Client: Metropolitan St. Louis Sewer District
Location: St. Louis, Missouri

TSi provided a geotechnical engineering investigative study to construct large storage tanks along the existing sewer at critical locations where excess storm flows could be pumped into the tanks for temporary containment during the peak flow period, usually measured in hours. The first of these systems, Site A,
was recently completed. TSi performed the geotechnical study for the Site A tank and peripheral facilities, including diversion structures, pumping stations, and related piping. Laboratory consolidation testing and detailed settlement analyses were performed. A preload fill was recommended, installed and monitored, with review of the settlement performance by TSi.

Client: American Water Company
Location: East St. Louis, Missouri

TSi performed six hydrometer tests to determine the grain size distribution on materials taken from within the water
treatment facility in East St. Louis.

Client: Metropolitan St. Louis Sewer District
Location: St. Louis, Missouri

As a subconsultant, TSi completed a geotechnical study for improvements to the existing Coldwater Creek WWTP, originally
constructed in 1965. Improvements included addition of five new clarifiers, headworks building, thickener, sludge and grit
pump station, and new blower and maintenance buildings. TSi completed 23 borings up to 50 feet deep and a laboratory
testing program. TSi’s geotechnical recommendations included foundations, settlement, and seismic considerations.

Client: Metropolitan St. Louis Sewer District
Location: Maryland Heights, Missouri

TSi completed a subsurface investigation and geotechnical engineering evaluation for improvements to this WWTP, which increased the capacity of the plant to process 38 million gpd. TSi completed 24 borings to depths of 100 feet. TSi provided geotechnical recommendations for the design and construction as well as provided review of geotechnical-related contractor submittals during construction, and made site visits to verify subsurface conditions.

Client: Metropolitan St. Louis Sewer District
Location: Maryland Heights, Missouri

TSi completed a subsurface investigation and geotechnical engineering evaluation for a new Biofiltration System, located between Primary Clarifier No.1 and Grit Building No. 1. The Biofiltration System includes a building, pump discharge and piping. TSi conducted a subsurface exploration consisting of several borings in the plant and a laboratory testing program on samples, then provided design recommendations for existing fill, shallow foundations, settlement, floor slabs, and lateral earth pressures, as well as site preparation, excavation, and regional seismicity considerations.

Client: Metropolitan St. Louis Sewer District
Location: St. Louis, Missouri

TSi was selected to perform a subsurface exploration and geotechnical engineering evaluation for the design and
construction of a separate process system to treat the increased inflow to the plant that results from large storm events.
The expansion included four 140-foot-diameter primary clarifiers, grit basin complex, sludge pumping station, and a new
large-diameter outfall pipeline extending from the plant to discharge into the nearby Mississippi River. TSi drilled 29
borings at the site, conducted laboratory test programs on samples, and submitted a report that included the geotechnical
assessments and recommendations for design and construction of the expansion.

Client: Metropolitan St. Louis Sewer District
Location: South St. Louis County

TSi prepared the geotechnical study and subsequent engineering design for this WWTP in south St. Louis County. The
project included the plant, a 7,600-foot-long, 78-inch outfall pipe to the Mississippi River, a wetlands demonstration area, and
recreation/education facilities. TSi completed 33 test borings, 12 of which were extended to bedrock at a depth of 100 feet.
Geotechnical challenges included compressibility of soft floodplain soils, shallow groundwater conditions, periodic flooding of the area, and the stability and disposition of the existing treatment lagoons and old fill. TSi provided recommendations for foundations, settlement estimates, seismic considerations, dewatering, excavation, and fill replacement.

Client: City of Kansas City
Location: Kansas City, Missouri

The project provided for design of up to 3,000,000 gallons of stormwater storage in an effort to meet both the Percent Capture of Wet Weather Flows and Performance Criteria set forth in the Federal Consent Decree pertaining to the Kansas City Overflow Control Program. TSi served as geotechnical engineer, planning and executing drilling, sampling, testing, and analyses, and producing a final report. The approach uses three tiers of storage basin sizes with green infrastructure concepts and strategic sewer separation to reduce the number of overflow events. Most of the improvements are along the streets but some improvements are on properties. The primary geotechnical concerns are the
presence of fat clay and shallow bedrock which limit the infiltration of stormwater.

Client: City of Belton
Location: Belton, Missouri

This project consisted of constructing an influent pumping station (IPS), IPS electrical building, and headworks facility structure at the Belton WWTP, as well as construction of an access road for the IPS facility. The headworks facility, built on the north edge of the Belton WWTP, is a masonry wall structure supported
by a stem wall on spread footings. The IPS is a partially buried concrete structure while the IPS electrical building is a masonry wall structure. Associated structures of the IPS are supported by reinforced mat foundations. TSi provided drilling, laboratory testing and geotechnical services. TSi’s report included
recommendations for foundations, settlement, lateral earth pressures, pipe support, and subgrade modulus for the design of pavements.

