When the City of Greenfield set out to expand and modernize its wastewater treatment plant, the project team anticipated the usual environmental and geotechnical challenges that accompany large utility improvement projects. What they didn’t expect to find was a former unregulated dump site, long forgotten but still causing environmental and geotechnical challenges.

During preliminary geotechnical investigations, SME’s team encountered unexpected fill material containing trash and debris. Recognizing the potential implications, our Environmental Consulting team was brought in to evaluate the extent of the waste and its impact on the planned construction. Through geophysical testing and targeted test pits, SME identified the area as a “Closed Open Dump”, an old, unregulated disposal site that had never been officially closed or capped.

SME worked closely with the Indiana Department of Environmental Management (IDEM) to delineate the dump, manage excavated waste materials, and develop a closure and maintenance plan that met regulatory expectations. SME’s environmental field staff remained onsite during mass excavation to verify that unsuitable materials were removed to natural soil, track disposal manifests, and oversee the careful segregation of reusable clay fill, reducing both disposal costs and imported material needs.

As work progressed, a second nearby dump area was identified. SME again partnered with the City and IDEM to address this additional site, ensuring compliance and continuity so construction could continue safely and responsibly.

Through collaboration and practical problem-solving, SME helped keep the City of Greenfield’s essential utility improvements on track. The new wastewater treatment plant will serve as a sustainable foundation for the city’s growth.