Renewable Energy at Closed Landfills Workshop: Landfill Post Closure Use Critical Components July 26, 2012 John Carrigan MassDEP Northeast Regional Office

Critical Application Components What the DEP permit reviewer will be most focused on: Foundations Storm Water Controls Long-Term Maintenance

Foundations Must not compromise the function and integrity of the landfill cap/final cover system: Keep water out, Management of storm water runoff, and Keep landfill gas in. Must be structurally stable and accommodate loading/settlement.

Landfill Gas Control and Monitoring Plan Address Impact of Facility Design on Landfill Gas Controls and of Landfill Gas on the Facility Design criteria Public Health (toxic compounds in ambient) Safety (explosion, fire, asphyxiation) Welfare (nuisance odors) Landfill Gas Control and Risk Reduction Methods Engineering Management controls Monitoring

Geotechnical Analysis – Settlement & Stability Demonstrate No Adverse Impact to Final Cover and Design is Structurally Stable Site/Design Specific Geotechnical/Stability Analysis Pre and Post Construction Monitoring

Stormwater Controls Consider: the foundation design and density of development. location and orientation of power lines from development. Will these factors concentrate runoff and erosion potential or create water bars? Design for the 24-hour, 25 year storm event. Evaluate flooding potential from the 24- hour, 100 year storm event.

Long-Term Maintenance Maintenance ensures the continued functionality of the cap/final cover system and all of its components. Designed well: Maintenance should be minimal. Designed poorly: may need efforts to address instability, frequent erosion/cap repairs, and/or labor intensive vegetation control.

Post Closure Monitoring & Maintenance Plan Inspections professional engineer or qualified professional problems noted & scheduled for follow-up attention Routine Monitoring and Repairs mowing, removing brush and trees, reseeding storm water landfill gas collection system leachate collection system environmental monitoring system Post Closure Monitoring evaluate effectiveness of final cover system post closure use areas

IT’S NOT ROCKET SCIENCE Design Considerations Impact of the Facility on the Landfill Integrity and Function of the Cap, Landfill Gas and Storm Waster Controls Impact of the Landfill on the Facility Post-Closure Operation, Monitoring, and Maintenance of the Landfill including the Facility