What is a Wastewater Comprehensive Plan?

The Sammamish Plateau Water and Sewer District has embarked on an update of the long-range planning effort for the future of wastewater management on the Plateau. The plan is due to be completed near the end of 2002, and will provide guidance for the provision of sewer service and a “road map” of where new sewer pipes, pumping stations, and other facilities will be required to satisfy the King County requirement of providing sewer service for all customers within the urban growth boundary.

Over the past 25 to 30 years the District has developed basic policies to implement the provision of sewer service. During the comprehensive planning process these policies will be reviewed and considered for continuation and/or modification. The Board may also consider adoption of new policies.

The planning process associated with determining where sewer facilities may be installed will happen in three steps. First, a comprehensive map has been created of existing sewer pipes and how they relate to the overall topography and varied elevations of the Plateau. Second, the projected wastewater demands for the service area will be compared to the existing system to identify future service needs. Finally, a portrait will emerge of where new pipes will be required.

The Wastewater Comprehensive Plan will examine where new sewer pipe corridors could be located, their size, and when they may be needed. The District’s policy is to use gravity wherever possible to keep the system simple to operate and avoid the cost of operation and maintenance of pumps to move wastewater. The Plan will also identify where pump facilities may be needed. After a review of the alternatives by District staff, the District’s elected commissioners, and the public, the draft Plan will be revised and adopted as a final Wastewater Comprehensive Plan. The Plan does not commit the District to a schedule of construction, but it does identify where the system will likely be when individual pieces are built.