Bill aims to add more protections for California groundwater from oil and gas drilling contamination

Feb 17, 2015

A new bill up for consideration in Sacramento is aimed at protecting groundwater from oil and gas drilling operations.

Roughly 60 percent of the oil pumped to the surface in California comes from Class II injection wells, according to the state. This oil field is in Kern County, Calif.
Credit Flickr/Ben Klocek

Central Coast Assembly Member Das Williams (D-Carpinteria) introduced AB-356 on Tuesday. It would require monitoring near Class II injection wells.

Currently, there are nearly 42,000 oil field injection wells operating in the state, according to the California Department of Conservation. These wells are designed to increase oil recovery and "safely dispose of the salt and fresh water produced with oil and natural gas" the department states.

Well over half of the oil produced in California is pumped from the ground through injection wells.

SB 4, which was signed into law by Governor Brown last September, set new rules for monitoring fracking or acidizing wells. Williams says his version builds on that program and would further protect local water supplies that he believes are currently at risk.

"Some of these wells in Santa Barbara County may be connected to potable water supplies, there are two that are particularly high likelihood," said Williams. "The most outrageous thing is that while the review is going on, they can continue to inject into these wells."

Current state and federal regulations allow some fluids produced during the production process to be injected into a Class II well. These fluids include:

  • Diatomaceous earth-filter backwash
  • Thermally enhanced oil recovery cogeneration plant fluid
  • Water-softener regeneration brine
  • Air scrubber waste
  • Drilling mud filtrate
  • Naturally occurring radioactive materials (NORM)
  • Slurrified crude-oil
  • Saturated soils
  • Tank bottoms

Earlier this month, the State of California revealed that 2500 wells around the state were found in violation of the Federal Safe Drinking Water Act.