018information to help you inspect your septic tank and drainfield available at our customer service center in room 130 of Courthouse. In addition, the Clean Water Herald “Septics Edition”newsletter focuses on septic system operation and maintenance topics. See our Septics 201: DIY Septic System Inspection Program to become certified to inspect your septic system and submit online inspection reports directly to CCEH. The EPA runs the Septic Smart website with additional information and the promotional materials for the annual celebration of SepticSmart Week.

Some additional information is also available online from the Washington State Department of Health:

Washington State University Extension Office also offers information about septic systems:

On their home page search “septic systems” for additional related information about septic systems.

Return to the On-site Septic Systems main page.

Clallam County Health & Human Services
Contact Information | Email Us