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City of Tiffin Landfill
Tiffin, Ohio

Tiffin Landfill, Tiffin, Ohio Client: City of Tiffin, Ohio

Hull partnered with the City of Tiffin to negotiate a responsible site assessment and corrective measures strategy at a pre-1976 closed landfill owned by the city.  This was in response to Clean Water Act violations issued by Ohio Environmental Protection Agency (EPA) as a result of a verified citizen’s complaint.

Hull negotiated a responsible site assessment and corrective measures strategy at the closed landfill.  As part of the assessment, Hull completed:

• Site-specific and regional groundwater studies to establish a baseline understanding of site conditions and potential environmental impacts;
• conceptual site model;
• A groundwater monitoring program to monitor water quality and flow data, subsequently used in modeling and risk assessment studies;
• Surface water studies to model storm water flow and quality and its relationship to groundwater, as well as wetlands determinations/delineations, biotic integrity reviews and an assessment of the water quality and aquatic indicators in the Sandusky River; and 
• Studies to develop a conceptual model of how the landfill was constructed, materials managed at the site, and current conditions within the landfill, including leachate distribution, quality and physical landfill cap characteristics, storm water and surface water runoff, and the overall relationship between the landfill and its surrounding environs.

Hull also negotiated an innovative corrective measures strategy that has been implemented and was approved by the Ohio EPA as final in October 2008.  This strategy includes risk-based target cleanup standards for groundwater and alternate criteria for surface water discharges to wetlands.  Also, the strategy focused on appropriateness and cost and equivalency of the corrective measures, considering that it was an unregulated landfill with minimal cap design requirements.

Corrective measures implemented at the site included:

• Targeted landfill cover (cap) improvements to minimize infiltration of surface water runoff and to minimize leachate migration;
• Surface water and storm water management to improve drainage to minimize ponding of water;
• Landfill gas management to relieve gas pressure within the landfill;
• Wetland maintenance, monitoring and development of alternate discharge criteria to address surface and groundwater discharges to the wetland; and
• Institutional control to provide access and to allow a buffer zone between waste and adjacent properties. 

Cap enhancements focused on establishing positive drainage and were designed to make improvements away from areas where mature vegetation was present (materials were only added to achieve a 1976 OAC cap thickness).  Also, monitoring programs for various media were established to evaluate the performance of the corrective measures, and a contingency plan was developed.

The alternate discharge criteria approved by the Ohio EPA was the first approved in the State of Ohio and allows for a site-specific discharge standard to be determined and implemented at the landfill.  Furthermore, monitoring of the wetland’s hydrology, water and soil quality, and plant life is currently being performed as tool in the assessment of whether the landfill is negatively impacting the wetland or if the wetland is serving as a natural filter for the contaminants being discharged by the landfill.

 Due to the high level of interest by the local media and residents living near the landfill, Hull directed several events to help inform residents about results of landfill investigations and helped correct misinformation being disseminated in the community.  Hull established and maintained an information repository at the local library, held press conferences, a public meeting, and responded to media inquiries on behalf of the City.

To find out how Hull can help, please contact Hull's Landfill Engineering Practice Leader, Angela Gerdeman, PE at (419) 385-2018.