Experience & Expertise
See our work first-hand by viewing our past projects.
TERREX ENGINEERING & CONStRUCTION
Reference significant projects
Terrex Engineering & Construction, LLC (Terrex) is a relatively new-startup company. The engineering and construction experience presented below is experience acquired by Terrex’s President and Corporate Engineering Manager, Mr. E. Hal Christensen, SE, PE, over an extended 40 year career as a civil-environmental engineer. Mr. Christensen has been involved with the design and construction of a broad range of water, wastewater, transportation, and land development projects. Mr. Christensen acquired the bulk of his extensive experience while employed by three international civil and environmental consulting firms as a Senior Project Manager; the Utah Department of Water Resources as a Senior Water Resources Planner, on the USBR Columbia Basin Project Washington State as the District Engineer for the South Columbia Basin Irrigation District; and as an Operating Engineer for a regional heavy road construction company while attending the College of Engineering at Utah State University.
Water Conveyance & hydroelectric generation facilities
Block 24 Pump Station and High-Pressure Pipeline
South Columbia Basin/irrigation/Water District/USBR Columbia Basin Project | Pasco, Washington
Scope of Work: Design and construction management of 3.5 miles of a 48-inch high pressure cement mortar lined steel pipeline and 12,000 gpm pumping station. Pumping station consists of six horizontally mounted split case centrifugal pumps with individual capacities ranging from 500 gpm to 100 gpm. Pumps were designed to take suction from a common intake manifold utilizing a major feeder canal as an equalization reservoir. The downstream water distribution pipe network provides high pressure irrigation water service to 1,920 acres of farmland within an isolated District service area (Wahatis, Washington).
Project Construction Cost: $5.5 million
Russel D. Smith Potholes East Canal Low Head Hydroelectric Power Generation Facility
South Columbia Basin/irrigation/Water District/USBR Columbia Basin Project | Pasco, Washington
Scope of Work: Design and construction management of a 6.1 MW low-head hydroelectric power generation plant. Plant was constructed on the District’s main feeder canal (Potholes East Canal) immediately adjacent to a 40.0 ft. energy dissipation drop structure. General project scope of work included a preliminary power generation versus gross revenue feasibility study, preliminary evaluation of low head turbine and generator manufacturer options, power grid connection requirements, power revenue potential over a 50 year planning period, plant inlet and penstock hydraulic design, geotechnical foundation design, preparation of construction drawings and specifications, and general project construction management.
Project Construction Cost: $15.8 million
Low Head Gravity Flow Pipelines
South Columbia Basin/irrigation/Water District/USBR Columbia Basin Project | Pasco, Washington
Scope of Work: Design and construction management of an estimated 20.0 miles of low pressure-gravity flow RCP pipelines (diameters to 60 inches) to replace existing open canal delivery networks due to changes with on-farm center-pivot irrigation practices. A considerable percentage of these pipelines were constructed within extreme groundwater and unstable soil profile conditions requiring extensive dewatering practices.
Total Estimate of Construction Costs: $15.9 million
Expansion and Rehabilitation of Exiting Pumping Stations
South Columbia Basin/irrigation/Water District/USBR Columbia Basin Project | Pasco, Washington
Project Scope of Work: Design and construction management of numerous projects associated with the placement of additional pumping stations to meet a growing demand for irrigation water by new corporate farming interests throughout the extended District service boundaries. New installations included high pressure horizontal centrifugal pumping facilities with capacities to 1,200 cfs in addition to low head-high volume vertical turbine pumping facilities with capacities to 150 cfs.
Total Estimated Construction Costs: $7 million
Open Channel Reconstructions
South Columbia Basin/irrigation/Water District/USBR Columbia Basin Project | Pasco, Washington
Scope of Work: Design and construction management of projects associated with the rehabilitation of existing open canal and delivery lateral systems including: the resurfacing of concrete aprons within drop and erosion control structures, reconstruction of automated radial gate structures, reconstruction and recalibration of water delivery flow measurement structures, and replacement of both concrete and clay lining materials for open canals and laterals subject to excessive seepage and groundwater infiltration.
Total Estimated Construction Costs: $20 million
Rattle Snake Mountain High Pressure Raw Water Trunkline
Town of Hanna, Wyoming
Scope of Work: Design of a 15 mile-15 inch raw water pipeline extending from the City’s existing Rattle Snake Mountain reservoir within the adjacent Elk Mountain watershed to the City’s existing water treatment plant. Key project features include a major Interstate 80 crossing (jack and bore construction with heavy-wall steel carrier piping), a pressure reduction valve (PRV) station, numerous isolation valve stations, strategically located lateral mainline turn-out stations, screened reservoir intake structure, etc.
