A Marcellus Shale drilling company resumed fracking operations Friday at a Wyoming County, PA, site where a breach in equipment caused thousands of gallons of fluid to flow from the uncontrolled natural gas well last month.
Carrizo Oil and Gas received permission from the Department of Environmental Protection to resume fracking at the Yarasavage pad in Washington Twp. after meeting with regulators and agreeing to make changes to improve its fracking procedures, the company said.
The company’s fracking operations throughout Pennsylvania remained on hold after a failure in an above-ground piece of well equipment called a “frac tree” on March 13 allowed about 200,000 gallons of fluids to flow from the Yarasavage well. That incident spurred an overnight evacuation of three families from nearby homes until workers could bring the well under control the next day.
Officials said they were able to capture most of the fluid in tanks at the site but some ran off the pad into an adjacent field and a roadside ditch. Water testing around the site is ongoing and regulators said they have found no clear signs of contamination during the “extensive” sampling performed so far.
“Carrizo will continue sampling for some time to fully evaluate whether there are any impacts to water resources,” DEP spokeswoman Colleen Connolly said. The company will characterize the environmental conditions at the site and remediate it if necessary as part of the clean-up process, she said.
Richard Hunter, a Carrizo spokesman, said the initial round of the company’s tests found “nothing unusual, nothing unexpected in the water.”
In the weeks since the incident, regulators and the company have learned more about its cause and impact.
The problem started while crews were in the 23rd stage of fracking the well, a process of injecting chemically treated water and sand underground at high pressure to crack the gas-bearing shale. Each fracking stage releases gas from a new section of a horizontally drilled well.
In a response to DEP’s request for more information about the incident, Carrizo said the equipment ended up breached at a flange that possibly loosened by pressure or temperatures cycles or vibration caused by the pumping operations during fracking. The sand-laden fluid, which DEP said was a mixture of fresh water, chemicals and acid when it injected into the well, rushed through the gap and began to erode other parts of the assembly.
The company collected about 360,000 gallons of fluid from the site, including a mixture of rain and snow melt and about 220,000 gallons Carrizo said originated in the well, Connolly said.
“Carrizo is implementing an increased preventative maintenance and inspection program during hydraulic fracturing operations to prevent a similar failure,” she said.
In a March 18 letter, DEP “strongly” recommended Carrizo halt its fracking operations in Pennsylvania “until the cause of this problem and a solution are identified,” a request the company honored. The agency also cited the company for violating environmental laws regarding fluid containment, surface water protection, waste management and well control.
The violation notice said the spilled frack fluid flowed into a ditch that receives shallow groundwater in a wetland, but Connolly said the department does not think any fluids or contaminants reached nearby streams.