Pollution Source: On-site Sewage Systems (OSS)
On this page:
- Identifying Potential Source of Pollution
- Validating Source of Pollution
- Verifying Pollution Source Has Been Corrected
- For more topics see sidebar at right.
Identifying Potential Pollution Source
Burley Lagoon, Filucy Bay, Rocky Bay Shellfish Protection Districts (SPDs) / Pierce County Pollution Identification and Correction (PIC)
Failing OSSs are identified through complaints, sanitary surveys, water quality sampling (shoreline evaluations and upland sampling), pumper and Operations and Maintenance (O&M) reports, and self-referrals.
Henderson and Nisqually SPDs
In the Henderson and Nisqually Marine Recovery Areas, all property owners with OSSs need to have a current operational certificate. The OSS O&M program includes the following activities:
- Maintaining the property roll and managing records;
- Sending inspection notices and reviewing inspection reports;
- Issuing operation certificates;
- Conducting dye tests;
- Enforcement; Technical assistance;
- Quality control inspections;
- Administering an incentive program and financial assistance program.
The OSS O&M program has requirements based on potential risk to surface water: Low risk systems should be inspected every three years, conducted by a certified OSS professional or by a trained and certified homeowner. 10% of these systems are verified by county staff. High risk systems should be inspected every three years and pass a dye test every six years. Dye tests are performed by county staff.
Tank pumping is the most common maintenance item, with almost half of tanks inspected needing pumping during the first inspection cycle. The County defines “Failure” in Article IV as “a condition of an OSS or component that threatens the public health by inadequately treating sewage or by creating a potentital for direct or indirect contact between sewage and the public.”
Jefferson County Clean Water District (CWD)
Jefferson County has found that freshwater water quality monitoring at the marine interface (intertidal zone) as well as tracking complaints are the most reliable and efficient ways of finding problem OSS. Comprehensive stream monitoring is useful in finding OSS issues, although it is energy intensive. Six stream flow gauges are used; loadings are not generally calculated. Ambient freshwater samples are taken on a rotating basis, with the goal of sampling one drainage basin every other year in most of the CWD. There are approximately 20 stream sites in each basin, plus about 200 miles of shoreline monitoring. There are about 150 total sampling stations in Jefferson County. Washington State Department of Health (DOH) is notified when confirmed problem areas are found. Problems are defined and corrected based on Jefferson County Ordinance 06-0517-12, which allows Jefferson County Environmental Health to enforce septic violations. The Jefferson County Code 8.15.150 (PDF) requires OSS O&M for all new systems. Existing systems must be monitored at time of sale, upon issuing new permits, or if a Marine Recovery Area (MRA) is designated. In 2013, Jefferson County allowed homeowners to inspect their own systems, provided they are authorized and pay the $50 inspection filing fee.
Kitsap Public Health District
Kitsap uses a “closed loop process” that coordinates water quality work within the stormwater utility between four agencies: Kitsap County, Kitsap Public Health District, Kitsap Conservation District (KCD) and the Washington State University (WSU) Cooperative Extension.
Kitsap Health developed the first comprehensive OSS O&M program in Washington State. The program protects public health and water quality through an ongoing OSS inspection program conducted by certified contractors, staff follow-up, enforcement of needed corrections, and public education and outreach.
An O&M database was developed and is vital to the success of the program. It allows contractors to enter inspection information online, run reports showing when a property is due for inspection, and download OSS permit records. Kitsap Health uses the database to track required contracts, inspection deficiencies, OSS failures, and performance of various type of systems/technologies. Washington State licensed designers and certified septic installers, O&M specialists, and pumpers are required to report OSS inspection and pumping data online and to report failures and system deficiencies. OSS failures are also identified and confirmed through the public complaint process.
The County defines “failure” in Appendix A of Ordinance 2008A-01 (PDF). Kitsap Health's trend monitoring program was established in 1997 to collect monthly samples from fresh water and receiving marine waters, assess data and compare to state water quality standards, and evaluate for short-term and long-term trends. Marine water monitoring is coordinated with DOH marine water monitoring. Areas that do not meet water quality standards are evaluated and ranked for PIC corrective work.
A shoreline survey is the inventory and bacterial assessment of all flowing discharges to the project area shoreline. Dry season events, May 1 through September 30, can identify problems in areas where stormwater masks pollution sources or where residences are only occupied in the summer. Wet season assessments, October 1 through April 30, can identify OSS failures caused by high seasonal groundwater and surface water drainage issues. Samples are collected at low tide to target the discharge of fresh groundwater versus the drainage of residual marine water.