Project Construction Cost: $4.8 million
Water resources master planning
River Basin Master Plans-Weber and Virgin River Basins
Utah Division of Water Resources, Salt Lake City, Utah
Scope of Work: Preparation of comprehensive water master plans for two of Utah’s major river basins supplying municipal and irrigation water to over one-third of Utah’s population base, commercial businesses, and irrigated agriculture. Conduct basic research to assess and identify a comprehensive list of issues typically associated with water supply, water use, flood runoff (drainage), water quality, water-related wildlife resources, and general surface and groundwater environmental degradation that may be associated with both the Weber and Virgin River Basins. Master Plans were utilized by municipalities, counties, and public water districts within both river basins to project water demand and miscellaneous water-related issues for a 30-year planning period.
Scope of work also included the scheduling and presiding over preliminary planning meetings with local, state, and federal agencies in addition to special interest organizations impacted by water issues within a selected river basin. Federal agencies included the Bureau of Reclamation, Army Corps of Engineers, Fish & Wildlife Service, Natural Resources Conservation Service, and Environmental Protection Agency. State agencies included the Utah divisions of Water Resources, Drinking Water, Water Quality, Water Rights, and Wildlife Resources. Local water agencies included water conservation districts, wastewater (sewer) improvement districts, irrigation districts (canal/ditch companies), municipal/county public works departments, municipal/county government bodies in addition to municipal/county health departments. Non-public agencies included Wilderness Utah, National Wildlife Refuge Association, Nature Conservancy, National Audubon Society, Sierra Club, etc.
Wastewater collection & treatment systems/facilities
Platte River Sludge Injection Project
City of Fort Collins, Colorado
Scope of Work: Preparation of construction drawings and specifications for pumping stations, piped conveyance networks, storage tanks, and quick-coupling connection stations for an on-farm agricultural sludge injection site and/or facility. The land application of digested domestic sludge was accomplished by subsurface pressurized injection shanks as mounted to a dozer crawler tractor. Shank bars were fed sludge from vertical injection ports at locations throughout the 100-acre agricultural farm site to accommodate a high-pressure sludge feed hose system. The overall design effort included significant revisions to the existing irrigation system to allow for flood irrigation methods typically utilized for livestock forage crops.
Project Construction Costs: $14.5 million
Hyperion WWTP Sludge Thickening Facility
Los Angeles Sanitation District-City of Los Angeles, California
Scope of Work: Preparation of an engineering study to identify performance characteristics of individual 1,000 gpm centrifuge units as manufactured by two prominent international manufacturers. The completed study provided recommendations for final selection and installation of centrifuges into the new Hyperion Sludge Thickening Facility. Scope of work also included the design of the new 24,000 gpm Hyperion Sludge Thickening Facility including secondary sludge holding basins, sludge feed piping system, polymer storage and feed pumping system, cent-rate return flow piping, and thickened sludge conveyor belt discharge system.
Project Construction Cost: $45 million
Wastewater Sewage Lagoon Enlargement and Improvements
City of Douglas, Wyoming
Scope of Work: Design and construction management of a 2.0 mgd aerated lagoon wastewater treatment facility including earthen-fill detention cells, aeration piping system, blower building, chlorine storage and injection facility/basin, and miscellaneous effluent flow control structures. Project also included the design and construction management of 3.5 miles of a 10 in. to 12 in. sanitary sewer.
Project Construction Cost: $3.8 million
Secondary Domestic Sludge Compost Pilot Demonstration
Metro Wastewater Reclamation District, Denver, Colorado
Scope of Work: Preparation of an engineering study to assess compost amendment material options considering process odor control, material availability and costs, feasibility and marketing of stabilized landscape mulch end product. Project also included basic design of a 10.0 ton-per-day vacuum-trench aerated composting facility and related odor control scrubber tank and air piping system. Project
Project Construction Cost: $600,000
Laughlin WWTP Liquid Train and Secondary Effluent Center Pivot Irrigation System
Clark County Water Reclamation District, Laughlin, Nevada
Scope of Work: Design of a liquid train conveyance system and belt-press solids handling facilities for a 4.5 mgd oxidation ditch WWTP. Design also included the design of a center-pivot land application system to apply secondary effluent to a bermuda grass agricultural farm site immediately adjacent to the proposed WWTP.
Project Construction Cost: $18.5 million
Rancho Cucamonga WWTP liquid and Solids Train Improvements
Inland Empire Utilities Agency, Ontario, California
Scope of Work: Design and construction management of a 44.0 mgd expansion to the WWTP’s liquid train and solids handling facilities. Liquid train improvements include hydraulic expansions to the plant headworks facility, additional primary clarifiers, aeration basins, secondary clarifiers, and chlorine contact basins. Solids handling improvements included additional primary and secondary sludge pumps, increased RAS/WAS pumping and piping capacity, new belt press facility, and solid waste tanker truck loading facility with gravity feed silo storage tanks.
