PA Environment Digest Blog: DEP: Blackhill Energy LLC 2nd ‘Inadvertent Return’ During Horizontal Drilling Of Brad-Tenn Loop Pipeline In Bradford County

On September 29, 2025, Blackhill Energy LLC notified DEP of a second inadvertent return of bentonite drilling mud from horizontal drilling of the Brad-Tenn Loop Pipeline this time in West Burlington Township, Bradford County. DEP’s Sept. 30 inspection report.

On September 8, DEP was notified by Blackhill Energy of an “inadvertent return” from horizontal drilling during construction of the same pipeline in Granville Township, Bradford County that resulted in an 18,000 gallon spill. Read more here.

The second inadvertent return occurred while boring 40 feet under Sugar Creek and Route 6 when approximately 100 gallons of mud returned to the surface.

However, to recover the drilling mud, “Two water trucks were utilized to recover the mud. A crew worked to add freshwater to the mud to allow the water trucks to easily pump it.

“One of the trucks was pumping directly from the area where the mud continues to come to the surface while the other was used to clean up the surrounding area.”

No impacts to Sugar Creek or a nearby wetland were observed during the inspection, but “Blackhill Energy continues to monitor the resources in the area.”

DEP requested a “more accurate estimate” of the amount of mud that spilled during the incident.

“Blackhill Energy had silt fence, hay bales and sand bags installed around the direct area where mud was coming to the surface.”

DEP’s inspection report said horizontal drilling activities were “ongoing during the inspection.”

“Blackhill Energy plans to finish the last sections of the bore and continue recovering the mud as it comes to the surface.”

DEP marked violations related to the inadvertent returns as “recurring” and continuing since the violation was issued for the September 8 incident.

No response from Blackhill Energy was requested by DEP. DEP inspection report..

DEP Trenchless Drilling Guidance

In February 2024, DEP adopted new technical guidance on the planning and operation of pipeline construction projects using trenchless technology. Read more here.

The guidance was supposed to reduce the significant problems experienced with natural gas pipeline construction all across the state, but in particular with the Energy Transfer/Sunoco Mariner East Pipelines.

The guidance includes sections on site suitability and alternatives analysis, emergency response planning, risk evaluation to water supplies and other features and more.

It is not known whether Blackhill Energy was following this guidance for this project.

Visit DEP’s Trenchless Technologies Resource Page for more documents related to the technical guidance.

Report Violations

To report oil and gas violations or any environmental emergency or complaint, visit DEP’s Environmental Complaint webpage.

Text photos and the location of abandoned wells to 717-788-8990.

Check These Resources

Visit DEP’s Compliance Reporting Database and Inspection Reports Viewer webpages to search their compliance records by date and owner.

Sign up for DEP’s eNOTICE service which sends you information on oil and gas and other permits submitted to DEP for review in your community.

Use DEP’s Oil and Gas Mapping Tool to find if there are oil and gas wells near or on your property and to find wells using latitude and longitude on well inspection reports.

[Note: If you believe your company was listed in error, contact DEP’s Oil and Gas Program.]

[Note: These may not be all the NOVs issued to oil and gas companies during this time period. Additional inspection reports may be added to DEP’s Oil and Gas Compliance Database.]

Resource Links - Inadvertent Returns

-- DEP: Blackhill Energy Pipeline Horizontal Drilling Accident Results In 18,000 Gallon Spill In Granville Twp., Bradford County [PaEN]

-- DEP: 3rd & 4th Spills From Horizontal Drilling At EQM Gathering Pipeline Project In Washington County; Overflowing Tanks; Water Supply Complaint Investigated [PaEN]

-- DEP: Second Spill From Horizontal Drilling At EQM Gathering Pipeline Construction Project In Washington County Contaminates Spring [PaEN]

PA Oil & Gas Industry Public Notice Dashboards:

-- PA Oil & Gas Weekly Compliance Dashboard - Sept. 27 to Oct. 3 - 940,000 Gallon Shale Gas Wastewater Spill; Order Ceasing Production Of 551 Conventional Wells; Is Conventional Well Owner Abandoning 475 Wells In 6 Counties? [PaEN]

-- PA Oil & Gas Industrial Facilities: Permit Notices, Opportunities To Comment - October 4 [PaEN]

-- DEP Opportunity To Bid On Plugging 15 Abandoned Conventional Oil, Gas Wells At Taxpayer Expense In Butler County

-- DEP Invites Comments On Air Quality Permit For 77 Emergency Power Generators At The Amazon Data Center In Salem Twp., Luzerne County [PaEN]

-- DEP To Hold Nov. 14 Hearing On Renewal Of An Air Quality Permit For The Coal, Natural Gas-Fired Brunner Island Power Plant In York County [PaEN]

-- DEP Invites Comments On An Air Quality Permit For The Tenaska PA Partners, LLC Natural Gas-Fired Power Plant In Westmoreland County [PaEN]

-- DEP Accepting Comments On The Renewal Of An Air Quality Permit For The Wolf Run Energy, LLC Natural Gas Power Plant In Bradford County [PaEN]