Steps could be taken Tuesday by the Ripon City Council that could ultimately allow Well 3 to produce safe drinking water.

Corona Environmental Consulting could be awarded a $72,670 contract to prepare design support, preparation of a technical report and operations plan as well as completion of a treatment system data sheet for the well.

The work covered in the contract is a precursor to installing two granular activated carbon filters at Well 3 to treat the water and allow the well to be returned to potable water service. The California Department of Drinking Water must review and approve the treatment system and operations plan before the well can be placed back in service.

Well 3 is one of the City’s drinking water supply wells.

Water quality testing at Well 3 has detected trichloroethylene (TCE) and cis-1,2-dichloroethylene (cis-1,2-DCE), which are both associated with the Nestle groundwater contamination.

Although concentration of both constituents have remained below federal and state Maximum Contaminant Levels (MCLs), concentrations have increased in recent years and could exceed the applicable MCLs in the future.

In response, the City proactively discontinued production of Well 3 to further evaluate the well and determine the best approach for future use based on concentration trends of TCE and cis-1,2DCE. This will help ensure the City can continue to provide a reliable and safe drinking water supply.

Well 3 also contains per-and polyfluoroalkyl substances (PFAS). California is currently developing regulatory MCLs for PFAS.

Because the final PFAS MCLs and the timing of compliance requirements have not yet been established, the wellhead treatment system will be designed to reduce PFAS concentrations to levels that are below the anticipated regulatory requirements.

The cost of the contract will be covered by Ripon’s water maintenance and operations fund.

To contact Dennis Wyatt, email dwyatt@mantebulltin.com