Services we provide
LANDFILL SERVICES
GAI’s staff has designed and permitted numerous CCR landfills since the 1980’s and we continue to provide operational and capital project support for many of those facilities to this day. Our CCR team takes pride in recommending innovative designs that reduce disposal costs, and we have proven expertise in providing services including:
- Difficult-to-permit sites such as strip mines, sinkhole-prone areas above karst formations, and deep-mine workings
- Designing geosynthetic and clay bottom liner and final cover systems
- Geotechnical engineering of detailed veneer and global stability analyses for CCR and coal refuse landfills
- Hydrologic and hydraulic engineering for the design of run-off and run-on control systems for landfill facilities, including leachate and stormwater basin design, HELP modeling, channel design and downchutes
- Operational support for numerous CCR landfills including 7-day inspections, annual inspections, operational development plans, and groundwater monitoring.
IMPOUNDMENT SERVICES
GAI is a valuable policy resource for interpreting the regulations that apply to disposal practices and plant-specific or system-wide compliance costs. Our planning studies evaluate long-term disposal options for impoundment closures, including conversions to dry ash handling systems. Our experienced engineers, hydrogeologists, archaeologists, and natural resource specialists work with state-of-practice tools and methods, including Geographic Information Systems (GIS), to identify, rank, and select new disposal facility sites that meet applicable federal and state selection criteria.
Our geotechnical engineers specialize in detailed steady-state liquefaction evaluations, and static and seismic stability analyses of ash and coal refuse landfills.
CQA
GAI’s full-service approach to construction quality assurance (CQA) in managing the construction and operation of disposal facilities includes bid documents, construction administration, and construction QA/QC monitoring, with field teams trained to keep pace with the rigorous documentation requirements required during liner system installation.
CCR RULE COMPLIANCE
U.S. Environmental Protection Agency (EPA) rules have prompted the closure of hundreds of CCR disposal impoundments in the U.S. Having completed hundreds of projects involving design, instrumentation, rehabilitation, and closure of many types of dams and impoundments, GAI has provided proven solutions including in-place CCR stabilization and conversions of ponds to landfills. In accordance with the CCR Rule, GAI has assisted multiple clients in developing the reports, certifications, and plans required for their existing and proposed CCR landfills and CCR impoundments.
BENEFICIAL REUSE
GAI has promoted the beneficial uses of CCRs), coal combustion products (CCPs), and coal combustion by-products (CCBs), including fly ash, for over 55 years, by using the engineering properties of fly ash to set the stage for innovative and beneficial reuse of the materials. Based on research in this area, we are a known leader for incorporating beneficial use of CCPs in construction applications as structural fill, flowable backfill, road base and subgrade stabilization, underground mine stabilization, and soil amendment.
WATER MANAGEMENT
The EPA’s CCR Rule and Effluent Limitations Guidelines (ELGs) set new or additional requirements for wastewater streams associated with multiple processes critical to power generation and the management of CCR. GAI has a deep understanding of these regulations and how they impact facility operations and environmental compliance with respect to water management. GAI works with our clients to understand a facility’s water balance, identify any issues, and develop solutions. GAI has extensive experience working with many processes including leachate treatment systems, flue gas desulphurization system wastewater treatment systems, and ash water recycle systems. GAI has the design experience to support innovative water reuse alternatives or to optimize treatment systems to meet the regulations. GAI’s extensive permitting experience works to help make sure the solutions we create for our clients comply with the applicable federal, state, and local regulations.
GROUNDWATER SERVICES
GAI provides expert solutions to our clients’ groundwater assessment, investigation, monitoring, restoration, and remediation needs. Our hydrogeologists, geologists, environmental engineers, and environmental scientists apply the principles of hydrogeology and geology to formulate efficient and cost-effective solutions to groundwater challenges and impacts. Our groundwater professionals are highly experienced in the design and installation of effective groundwater monitoring networks in complex geologic conditions. Our experienced hydrogeologists routinely perform statistical analyses to define background water quality and evaluate potential impacts at downgradient points of compliance. Should there be the need to quantitatively determine aquifer parameters or evaluate remedial options, aquifer testing is performed to define aquifer characteristics and estimate the rate of groundwater transport. We use state-of-the-art computer models to conduct hydrogeologic analyses, design efficient extraction well/trench drain networks, and evaluate the radii of influence and capture zones. GAI’s groundwater investigation and remediation experience encompasses landfills, impoundments, waste disposal sites, underground storage tanks, Resource Conservation Recovery Act facilities, and sites that fall under the Comprehensive Environmental Response, Compensation, and Liability Act. Learn more about our Groundwater Engineering Services.