Detailed field notes, photographs and Global Positioning System (GPS) coordinates are collected in support of samples. Confirmation samples are collected in drainages with results above a predetermined threshold and hotspot investigations are conducted when the geometric mean of the confirmation samples exceed that threshold. Kitsap County typically uses E. Coli (EC) for shoreline surveys and the PIC Protocol establishes the confirmation and investigation threshold at 406 counts of EC per 100mL.
Oakland Bay CWD
The Mason County OSS/ water quality program uses a mix of Geographic Information Systems (GIS), permits, and shoreline surveys to ensure shoreline OSSs are in compliance. OSS O&M is verified when the homeowner sells a house, applies for permits, or through complaints. The creation of a GIS data layer that contains OSS records is used to cross check permits, locations of systems, and structured lots without OSSs or maintenance. In order to gauge whether OSS inspections are being completed, Mason County does ambient monitoring of a third of the Oakland Bay shoreline each year in a three year rotation, uses DOH marine sampling data, and follows up on complaints or unsatisfactory service reports.
Sequim Bay Dungeness Watershed CWD
The County uses surfacing sewage and dye testing to identify failing OSS. For the past couple of years, however, they have not found OSS that are close enough to a water body to suggest those systems would be cause of elevated levels of fecal coliform (FC) in the water.
Skagit County Clean Water Program (CWP) / The Clean Samish Initiative (CSI) / PIC Program
Skagit County regulations for OSS mirror state regulations. Conventional gravity OSSs are to be inspected every three years while all other OSSs are required to have annual inspections. All records, inspections, and permits are tracked through a database, and maps of MRAs and OSSs' status in the twelve MRAs are posted on the web.
South Holmes Harbor SPD
The SPD conducts water quality sampling downstream, then works upstream into smaller streams and ditches to zero in on source areas. Targeted campaigns have been created with door to door outreach in areas of known compliance problems. The SPD uses surfacing sewage, non-conforming use, positive dye testing, and water quality sampling to identify and confirm if an OSS is failing. The County often finds seasonal failures due to the rising water table. They try to start with water quality sampling and then approach property owners for dye testing. Fecal coliform levels are only used as an indicator of a failure; dye testing is used to confirm a failure.
Stillaguamish River CWD
Reports of failing OSSs are complaint driven, along with some sanitary surveys and tracking of sewage permits (according to health code 8.1.2 (PDF)).
Validating Source of Pollution
Burley Lagoon, Filucy Bay, Rocky Bay SPDs / Pierce County PIC
An OSS is verified to be failing through an investigation either by the Tacoma-Pierce County Health Department (TPCHD) Code Enforcement Program or the Septic Repair Facilitator (SRF). The SRF is a position that was initiated through a Puget Sound United States Environmental Protection Agency (EPA) grant and this individual investigates sources of bacterial pollution in the shellfish watersheds of Pierce County. Once a pollution source has been verified, the SRF facilitates the correction of the problem. Verification of a failing OSS usually involves a dye test, sometimes using charcoal packets and collecting additional water samples for bacterial analysis.
Jefferson County CWD
Dye tests are used when appropriate to confirm connectivity with local surface waters. A Microbial Source Tracking (MST) study in 2012 confirmed the presence of human indicators throughout the basin.
Kitsap Public Health District
Pollution sources are confirmed through parcel surveys, water samples, and dye testing.
Oakland Bay CWD
Mason County Public Health (MCPH) follows approved standard operating procedures.
Sequim Bay Dungeness Watershed CWD
All information, complaints and inquires regarding failing OSSs are investigated by EH. Bacterial testing and, when warranted, dye testing is used to validate problem OSS.
Skagit County CWP / The CSI / PIC Program
Inspections are done by individuals certified by Skagit County Public Health (SCPH). These O&M specialist certifications must be renewed annually. Any reports of deficiencies or ponding sewage are followed-up by SCPH staff via a site visit. Potential OSS system failures as identified by the Skagit County Public Works PIC program also receive SCPH follow-up.
SCPH is also working with commercial OSS inspectors to ensure adequate inspections, and has developed a quality control program for commercial and homeowner inspections.
South Holmes Harbor SPD
The SPD carries out different types of sampling to narrow down the source of pollution, including dye tests, fecal coliform counts and caffeine sampling.
Verifying Pollution Source Has Been Corrected
Burley Lagoon, Filucy Bay, Rocky Bay SPDs / Pierce County PIC
If a new, replacement OSS is installed, TPCHD approves the design and installation of the system. If a failing OSS is repaired, the system is usually dye tested (again) to verify the problem has been corrected.
