Posted on May 1, 2015 by Mark Walker

Oklahoma has quietly earned the dubious distinction of earthquake capital of the Lower 48, having surpassed California last year.  In 2014, Oklahoma had 585 earthquakes of magnitude 3.0 or higher compared to California’s 180.  The cause of this dramatic rise in seismic activity, and whether it is induced by human activity, particularly by oil and gas operations, has been the subject of much discussion and scientific study.

When I last blogged about this subject (June 2014) the U.S. Geological Survey (USGS) and the Oklahoma Geological Survey (OGS) had just issued a joint warning of the increased risk of a M5.5 or greater earthquake in central Oklahoma, stating that the science suggests that a “likely contributing factor” to the increase in earthquakes is injection of oilfield wastewater into deep geologic formations.  Despite several sensational articles implying that industry has exercised undue influence over the OGS and its scientific conclusions, on April 21, 2015, the OGS issued a statement in which it reiterated the view that “the primary suspected source of triggered seismicity is…from the injection/disposal of water associated with oil and gas production…the OGS considers it very likely that the majority of recent earthquakes…are triggered by the injection of produced water in disposal wells . . . .”

On April 23, 2015, the USGS released a new report which again noted the connection between earthquakes and certain deep disposal wells, but concluded that, “induced seismicity does not occur near every disposal well, so it is important that we continue to study and learn more about how these earthquakes are generated…These changes may be related to oil and gas exploration activity but they also may depend on physical processes, which are poorly understood…many questions remain”.

As the science develops, the Oklahoma Corporation Commission (OCC), which regulates oil and gas wastewater disposal wells in Oklahoma under the SDWA Underground Injection Control program, has taken an aggressive approach.  The OCC has identified “areas of interest”, which are areas within 10 kilometers of any earthquake swarm.  Eight areas of interest encompassing approximately 112 square miles have been identified.  On March 12, 2015, the OCC sent letters to operators who dispose of oilfield wastewater into the deep Arbuckle formation within these areas of interest directing that they provide information from which it can be determined whether such disposal is in communication with the underlying crystalline basement rock.  If it is, the OCC is requiring that disposal into the Arbuckle be discontinued.  Failure to produce the information results in immediate curtailment of disposal by 50%.

With the downturn in crude oil prices, most companies have dramatically cut back on drilling and completing new wells.  This downturn itself may provide a scientific opportunity to see if reduced oilfield activity produces fewer earthquakes in Oklahoma.

Another Temporary Truce in the Arkansas/Oklahoma Water Wars

Posted on April 25, 2013 by Allan Gates

After decades of sparring over nutrient loading in the Illinois River, and following several short term extensions of a previous truce, Arkansas and Oklahoma recently executed an agreement, the “Second Statement of Joint Principles and Actions”, that establishes a procedural framework for attempting to resolve their long running trans-boundary water quality dispute.

The Illinois River heads up in a rapidly developing section of Northwest Arkansas and flows west into a comparatively undeveloped portion of Northeast Oklahoma, where the river is designated by state statute as a scenic river.  For more than two decades Oklahoma has worked to reduce the amount of nutrients, and particularly phosphorus, discharged into the Illinois River watershed.  In 2002 Oklahoma adopted a numeric water quality criterion for Total Phosphorus that many considered impossible to attain in a developed watershed.  In an effort to avoid litigation over the validity of the numeric criterion, Arkansas and Oklahoma entered into an agreement in 2003 known as the Statement of Joint Principles and Actions.  This agreement provided, among other things, that:  (i) Oklahoma would postpone for 10 years the date on which the numeric criterion would be fully effective; (ii) Arkansas sources would take a number of steps to reduce phosphorus discharges; and (iii) Oklahoma would review the existing numeric criterion, with an opportunity for Arkansas representatives to participate, before the end of the ten year period to determine whether the numeric criterion should be changed.

The ten year truce created by the Statement of Joint Principles and Actions was originally scheduled to expire in July 2012.  During the ten year period Arkansas sources made significant progress in reducing the amount of phosphorus they discharged in the watershed.  As a result, phosphorus levels in the Illinois River began to decline and most observers agreed that conditions in the river were significantly improved.  Towards the end of the ten year period Oklahoma undertook a review, with full participation by representatives of Arkansas, EPA, and the Cherokee Nation.  The review ended in a sharply divided report, with Oklahoma representatives stating that no change in the numeric phosphorus criterion was warranted and Arkansas representative stating that significant change was necessary.

As the end of the ten year truce approached, officials from Arkansas and Oklahoma began negotiations once again on how to avoid litigation.  Focus on the potential for costly litigation was sharpened by the fact that EPA had publicly commenced work on a Phosphorus TMDL for the entire Illinois River watershed.  After several agreements on short term extensions of the July 2012 deadline, Arkansas and Oklahoma reached agreement in February 2013 on a Second Statement of Joint Principles and Actions.  This new agreement provides, among other things, that Arkansas and Oklahoma will fund a joint three year water quality study using EPA protocols to determine the threshold Total Phosphorus levels at which shifts in algal species or biomass production occur that result in undesirable aesthetic or water quality conditions.  Oklahoma and Arkansas agree in the Second Statement to be bound by the findings of the joint study, and Oklahoma agrees to adopt a new numeric criterion for Total Phosphorus in the Illinois River if the results of the joint study are significantly different from the existing criterion (i.e., more than -0.010 mg/l or +0.010 mg/l than the existing .037 mg/l criterion).  During the term of the Second Statement of Joint Principles and Actions, both states agree not to initiate or maintain litigation contrary to the terms of the agreement, and the statute of limitations on all claims is extended.  Oklahoma agrees that it will postpone for the duration of the new agreement the date on which its existing, hotly disputed numeric criterion is to be fully effective.

EPA was not a party to the negotiation of the new agreement and it has not announced any formal position on its effect.  It is not clear what impact the new agreement will have on EPA’s work to develop a TMDL for Phosphorus in the Illinois River watershed or on the various NPDES permits for POTWs on the Illinois River that are currently pending review in EPA Region 6.