The Top 10 Trenchless Design Firms have done some incredible work. Here, each has highlighted one trenchless project. For information on how to participate in the 2015 Top 50 Trenchless Design Firms survey, contact Sharon M. Bueno, managing editor, at email@example.com. Click here to download the complete list of Top 50 Design Firms.
AECOM Technology Corp.
Government Cut and Norris Cut Utilities Replacement, Miami, Fla.
AECOM was contacted by the Miami-Dade Water and Sewer Department to develop the design criteria, technical documents, 30 percent plans and provide limited construction support services for two separate design-build projects. The first project constructed a replacement 54-in. force main that extended from Miami Beach to Fisher Island and a 20-in. water main between Port of Miami and Fisher Island. The second project was to replace the existing damaged PCCP FM that traverses the sensitive ecological habitats of Norris Cut, identified as being at risk of structural failure. The complex projects involved connections on four land masses separated by federally protected waters.
AECOM led the effort that included completing geotechnical borings, contamination screening studies, benthic surveys, topographic and bathymetric surveys, right of way engineering/analysis and detailed engineering analysis for numerous horizontal and vertical alternatives to replace the existing utilities using a myriad of trenchless methods which included multi-bore/barrel horizontal directional drilling (HDD) schemes, microtunneling and tunnel boring with segment liners. AECOM ultimately developed base criteria and robust conceptual designs for 2,000 lf of 60-in. diameter microtunnel Government Cut; 5,300 lf, 10-ft tunnel under Norris Cut; and 1,000 lf of 10-in. HDD on Fisher Island.
Hatch Mott MacDonald
Keswick Effluent Outfall, Keswick, Ontario
In the course of upgrading the Keswick Water Pollution Control Plant in Ontario, Canada, the Region of York became aware that the existing outfall would not provide enough capacity for the future expansion of the plant.
The onshore alignment of the proposed new outfall crossed a complex “five corner” intersection, heavily traveled roadways, a city park and a residential neighborhood with narrow roadways. A pre-approved environmental assessment prevented the acquisition of more property for permanent easements.
HMM recommended a trenchless solution that included the first curved microtunnel drive completed in Canada, the first underwater reception of a microtunnel drive completed in Canada, and the first compound curve microtunnel drive completed in North America.
The project was recognized as a 2013 Project of the Year by the Ontario Public Works Association and as the New Installation Runner Up for Project of the Year by Trenchless Technology magazine, which wrote, “The project has proven to be a tremendous success.” The American Public Works Association (APWA) selected the Keswick Effluent Outfall as one of its Public Works Projects of the Year for 2014.
Infrastructure Condition Assessment Confronts Extremes, Anchorage, Alaska
CH2M HILL led an inspection study for the Anchorage Water and Wastewater Utility (AWWU) that involved a baseline interceptor condition assessment to create long-term and cost-efficient asset management for AWWU’s 751-mile wastewater conveyance system.
CH2M HILL mobilized crews and equipment to complete the assessment in five months. Twelve sites were monitored and inspections were implemented using a tiered approach. More than 240 manhole and pipeline inspections were conducted using digital zoom cameras during the initial tier. Deficiencies were identified and the next tier for inspection was implemented using closed circuit television and sonar to inspect approximately 90,000 ft of pipeline. The team also conducted robotic and laser inspections for the most challenging assets such as long reaches without manhole access. By identifying only those lines needing advanced inspections, CH2M HILL helped AWWU innovate a cost-effective solution.
Challenges included heavy snows and extreme temperatures. The team also had to solve equipment challenges such as frozen LCD screens, fog-filled pipelines and intermittent cellular signals. Manhole access often required special permits or transportation to difficult locations by ATV or snowmobiles. Inspection data was used to determine remaining service life, calculation of risk, corrosion potential and to recommend system improvements.
Black & Veatch Corp.
White River CCS Phase I, Indianapolis, Ind.
The White River CCS (Collection Consolidation Sewer) Phase I Project is part of Indianapolis’ consent decree to clean up Indianapolis’ waterways. The Black & Veatch-designed project included 1,254 ft of 54- to 108-in. diameter sewer at depths of 8 to 30 ft, two sets of tangential vortex drop shafts to approximately 230 ft below the surface and several structures to divert combined sewer flow to the drop shafts. This system will eventually connect to more than 25 miles of 18-ft diameter tunnel constructed through limestone and dolomite.
Two sections of sewer installed on the project were constructed by trenchless methods. The trenchless subcontractor, Midwest Mole Inc., used Aker tunneling shields with sand shelves and hand mining techniques to perform the drives. The first drive was 180 ft of 72-in. inside diameter (ID) reinforced concrete pipe (RCP) through well-graded, granular soils that had been dewatered. The second drive included 70 ft of 108-in., ID RCP through mostly cohesive fill material that included limestone blocks from an old bridge pier. The cohesive fill and hand mining techniques allowed the contractor to break apart and remove the limestone blocks while minimizing settlement at the surface.
CSO, SSO Reduction, Nashville, Tenn.
CDM Smith was selected by the Metropolitan Government of Nashville and Davidson County as the program manager to support Metro Water Services (MWS) in implementing the requirements of a federal Consent Decree designed to reduce combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs). CDM Smith is leading a team of locally-based firms to support Nashville with program cost, schedule and scope control. CDM Smith is assigned to provide technical and management support to implement the projects identified in two main planning documents, the Corrective Action Plan/Engineering Report (CAP/ER) and the Long Term Control Plan (LTCP). MWS currently operates three wastewater treatment plants, more than 100 pumping stations and almost 3,000 miles of gravity sewers.
