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.

Wentzville High School

April 24th, 2015

Location: Wentzville, Missouri
Owner: Wentzville R-IV School District
Client: Hoerner Associates, Inc.
Services: Environmental, Water Resource Management

Geotechnology provided geotechnical engineering, Phase I ESA, and natural systems consulting services related to wetlands/Waters of the United States (WOUS) delineation and 404/401 permit application.

Phase I ESA performed during the due diligence period did not indicate the presence of Recognized Environmental Conditions (RECs) on the site; however, during the initial Phase I ESA research, it was apparent that potential jurisdictional Waters of the United States (WOUS) may be present on the site. In particular, an unnamed tributary with an established riparian corridor, two ponds and apparent isolated wetlands. Results of the delineation and USACE coordination indicated that the project site contained jurisdictional WOUS that would be subject to Section 404 and 401 reviews; specifically, two tributaries and a drainageway.

Geotechnology worked with the design team and came up with a mitigation strategy that reduced stream impacts, leaving several hundred feet of stream undisturbed. Based on the reduction in stream impacts, Geotechnology was able to formulate an on-site mitigation plan, thus eliminating the need to buy stream mitigation credits from an off-site mitigation bank. The mitigation plan included extensive bush honeysuckle removal in the existing riparian corridor as well as supplemental planting of native grasses, shrubs, and trees.The removal of bush honeysuckle not only met mitigation needs, but also opened up the stream corridors for better visibility as desired by the School District.

By reducing stream impacts and mitigating on-site, Geotechnology and the design team helped reduce mitigation costs by approximately $300,000. Additionally, due to the minimal impacts proposed for the project, the USACE processed the Section 404 permit as a Nationwide Permit instead of an Individual Permit. Issuance of a Nationwide Permit effectively reduced the permitting time frame by at least three months. The final project preserved the majority of the jurisdictional streams on the site and enhanced the riparian corridor.

St. Louis Arch Grounds – City+Arch+River

January 15th, 2015

Client/Owner: National Park Services CityArchRiver 2015 Foundation
Location: St. Louis, Missouri
Services: Drilling, Geotechnical, Special Inspections

In fall 2010, Michael Van Valkenburgh & Associates (MVVA) won The City+The Arch+The River 2015 International Design Competition to develop a new concept for the Jefferson National Expansion Memorial (JNEM) commonly known as the St. Louis Gateway Arch Grounds. Elements of the new design for the grounds include expanding the Arch Museum and adding a major new entry facing Memorial Drive; creating a beer garden/restaurant that converts to an ice skating rink in the center; an urban ecology center; a wetland/bird sanctuary, a cobblestone walkway and three new parking garages. Final design and construction is to commence by 2015, the 50th anniversary of the completion of the Gateway Arch.

In 2012, Geotechnology provided subsurface exploration and engineering recommendations for the Park Over the Highway portion of the project which includes the landscaped bridge and replacement bridge over the depressed section of I-70. In coordination with MoDOT and the City of St. Louis special traffic control procedures were used and drilling was performed at night when there was less commuter traffic. Difficulties during drilling included working around the Cardinal’s Post-season games, numerous utilities rubble fill and varying rock quality. In addition, Memorial Drive was required to be open by 5:00 a.m. each morning. The structure was designed with minimal impact to the existing retaining walls (i.e. foundations were installed behind the walls). Special hybrid drilled shafts were also designed to expedite construction and reduce vibrations on neighboring structures (predominately the Old Cathedral).

Geotechnology provided a Phase I Environmental Site Assessment, a geotechnical desk study, and an archaeological desk study. The purpose of these services was to identify potential ground hazards and corresponding primary risks at an early stage so that these risks could be better managed during the design and construction processes. The geotechnical report addressed deep foundation excavation and shoring considerations, impacts of soil types, obstructions and environmentally impacted material on site grading, structural foundations considerations, and groundwater related considerations. The purpose of the Phase I ESA is to provide a professional opinion as to the potential for Recognized Environmental Conditions (RECs) to exist on the site, particularly hazardous substances or petroleum products on the property or that may have been released onto the property, the subsurface or surface waters in the past.

