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Sanitary Sewer Management Plan

This Sewer System Management Plan (SSMP) has been prepared in compliance with requirements of the State Water Resource Control Board (SWRCB) pursuant to Order No. 2022-0103, Statewide General Waste Discharge Requirements (WDR) for Sanitary Sewer Systems. The WDR requires development and implementation of a written SSMP, and defines eleven mandatory SSMP elements. The WDR also defines associated monitoring, record keeping, reporting, and public notification requirements. 

The McKinleyville Community Services District's (MCSD’s) SSMP has been prepared with the assistance of Freshwater Environmental Services (FES), as described in the agreement between the MCSD and FES dated December 27, 2010. This initial SSMP will become a living document, and should be updated as needed to reflect changes to the SSMP elements. The intent of this SSMP is to meet the requirements of the Statewide WDR.

This document presents eleven elements in the order presented in the WDR:

  1. Goals;
  2. Organization;
  3. Legal Authority;
  4. Operation and Maintenance Program;
  5. Design and Performance Provisions;
  6. Overflow Emergency Response Plan;
  7. Sewer Pipe Blockage (SPB) Control Program;
  8. System Evaluation and Capacity Assurance Plan;
  9. Monitoring, Measurement, and Program Modifications;
  10. SSMP Program Audits; and
  11. Communication Plan.

As contained in the MCSD National Pollution Discharge Elimination System (NPDES) permit, the MCSD (or District) owns and operates a secondary treatment facility. The treatment system consists of four aerated ponds followed by a treatment wetlands. During the discharge season, which extends from October 1 through May 14, wastewater is discharged from Discharge Point 001 to the Mad River, a water of the United States within the Blue Lake hydrologic area 109.10 and to percolation ponds adjacent to the Mad River Estuary when the flow in the Mad River is less than 200 cubic feet per second (cfs).

During summer, a portion of the wastewater treatment plant effluent is used to irrigate the Hiller storm water treatment marsh where it provides moisture to sustain wetland vegetation through the dry season. Runoff producing rainfall events cause the Hiller storm water treatment marsh to overflow into an unnamed tributary to the Mad River estuary. Prior to the onset of the wet season and storm water overflows from the marsh, the wastewater application to the treatment marsh is ceased and the treatment marsh is allowed to dry through evaporation and evapotranspiration.

McKinleyville C.S.D. Sanitary Sewer Management Plan (SSMP)

(Updated April 10, 2023)