The CAP/ER, developed by CDM Smith, addresses capacity and wet-weather issues in the separate sanitary sewer system, and the LTCP addresses improvements planned for the combined sewer system, following EPA’s CSO control policy. In total, the planned improvements are estimated to cost in excess of $1 billion with approximately one third of the program sewer system rehabilitation.
Jollyville Transmission Main, Austin, Texas
The new Austin Water Treatment Plant No. 4 will take raw water from Lake Travis and connect to a pump station via a 9-ft finished diameter tunnel. The raw water pump station houses vertical turbine pumps in a building with similar architectural features found in the nearby development. From this pump station, raw water is pumped up to the water treatment facility. The Jollyville transmission main was tunneled and includes approximately 36,300 lf of 84-in. pipe. The project is charged to attain a U.S. Green Building Council’s LEED Silver rating for the new buildings. MWH has partnered with many local subcontractors and used more than 25 percent local minority and women-owned businesses during its preconstruction activities. MWH also met the city’s standards by integrating innovative construction concepts for sustainability and environmental mitigation. MWH served as construction manager-at-risk.
Sullivan’s Island Sewer Rehab, Sullivan’s Island, S.C.
ARCADIS is providing Construction Management at Risk (CMAR) construction services to the Town of Sullivan’s Island, S.C., for rehabilitation of the barrier island’s leaking sewer pipelines. The goal of the project is to lower leakage from the sewer system by 25 to 40 percent and to stabilize the structural condition of the pipes for the next 30 years. Work will include sewer cleaning and condition assessment, rehabilitation of the sewers primarily using grout sealing technologies, minor mainline lining and open-cut point repairs, evaluation of grouting efficacy and recommendation of future additional rehabilitation measures.
Big Lake Offsite Sanitary Gravity Portion, Edmonton, Alberta
The Big Lake Offsite Sanitary Gravity Portion project in Edmonton, Alberta, consists of 2.3 km (1.4 miles) of 1,200-mm (47-in.) gravity sewer installed at depths from 4 m (13 ft) to 11 m (36 ft). The trunk conveys wastewater flows from a fast growing development and industrial area that are projected to reach 13 MLD (3.4 MGD) by 2024. The ground conditions along the proposed alignment were extremely poor, including a near groundwater table, wet sand, peat layers and the potential for flowing silt and hard cobbles. The alignment crossed two high-traffic roads and Anthony Henday Drive on-ramps. Scheduling was also a concern, as sewage from the development would have had to be hauled by truck until the sewer was in service. Stantec used microtunneling to install a combination of Hobas and Flowcrete pipes, with Permalock casing pipe for the road crossings. Microtunneling was an effective method for installation through poor ground, maintaining line and grade with no settlement. The innovative use of various pipe and casing materials addressed settlement and floatation issues, while providing a sanitary trunk sewer that is resistant to corrosion and H2S attack. To Stantec’s knowledge, this is the first installation of Flowcrete pipe in North America.
Brown & Caldwell
High-Level Sewershed Improvement Recommendations , Baltimore, Md.
Brown and Caldwell worked with the City of Baltimore on a fast-track basis for sewer repair, rehabilitation and replacement, including microtunneling design. BC provided evaluation and improvement recommendations for both first- and second-priority sewer rehabilitation and replacement needs for the High Level Sewershed. Key work included CIPP rehabilitation of 57,500 lf of sewer and trenchless rehabilitation of more than 950 sanitary house connections.
As part of the effort, BC reviewed CCTV data for 57,725 lf of 8- to 52-in. pipe, including 1,288 laterals. BC’s construction administration services include bid and award support, RFI response, change order review, shop drawing review, construction inspection and as-needed consultations during construction. BC also provides manhole and CCTV inspection to quantify pre- and post-construction conditions, verifying the effectiveness of the design and construction work.
Also under this contract, BC is supporting the microtunneling construction of 2,360 lf of 30-in. interceptor sewer in Lower Gwynns Run, which will provide relief to the Upper Gwynns Run Basin of the High Level Sewershed. BC supported design aspects of the project, including writing microtunneling specifications, coordinating design aspects with the prime consultant and coordinating design feedback from potential microtunneling contractors.
Wekiva Parkway (State Road 429) Subsurface Utility Engineering, Orange, Lake and Seminole Counties, Florida
Growth and increased travel between Orange, Lake and Seminole Counties resulted in problematic traffic congestion on US 441 and State Road (SR) 46. To relieve congestion, the 25-mile SR 429, or Wekiva Parkway, was constructed to connect to SR 417 and complete the beltway around northwest metropolitan Orlando, providing an alternative to Interstate 4.
Cardno provided 3D radar tomography along with conventional subsurface utility engineering and supporting survey services to collect accurate horizontal and vertical locations of existing underground utilities. The project limits comprised two areas totaling approximately 17 acres. Cardno completed advanced designating (CI/ASCE 38-02 Quality Level B) to mark the approximate horizontal location of the subsurface utilities while obtaining electronic depth values to compare to the radar tomography results, and completed test holes (CI/ASCE 38-02 Quality Level A) with vacuum excavation equipment. As a result of the investigation, Cardno reduced potential impacts to the construction schedule by accurately mapping over 41,000 lf of utilities, and most importantly, nearly 13,000 ft of existing utilities not previously depicted by available record information.