Midwest U.S. power-generation station projects

Project Summary

For more than 50 years, Hanson has provided various energy- and industry-related services at power-generation stations located throughout the Midwest.  Highlights include:

Midwest power station coal-combustion byproduct disposal facility: Hanson provided siting, permitting and design services for a 120-acre coal-combustion byproduct (CCB) landfill at a 15,000-acre power plant site.  After completing a three-phase hydrogeologic site investigation, Hanson designed the landfill.  Because of the relatively high-permeability native soils at the site, Hanson’s liner design utilizes a geocomposite clay liner (GCL) thus avoiding the expensive import of low-permeability soils.  The landfill is currently being constructed with compacted clay, geocomposite clay, and synthetic liners, meeting regulatory requirements.  Also, landfill permitting will allow for future disposal of CCB from other power plants. 

Midwest power station gypsum management facility:  Hanson provided siting, permitting, and design services for a 60-acre facility with an initial 30-acre gypsum stack and a 15-acre recycle pond to manage the gypsum produced by a proposed new wet flue gas desulphurization (FGD) scrubber.  After completing a hydrogeologic site investigation and groundwater impact assessment for the project, Hanson procured state EPA and DNR permits, the first in the state for a FGD-gypsum stack structure.  To meet EPA Bureau of Water requirements for water treatment facilities and EPA Bureau of Land requirements for solid waste disposal facilities, the design includes a double liner system, with a leachate collection system to be activated when sluicing activities cease.  Hanson also is providing construction management and quality assurance services for this project.

Dam inspections, repairs and modifications:  Hanson has performed more than 100 dam inspections at various utility-owned facilities to help our clients address state-compliance requirements.  The primary impoundments at these power plants sites are the cooling water lakes where fairly large dams block significant creeks to create the impoundment.  The cooling water lakes are generally 35,000 acre-feet to 60,000 acre-feet in size and are impounded by 50-foot to 125-foot-tall earth dams.  The size classifications range from intermediate to large, and the hazard classifications are significant (Class II) to high (Class I), where Class I dams are defined as “dams located where failure has a high probability for causing loss of life.”  States typically require Class III dams to be inspected every five years, while the Class I and II structures require inspection every year and every three years, respectively.  This effort typically includes compiling monitoring data, providing visual observations and photographs, and providing construction management.

Midwest utility company on-call structural engineering:  We provided on-call structural engineering services at seven different power generating stations, including evaluation and design services under emergency and non-emergency conditions.  The following list includes typical assignments that have been completed under the contract:  valve and boiler platform modifications, hoist beam rating, boiler and turbine room wheel crane evaluation, condensate pump monorail upgrades, cooling tower deck repairs, crib house pre-cast channel live load capacity rating, transformer foundation evaluation and repairs, turbine and boiler room operating floor laydown analysis, condensor hydro test structural evaluation, and switchgear replacement slab cut and resupport.