Water & Wastewater

Wilson Engineering provides a full range of engineering services for water and wastewater collection and treatment projects.

We represent clients through all phases of planning, design, and construction of new or upgraded water and wastewater facilities.  As regulations and technologies change rapidly, we investigate what is new and innovate where appropriate. Our designs are cost effective to construct, yet state of the art, and meet the operating needs and resources of the communities they serve.

Port Gamble Collection Pump Station

Our wastewater collection and treatment expertise includes water reuse and reclamation, gravity and pressure systems, MBR treatment, conventional activated sludge process, lagoon rehabilitation, headworks, screening, grit removal, UV disinfection, biosolids stabilization and much more.

Our water collection, distribution, and treatment expertise includes well investigation and design, municipal distribution systems, slow sand filters, Reverse Osmosis (RO) treatment, water tank storage, and more.


  • Facilities and Utilities Planning
  • Regulatory Compliance & Permitting
  • Engineering Design
  • Engineering Reports
  • Construction Management
  • Treatment & Effluent Management
  • Reuse & Reclamation

Facility Types

  • Water and Wastewater Treatment Plants
  • Conveyance and Collection
  • Large On-Site Septic (LOSS) Systems
  • Pump Stations & Flow Control
  • Biosolids Management
  • Odor Control
  • Septic Tank Effluent Pump (STEP) Systems

Key Projects

Moses Lake Wastewater Treatment Plants

Engineering and construction management for two new wastewater treatment plants (4 MGD and 0.75 MGD), and a new central headworks facility.

Skagit Casino MBR Water Reclamation Facility

Engineering and construction management services for new membrane bioreactor (MBR) Water Reclamation Facility (WRF) that meets primary drinking water standards.

Ferndale WWTP Improvements

New Extended Aeration Wastewater Treatment Plant design and construction.

Port Gamble MBR/LOSS Wastewater Treatment Plant

Design, Construction, Permitting, and Value Engineering for a new 100,000 GPD MBR Package Plant.

Lake Whatcom Water & Sewer - AC Water Main Replacement

Provided design and construction phase services for replacing 13,000 feet of asbestos cement water mains in residential areas.

Ferndale WTP Reverse Osmosis Water Softening Project

Following a thorough evaluation of water chemistry and supply needs, reverse osmosis was selected as the best alternative for improving water quality.