On-site Sewage System Projects (OSS)
Effects of On-Site Sewage Systems (OSS) on the Drayton Harbor Watershed
Currently there are approximately 3,000 OSS in the Drayton Harbor watershed. A failing OSS has implications that are larger than just the cost of repairs. A failing OSS may allow potentially harmful bacteria, protozoa, or viruses to contaminate our streams, groundwater, and harbor as well as create the potential for direct contact between sewage and the public. Additionally, sewage leaking from a failing OSS can result in greater algae and plant growth and lower levels of dissolved oxygen for fish as a result of added nutrients such as phosphorus and nitrogen.
Operation and Maintenance Program
OSS can fail for a number of reasons such as improper installation, inadequate soils for the system type, advanced age, damage to the system, or improper maintenance. On-site sewage system owners are now required to have their systems evaluated every three years for gravity systems and annually for all other system types. In addition, a current OSS evaluation must be on file when a residence is offered for sale. The Whatcom County Health Department's OSS Operation and Maintenance Program provides details on these maintenance requirements.