Construction Cost: $65 million
Canal Cities WWTP Reconstruction Project
United States Agency for International Development, Cairo, Egypt
Scope of Work: Preparation of a comprehensive reconnaissance level study to assess existing conditions of three WWTPs at the Egyptian canal cities of Suez, Ismalia and Port Said. The study addressed the extent of damage to all three plants as a result of the six-day Egyptian and Israeli war in 1967. The report identified the inherent treatment process of all three plants and estimated costs to upgrade each facility to comply with Egyptian law for effluent quality to adjacent receiving streams.
Projected Combined WWTP Improvement Construction Cost: $250 million
Existing Sanitary Sewer Hydraulic and Collection Piping Storage Study
Los Angeles Sanitation District-City of Los Angeles, California
Scope of Work: Preparation of a study to assess potential wastewater storage options within the Hyperion basin sanitary sewer system to effectively reduce peak flows from service areas immediately adjacent to the existing plant site, and within the extended Los Angeles drainage basin. Sanitary sewers with up to 144 in. diameters were evaluated with flow capacities to 150 mgd.
Projected Sanitary Sewer Improvements Construction Costs: $120 million
Bulk Chlorine Storage and Energy Recovery Expansion Facilities
North Davis County Sewer Improvement District, Syracuse, Utah
Scope of Work: Design of a bulk chlorine storage and injection building in addition to a new energy recover facility. The bulk storage building was designed to transfer railroad tanker loads of chlorine to two 10,000 gal. steel bulk storage tanks within an enclosed steel framed storage and chlorine injection building . Effluent chlorination was accomplished by a bank of Wallace & Tiernan chlorinators. The Energy Recovery facility incorporated two 310-kw Waukesha engine-generator sets fueled by digester and natural gas to provide co-generation power capabilities to effectively reduce outside utility energy requirements.
Project Construction Cost: $18 million
Sanitary Sewer Capital Improvement Program
Lake Havasu City, Arizona
Scope of Work: Master planning, design, and construction management of a comprehensive capital improvement project to replace residential septic tank and drain field sewage disposal systems with piped sanitary sewers in addition to major expansions to the City’s existing North Regional Wastewater Treatment Plant. The planning, design and construction of the indicated capital improvement projects were mandated by the Arizona Department of Environmental Quality to mitigate excessive groundwater nutrient migration and resulting eutrophication of Lake Havasu. 125 sanitary sewer collection systems were designed and constructed for individual subdivisions throughout the city’s east bench area with pipe diameters ranging from 10 in. to 18 in. in diameter. Project also included 4.0 miles of main sewer trunklines ranging in pipe sizes from 12 in. to 24 in. in diameter in addition to nine new sewage lift stations.
Total Project Construction Cost: $450 million
Yellow Stone River WWTP Upgrade
City of Laurel, Montana
Scope of Work: Design of various biological and chemical removal facilities and/or systems. Design included the preparation of detailed construction drawings and specifications for: two 8,500 gallon aerobic and anoxic microbiological mixing tanks; a new blower building; major expansions to the existing RAS/WAS pumping station and secondary clarifiers; replacement of the existing chlorine contact basin and chlorine injection system with a UV disinfection system; a new secondary sludge de-watering facility/building.
Project Construction Cost: $6.8 million
Transportation & Pavement
Reconstruction of Heavy Lift Main Aircraft Runway
US Department of Defense-Hill Air Force Base
Scope of Work: reconstruction of the main heavy lift aircraft runway to accommodate the USAF’s entire arsenal of heavy bombers and heavy lift cargo aircraft. Reconstruction included patch and repair of deteriorated runway sections and the placement of 1.0 ft. of new asphaltic pavement over existing reinforced concrete pavement subbase.
Project Construction Cost: $15 million
Reconstruction of 6.5 Miles of Interstate 84-Morgan Utah to Echo Canyon Road
Utah Department of Transportation, Salt Lake City, Utah
Scope of Work: Resurfacing of interstate highway with aliphatic seal coat pavement per UDOT specifications for interstate highway heavy traffic wheel-loads through cold weather climates.
Project Construction Cost: $4.5 million
General Municipal Street Construction
Description: Numerous municipal street construction projects for residential subdivisions, arterial streets, county roads, private driveways, and commercial parking lots.
Accumulative Estimate Five Year Project Construction Costs: $50 to $75 million
Land Development
General Development Projects
Kamelot Subdivision, Marriott Construction, Plain City, Utah
Description: 21 Acre-41 Lot Residential Subdivision
Canyon Park Estates, Marriott Construction
Description: 2.80 Acre-8 Lot Residential Subdivision
Staker Farmstead Estates, Wayne Ball, Taylor, Utah
Description: 13.8 Acre-18 Lot Residential Subdivision
Scope of Work: Attendance at preliminary project scoping and planning meetings with city and county agencies to acquire preliminary project approvals, supervision of all site boundary and topographic surveys by contract surveyors, supervision of site geotechnical investigations and soils engineering reports by contract subconsultants, preparation of subdivision project construction drawings, preparation of real estate market evaluations to assess project profitability and lot absorption projections, construction management, and preparation of project as-built construction drawings.