Henderson and Nisqually SPDs
The OSS O&M program for the MRAs has designated compliance staff to ensure that failing and deficient systems are repaired. The County uses a permit tracking system to track an OSS repair permit to its completion. When a failure is identified, the violation is also tracked in the system by compliance staff. If the full OSS system is replaced (permitted), there is no follow-up beyond the normal permitting and inspection process. If the repair is minor (unpermitted), such as the replacement of a broken pipe, the County would do a second dye test to confirm the repair has been completed.
Jefferson County CWD
Follow-up sampling is conducted after OSS repairs when appropriate.
Kitsap Public Health District
Post-corrective monitoring is conducted to determine whether follow-up dye testing is necessary to verify that the pollution source has been corrected. Trend monitoring data and O&M reporting provide additional confirmation.
Sequim Bay Dungeness Watershed CWD
Follow through to ensure failing systems are repaired is conducted a majority of the time. The County tracks the case and follows up with property owners to make sure they have collected repair permits. In some cases, problem systems languish due to the inability of the Prosecutor's Office to follow through with enforcement orders or court action when dealing with recalcitrant property owners.
Skagit County CWP / The CSI / PIC Program
OSS failures are tracked to assure correction in a timely manner. If the system cannot be corrected right away (often due to weather conditions) processes are put in place to assure pollution is stopped. For instance, SCPH orders that the outlet to the septic tank is plugged so that the tank works as a holding tank only. A contract with a licensed OSS pumper is required to assure the tank gets pumped regularly.
South Holmes Harbor SPD
Correction is verified through continued sampling.
Establishing a Threshold (Concentration, Number of Counts, or Flow Rate)
Burley Lagoon, Filucy Bay, Rocky Bay SPDs / Pierce County PIC
The County considers any flow rate over one gallon per minute as worthy of sampling. Lower flows may also be sampled if there is an indication of a failing OSS (sewage odor, excessive algae growth, etc.). Shoreline samples are considered elevated when FC results are 200 cfu/100mL or greater. Confirmation sampling is performed at sites where the initial FC result is elevated. The County uses a dye test resulting in visible dye either on the ground or using charcoal packets, and a FC count of 200 cfu/100mL or greater to confirm system failure. Occasionally false positives are seen. There are a fair number of sites with high counts and when a dye test was performed no dye was observed.
Henderson and Nisqually SPDs
The County follows state standards that apply to the body of water being sampled. According to Article IV (PDF), a failure would include a positive dye test results and a FC bacteria sample result of at least 200 cfu/100 mL or above established background concentrations collected within six months of the dye test and collected at the same location as the dye-positive site.
Jefferson County CWD
Jefferson County complies with Washington State water quality standards. High FC counts are defined as a minimum of 500 organisms per 100 mL of water. For shoreline sampling, the County uses 100 counts of EC as a threshold. Sampling results are only used to coordinate with property owners and encourage them to improve their behaviors. To be confirmed as failing, an OSS must have high sampling levels, a confirmed dye test, and/or visible surfacing sewage.
Kitsap Public Health District
Kitsap Health identifies pollution areas of concern based on whether trend monitoring data meets the state water quality standard for FC. The PIC Protocol establishes a threshold for when shoreline survey samples need confirmation and for determining “hotspots” that need investigation. Kitsap County recently participated in a rotating shoreline survey pilot project with funding from EPA. This proved to be a cost effective method of targeting the areas that are currently impacting the shoreline's water quality. Previously, lower level thresholds (160 EC/100 mL) resulted in a number of indicated hotspots that were unable to be tracked back to pollution sources. Kitsap County typically tests EC counts for shoreline surveys because it is a better indicator of fresh water for public health and is cheaper to measure. The PIC Protocol establishes the new confirmation and investigation threshold at 406 EC/100mL.
The County is working with the Hood Canal Coordinating Council on a Hood Canal PIC program that uses slightly different thresholds since Kitsap County is compromising and collaborating with Mason and Jefferson Counties. The regional guidance document uses thresholds of 200 FC per 100 mL or 100 EC/100 mL, with one or two confirmation sampling rounds. Kitsap County prefers three samples to create a geometric mean. The Hood Canal regional PIC will use an investigation threshold of 500 FC/100 mL or 320 EC/100 mL.
Oakland Bay CWD
These parameters are defined in the SPD's Standard Operating Procedures (PDF) and/or the Quality Assurance Project Plan (QAPP) for particular grant funded projects in the watershed/CWD.
Sequim Bay Dungeness Watershed CWD
The County uses state and EPA standards for FC concentrations. Any elevated levels are documented in a database. When PIC program funding becomes available, staff will look at trends in certain locations and then will select locations to receive more intensive monitoring and segmenting.
South Holmes Harbor SPD
The SPD uses the state standard (a threshold of 100 cfu/mL FC) to determine exceedances.