Skip Navigation LinksWilldan Engineering | Total Water Resources | Wastewater Management


Willdan offers a broad range of engineering services for the planning, design, inspection, evaluation, and rehabilitation of sewage systems, wastewater collection, and sewage lift stations, as well as financial, legal, political, regulatory, security and technical requirements.

Representative Projects

City of La Canada Flintridge, Sanitary Sewer System in 5 Districts — Los Angeles County, California

La Canada Sewer System construction

APWA Southern California Water/Wastewater Project of the Year

This ongoing city-wide project to replace aging septic tanks received the Project of the Year award from the American Public Works Association Southern California branch in 2004 in the category Water/Wastewater Projects for a population under 30,000. For Districts 1 and 2, which improved 2,300 homes and businesses, Willdan provided complete turn-key services that included conceptual planning, final design, construction management, and the formation of two assessment districts in compliance with Proposition 218. We also directed an extensive public relations program, involving community meetings, newsletters, informal ballots, and lateral and septic tank location mailings.

Willdan also performed preliminary and final engineering services for Districts 3-5.

City of Sierra Madre, Sewer System Management Plan — Los Angeles County, California

Willdan assisted in the City’s compliance with SWRCB Order No. 2006-0003-DWQ “Statewide General Waste Discharge Requirements for Sanitary Sewer Systems,” which required each sewering entity to develop and implement a Sewer System Management Plan. The process involved review and evaluation of all sewer system related codes, policies, practices, mapping, reporting, records, financing and public information dissemination. The objective was to develop composite reference and training guidelines that would be used by the City to meet its sewer system operations and maintenance criteria, and to prevent/reduce the risks and impacts associated with sanitary sewer overflows. Willdan also provided an update to the City’s Master Plan of sewers, a thorough cleaning and CCTV inspection of the entire sewer system, and six flow monitoring measurements to validate the system.

Representative Projects

Morongo Band of Mission Indians, Wastewater Treatment Plant — San Bernardino County, California

Morongo Wastewater

The wastewater portion of the project involved the Design/Build of a 0.75 mgd plant with a 900 mg/l BOD load. The project management included sizing the plant, writing the Request for Proposal, reviewing the bids and assisting the Owner with the selection of the design/build firm. As Owner's Representative, Willdan also coordinated the plan check, inspection and processing pay estimates and change orders plus assisting the owner with the negotiation of the operations contract.

Covina Citywide Sewer Replacement - Los Angeles County, California

APWA Southern California Water/Wastewater Project of the Year, 2013

The largest sewer pipe-bursting project in Southern California and possibly statewide, this project accomplished 32,000 feet of sewer pipe replacement to overcome capacity constraints. Pipe bursting was the replacement method for 85% of the pipe while the remaining 15% was traditional open trench. Cost savings to the community was about 50% of the bid for traditional open trench placement, and with fewer traffic impacts.

Willdan provided both civil design and construction management/observation services. Since the project was funded using revenue anticipation bonds, our Willdan Financial Services Division is supporting the City in meeting its bond compliance requirements and reporting.