Tunnel updates

Eillicott City, Maryland, Extended North Tunnel (Photo: Howard County).

ALABAMA

Decatur
Moulton Street Collector Gravity Sewer Improvements
Turn – Key Tunneling, Inc.
The overall project of Moulton Street Collector Gravity Sewer Improvements includes the installation and construction of approximately 7,500 linear feet of a new 60-in. gravity sewer line. The alignment parallels the existing 36- and 42-in. diameter sewer lines from Dry Creek WWTP to Moulton Street.

John Plott Company, Inc. of Tuscaloos, Alabama, subcontracted Turn – Key Tunneling, Inc. (TKT) of Columbus, Ohio, to install the roadway tunnel (210 lf) of 90-in. liner plate for 60-in. DIP sewer across Alabama State Route 20 (ALT 72) right of way and the railroad tunnel (185 lf) of 90-in. liner plate for 60-in. DIP sewer across Norfolk Southern Railroad right of way. This work included TKT installing a 20’ liner plate receiving shaft at the manhole and a 20’ liner plate working shaft at the Dry Creek tie-in.

The bid cost was $2.673 million. The contract dates are from Jan. 27, 2025, to July 3, 2025. The owner is Decatur Utilities.

Personnel: Andy Harshman – John Plott PM; Dale Dockins – John Plott Supt.; Chris Leonard – TKT Senior PM; Clinton Hudkins – TKT Supt.; Domonic Thompson – TKT Foreman; Adam Salyers – TKT Foreman.

CALIFORNIA

Carson/Los Angeles/Rancho Palos Verdes
Joint Water Pollution Control Plant Effluent Outfall Tunnel
FlatironDragados USA
The Joint Water Pollution Control Plant Effluent Outfall Tunnel for the Los Angeles County Sanitation Districts is a $630.5 million project involves constructing a tunnel approximately 7 miles long and 21.5 feet in excavated diameter (18 feet in internal diameter). NTP was issued in April 2019. Current scheduled completion date is June 2029.

In addition to the tunnel, the job involves building one one launch shaft, one reception shaft and three safe havens (jet grouted blocks for TBM cutterhead maintenance). Ground conditions are varied. The first 19,500 lf is in soft ground, including clays, sands and silts, while the remaining 17,300 lf is in rock, including siltstone, claystone, sandstone, dolomite, chert and diatomite. The tunnel is being mined with a Herrenknecht Slurry TBM.

Overall, the project is 73.2% complete. The tunnel drive is 78% complete. The drive launched in September 2021 and is expected to complete the drive in Q4/2025. Mobilization commenced in April 2025 to prepare the Royal Palms Beach area for the reception shaft construction and other Support of Excavation works. Fabrication of 1,400 lf of 16-ft diameter steel liners is complete for later in-tunnel installation though identified areas in the contract at fault zones, beneath I-110 and at the launch/reception shafts.

Special/unique features of the job include the use of post-tensioned tunnel linings and tunnel excavation through squeezing ground.

Major parties affiliated with the project include Sener, Pini, Traylor Bros. Precast, and Herrenknecht.

Personnel: Los Angeles County Sanitation Districts – Construction Management Section: Matthew Palma, Section Head; Phil Kang, Resident Engineer/Construction Manager; Sewer Design Section: Anthony Howard, Section Head; Don Drorbaugh, Supervising Engineer; Yoonkee Min, Senior Engineer; Edgar Rocha, Engineering Associate; Cecilia Dominguez, Civil Engineer. Parsons – Bill Lu, Project Manager. Delve Underground –Matt Gallagher, Lead Tunnel Design Consultant. Mott MacDonald – Brendan Reilly, Lead Tunnel Consultant; Max Gleichman, Chief Tunnel Inspector. Dragados – Matt Kendall, Project Manager; Nicholas Karlin, Deputy Project Manager; Tony Hupfauf, Superintendent.

Los Angeles
D Line (Purple Line) Extension Transit Project
The Purple (D Line) Extension Project is a 9-mile long project being built by the Los Angeles County Metropolitan Transportation Authority (Metro) that consists of three Sections.
Section 1 is a 3.92-mile long subway alignment with three stations being constructed under Wilshire Boulevard in gassy ground and tar sands with prehistoric fossil deposits. It was built by Skanska/Traylor/Shea JV under a $1.636 billion contract.

