Henderson-Nisqually Shellfish Protection District - Tools for Correcting Pollution Sources

Water Quality Monitoring and Dye-testing

(Includes establishing water quality monitoring, ambient monitoring, targeted shoreline monitoring, storm/event sampling.)

Thurston County has an ambient stream monitoring program that includes monthly sampling of the major tributaries to Henderson Inlet and Nisqually Reach. The county may notify a partner agency or sample in other locations if is a sample is considered elevated. There is no targeted sampling to identify problem areas. The on-site sewage system (OSS) operation and maintenance program inspection requirements are based on potential risk to surface water: Low risk systems must be inspected every three years, conducted by certified OSS professional or by a trained and certified homeowner. Ten percent of systems are verified by county staff. High risk systems must be inspected every three years and pass a dye test every six years. Dye tests are performed by county staff.

Office Evaluation

(Includes GIS and other existing data evaluation.)

The county uses aerial photos (and dye tests) to find OSS problems.

Parcel Inspection (Sanitary Survey)

OSS's are required to be inspected every three years in most cases. The Thurston Public Health and Social Services Department (TPH&SSD) mails notices to the owner two months prior to the due date to let them know it is time for the inspection. They have up to four months beyond the due date to complete the inspections and any needed maintenance or repairs. If the work is not completed the system is in violation of the sanitary code and designated as “non-conforming.” Program details can be found in Article VI of the Thurston Sanitary Code (PDF).

Visual Inspections from Vehicle

n/a

Experimental Methods

Microbial Source Tracking (MST)

Microbial source tracking (PDF) was used and found human and canine sources. This information was part of the body of evidence used by the SPD Citizen Advisory Committee and the County elected officials to conclude that OSS O&M was needed.

Plane Fly-Overs

n/a

Scent Testing

n/a

Incentives

Incentive and assistance programs include: riser rebates, waiving the program charge for low income senior and disabled citizens, low interest loans for system repairs, small grants to low-income owners to assist with the cost of inspections and maintenance, and owner inspector certification classes which have been very popular. The county built a septic demonstration park as a training tool to teach owners how to inspect their systems as part of the certification program. That certification is revoked if an owner fails to complete their inspections; the county has revoked 9% of certifications in the first five years.

Agricultural Best Management Practices (BMPs)

Fencing of Heavy Use Areas

n/a

Riparian Buffers

n/a

Farm Plans

n/a

Operation and Maintenance

TPH&SSD mails O&M notices to the owner two months prior to the due date to let them know it is time for the inspection.

Other Tools

n/a

More About Henderson/Nisqually Shellfish Protection District

Other Shellfish Protection Districts