Geotechnology also provided utility locating services and detailed geotechnical exploration for the new visitors center, regraded slope over TRRA rail tunnel down to the Leonore K. Sullivan Boulevard, and new Rangers Station. Geotechnology provided specialist sampling and analysis services for soils nutrient assessment.

Former Forest Park Hospital – St. Louis Zoo Expansion

October 20th, 2014

Location: St. Louis, Missouri
Client/Owner: Saint Louis Zoo
Services: Environmental

Geotechnology was selected to provide a wide range of environmental consulting services for the demolition of 9 buildings at the 13.5 acre former Forest Park Hospital site. The St. Louis Zoo acquired the site to create greenspace as they plan future expansion alternatives. Building footprints ranged from under one thousand to several hundred thousand square feet, and the site structures were in various states of disrepair as the site had been vacated. Geotechnology worked closely with the Zoo and their design and construction administration teams to develop a scope of work that would adequately address the following:

  • Preparation of a Phase I Environmental Site Assessment Report
  • Conducting limited soil and groundwater sampling and testing for screening purposes
  • Conducting asbestos and hazardous waste surveys
  • Conducting heavy metals-based paint (including lead) surveys
  • Preparing abatement cost estimates
  • Assisting with bid solicitation and review of contractor bids
  • Third party monitoring during the 7 months of abatement activities and removal of hazardous waste
  • Underground storage tank closure, including regulatory notification, soil and waste characterization sampling and the submission of a closure report for which the Missouri Department of Natural Resources issued a No Further Action letter
  • Periodic perimeter dust monitoring during demolition

City of Clayton New Police Headquarters & Garage

October 20th, 2014

Client/Owner: City of Clayton
Location: Clayton, Missouri
Services: Environmental, construction observation and materials testing

Geotechnology provided environmental surveys including asbestos, lead-based paint and hazardous materials surveys; geotechnical subsurface exploration; refraction microtremor surveying; third party asbestos abatement monitoring, oversight and clearance sampling; and construction observation/materials testing services for the renovation of a 6-story office building. The project involved renovation of the office building for the City of Clayton’s new police headquarters. The building was partially occupied during the initial environmental sampling and testing, so Geotechnology’s services needed to be performed after business hours. The facility is currently being renovated to achieve LEED Silver certification.

In 2014, Geotechnology was asked to provide construction observation and materials testing services for the Garage. These services included concrete tests for measurement of air content, slump and temperature and making concrete cylinders for compression tests. Checking the configuration of the reinforcing steel for compliance with project plans and specifications and documenting repair/replacement of damaged PT cables. Observation services were performed during the stressing of PT cables and performed pullout tests to check the bond between the new and existing concrete in patched areas and in areas where the concrete is removed to check that loose pieces and dust were removed.


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.

Underground Storage Tank (UST) Geophysical Survey

February 17th, 2014

Client: Hospitality Builders of America
Location: Memphis, Tennessee
Services: Environmental, Geophysics

Geotechnology conducted geophysical surveying at the subject property consisting of a 1.21-acre asphalt-covered parking lot located at 235 Union Avenue in Memphis, Tennessee. In the northern portion of the subject site (approximately 120 foot by 200 foot area), ground penetrating radar (GPR) was used in an attempt to locate possible
underground storage tanks (USTs) that were associated with a former service station that was located in the northern portion of the subject site (based on the preliminary findings of our Phase I Environmental Site

The remainder of the site will be surveyed using frequency-domain electromagnetics with an EM31. A Scope of Services is attached. The field survey required only one day to complete. Preliminary findings of the geophysical surveying were provided to the client within 5 business days of data acquisition.

After collecting and analyzing the GPR and EM31 data, Geotechnology summarized the geophysical survey results in the Phase I Environmental Site Assessment report that included a description of the geophysical methods, data collection procedures, a contour map of the EM data, representative GPR data, and a site plan showing interpreted locations of USTs based on the geophysical data.

Underground Storage Tank (UST) Closure Services

February 17th, 2014

Owner/Client: MOHELA
Location: Chesterfield, Missouri
Services: Environmental

During parking lot construction at the Missouri Higher Education and Loan Authority (MOHELA) headquarters in Chesterfield, Missouri, an unregistered heating oil underground storage tank (UST) was discovered. Although heating oil USTs are unregulated in the State of Missouri, Geotechnology assisted MOHELA in contacting an environmental contractor to remove the UST in an expedited manner so that construction activities could continue. Geotechnology provided UST removal observations, closure sampling and reporting to document the removal for MOHELA. The UST was removed within 10 days of discovery, and the contractors were able to proceed with parking lot construction in the area of the tank.

