When the City of Ripon’s Well 19 was constructed in 2022, it was permitted by the State of California to supply drinking water that following year.

Located at Mistlin Sports Park, the well was discovered to have two water quality issues – Chromium 6 and nitrates.

No discussion was necessary at the Nov. 10 Ripon City Council meeting on bringing in the Stantec Consulting Services to evaluate the water quality of Well 19 in the amount not exceed $52,069 paid via the Water Enterprise Capital Fund.

Public Works Director James Pease said in his report that Chromium 6 is an odorless and tasteless metal that occurs naturally throughout the environment. He noted that some contaminated waste from certain industrial activities could also contribute to ground water contamination – the State Water Board have recently established for Chromium 6 in public drinking water systems.

“The City was required to conduct initial monitoring for all of its drinking water wells and the only well impacted by these regulations is Well 19,” Pease said.

California water suppliers with systems the size of Ripon, meanwhile, are not required to meet these new regulations until October 2027 – suppliers, however, are still required to perform prescribed water quality testing prior to this date, Pease added.

Based on the testing completed to date, he’s anticipating the concentration of Chromium 6 in Well 19 to be very close to or exceed the State of California regulatory Maximum Contaminant Limit.

The nitrate concentration had increased since the well went into service and based on the trending data would likely exceed the regulatory MCL in the near future if the well continued to be used as a primary water source.

Pease said that Public Works have already taken steps to use Well 19 only as a stand-by until the completion of the investigation to evaluate options.

Stantec Consulting Services will sample and analyze two monitoring wells and the production of Well 19.

Consultants would then give some direction and oversight of sampling activities while also providing a technical memorandum and recommendations. 

They’ll also develop a vertical well profiling program based on the initial same results and recommendations in order to identify the specific quality of water within each screened interal.

In addition, they’ll present options for well modifications that would eventually allow the City to use Well 19 as primary water source – in order to do so, Well 19 would have to meet all state and federal regulatory concentrations for Chromium 6 and nitrates.