GEI has been a leader in managing former manufactured gas plant (MGP) sites for more than 30 years. We have been involved in over 600 MGP site historical investigations, site characterizations, risk assessments and feasibility studies for utility and industrial clients, and completed more than 100 MGP site remedial designs.
GEI’s experts in environmental science and engineering, ecological risk, civil, geotechnical and geo-structural engineering and construction management come together to implement innovative remedies that meet client, stakeholder and regulatory goals.
GEI’s senior staff have strong backgrounds in program management, review and cost recovery support to economize approaches to MGP site management. These types of services include litigation support for potentially responsible parties (PRPs) or insurance recovery, reasonableness and prudent evaluation for utility MGP portfolios and other expert services that combine working knowledge, scientific research and historic assessment. We also provide program consulting services to support clients in planning strategies for investigating single or multiple MGP sites. In the case of multiple sites, we have extensive experience in site prioritization and in supporting clients’ internal prioritization efforts.
GEI has conducted human health and ecological risk characterizations at dozens of former MGP sites using in-house resources. Our risk assessment teams regularly participate in remedial investigations to determine the potential ecological risks of MGP wastes in terrestrial and wetland environments, and in waterways, which are often adjacent to MGP sites. Results are then used, in collaboration with GEI’s geologists and remedial design engineers, to help refine remedial goals using current scientific tools. GEI conducts risk assessments at MGP sites under many regulatory frameworks ranging from smaller state-led cleanup sites to the largest and most complex CERCLA or Superfund sediment investigations.
Operations, Maintenance, and Monitoring
GEI has conducted operations, maintenance and monitoring (OM&M) services at more than 40 MGP sites across the U.S. These include ongoing NAPL recovery systems, groundwater treatment systems, enhanced natural attenuation and monitored natural attenuation and land use restrictions.
GEI has a strong national contaminated sediments practice. Services range from complete sediment site characterization and management and related civil and structural engineering, to alternative shoreline stabilization design; river, harbor and estuary management; and species assessment and impact mitigation. We have completed numerous complex projects involving contaminated sediment in streams, rivers, canals, estuaries and harbors. Clients often look for innovative design and remediation solutions in all phases of the project life cycle. GEI is positioned to deliver – whether in site investigation, permitting, remedial design, capping, dredging, transport, new structures, restoration or aquatic and/or marine monitoring.
We integrate the MGP remediation aspects of the design with the geotechnical and civil design aspects. This results in tighter designs and fewer change orders during construction. Many projects involve special handling of soils, water, miscellaneous solids, difficult subsurface conditions and have required special construction techniques. GEI is equipped with construction professionals to support MGP projects involving ground remediation, vertical construction and other types of construction activity. Construction management starts at design with constructability reviews to allow for course corrections to minimize construction costs, drive a safer and more constructible remedy and avoid claims and change orders. GEI also manages the entire contractor procurement process, from prequalifying potential bidders through negotiation support.