Illinois Department of Transportation (IDOT)

June 18th, 2013

Owner: Illinois Department of Transportation (IDOT)
Client: Various
Location: Various locations throughout Southwestern Illinois
Services: Geotechnical, Geophysics, Drilling, Environmental, Construction Materials Testing, Soils & Materials Testing

Geotechnology, Inc. has provided geotechnical engineering, drilling, geophysics, construction observation and materials testing, and environmental engineering services on a significant number of road and bridge projects. Services have included:

  • Drilling, sampling, laboratory testing, and engineering analyses to develop foundation and site design parameters for proposed roadway alignments, new and existing bridge structures, renovation and repair of existing pavements, new asphalt and concrete pavements, and seismic retrofit evaluations of existing bridge structures.
  • Subsurface Utility Engineering Quality Levels D, C, B and A including record searches, site reconnaissance, geophysical surveys, and vacuum excavation (a drilling technique using high pressure air and vacuum to remove soil without harming subsurface structures), all combined with land surveying, and GIS to produce a final map depicting locations of identified utilities.
  • Geophysical surveys and analyses related to proposed roadway alignment geology, structural condition of existing bridge support systems, bridge subsidence investigations and analyses, and investigation of pavement subgrade systems.
  • Materials testing services for new and existing asphalt and concrete pavement, including concrete and asphaltic concrete mix design; Superpave mix design, verification of aggregate quality and compaction testing; slump and air content testing; compressive strength testing of samples; flexural strength testing of beams and structural components; testing of welded and bolted connections; foundation construction observation and testing, including Pile Dynamic Analyses™ (PDA) testing of steel H-piles, Pile Integrity testing of cast-in-place augercast piles, static load tests to determine actual load stresses and/or coordinate PDA test results; cross-hole sonic logging, TV camera inspections, and contract drilling of drilled shafts; and developing temperature models to predict temperature variations on main bridge cast-in-place elements in order to control cracking.
  • Environmental assessments, asbestos surveys, and underground storage tank management related to proposed roadway alignments.

Geotechnology, Inc. has provided these and related services for numerous municipalities, cities and counties, as well as for State agencies and the Federal Highway Administration interstate highway system. This includes projects in the Illinois counties of St. Clair and Madison in the Metro East St. Louis area.

A sampling of projects performed for IDOT include:

MoDOT I-70 Connector for New Mississippi River Bridge

June 18th, 2013

Owner: Missouri Department of Transportation (MoDOT)
Client: Crawford, Murphy, & Tilly, Inc.
Location: St. Louis, Missouri
Services: Environmental

Geotechnology provided environmental consulting, sampling and testing to support the design and construction of the I-70 Missouri Connector and Main Span Corridor project related to the New I-70 Mississippi River Bridge. The four-lane, cable-stayed main span, located south of the McKinley Bridge and about a mile north of the Martin Luther King Bridge will connect the City of St. Louis to the Metro East area of Illinois.

To assist the design team in evaluating the historically urban, industrial area, Phase II Environmental Site Assessments were needed to prepare for construction. The project area included properties both west of Broadway (MoDOT Connector) and east of Broadway (Main Span Corridor). The Assessment identified existing and prior site uses including a prison work release center, railroad track, storage for rubble collected from building demolition throughout the city, cement storage and packing, mattress factory, scrap metal and rubber warehouse, warehouse, railroad tie storage, gasoline filling station, and furniture frame manufacturing company.

The scope of services included reviewing the environmental assessment reports prepared by others, and sampling and testing in conjunction with the geotechnical investigation where impacted soil and/or groundwater were suspected or encountered. Thirty environmental borings were advanced, samples extracted and tested for a suite of parameters including volatile organic compounds, metals and PCBs. Monitoring wells were also installed in borings where water was encountered, and groundwater was later sampled and tested for contamination. All field activities were conducted according to the Missouri Department of Natural Resources (MDNR) regulations and testing was in accordance with MDNR Missouri Risk-Based Corrective Action (MRBCA) guidelines.