The $1.37 billion Section 2 project includes 2.6 miles of twin bore tunnel and two new stations and built by Tutor Perini/O&G.

Section 3 is a 2.6-mile extension built by Frontier-Kemper/Tutor Perini JV under a $410 million contract for tunnel construction. Tutor Perini/O&G Joint Venture was awarded the Section 3 stations contract, which is valued at $1.4 billion and includes the construction of two new stations.

On April 2, 2024, Metro announced that it has successfully completed all tunneling. This major construction milestone was accomplished safely in one of the densest and most geologically challenging urban corridors in the L.A. region and nation. Contractors utilized the latest tunnel boring machine (TBM) technology to excavate approximately 40-60 ft per day to help complete tunneling for the project.
During its five years of tunneling, Metro faced and successfully overcame many technical challenges like gassy ground, tar sands and abandoned oil wells. Near the La Brea Tarpits, for example, Metro’s advanced TBMs made their way through tar sands, and used horizontal directional drillings to probe the earth so contractors could identify and remove potential objects before any TBM damage occurred. Metro also safely used the same methods to identify and avoid unmapped and abandoned oil wells underneath Beverly Hills High School.

Project opening dates for the segments are: Section 1 – fall 2025; Section 2 – 2026; and Section 3 – 2027.

Menlo Park
Stanford Linear Accelerator (SLAC) – Low Emittance Injector Tunnel (LEIT)
Obayashi Drill Tech Joint Venture (OCDT)
This $48.3 million project for SLAC National Accelerator Laboratory (SLAC) was issued NTP in April 2024 with surface work and shaft excavation scheduled to start in July 20205. Tunnel work is expected to start in January 2026 with substantial completion in February 2027.
The job includes 220 lf of new tunnel, ~20-ft diameter and 35 lf of ~15-ft diameter skewed tunnel off new tunnel pointed toward existing tunnel. A bulkhead is to be built against existing tunnel. Penetrations will then be added to allow for new laser beam alignment

The shaft is 20-ft x 30-ft rectangular, 40 ft deep. The soil nail/soldier pile portal will involve ~1,800 CY of excavation. The Whiskey Hill rock formation is anticipated along with some engineered fill adjacent to the existing tunnel. Mining excavators are planned for tunnel excavation. Initial liner calls for lattice girders and poly fiber reinforced shotcrete

A planned shutdown will take place from October 2025 through December 2025 for experiments to take place, with heavy civil work resuming in January 2026.

Tunnel Designer – Mott MacDonald; General Contractor – Obayashi Drill Tech Joint Venture (OCDT); Owner – SLAC National Accelerator Laboratory (SLAC); Construction Manager – Stantec

Personnel: Tunnel Designer – Mott MacDonald, Justin Lianides; General Contractor/Tunnel Contractor – Obayashi Drill Tech Joint Venture (OCDT), Alex Folchi; Owner – SLAC National Accelerator Laboratory (SLAC) – Irene Bendanillo; Construction Manager – Stantec, Mike Bruen.

Oakdale
Paulsell Lateral Tunnels 1 & 2
Drill Tech Drilling and Shoring, Inc.
This $3.3 million project for the Oakdale Irrigation District consisted of enlarging existing 3-ft x 7-ft irrigation canal tunnels to ~10-ft x 10-ft. Tunnel 1 is ~750 lf and Tunnel 2 is ~330 lf.

Drill Tech crews used AM-50/AM-150 roadheaders to mine soft claystone/sandstone. The excavation is supported with fiber reinforced shotcrete and WWF in sandy spots.

NTP was issued Oct. 2, 2024, with tunnel scope beginning November 2024 and was completed in February 2025. Final completion/full demobe occurred in March 2025.

Crews mined two tunnels at once and adhered to a tight schedule to meet outage requirements from OID. Environmental regulations required that no work be done during fog, rain events, and 24 hours after rain events.

Tunnel Designer – Provost & Pritchard Consulting Group; General Contractor – Drill Tech Drilling and Shoring, Inc.; Owner – Oakdale Irrigation District; Construction Manager – Provost & Pritchard Consulting Group.

