WEST CHESTER, PA — The recurring development of sinkholes near or beneath roadways in the East Whiteland Township area is all the more reason why the region is the wrong place for pipelines, state Senator Andy Dinniman said this week.
Karst is a geologic term for an area underlain by limestone that has been eroded by flowing water, producing sinkholes, caves, and fissures. This makes drilling risky due to gaps, ridges, and channels in the limestone.
PennDOT is currently planning to reconstruct a portion of State Route 29 (Morehall Road) to correct existing sinkhole and pavement subsidence issues driven by the local karst geology.
The project, which is set to begin this spring, is located between the Pennsylvania Turnpike/State Route 29 Interchange and the North Atwater Drive/General Warren Boulevard intersection.
Dinniman, who sits on both the Senate Transportation and the Senate Environmental Resource and Energy Committees, said it was no coincidence that in the Route 30 corridor, a region known for its unique karst geologic formation, pipeline construction has resulted in the contamination of almost two dozen wells, damage to aquifers, and the development of an expanding sinkhole that currently threatens at least two private homes and is within 100 feet of Amtrak’s Keystone Line.
In fact, from the beginning, both Sunoco and DEP were aware of the potential risks surrounding horizontal direct drilling given the underlying karst geologic formation.
“Karst area near Exton and the East Whiteland compressor branch present additional risks of IRs (inadvertent releases) during HDD (horizontal directional drilling),” read a DEP analysis of pipeline construction filed Feb. 6, 2017.
And later, the very company that Sunoco hired to reevaluate its project in East and West Whiteland concluded that there is just not enough information on the extent of the karst formation to determine its risks.
In the HDD Hydrogeologic Reevaluation Report dated October 16, 2017, Groundwater Environmental Services, Inc. (GES) stated that, “A geophysical study is required to determine the extent of the karst development along the profile, especially in light of installation challenges that are being experienced due south, including excessive groundwater discharge; loss of fluids, and difficulties steering the pilot hole.”
“At the same time that we’re pouring millions of taxpayer dollars into our transportation infrastructure, including significant upgrades to the Keystone Line and major improvements to highways, the current administration is letting a pipeline company resume drilling in an area that is known to be geologically problematic. In some cases, the pipeline crosses directly under our rail system and our highly-traveled roadways,” Dinniman said. “And yet, drilling was and is allowed to continue. It truly boggles the mind.”
Regarding the Route 29 sinkhole, Dinniman thanked PennDOT for its thorough study of the issue and for keeping the public informed of its construction plan.
The work schedule for that project is as follows:
- This spring work crews will reinforce the southbound shoulder of Route 29 in order for the pavement to carry traffic in later stages of construction. Other pre-stage work will involve drainage improvement and the relocation of underground utilities. Short-term lane closures will occur during off-peak hours.
- Beginning in early June, crews will begin excavating and rebuilding the northbound travel lanes while performing sinkhole remediation and other geotechnical treatments. During this phase, the northbound and southbound travel lanes of Route 29 will merge from two to one lane with the work zone around the clock.
- Beginning in mid-July, crews will begin excavating and rebuilding the southbound travel lanes while performing sinkhole remediation and other geotechnical treatments. During this phase, the northbound and southbound travel lanes of Route 29 will remain merged from two to one lane with the work zone around the clock.
All construction activities that require travel restrictions are scheduled to be completed by August 2018.
The contractor for the $2.69 million contract is Allan A. Myers, LP.
For more information on the Route 29 project, visit http://www.charlestown.pa.us/roads_2017_rt_29_sinkhole_repair.aspx.
Source: Andrew E. Dinniman (D), Pennsylvania State Senate, Senate District 19
Thanks for visiting! MyChesCo brings reliable information and resources to Chester County, Pennsylvania. Please consider supporting us in our efforts. Your generous donation will help us continue this work and keep it free of charge. Show your support today by clicking here and becoming a patron.