Fly Ash Ponds and Bottom Ash Pond Closure

January 19th, 2017

Owner/Client: Ameren
Location: Hutsonville, Illinois
Services: Environmental

Per Illinois Pollution Control Board rulemaking, Ameren developed procedures for ash pond closure at their Hutsonville, Illinois Power Station. These procedures outlined the final cover system, as well as a Construction Quality Assurance (CQA) Program.

The Ameren Hutsonville Power Plant has been decommissioned. In a previous project, the unlined Ash Pond D was capped in place and a groundwater collection system was installed to address environmental impacts. Four additional ash ponds remained on site, including the unlined Bottom Ash Pond and the lined Ash Pond A, Ash Pond B, and Ash Pond C. The ash in the Bottom Ash Pond, Ash Pond B, and Ash Pond C was relocated to Ash Pond A and they were clean closed with storm water controls. Ash Pond A was capped using a traditional RCRA Subtitle D cap of 40-mil HDPE liner with a 3-foot vegetative cover.

Geotechnology implemented the CQA which included QA/QC for clean closure of three ash ponds and a cap closure of one ash pond which included base subgrade, geosynthetic liner, vegetative cover, and storm water controls. Soils testing was performed by Geotechnology’s geotechnical soil laboratories. The CQA plan also included CQA monitoring, inspection and sampling/testing to verify compliance with project plans and specifications. It also required preparation of an acceptance report at the end of construction that provided all inspection and testing documentation and certifies that the facility has been constructed in accordance with the engineering design.

Weekly reports were prepared for the owners review that included construction activities/progress, equipment and personnel on-site, and copies of daily field observation reports.

Geotechnology’s ash pond closure experience provided real-time solutions to issues that developed during this large scale project.

The successful completion of this project represents one of the first regulated and engineered ash pond closures in Illinois. The project will be an important model for future ash pond closures.

For further information regarding ash pond closure and regulations, click here.

Tennessee Valley Authority (TVA)

April 10th, 2015

Owner/Client: Tennessee Valley Authority (TVA)
Location: Eastern Tennessee and Western North Carolina
Services: Drilling

Geotechnology, Inc.’s Drilling Division was asked to provide a variety of drilling services to URS Corporation in support of their evaluation of five existing concrete dams operated by the Tennessee Valley Authority (TVA). These dams, constructed in the 1940’s and 1950’s, were evaluated as part of a larger evaluation program in support of TVA’s permit application for an additional nuclear unit at its Watts Bar Plant.

All work was performed under TVA’s comprehensive safety and environmental protection program. The core holes along the crest of the dams were particularly challenging due to very limited space and on-going operations at the dam. Despite these challenges, Geotechnology’s crews completed all fieldwork without any interruptions to dam operations or violations of TVA’s strict environmental and safety policies.

Geotechnology, Inc. was initially assigned work at only the Boone Hydro Plant in Kingsport, TN. However, due to the crews’ productivity and commitment to quality and safety, Geotechnology, Inc. was ultimately awarded an entire second site (Melton Hill) and assisted other drilling contractors at Apalachia Dam and Ft. Patrick Henry Dam. Ultimately, Geotechnology, Inc. crews cored more than 2,700 lineal feet of in place concrete and underlying metamorphic bedrock with a core recovery greater than 99%. In multiple cases, our crews were able to recover the dam/bedrock contact as an intact core.

Services required included wireline core sampling of the dam structure and the underlying bedrock using a combination of PQ (3.25” core) and HQ (2.50” core) tool strings. Core holes were packer tested and electronically logged upon completion. Additionally, soil borings, rock core borings and piezometers were installed in the abutments of each dam.

Spirit Energy, Underground Storage Tanks (UST)

February 17th, 2014

Owner/Client: Spirit Energy, LLC
Location: Missouri and Illinois
Services: Environmental, Geophysics, Drilling,

Geotechnology conducted environmental sampling at 69 retail gasoline service stations for Spirit Energy. The work was the result of a nationwide owner of convenience stores/service stations purchasing these sites from Spirit Energy. Fifty-nine of the sites were located in Missouri while 10 were in Illinois. Geotechnology previously provided environmental services at some of the sites through our relationships with Site Oil and Shell. Spirit Energy is a joint business venture between the two firms.

Geotechnology’s scope of services involved completing an established number of borings at each site to assess potential soil and groundwater impacts from underground storage tanks. The drilling was accomplished with a direct-push sampling unit. Temporary monitoring wells were constructed in each of the borings to assess groundwater conditions. The wells were also used to assess the groundwater flow direction at each site.

Prior to drilling, Geotechnology developed a site specific Health and Safety Plan for each site, and contacted the appropriate state one-call system to locate utilities in public right-of-ways. We also utilized our geophysics group to clear private utilities prior to drilling. The geophysicists used Ground Penetrating Radar (GPR), Radio Detection (RD 4000) Magnetics and Electromagnetics (EM31) to identify underground utilities.

Ameren Ash Pond Assessment & Monitoring

July 10th, 2013

Owner/Client: Ameren
Location: Multiple Power Plants throughout Illinois

Services: Geotechnical, Environmental

Geotechnology provided geotechnical and environmental consulting services with the purpose of evaluating the stability of ash pond embankments, develop groundwater monitoring wells and complete one round of groundwater sampling. This work was completed for eight Ameren Energy Resources power plant sites in Illinois.

