Clark County Public Health’s On-Site Septic System Operation and Maintenance Program (CCPH OSS O&M) regularly sends notices to system owners who are past due on their O&M inspections. Regular inspections are required by state law to protect public health and groundwater.
It is important to maintain your septic system to protect:
- public health
- local creeks, streams and rivers
- drinking water
- your investment
Operation and maintenance of your system
Septic systems are usually not considered an essential part of a home. But replacing a residential septic treatment system may cost between $7,000 and $15,000! Periodic inspection and timely repair of your system components can prevent damage to the soil and water in the ground around your home, and may extend the useful life of your system.
Washington Administrative Code chapter 246-272A and Clark County Code 24.17 requires homeowners whose property is not connected to a municipal sewer system to ensure that the property includes an approved, correctly functioning on-site septic system. Proper maintenance is defined in the code as:
- Determining the level of solids and scum in the septic tank every three years.
- Employing an approved pumper to remove septage from the tank when necessary.
- Protecting the system components and required reserve septic area from damage by structures or materials, surface drainage, soil compaction, soil removal or grade alteration.
- Keeping the sewage flow at or below designed quantity and waste strength.
- Directing roof drains away from the area of the sewage treatment system.
- Operating and maintaining alternative sewage disposal systems if directed by the County Health Officer.
Inspection frequency
For all systems ensure that a current report of system status is on file with Clark County Public Health when a property served by anon-site septic system is offered for sale. The report of system status is considered current for purposes of this subsection if it was completed within one (1) year of the date of sale.
- Every 3 years: Simple gravity with or without a pump
- Every 2 years: Pressure distribution (Clark County received a waiver from WA-DOH for inspection every 2 years.)
- Annually: All alternative systems (sand mounds, ATU, Glendons, etc.) and all food establishments
- Note: Some systems are so complex the manufacturer recommends inspection more often for the first 2 years; be sure to meet the conditions of your warranty.
Maintaining your septic tank
The lack of septic tank maintenance can cause sewage to back up into your house or solids to overflow to the drainfield. Once solids overflow and leave through the tank outlet, they can quickly clog a drain field to the point that a new one is required. Most septic tanks need to be pumped every three to five years, depending on the tank size and the amount and type of solids entering the tank. The inspection of the sludge and scum levels is the only way to determine when a tank needs to be pumped. This is not necessarily a pleasant task, but can be done relatively easily. Septic tank pumping firms are available to perform the inspection. For more information please see our Guide to the proper care and maintenance of your on-site septic system.
Do-it-yourself inspections
If you have a simple gravity system, you may be able to inspect your own system. Clark County Public Health offers a course where homeowners learn to correctly inspect their septic system and keep their investment working properly.
An inspection by a resident homeowner can be carried out no more than every six years (every other inspection is to be done by a certified O&M specialist). The inspection reporting form will be provided at the workshop.
To be added to the Septic Inspection Certification Class waitlist contact:
Terry Koper at 564.397.6060 extension 5729.
Certified/licensed professionals
Our office does not recommend any particular septic operation and maintenance specialist, but does provide a list of persons/businesses who are currently certified with Clark County Public Health to conduct septic system inspections. Questions? Call 360.397.8428.
Frequently asked questions
Related links
Report a public health concern
Clark County Property Information Center
Basic Principles of on-site septic system
Understanding and caring for your septic tank
On-Site Sewage (septic) System Rules and Regulations of Clark County Public Health
Washington State on-site sewage (septic) systems rules regulations
Clark County Regional Wastewater District – Information for Homeowners