Guest Blog: Water Regulator Confirms No Contamination of Groundwater; SF Chronicle Headline Suggests Opposite

Note: Energy in Depth and the Bakersfield Californian have covered this issue previously.

A recent San Francisco Chronicle alarmist headline concerning the state’s regulation of injection wells – “State let oil companies taint drinkable water in Central Valley” – has exacerbated fears that are unwarranted and not in line with the facts.

State regulators have successfully regulated injection of produced water from oil and gas operations for decades. To date, there has not been a single case where the state has allowed injected water to taint drinkable water.  The U.S. Environmental Protection Agency (EPA) has asked the state to help it update the paperwork used to regulate the practice and the state has developed a work plan to do so.  Those are the facts.

The headline of the article falsely suggests that state regulators have allowed oil and gas companies to “taint drinkable water.”  The article, however, not only fails to cite one incident where this has been the case, but goes on to admit that the opposite has actually been shown.  After numerous tests of water wells that lie above injection wells, the State Water Resources Control Board stated in a Sept. 23 report:

“Thus far, the test results indicate that the injection wells have not degraded groundwater quality in the tested water supply wells.” [emphasis added]

There are thousands of fully permitted injection wells used by the oil and gas industry in California.  The water reinjected is simply the water that was naturally in the rock and comingled with the oil and natural gas. The oil and gas are removed from the water and it is reinjected back from where it came, cleaner than it was when it was initially removed.

Produced water can only be reinjected into zones where the water is not suitable for drinking. Typically, the produced water is reinjected right back into the same oil-bearing zone from which it came.  When produced water is injected into a different nearby zone, state regulators examine the geology of the zone to ensure it is proper for injection.  This same practice is occurring with U.S. EPA’s permission and oversight in all oil and gas regions of the country.

The Chronicle article mistakenly defined “drinkable water” as any water below 3,000 Total Dissolved Solids (TDS).  But those with knowledge of the science behind what constitutes drinkable water know that TDS levels are only one of many criteria that determine water quality.  Water containing oil and gas is not “suitable for drinking” regardless of its TDS level.

Last July, the State Water Board and the Division of Oil and Gas did a review of all injection wells and identified only 11 wells out of thousands in the state that were installed near sources of potential drinking water.  Even though the injection occurs thousands of feet below the water wells and aquifers, out of an abundance of caution, the state agencies shut down those wells and ordered tests to see if any of the injected fluid had migrated to those water supply wells.  As noted in the Chronicle’s article, they found they had not.

There are occasions when the produced water is of a high enough quality that it has a beneficial reuse.  Currently, oil producers are providing over 30,000 acre feet of water each year to farmers in Kern County to irrigate their crops.  Oil companies are providing this desperately needed resource during our drought that otherwise would stay in the ground and be unavailable to farmers.

There are tens of thousands of injection wells in the Western US used by many different industries and government municipalities.  Unlike oil and gas injection wells which inject mainly naturally occurring fluid thousands of feet below the surface, many non-oil and gas injection wells inject both hazardous and non-hazardous waste that are created into shallow formations.  The US EPA is the permitting agency for many of these types of wells.  Interestingly, neither activist groups nor the San Francisco Chronicle have expressed any concern about any of the other 30,000 plus injection wells.

Rather than being a threat to the environment, the entire issue outlined in the Chronicle article is predominantly about updating paperwork issues stemming from the existence of 35 year-old documents.

Over time, more has become known about the actual geologic boundaries of the oil and gas producing aquifers and the state permitted new wells that were near the original map boundaries.  However, the map boundaries didn’t keep up with new geologic knowledge.  The work plan the state will be presenting to the US EPA this week will outline how the state will conduct a review of all those permits to allow the US EPA to concur that those zones are proper for injection.  If any are found to threaten drinking water sources, they will be shut down.  Given the nature of deep injection wells in California, it’s unlikely many, if any, will pose such a threat.  All the testing to date has shown no harm.  Industry is committed to assisting the state and US EPA to conduct this review and solve this paperwork problem.


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