Liquids Management – Integrated Landfilling and Leachate Management

Frederick County Sanitary Landfill

Frederick County is a repeat client for SCS for over 20 years. Currently, SCS works on the County’s three landfills: Permits 40 (MSW, unlined, closed), 529 (MSW, Subtitle D design, active), and 591 (CDD, active). The facility encompasses about 1,000 acres. The facility’s disposal limit is 1,600 tons/day (1,000 tons/day for Permit 529).

The County has faced several challenges over the years supported by SCS. The most recent and prevalent challenge has centered on liquids management. Rainfall amounts in 2018 were at record levels, which inundated the landfill’s capacity for leachate management.

Outcomes and Benefits
SCS has worked with the County to face this challenge using an integrated landfilling and leachate management approach. Rather than rushing to treatment and disposal of leachate, we first took a step back to assess the bigger picture. We ultimately recommended to first minimize the creation of leachate by targeting it at its source. Our studies determined that leachate volumes could be reduced by preventing stormwater and groundwater from infiltrating into the landfill. This holistic approach has led to the following outcomes and benefits:

  • Use of rain covers in areas that would have intermediate cover for extended periods of time.
  • Use of GPS on the landfill compactor and dozer so that operations filling plan designs could be followed accurately with proper control of stormwater diversion.
  • Design/build of a 4 MG leachate storage lagoon to adequately store leachate during record- level rain events.
  • Consideration for reclaiming the Permit 40 MSW landfill. This will resolve issues with leachate creation via stormwater and groundwater infiltration, and add airspace and increase the lifespan of the landfill to about the Year 2080. SCS has begun work for a Part A permit application that would allow this reclamation project.
  • Preparation of a preliminary engineering report which considers leachate pretreatment and treatment options using sequencing batch reactors and reverse osmosis processes. The full treatment option would allow the County to take full responsibility for its leachate treatment and not rely on the local wastewater plant.

Additional relevant services that SCS provides to the County include the following:

  • Parts A and B permit amendments as needed.
  • Designs of landfill expansion, cell constructions, and capping projects.
  • Operation filling/sequencing plans to maximize the filling potential of the existing permitted landfill while properly managing vehicle access to fill areas, stormwater, and leachate volumes.
  • Design of landfill facilities including the roadways, scale house, 1,000 tons per day convenience center, household hazardous waste storage building, and truck wash station.
  • Design for leachate recirculation.
  • Design/build for a 2 MW LFG power plant, 4 MG leachate storage lagoon, leachate pump stations and force mains, and LFG wellfield expansions.
  • Stormwater channel and sedimentation pond designs to include proper soil erosion and sediment controls.
  • Attendance and presentations at meetings and public hearings.
  • Construction administration and CQA inspection services as needed.
  • Post-closure care plan.
  • Air emission monitoring, recordkeeping, reporting, and application (including Title V and NESHAP)
  • Assistance with negotiations with regulators (VDEQ).
  • Groundwater and surface water sampling and analysis.
  • Groundwater data validation, management, and statistical analysis.