Environmental Health
Surface Water (Lakes, Rivers & Streams)
Henderson WPA Septic System O&M Program
  Henderson & Nisqually Reach Watershed Protection Area  

Septic System O&M Program —
Operational Certificate Renewal

  What is an Operational Certificate?  l  What is needed to renew the Certificate?  l

How do I know when to renew my certificate?  l  Who can do the inspection?  l

Is the Certificate renewed at transfer of property?  l  What if requirements are not completed?

What is needed to renew the Certificate?

A Septic System Inspection

An inspection includes checking all parts of the septic system:

  • Scum and sludge build-up in the septic tank must be measured
  • Baffles and water levels checked
  • Effluent filters (if present) should be cleaned
  • Pumps, pump tanks, floats, and alarms checked (if present)
  • Drainfield area inspected
  • Drainfield Monitoring ports (if present) opened and inspected

What if the system needs to be pumped?

  • For the criteria for pumping, see Inspecting Your Septic Tank.
  • If the tank is pumped, the pumper service report must be included with the inspection report and filed electronically by the septic professional at www.onlinerme.com.

What is an Operational Certificate?

All septic systems within the Henderson and Nisqually Reach Watershed Protection Area (HWPA & NWPA) must have renewable Operational Certificates. Most Operational Certificates are renewable every three years, however, some complex systems have certificates that must be renewed annually.

A certificate is issued by the County to the owner after the required septic system inspection and needed maintenance is completed and reports are submitted to Environmental Health.

NOTE: For systems designated as “High Risk”, a dye test evaluation is required as a condition of the operational certificate renewal (noted in the renewal notice).

A dye test is used to help determine if a septic system is failing. While it does not find all possible problems, it is especially useful in disclosing seepage failures. It involves flushing a non-toxic tracer dye down a toilet and placing charcoal packets downhill of the septic system to collect any dye that may be leaking (with the sewage) from the system.

Dye test evaluations must be done every other renewal cycle or every 6 years. These evaluations may be performed by County health department staff or approved professionals.

Consent forms will be sent with the renewal notice when the dye test is due, please return the form by email or mail, or call 360-867-2644 to schedule an appointment.

How do I know when it's time to renew my certificate?

The County will send a notice in the mail 60 days before the due date. Included with the notice is a Septic Pumping Coupon, Tips for Septic Owners, and Septic Tank Riser Rebate Information.

Who can do the inspection?

Industry Professional

The Operational Certificate renewal notice will include an Inspection Form. These forms have been color-coded to help you determine which industry professionals can do the required inspection of your system. For example, if you receive an orange Inspection Form, only a Certified Monitoring Specialist or Professional Engineer can inspect your system.

The following industry professionals can do the required inspections:

  • Certified Monitoring Specialist
  • Professional Engineer
  • Septic System Designer
  • Septic System Installer
  • Septic System Pumper

For a list of Industry Professionals, see Industry Professionals or look in the Yellow Pages under "Septic".

NOTE: Thurston County does not regulate the business practices of certified contractors. Get several estimates, check references, and be clear what services are requested before hiring a contractor.

Owner Certification

Owner certification to inspect is available through the County Health Department. Only Henderson Inlet and Nisqually Reach WPA homeowners with a gravity, mound, pressure distribution, or Glendon® Biofilter system are eligible. To sign up for a one-day workshop, see Septic System Inspection Certification or call 360-867-2644.

Is the O&M certificate renewed at the transfer of property?

 A septic system must be inspected and all septic tank(s) pumped when property ownership changes, or it must have been done within one year of the sale.

An inspection and pump out done at the time of transfer can be used to renew the operational certificate for the new owner if the system is functioning properly and permits are in order.

What happens if Certificate requirements are not completed?

If you do not complete the inspections and needed maintenance required in order for the Health Dept to issue an Operational Certificate, your sewage system will be in violation of the County Sanitary Code and classified as "non-conforming". This means, at a minimum, that other permit approvals will be withheld until the Certificate is renewed.

To bring a non-conforming system into compliance requires an inspection of the system by County staff. By completing your inspection when required, you will assure your septic system is working properly and avoid any untimely delays during future building projects or property sales.

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This page last updated: 01/28/22