Water Tunnel Experience by hntbcompanies

WATER

Tunnel Experience

EXPERIENCE DESIGNING TUNNELS HNTB’s collective tunneling experience for wet infrastructure is a testament to our world-class

DC Water Northeast Boundary Tunnel Washington, D.C.

Milwaukee County Grounds Flood Management Tunnel Wisconsin

DC Water Northeast Tunnel Northwest Side ReliefBoundary Sewer Tunnel Washington, D.C. Wisconsin

North 27th Street Inline Sewer System Tunnel Wisconsin

Sewer Design and Construction Engineering Services Illinois

Mill Creek and Peaks Branch Drainage Improvements Texas

reputation. We have provided effective, innovative and tailored solutions to technical challenges toward greater safety, efficiency and environmental sustainability. HNTB brings comprehensive expertise to help clients navigate through the inevitable uncertainty, to optimize investment decisions and maximize and enhance flood control resiliency for end users.

PROJECT DETAILS Location: Washington D.C. Owner: DC Water Completion date: In-progress

DC WATER NORTHEAST BOUNDARY TUNNEL Since May 2019, HNTB has been providing tunnel inspection services as part of CM team for construction of the Northeast Boundary Tunnel project in Washington, D.C. As part of DC Water’s Rivers Project, this $580 million construction contract extends from the northern terminus of the Anacostia River Tunnel at CSO 019 North Drop Shaft to end near the intersection of R Street NW and 6th Street NW. The project features a 23-foot inside diameter 27,000 linear foot long tunnel passing beneath the RFK Stadium parking lot, Langston Golf Course, National Arboretum, Mount Olivet Road/ Cemetery, Fenwick St, New York Avenue, Amtrak Rail Yard, 13th St, Bryant St and Rhode Island Avenue with seven drop/ junction shafts, connecting adits, near surface structures and a tie-in to the First Street Connection Tunnel. Our inspection has been primarily focused on the construction (excavation & permanent concrete) of the shaft and adit connections to the primary tunnel.

PROJECT DETAILS Location: Milwaukee, Wisconsin Owner: Milwaukee Metropolitan Sewerage District (MMSD) Completion date: 1/2005—6/2011

MILWAUKEE COUNTY GROUNDS FLOOD MANAGEMENT TUNNEL The Milwaukee County Grounds (MCG) Flood Management Facility is located upstream of flood-prone areas along the Menominee River. To reduce flooding along the river, the connecting tunnel and diversion structure were built to capture and store portion of the flow in Underwood Creek, which would otherwise cause flooding at downstream areas. Major Features:

» A 2,728-foot long, 17-foot finished diameter tunnel through highly variable soils, including boulders » Earth Pressure Balance (EPB) Tunnel Boring Machine (TBM) with gasketed precast concrete liner » 950-acre foot excavated basin

» Tunnel connecting diversion structure to basin passes under sensitive Wisconsin Department of Natural Resources (WDNR) Forestry Education facility and U.S. 45 and Underwood Parkway » Concrete diversion structure

HNTB’s responsibilities included planning, design and engineering during construction, including three large structures (diversion structure, basin, lower level outlet and spillway) and connecting tunnel. Scope included preliminary design report, Environmental Assessment and permit applications, as well as public involvement meetings; developing plans, specifications and construction cost estimate for final design of tunnel and facility structures; and engineering during construction, including assisting contractors bid review and selection, and review of shop drawings and submittals.

PROJECT DETAILS Location: Milwaukee, Wisconsin Owner: Milwaukee Metropolitan Sewerage District (MMSD) Completion date: 11/2000—6/2006

NORTHWEST SIDE RELIEF SEWER TUNNEL Milwaukee Metropolitan Sewerage District (MMSD) Northwest Side Relief Tunnel consists of a 7.2-mile long 20-foot diameter rock tunnel at depths ranging from 160 feet to 180 feet below ground surface. This sewer is located in the northwest section of Milwaukee. It provides 89 MG of additional capacity to the Inline Storage System during wet weather to prevent sewage overflows and basement backups within the MMSD service area. HNTB provided design, plans, specifications and construction cost estimates for three diversion structures, three drop shafts, approach channel, vortex generator, deaeration chamber, vent shaft configurations and a siphon drain shaft with cone valves to drain the storage tunnel. Scope included Phase 2 environmental site assessment, real estate acquisition plan, site plans for shaft locations, hydraulic analysis and instrumentation and control for filling and emptying the tunnel, resident inspection, shop drawing review and development of record drawings during construction.

