DEP: MarkWest Liberty Midstream Reports 3 More Drilling Fluid Losses Into Mine Voids In Washington County; Total Losses Now 851,900 Gallons

On January 8, 9 and 10, MarkWest Liberty Midstream & Resources LLC notified DEP horizontal drilling operations on the construction of the shale gas-related Chiarelli to Imperial pipeline in Mount Pleasant and Robinson Townships, Washington County resulted in the loss of 117,300 gallons of drilling fluids into abandoned mine voids.

This brings the total number of reported incidents for this project to 16 with a total fluid loss of 851,900 gallons that began on October 27.

The incidents happened--

-- January 8, 2026 when 117,300 gallons were lost [DEP inspection report];

-- January 9, 2026 - no estimate of losses yet; and

-- January 10, 2026 - no estimate of losses yet.

MarkWest will continue drilling as a "practical solution" to the loss of drilling fluids.

DEP said “violations may be forthcoming pending further investigation.”

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.]

Related Articles Last Week:

-- DEP: MarkWest Liberty Midstream Reports Losing 197,000 Gallons Of Pipeline Drilling Fluid Into Abandoned Mine Voids In 3 Incidents In Washington County; Total Losses Reach 734,600 Gallons  [PaEN] 

-- DEP Issued Lazy Oil Company Violations For Abandoning 12 More Conventional Oil & Gas Wells In Butler, Venango Counties  [PaEN]  

-- DEP: Report Submitted By CNX Gas Company/Consol Coal Company On Cleanup Of A Major Shale Gas Wastewater Spill In Morris Twp., Greene County Failed To Show It Met  Act 2 Cleanup Standards  [PaEN]

Related Article This Week:

-- DEP: Rice Drilling (EQT) Failed To Plug Abandoned Shale Gas Well For Over 5 Years In Washington County  [PaEN] 

-- DEP: MarkWest Liberty Midstream Reports 3 More Drilling Fluid Losses Into Mine Voids In Washington County; Total Losses Now 851,900 Gallons  [PaEN] 

-- DEP: Truck Loses Load Of Shale Gas Wastewater On Access, Local Road To EQT Sarah Well Pad In Union Township, Washington County  [PaEN] 

-- DEP Day 239: Seneca Resources Wastewater Cleanup, Monitoring Efforts Continue At Vandergrift Shale Gas Well Pad In Charleston Twp., Tioga County  [PaEN] 

[Posted: January 13, 2026]  PA Environment Digest