Comprehensive General Sewer Plan Update, Clark Regional Wastewater District

About

Clark Regional Wastewater District is one of the largest sewer districts in the state, currently providing sewer service to nearly 100,000 people, 30,000 employees, 25,000 students, and 300 acres of industrial users. The District service area extends for more than 50 square miles and includes all or portions of three cities (Cities of Ridgefield, Battle Ground, and Vancouver) and unincorporated Clark County. The District owns and maintains more than 600 miles of sewer pipes, 60 pump stations, and 800 individual STEP systems. Growth and development within the District service area have been very robust and among the healthiest in the state. As a result, an aggressive Capital Improvements Program (CIP) to support this economic development and population growth was developed as part of the Comprehensive General Sewer Plan (Plan). The Plan was used as an effective tool in sizing and extending the sewer system to the unserved areas while accommodating growth in existing service areas.

Features:

  • Complex regional hydraulic model development and calibration
  • Wastewater utility planning
  • Developed and updated policies regarding the wastewater utility

Sewer Model Development and Analysis, Clark Regional Wastewater District

About

BHC developed a comprehensive model of the District’s sanitary collection system, using MIKE Urban software. The model was created by importing collection system data from the District’s GIS database, including over 10,000 pipes and 67 pump stations. Existing, 20-year, and buildout flow scenarios were analyzed to identify improvements necessary to re-direct Ridgefield flows to the District’s system, mitigate surcharging, accommodate growth, and efficiently convey flows to the Salmon Creek WWTP.

Features:

  • MIKE Urban model with Rainfall Dependent Infiltration (RDI) Module
  • Flow loading and dry-and wet-weather calibration to District meter data
  • Flow projections and I/I degradation for future scenario analysis