Test area shrinks for drilling near Rulison nuke site
A revised Colorado Oil and Gas Conservation Commission plan of testing for radioactivity by oil and gas companies operating near the site of a 1969 underground nuclear blast test site in Garfield County shrinks the area where such testing is required.
The revision, completed in July, also eliminates ground and surface water monitoring requirements, saying other testing requirements make them unnecessary.
The area subject to testing has been reduced from 25 square miles, encompassing a circular area extending three miles in all directions from what’s known as the Project Rulison blast site, to an oval area of just under 6.3 square miles, and ranging from 1.5 to two miles away from the site.
The revised plan also gets rid of a limit on the number of drilling rigs concurrently operating in the monitoring zone “because this has not been an administrative problem in recent years,” it says.
Project Rulison involved the explosion of a nuclear bomb more than 8,000 feet underground in the mountains south of Rulison in a federal/private experiment to try to boost natural gas production in the Williams Fork sandstone formation. The project succeeded in producing gas, but it was radioactive and was flared off as part of the experiment.
More recently, energy companies have extensively produced gas in the Williams Fork formation through the use of hydraulic fracturing to crack open the sandstone and foster gas flow.
The federal government restricts drilling deeper than 6,000 feet in a 40-acre area at the blast site. Currently there are no wells within a half-mile of Project Rulison, and any applications to drill that close would be subject to a state oil and gas commission hearing process.
The state also subjects companies to two levels of sampling and testing requirements for radioactivity when it comes to things such drilling cuttings, produced gas and produced water. One level has applied to wells within a mile of the blast site, and it continues to apply under the new plan.
The second level had applied to an arbitrary circular testing area having a three-mile radius, but the revised plan says it now applies to a smaller ellipse aligned with the pattern for fractures in the Williams Fork formation in the area of the blast site.
The plan also eliminates an environmental monitoring program for ground and surface water, stating that “there is no credible mechanism to transport Rulison-related activity to the surface except through natural gas production,” which the sampling plan already covers.
The plan says numerous monitoring studies conducted by federal agencies and oil and gas companies show that “no known release of radionuclides has occurred from Project Rulison,” except during natural gas flaring and production tests immediately following the blast.
The monitoring program is intended to protect workers, the public and the environment during oil and gas operations, the plan says.