Landfill Gas Collection and Control

LFG-Collection-Control

Gas Collection and Control Systems (GCCS) are a common and major component of most sanitary landfills. They are designed to help control odors, minimize non-methanogenic organic compound releases to the atmosphere, and increase safety by controlling migration.

SCS Engineers has a long, successful track record designing, building, and managing LFG programs and GCCS. SCS can deliver individual landfill services as needed, or we can provide a full complement of integrated services based on our vast experience with all landfill components. The value in combining our services is that a carefully designed and built system will last longer and function more efficiently. We provide operations, monitoring, and maintenance (OM&M), system troubleshooting, and management of all the data it takes to keep a system functioning efficiently.

SCS Engineers offers the following services for the collection and control of landfill gas:

Combustible Gas Migration Control

  • Control System Design
  • Gas Monitoring
  • Underground Fire Control, Response, and Recovery
  • Long-Term Monitoring and Certification
  • Permits and Regulatory Support

Energy Recovery

  • Construction and Operation Services
  • Feasibility Studies
  • Field Test Programs
  • Gas Modeling
  • Gas Sale Contract Services
  • Long-Term Monitoring and Certification
  • Market Investigations
  • System Design

A properly designed and constructed GCCS will operate for many years without major problems, but every system requires periodic and continuous maintenance. A GCCS is often installed in landfills where waste filling has concluded; however, the landfill will continue to undergo changes that affect the rate of gas production and the ability of the GCCS to collect gas efficiently. Our O&M staff inspect and tune wells on a regular schedule so the system is well-maintained. We combine modern technology and extensive field experience to identify factors that can adversely affect GCCS performance. Our experienced technicians can identify a problem and make needed repairs and adjustments.

Data Management

Managing GCCS documents and data can be challenging. Once plans have been created, they typically are filed away until an emergency occurs with the system or construction is underway. It can be exasperating not to be able to locate a set of plans when they are needed. One way SCS manages this information and keeps it readily available is by using a geographic information system (GIS) as a document management system. Portable document format (PDF) files placed into a GIS map provide the exact locations of the GCCS components. Our SCSeTools™ help meet the challenges of database and data management. We also use 3D models of landfills and control systems in order to visualize how all of these items interact and increase working knowledge of the system, resulting in timely maintenance, more effective response to regulatory agency concerns, more effective troubleshooting of problems, stable performance of the GCCS, and reduced operational and maintenance costs.

Landfill Fire Control, Subsurface Reactions Response and Recovery

SCS Engineers has substantial experience locating, containing, and extinguishing subsurface landfill fires, and we provide engineering, management, and turnkey services for landfill fire suppression.

Services we offer include:

  • On-site investigation and identification of landfill fire
  • Identification, characterization, and solutions for area-wide landfill reactions (not a fire), including wellhead protection
  • Planning and performance of thermographic aerial and on-site surveys, and interpretation of results
  • Assessment of potential regulatory impacts (air quality, water quality, etc.)
  • Development and implementation of fire detection boring and monitoring program
  • Preparation and submittal of fire mitigation plan
  • Injection of appropriate inert gases (CO2, N2)
  • Excavation and exposure of buried refuse and smothering with soil
  • Installation of fire breaks
  • Addition of cover soil
  • Surface and subsurface flooding of impacted areas
  • Utilization of fire suppressant foams
  • Repair and re-grading of site surface and affected subsurface area
  • Monitoring and regulatory reporting

LFG Due Diligence Services

SCS Engineers has served as the Independent Engineer on over 100 LFG projects with a loan value approaching $300 million over the past few years. Our clients have included lenders for recourse and non-recourse loans, open credit lines, and Section 29 and Section 45 tax credit investments. Typically, we are asked to perform the following tasks:

  • Concept design and cost estimates
  • Feasibility study reports
  • Cost-benefit analyses
  • Net present value or internal rate of return
  • Cash flow and financing options
  • Assessments of existing and proposed LFG collection systems
  • Contract document review to identify technical requirements, milestone dates, and project costs. Agreements typically reviewed for both Gascos and Gencos include lease agreements, power purchase agreements (PPAs), gas sales agreements, Gasco/Genco transfer agreements, engineering procurement and construction (EPC) contracts and O&M contracts
  • Solid waste, air emissions, and other permits from state and local permitting agencies
  • Third-party review
  • More information here

LFG Well Drilling

When designing and drilling LFG collection wells, one of SCS Engineers’ primary concerns is the potential occurrence of perched liquids within the refuse mass and their impact on the LFG collection. SCS Engineers provides the design and field experience, state-of-the art technology, and equipment necessary to address collection and migration control design challenges.