The project area in the 900 block of Cherry Street in Palmyra Borough has suffered from sinkholes on a regular basis for more than 50 years. Stormwater naturally drains to the location because of its low elevation, and because of flooding problems, the Borough constructed a stormwater injection well in the late 1960s. For the past three decades, this situation stalled all development in the area, relocated a residence, and the Borough repaired sinkholes as they occurred. Recent development of a roadway extension and stormwater detention basins, along with Tropical Storm Lee in 2011, added to the stress on the well.

RETTEW conducted an investigation of the injection well and determined the well was actually facilitating sinkhole development, instead of preventing it. As the Municipal Engineer for the Borough, with ongoing relationships and an understanding of the community’s unique needs, RETTEW was the obvious choice for identifying a replacement area for the injection of stormwater. Our team of experts discovered a significant cavern 365 feet below the surface able to meet the stormwater injection requirements. RETTEW sited, designed, permitted, and installed a new well, and designed a stormwater quality basin. Our analysis, design competency, and permitting expertise will save the Borough hundreds of thousands of dollars in future sinkhole repair.