When subsidence reports are received, staff will investigate the problem to determine if it was caused by an abandoned coal mine. Other potential causes of subsidence include rotting tree roots, water impoundment and drainage issues, broken utility lines, and improper preparation of building sites. The division is restricted by law to reclaim only those subsidence features caused by abandoned mines.
Sites where serious personal injury has occurred or appears imminent can be addressed through the Division’s Emergency Program. The Emergency Program was established to provide immediate assistance to secure the area from public access and mitigate the problem, generally within a few days. A private contractor may be contacted to perform the construction work.
Sites where personal injury is possible but not imminent can be addressed through the regular program. The law requires that each site undergo a series of reviews to identify any fish & wildlife, floodway, or archaeological issues at the site. A notice must also be placed in a local newspaper to allow for public comments. Due to the requirements of the review process, construction cannot occur until a few months after the initial site investigation.
For pit subsidences, reclamation typically involves excavating the subsidence to a stable base and backfilling with riprap and/or flowable fill. The area will be graded to allow for surface drainage and re-vegetated where appropriate. Sag subsidences that cover larger areas may require different reclamation methodology. Area sags that do not present a safety threat are given a lower priority and may not be scheduled for reclamation, but landowners may be able to obtain assistance through Partners for Reclamation.