Pipeline construction of Sunoco’s Mariner East 2 has caused three separate releases of drilling mud in May, with two incidents resulting in a combined total of 575 gallons of bentonite clay entering Chester Creek in Brookhaven, Delaware County, according to Sunoco Pipeline spokesman Jeff Shields. Bentonite is a non-toxic substance commonly used as a lubricant in horizontal directional drilling. Substantial amounts of bentonite released into waterways can impact aquatic life, especially organisms that live on the bottoms of streams and wetlands.
No fish were killed as a result of the leaks, referred to as “inadvertent returns,” according to the Pennsylvania Department of Environmental Protection.
Sunoco Pipeline spokesman Jeff Shields says the company doesn’t “anticipate any harm to the environment” resulting from the releases.
“Inadvertent returns of bentonite mud are an occasional component of directional drilling operations,” wrote Shields in an email. “Due to subsurface conditions and other geologic conditions of the locations, drilling mud is sometimes able to migrate through naturally occurring fractures in the soils and return to the surface.”