Personnel: Tunnel Designer – Provost & Pritchard Consulting Group, Scott Lewis; General Contractor/Tunnel Contractor – Drill Tech Drilling and Shoring, Inc. Alex Folchi; Owner – Oakdale Irrigation District – Joe Kosakiewicz; Construction Manager – Provost & Pritchard Consulting Group, Jake Feriani.

San Jose
VTA’s BART Silicon Valley Phase II Project
Kiewit/Shea/Traylor
The Bay Area Rapid Transit (BART) Silicon Valley Phase II Extension (BSVII) Project is the second phase of VTA’s BART Silicon Valley Program to expand BART service into Santa Clara County. It is the largest single public infrastructure project ever constructed in Santa Clara County. The BSVII Project will extend the BART System from north San José through downtown San José to Santa Clara and is estimated to carry 54,600 passengers each weekday to destinations throughout the Bay Area by 2040. Completion of the project will finally “ring the bay” with frequent rail service. The scope of the BSVII Project includes 5 miles of tunnel, 53.2-ft outside diameter and 48-ft inside diameter, and three underground stations. A fourth station, Santa Clara Station, and the Newhall Yard and Maintenance Facility are located at-grade at the west end of the BSVII extension in Santa Clara.

In November 2023, VTA announced that the TBM has been ordered from Herrenknecht. The $76 million TBM for the project will be the third largest TBM ever built. The largest TBM, Tuen Mun-Chek Lap Kok in Hong Kong, was 57-ft, 10-in., and the SR 99 TBM in Seattle was 57-ft, 3-in. Boring is scheduled to begin in 2027, per VTA. Completion of the TBM is near, factory acceptance is scheduled for June 2025. The TBM is planned to be stored in Germany before being shipped to California.

The project will be constructed within a variety of alluvial deposits that extend from the ground surface to depths of 300 ft. The deposits consist of non-sequential, laterally variable, interbedded, and discontinuous fine-grained and coarse-grained soils. Fine-grained soils include silts and clays and coarse-grained soils include sands and gravels. The tunnel alignment will vary in depth from approximately at grade to 160-ft below the ground surface. The entire tunnel alignment will be below the groundwater table with pressures ranging from 1 up to 4.5 bar.

Kiewit/Shea/Traylor joint venture was awarded the Stage 1 Pre Construction Services contract to complete an innovations phase, programming services, engineering design services, open book cost estimating, and schedule development. Stage 1 work is fully commenced, including kick off for the TBM launch structure.

Currently negotiations for Stage 2 to construct the TBM tunnel are underway. VTA has established a contracting task force and is conducting industry outreach to explore new contract packing methods, delivery models and risk sharing strategies. A VTA decision on a path forward is expected in June 2025. VTA is also continuing to evaluate ways to reduce project cost. New cost saving measures include refining stations, reducing structured parking and reconfiguring interior tunnel configuration. More in-depth refinements are currently being evaluated, including concurrent tunneling from two ends and reducing the size of part of the tunnel.

Project Parties: Kiewit Engineering Group – KIE, leads and manages design; Tunnel Designer: Arup; Construction Management Services: Bechtel Infrastructure Corp.; A joint venture of HNTB and WSP are providing program management services for the project and a Mott MacDonald/PGH Wong Engineering Inc. joint venture are providing General Engineering Services. Shannon & Wilson is the Geotechnical Engineer Consultant.

Shaver Lake
Helms Liner Repair Project
Drill Tech Drilling and Shoring, Inc.
This $2.8 million job for Pacific Gas & Electric comprises contact grouting 150 lf of steel lined 11- to 15-ft diameter penstock and 50 lf of 15-ft diameter concrete lined penstock directly upstream of large underground powerhouse (Helms).

NTP was issued July 2024 with tunnel scope beginning September 2024. Tunnel scope completion was achieved in January 2025. The project was completed during scheduled outage with multiple scopes growing in nature from bid time.

The project incluced: concrete liner repairs: ~ 50 CY excavated by hand/chipping gun and mucked by hand through a 30-in. diameter flange; arcylic resin stitch grouting: 300 lf of 0.5-in. diameter leaking cracks; and setup, maintain, and demobilize all underground safety and utilities (power, water, air, lighting, leakage water collection/pumping, etc.) for ~800 lf of tunnel for four different subcontractors during outage. The job was in a very remote project location, about 2 hours by car from the nearest town and at about 7,500 ft elevation.