PROJECT DETAILS Location: Milwaukee, Wisconsin Owner: Milwaukee Metropolitan Sewerage District (MMSD) Completion date: 1/2004—12/2010

NORTH 27TH STREET INLINE SEWER SYSTEM TUNNEL MMSD’s North 27th Street Inline Storage System (ISS) Extension project reduces separate sanitary sewer overflows in the northeast portion of the MMSD’s service area. Following evaluation of three alternatives (near-surface storage, satellite treatment facilities or storage tunnel at three alternative locations) based on hydraulics, geotechnical conditions, site constraints and cost; the final proposed option selected featured a two-mile long deep storage tunnel of 21-foot finished diameter, which serves as an extension of the existing North Shore ISS. Major Features:

» Two-mile long, 21-foot finished diameter deep storage tunnel » Two 23-foot diameter shafts up to 300 feet deep » Variable ground conditions, high water pressure requiring groundwater cut-off and complex grouting program

HNTB provided preliminary and final design, as well as construction services. HNTB prepared preliminary design report, 30-percent plans and a preliminary Geotechnical Baseline Report (GBR), including a limited geotechnical investigation and hydraulic modeling based on MMSD’s system model during preliminary design. Final design scope included tunnel design plans and specification, geotechnical data Report (GDR) and GBR. During construction, HNTB performed review of shop drawings, contract modifications and claims, and geologic mapping of the 300-foot deep shafts and the two-mile long tunnel.

PROJECT DETAILS Location: Chicago, Illinois Owner: Chicago Department of Water Management Completion date: Ongoing

SEWER DESIGN AND CONSTRUCTION ENGINEERING SERVICES This contract includes multiple task orders for design and construction phases services related to sewer replacement and repair, as well as drainage structure installations, such as junction chambers and tumbling basins. Some projects included sewer replacement of varying diameters up to approximately seven miles in length. One project included the design of 2,400-foot long, seven foot-diameter, soft ground tunnel under West 37th Street from Archer Avenue to Seely Avenue. Sewer pipes were installed via open cut and mined methods. HNTB provided design and construction phase services. Major Features:

» City-wide sewer replacement projects ranging from emergency point repairs to up to 5,800 lineal feet in length » Structure replacements » New junction chamber installations

PROJECT DETAILS Location: Dallas, Texas Owner: City of Dallas and Texas Department of Transportation (TXDOT) Completion date: 2019

MILL CREEK AND PEAKS BRANCH DRAINAGE IMPROVEMENTS As part of drainage relief system, including Mill Creek, Peaks Branch, East Peaks Branch and State Thomas drainage basins, the project plan addressed the City of Dallas’ immediate drainage relief needs and provided drainage protection of flood-prone areas. This plan included new horseshoe, 30-foot-diameter tunnels, associated drop shafts and a dewatering station, eliminated future drainage improvements, with savings of an estimated $100 million in construction cost and eliminating conflicts with TXDOT’s planned reconstruction of Interstate 30. It also avoided a crossing of the Dallas Floodway levees, which would have necessitated a 408 permit. Major Features:

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1.75 miles of 30-foot by 35.5-foot horseshoe shaped tunnel 3.25 miles of 30-foot-diameter tunnel Seven large drop shafts (11-foot to 40-foot diameter) 30,000 GPM dewatering station as part of drainage relief system

HNTB served as program manager overseeing the delivery of drainage relief system plan involving four drainage basins covering 6.6 square miles. Scope included review of alternative analyses, design, specifications, schedule and project estimates.

ROBERT PAGE, PE

MARK STEPHANI, PE

SANJA ZLATANIC, PE

Water Services Practice Leader rtpage@hntb.com (317) 917-5307

Central Region Tunnel Practice Lead mstephani@hntb.com (312) 798-0311

Chair, National Tunnel Practice szlatanic@hntb.com (212) 294-7567