Pollution Control Plan
Date Plan Created/Updated
April 2007
Process for Creating SPD/Plan
Closure Response Strategy Committee
Links to Pollution Control Plan
Annas Bay Closure Response Strategy (PDF)
Pollution Source: On-Site Sewage Systems (OSS)
Identifying Potential Pollution Source
Staff collected water quality samples from the shoreline for fecal coliform and nutrients. This process was called the shoreline survey. A total of 728 samples from 341 unique sites were collected as part of this project. A confirmation sample was taken from those sites where the initial results were elevated. Sites where both the initial sample and the confirmation sample were elevated were prioritized for on-site surveys and dye tests. The OSS and site evaluation (which may have included a dye test) was called a sanitary survey.
The District encompassed approximately 190 developed parcels with 30 of those located along the shoreline. Staff reviewed all available OSS records for developed parcels within the district to assess pollution potential. Staff performed sanitary surveys at 21 properties located along the eastern shoreline of Annas Bay. Eight OSS were dye tested; of those sites that were evaluated, four failing OSS were identified and repaired. A total of six OSS were repaired and six OSS were replaced during the project period. DOH marine sample station 197 triggered the closure of shellfish beds along the eastern shoreline of Annas Bay. Sanitary survey work identified a broken sewage line that was found to be discharging sewage to the surface of the ground above a culvert that discharged to the marine water directly adjacent to station 197. It is believed that this system may have been responsible for degraded water quality at station 197. After this system was repaired, water quality at station 197 improved and eventually the the downgraded growing area was reopened.
The tribe performed on-site sewage system (OSS) work on the reservation and fixed many systems.
Validating Source of Pollution
Staff collects fecal coliform water samples and performs dye tests of OSS. OSS failures are identified by surfacing sewage or by positive dye and fecal coliform results of 50 or greater.
Verifying Pollution Source Has Been Corrected
On-site septic system repairs were tracked by Mason County Public Health On-site Septic program. Follow-up monitoring was performed at sites that had pre-repair elevated fecal coliform levels that were identified as impacting the marine water. No follow-up monitoring was performed after an OSS was repaired.
Establishing a Threshold (concentration, number of counts or flow rate)
Fecal coliform concentrations of 50 FC/100 mL or greater were considered elevated and required additional follow-up. Fecal coliform levels of 50 FC/100ml or greater along with positive dye was used to confirm an OSS failure.
Pollution Source: Agriculture
Identifying Potential Pollution Source
Mason Conservation District conducts livestock and farm inventories.
Validating Source of Pollution
n/a
Verifying Pollution Source Has Been Corrected
n/a
Other Pollution Sources
Pet Waste
Pet waste station provided to Potlatch State Park.
Wastewater Treatment Plant
None in ABSPD during grant period. A new MBR treatment plant is now online at Potlatch another plant is planned for the Skokomish Reservation core within the SPD.
Other (including wildlife, stormwater, marinas)
The Annas Bay/Skokomish Delta is in a migratory bird pathway and the Skokomish Delta is an Audubon Important Bird Area. Deer, elk and raccoons are common within the watershed. One marina is located adjacent to the SPD.
The Webb Hill Biorecycling Center is a biosolids application site that straddles the groundwater divide between WRIA 14 (Oakland Bay) and WRIA 16 (Skokomish-Dosewallips). Further studies were performed to identify the direction of groundwater flow and the potential to impact Hood Canal. Both surface water and ground water was analyzed for pollutants and for flow directions.