Tunnel Designer – Delve Underground; General Contractor – Drill Tech Drilling and Shoring, Inc.; Owner – PG&E; Construction Manager – PG&E

Personnel: Tunnel Designer – Delve Underground, Shawn Spreng; General Contractor/Tunnel Contractor – Drill Tech Drilling and Shoring, Inc. Alex Folchi; Owner – PG&E – Rex Avila; Construction Manager – PG&E, Ryan Rabbon.

DISTRICT OF COLUMBIA

Washington
Potomac River Tunnel
CBNA/Halmar
The $819 million contract is the largest ever awarded by DC Water. The 5.5-mile-long tunnel will control combined sewer overflows to the Potomac River, improving water quality in this critical natural resource. This work is part of the larger Clean Rivers Project, a $2.99 billion program to improve the water quality of the Anacostia and Potomac rivers and Rock Creek by increasing the capacity of the sewer system.
A joint venture of CBNA and Halmar was selected based on its lowest price proposal and second highest technical score, therefore providing the best value.

DC Water announced on April 28 that the first of the two TBMs completed its factory acceptance test at the Herrenknecht facility in Schwanau, Germany. Factory acceptance testing for the second TBM is anticipated for October 2025.

The 18-ft diameter tunnel will run deep underground beneath the Georgetown waterfront, along the edge of the National Mall and East Potomac Park, past Hains Point and connect by gravity to the existing Anacostia River Tunnel. Construction will require two tunnel boring machines. Starting from West Potomac Park, one machine will mine south through mostly soft ground, and another machine will head north to bore through rock. Completion is expected in early 2030, in accordance with the schedule stipulated in the Consent Decree DC Water signed in 2005 with the U.S. Environmental Protection Agency, the Department of Justice, and the District of Columbia. Once the PRT is operational, it will reduce combined sewer overflows (CSOs) to the Potomac River by 93 percent in an average year of rainfall.

INDIANA

Indianapolis
Fall Creek Tunnel
Shea-Kiewit JV
The Fall Creek Tunnel is a 20,244-ft, 20-ft, 2-in diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are ten CSO connecting structures/deaeration chambers and adits. The work is for Citizens Energy Group’s DigIndy project, which is a CSO reduction program including six deep rock tunnels totaling over 28 miles.

All tunnel, shaft, adit, and deaeration chambers are 100% complete, and the Fall Creek Tunnel is now available for additional storage of CSO overflows from the four DigIndy Tunnel segments that have been previously commissioned. Surface connections to CSO outfalls along the Fall Creek Tunnel alignment are ongoing. Based on the terms of a federal consent decree, the Fall Creek Tunnel must be operational by the end of 2025.

Personnel – Construction PM: Eric Haacke.; Inspection PM: Sam Cain, P.E. (AECOM); Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Tunnel Construction Supervisor: John Morgan.

Indianapolis
Pleasant Run Tunnel
Shea-Kiewit JV
The Pleasant Run Tunnel is a 41,472-ft, 20-ft, 2-in diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are eight CSO connecting structures/deaeration chambers and adits. The work is for Citizens Energy Group’s DigIndy project, which is a CSO reduction program including six deep rock tunnels totaling over 28 miles.

All tunnel, shaft, adit, and deaeration chambers are 100% complete, and the Pleasant Run Tunnel is now available for additional storage of CSO overflows from the five DigIndy Tunnel segments that have been previously commissioned. Surface connections to CSO outfalls along the Pleasant Run Tunnel alignment are ongoing. Based on the terms of a federal consent decree, the Pleasant Run Tunnel must be operational by the end of 2025.

Personnel – Construction PM: Eric Haacke. ; Inspection PM: Sam Cain, P.E. (AECOM); Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Tunnel Construction Supervisor: John Morgan.

KENTUCKY

Lexington
University of Kentucky Thermal Utility Tunnel Project
Drill Tech Drilling & Shoring, Inc.
Drill Tech has been contracted to design and construct two drop shafts and a tunnel to extend thermal utilities underneath Limestone Road as part of a larger Cancer Research Center being constructed at the University of Kentucky. The shafts are approximately 29-ft OD and 35-ft deep supported by shotcrete and lattice girders. The tunnel is 13-ft square and 150-ft long supported by bolts, mesh and shotcrete.