Embankment stability evaluations focused on providing Ameren with information necessary to make decisions concerning the future study of the ash ponds. Global stability analysis was completed for each site which compared the sliding and restraining forces along possible slide planes and determining the factor of safety. The global stability analysis involved completing a number of subsurface borings per site and performing laboratory tests on samples obtained from the borings to develop geotechnical parameters needed to analyze slope stability.

The project also involved the installation of groundwater monitoring wells at the ash pond sites. Three to five monitoring wells were installed by Geotechnology’s drilling division for quarterly monitoring. Geotechnology completed the initial quarter of groundwater monitoring by developing the wells and then purging and sampling them.

Callaway Nuclear Steam Generator Replacement

December 27th, 2012

Owner/Client: Ameren
Location: Callaway, Missouri
Services: Geotechnical, Drilling

In part because of Geotechnology’s excellent safety record, the team was selected to perform drilling and geotechnical services for construction required to replace four steam generators. In order to replace these generators a new docking facility, river access road, creek crossing, old steam generator storage facility and various other support facilities needed to be constructed.

The varied surface conditions and access issues required the use of a number of different drill rig types including track-mounted, all-terrain, a remote-controlled vehicle for low clearance drilling, and a truck-mounted angle hole drilling rig to perform borings and Standard Penetration Tests (SPT’s) using an automatic hammer.

Due to the varied site conditions number of foundation recommendations were made including a multi-cell box culvert for the river crossing, crushed rock reinforced with a geogrid for certain sections, and mat foundations and strip and spread footings for the storage facilities.

Engineering Services: Enbridge Pipeline

October 31st, 2012

Location: Enbridge Pipeline: Wisconsin to Illinois
Services: geotechnical
, drilling

We provided geotechnical engineering services for 133 miles of 42-inch diameter mainline pipeline from Delevan, Wisconsin to Streeter, Illinois and 20-inch pipeline to Manhattan, Illinois.

Project Details:

The Enbridge Southern Access/Southern Lights project includes design and construction of a new pipeline running from Delevan, Wisconsin to Patoka, Illinois. The new pipeline is intended to accommodate growing production from the Alberta Oil Sands and is part of a broader Enbridge strategy to provide greater access to new U.S. markets for Canadian crude oil supplies. Our drilling, laboratory testing and engineering analysis services were provided at 14 Horizontal Directional Drill (HDD) sites.

Our foundation recommendations for these sites were included in Enbridge’s reports addressing footing loads from equipment. Design and construction recommendations for the mainline included Enbriconsiderations, suitable trench backfill recommendations and temporary shoring recommendations. Laboratory testing was performed on the soil samples to estimate index properties of the soil.
Our team also completed 500 borings along the main pipeline route, as well as, a geotechnical assessment of property at the end of the pipeline for a proposed new tank farm in Patoka.

Coffeen & Sioux Coal-Fired Power Plants

October 31st, 2012

Location: Illinois & Missouri
Services: materials testing
, subsurface utility engineering (SUE)

AmerenUE is constructing wet flue gas desulfurization retrofits on two of their coal-fired power plants, and we provided certified welding inspection services at the fabrication shops and job sites.

Coal-fired power plants utilize limestone material-handling systems with new effluent stacks. We provided services to verify weld quality of carbon steel ductwork and absorbers tanks including:

  • Shearweave ultrasonics
  • Radiography
  • Magnetic particle non-destructive testing
  • Writing weld procedures
  • Tracking welder certifications
  • Updating isometric piping drawings
  • Oversight of slip form construction of 450-foot emission chimneys
  • Temperature monitoring for mat foundation concrete & verification of reinforcing steel
  • SUE Quality Levels D, C, B and A

Electromagnetic terrain conductivity surveying was also used to locate previously unknown buried utilities. Suspected utilities, including a large electrical duct bank, were located using ground-penetrating radar (GPR), radio detection and magnetic methods. The locations and depths were verified by performing vacuum excavation. Additionally, our team members observed the installation and conducted Pile Integrity Testing (PIT) on approximately 600 augercast piles to support the fan, duct support and utility-rack foundations at the Coffeen & Sioux Coal-Fired Power Plant.

Comanche Peak Power Plant

October 31st, 2012

Location: Glen Rose, Texas
Client: Furgo Consultants, LP
Owner: TXU Power
Services: Drilling

Geotechnology drill crews provided Fugro Consultants with contract drilling services in support of the geotechnical investigation for various additions to the existing nuclear power plant. Geotechnology’s crew drilled more than 75 coreholes to depths ranging from 50 to 325 feet using HQ coring equipment. Geotechnology consistently maintained a core recovery of greater than 95%, while other contractors working at the site averaged recoveries of 80% or less in the soft limestone, shale and sandy shales found at the site. More than 950 drilling hours were logged on the project with no OSHA-reportable injury recorded nor were any notices of deficiency related to safety or quality of work received.



October 23rd, 2012

Location: Various locations throughout Missouri and Illinois
Client: Numerous
Owner: Ameren
Services: Water Resource Management, Geotechnical, Environmental, Drilling

Services provided to Ameren include:

  • Coal Combustion Waste Improvements
  • Drilling
  • Ash Pond Assessment, Monitoring & Closure
  • Embankment Stability Evaluations
  • Geotechnical Engineering & Consulting
  • Environmental Engineering & Consulting
  • Groundwater Monitoring Well Installation & Monitoring
  • Laboratory Testing of Soils & Rock
  • Construction Materials Oversight & Testing

An example of projects performed for Ameren include: