Press Release, November 2016

Press Release

Study: Oil & Gas Wastewater Injection Cannot Safely Continue in Monterey County

A case study published by the Environmental Action Center (EAC) found that the Division of Oil, Gas, and Geothermal Resources (DOGGR) – California’s regulatory agency charged with overseeing the safe development of oil and gas resources – has failed to require oil and gas companies to safely dispose of their potentially toxic wastewater.  The case study examined DOGGR’s own records for an oil and gas wastewater disposal project in the San Ardo Oil Field and several other projects in Fresno County.  Among the major findings were that the San Ardo Oil Field has been experiencing overpressure problems since at least the early 1980s, and DOGGR has allowed several oil and gas operators to inject wastewater into injection wells without the data and documentation required under federal and state law.

The case study found several examples of regulatory failures, coupled with an accommodating agency culture, that negatively impacted DOGGR’s oversight of the oil and gas industry.  In Monterey and Fresno counties, DOGGR allowed oil and gas wastewater injection projects to continue despite evidence of technical deficiencies, injection zone pressure issues, and missing data and documentation.  These regulatory measures are not only required by law, but they are critical to safe operation.  Safe Drinking Water Act protections work to ensure that when oil and gas companies inject potentially toxic oil and gas wastewater underground, the wastewater remains separated from drinking water resources.  However, when regulatory agencies like DOGGR fail to collect required information from industry operators, and allow continued wastewater injection above safe pressures, they jeopardize vital water resources.

These findings come as Monterey County residents are slated to vote on Measure Z, which if passed would ban certain oil and gas activities in Monterey County – activities that produce large volumes of wastewater.  As demonstrated by EAC’s case study, regulators and the public should not tolerate continued wastewater injection in violation of federal and state law.  At a time when California’s scarce water resources are at risk, regulators and the public must use all available resources to ensure that underground sources of drinking water are protected from oil and gas wastewater contamination.


The disposal of wastewater produced during oil and gas operations is one of the most significant environmental impacts resulting from oil and gas exploration and production.  Oil and gas operations use millions of gallons of water each year, and industry operators are faced with decisions regarding how to dispose of that wastewater.  One of the most economical methods of oil and gas wastewater disposal – injecting the wastewater back into underground injection wells – is also one of the most problematic.

An aquifer, or an underground source of drinking water, needs to be exempted by the United States Environmental Protection Agency or equivalent state agency to be used as a geologic zone for underground wastewater disposal.  Generally, deep underground aquifers are not suitable for drinking water, while more shallow aquifers are.  This presents a problem when oil and gas wells are also shallow, as they are in Monterey County, because the disposed oil and gas wastewater is closer in proximity to underground sources of drinking water.  If allowed to migrate far enough upwards – through fractures created by injecting oil and gas wastewater into wells at excessive pressures – the wastewater could potentially reach more shallow underground sources of drinking water.

Read EAC’s report on DOGGR’s lack of oversight of oil and gas wastewater disposal wells HERE.

Read about oil and gas wastewater injection problems in Monterey County at Protect Monterey County.


  1. California’s Out of Control Underground Injection Well Program: EAC’s Petition for Rulemaking | Environmental Action Center – […] Petition for Rulemaking […]

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