top of page

Wastewater Treatment Facility Improvements Project

Construction Completion – Spring 2020


The Mariposa Public Utility District (MPUD) Wastewater Treatment Facility (WWTF), constructed in 1983, requires significant unit process modifications to comply with final effluent water quality limitations specified in the State and Federal discharge permit for the facility.  MPUD began working on Facilities Plan, environmental documentation, design and funding applications 2008.  Project schedules were interrupted by the Friends of Mariposa Creek vs. MPUD lawsuit filed in 2014. (See FMC vs. MPUD News Release on the web page.)  The project features include: nitrate reduction, filtration, temperature control, ultraviolet light disinfection (to replace existing chlorination systems), replacement and modernization of electrical and control systems.


The MPUD Board of Directors awarded the construction contract for the Wastewater Treatment Facility Improvements Project phase 1, to Clark Bros. Inc. of Fresno, California in the amount of $8,556,000.  Construction began in September 2018 and is scheduled to be completed in March 2020.


The project was bid for the second time on May 31, 2018 as a phase 1 of a 2-phase project. The second phase may be completed in the future, as facility capacity, needs to be increased.  Plant capacity after phase 1 completion is 0.30 MGD.   Proposed project estimates (Phase 1) were approved by the Board with a MPUD cost share component added to the project of $621,000 with loan funds of $3,030,000 and grant funds of $6,000,000 for a total project cost of $9,651,000. The loan is scheduled to be paid off in 30 years at 1.7% interest.  The Board has approved additional MPUD cost share of $149,881.


Funding for this project has been provided by the Clean Water State Revolving fund through an agreement with the State Water Resources Control Board.  California’s Clean Water State Revolving Fund is capitalized through a variety of funding sources, including grants from the United States Environmental Protection Agency and state bond proceeds.

bottom of page