Class A Biosolids Treatment System and WWTP Upgrades

Compliance and revenue generation come with Varela’s wastewater treatment plant upgrade

The City of Oroville’s 30-year-old treatment plant was facing compliance issues with its biosolids disposal program and was required by regulators to complete facility upgrades. The City’s biosolids program included direct wasting of solids from the WWTP secondary clarifier to a City truck for land disposal.

Varela worked with the City on several improvement options to bring the City into compliance, as well as options for modernizing some of the plant components. Options included both Class A and B systems.

The City liked the flexibility of producing Class A biosolids and had local opportunities for application and selling of the Class A biosolids.

The selected process includes lime stabilization, polymer injection/flocculation, gravity thickening, and screw press dual function of dewatering and heated pasteurization. The selected process was produced and manufactured by FKC Systems.

Varela helped the City acquire CDBG grant funding and other funding for the project; completed pre-purchase procurement for the equipment; and designed and provided construction engineering for the project.

Project elements include:

Evaluation of Biosolids Alternatives and Engineering Report
Comprehensive evaluation of Class “A” and Class “B” alternatives
Cost estimating and comparison of alternatives
Class “A” Treatment System selection
Implementation scheduling and funding acquisition planning
Engineering Report/Ecology approval

Funding Applications and Assistance
Total project $1.9 Million
Provided assistance administering PWTF loan funding
Application and procurement of $900,000 CDBG ARRA grant and funding administration

Design

Biosolids treatment facility; FKC Class “A” treatment system; screw press, boiler skid, polymer injection, etc.
WAS upgrades; pH adjustment equipment and holding tank
Conversion of clarifier to sludge storage and aeration facilities
Electrical controls and upgrades
Site improvements, Class “A” biosolids storage, loading and transporting
Geotechnical investigations and specialty considerations

Construction