Client: City of Lee's Summit
Location: Lee's Summit, Missouri

The project consisted of constructing a new sanitary sewer system within the Cedar Creek drainage basin. The overall project length was 9,800 linear feet and followed Cedar Creek and its tributaries. The land along the proposed sewer alignment was a mix of undeveloped wooded areas, athletic fields and residential
property. The project was primarily constructed using open trench methods. TSi provided drilling services, laboratory testing, and geotechnical services. The geotechnical report included recommendations for sewer backfill requirements
for material and compaction effort; influence of groundwater; determination of potentially expansive, dispersive, or collapsing subgrade materials; inclinations of slopes; and corrosion potential or chemical attack to concrete.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi provided drilling, laboratory testing, and geotechnical engineering services for 2.2 miles of new force main. The
geotechnical report included preliminary recommendations for the type and capacity of the storage tank foundations; fill
and backfill materials, placement, and compaction; excavation considerations; corrosion protection; and force main layout.
The new large diameter above-ground storage tanks will hold 20 million gallons of overflow in wet weather. The geological
changes for the tanks showed evidence of large ground surface settlements observed at the existing 87th Street Pump
Station facility, which is located over an area that was previously used as a solid waste dump.

Client: City of Kansas City
Location: Kansas City, Missouri

Subsurface exploration, laboratory testing, and geotechnical engineering services for the new $12.5 million force main and
pump station. Pump station structures included the control building, generator pad, screening building, and valve vault,
all constructed with spread footings or mat foundations supported by clay soils or shale bedrock. Bearing depths for the
structures ranged from 5 feet to 31 feet below grade. The new 2-mile force main connects the pump station to the Rocky
Branch interceptor, and was constructed using cut-and-cover techniques except for the trenchless crossing at Hwy. 169.

Client: City of Kansas City
Location: Kansas City, Missouri

Geotechnical Engineering Services
Subsurface exploration, geotechnical engineering and final report for design of a new, 4-mile-long, 54-inch-diameter water main along North Oak Trafficway. Primary challenge was the route of the alignment down the steep bluff of the Missouri River valley, requiring significant amount of rock excavation. Phases 3 and 4 involved
an additional 54-inch transmission main to supplement two existing mains, for a total of 3.8 miles.

Client: City of Kansas City
Location: Kansas City, Missouri

Construction Observation and Materials Testing Services Construction observation and documentation, and testing servicesfor construction of Phase 2. TSi tested construction materials for compliance with specifications. TSi staff observed and inspected placement of the pipeline including checking welds and pipe alignment. The primary challenge was routing the pipeline along an urban corridor with numerous existing underground utilities. The pipeline was also routed into the City’s water treatment plant where several underground structures and existing water mains complicated the construction.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi is conducting geotechnical services for planned construction of 13,500 feet of sanitary sewers as well as separation of
260 acres of a CSS. The project’s objectives are to eliminate overflows, reduce the volume of untreated wastewater to the
receiving waters downstream, and meet regulatory requirements as part of KCMO’s Overflow Control Program.

Client: Bannister Properties
Location: North Creek Village, Missouri

TSi is providing subsurface exploration and geotechnical engineering services for the evaluation of a creek bank that is
eroding and undermining North Pomona Avenue within the North Creek Village subdivision in northern Kansas City. TSi
provided geotechnical recommendations for stabilization of the creek bank, including construction of a retaining wall
along the bank. TSi will also address other erosion and settlement issues for nearby culverts under the street.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi provided subsurface exploration as well as construction inspection and laboratory testing services for additions to two wastewater treatment plants in northern Kansas City. The Todd Creek and Rocky Branch plants include installation of disinfection equipment. TSi planned and completed a subsurface
exploration program at each site. TSi also completed laboratory testing of the soil samples and completed a geotechnical data report for each project site.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi was the geotechnical engineer for the expansion of the Fishing River WWTP in northern Kansas City. The expansion includes two aeration basins, two clarifiers, influent pump station, ultraviolet (UV) disinfection filter building, pump station,
blower building, classifier building, and grit chamber. TSi completed a subsurface exploration program resulting in a geotechnical engineering report. Primary geotechnical challenges included presence of deep, soft clays and variable depth to bedrock. Due to potential settlement, a program of preloading, ground improvements, deep foundations, and shallow foundations was developed.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi provided geotechnical engineering, construction observation and materials testing services for the design of modifications to an existing clarifier structure at the Birmingham WWTP in northern Kansas City. A new round clarifier was constructed inside of an existing square clarifier. TSi planned and directed the
subsurface exploration program, designed foundation recommendations, and completed the project’s geotechnical report. The project’s primary geotechnical challenge was the need for pile foundations to support the new structures.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi performed geotechnical engineering, laboratory testing, and construction observation and materials testing services for improvements to this WWTP. The project included construction of a new bulk sodium hypochlorite disinfection system/dechlorination system, a 96-inch-diameter, 2,900-foot-long effluent pipe; new clarifiers, aeration basins, control building and tank farm. TSi explored a potential borrow site to evaluate suitability of the borrow materials. TSi prepared a report that included recommendations for suitability of the existing fill and
possible stabilization treatments should the soils not be classified as CL material.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi provided the subsurface exploration, geotechnical engineering, construction observation and materials testing
services for the design of the new 22,000-linear-foot sanitary sewer within the First Creek basin in far northern Kansas
City. The sewer lines range from 24- to 36-inch diameter. TSi’s services included extensive coordination with land owners.
A geotechnical challenge on this project was the presence of shallow bedrock throughout the proposed sewer alignment.

Client: City of Kansas City
Location: Kansas City, Missouri

TSi provided the subsurface exploration and geotechnical engineering services for the design of the new 8-mile-long
sanitary sewer in far northern Kansas City. TSi planned and directed the subsurface exploration program, which required
extensive coordination with land owners. The primary geotechnical challenge on the project was the presence of shallow
bedrock throughout the proposed sewer alignment.