Competent limestone rock is expected throughout the excavation. Excavation methods will be by mechanical means via rocksplitting, breaking, and roadheader. Due to the proximity to the existing UK hospital, no blasting is permitted.

This project is currently in design stages. Initial support drawings being prepared by Kilduff Underground Engineering are near complete and will be submitted to owner and KYDT for permit acquisition by mid-May 2025 with final liner drawings being prepared simultaneously – expecting to be complete by end of May 2025.

As mentioned, excavated material is competent limestone rock with UCS values anywhere from 10,000 to 20,000 psi. Due to proximity of tunnel and shaft to the UK, no blasting is permitted. The rock will need to be excavated using mechanical means only.

The bid value of the project is $11,999,000. Estimated NTP is July 2025, with estimated construction completion by July 2026

Tunnel Designer – Kilduff Engineering; General Contractor – Walsh Healthcare Subcontractors for DTDS scope – Moran Waterproofing

Personnel: Derek McDonald, Project Manager, Drill Tech Drilling & Shoring, Inc.; Brian Harris, Project Sponsor, Drill Tech Drilling & Shoring, Inc.; Efrian Ortiz Quinonez, Project Superintendent, Drill Tech Drilling & Shoring, Inc.; Ryan O’Connell, Project Manager, Kilduff Underground Engineering; Arvid Veidmark, Project Engineer, Kilduff Underground Engineering

MARYLAND

Baltimore
Frederick Douglass Tunnel
Kiewit/Shea JV
The Frederick Douglass Tunnel for Amtrak comprises two new high capacity tubes, approximately 2 miles in length, designed to replace the Civil War era Baltimore & Potomac Tunnel, which is one of the largest bottlenecks along the Northeast Corridor (NEC).

Kiewit/J.F. Shea JV was awarded a CMAR contract for Package A, which includes tunnel construction. Clark Construction/Stacy and Witbeck JV was awarded a CMAR contract for Package B, which involves improving the southern approach. ADVANCE, a joint venture between major infrastructure firms AECOM and Jacobs, is the Delivery Partner. ESP/Parsons JV is the Engineer of Record.

Early construction activities are underway as part of the $6 billion modernization of this 10-mile section of the NEC. Activities anticipated for 2025 include manufacturing of the TBMs that are expected to begin mining within the next two years, completing demolition activities, continuing utility investigation and relocation, soil borings, site surveys and installation of instrumentation and monitoring devices.

Ellicott City
Extended North Tunnel
Kiewit-Traylor
The Extended North Tunnel, will be about 5,000 ft long, 18 ft in diameter and run up to 100 ft underground, just north of Main Street in Ellicott City, Maryland. The tunnel will carry 26,000 gallons of stormwater per second away from streets and foundations of Ellicott City and the West End and directly into the Patapsco River. The Extended North Tunnel is one of seven flood mitigation projects in the EC Safe and Sound Plan as a result of recent catastrophic flooding in the area.

In June 2024, Howard County held a ceremonial groundbreaking event for the project. Shaft sinking commenced in December 2024. Tunnel boring is expected to be completed in fall 2025. Final project completion is expected in 2027.

As a separate contract as part of the same program, Kiewit is installing 10-ft jacked tunnels under CSX railroad lines.

MISSOURI

St. Louis
Lower Meramec Tunnel
SAK Construction LLC (Affholder)
This is a $174 million project for the Metropolitan St. Louis Sewer District (MSD) comprising 35,903 ft (6.8 miles) of 11-ft excavated, 8-ft final diameter, 78 to 286 ft deep sanitary sewer tunnel which was excavated using a tunnel boring machine (TBM) entirely within limestone, shale and dolomite rock with two required construction shafts and six drop structures. The project, which was given NTP in January 2021, is approximately 80 percent complete.

The contractor has completed drilling the drop and vent shafts, installed secant piles at the TBM retrieval shaft and completed excavation of the retrieval shaft, tail tunnel, starter tunnel and the adit to the Fenton drop structure. The contractor has completed installation of the upper portion of the concrete lining at the working shaft. The TBM was assembled and started excavation in late April 2023. The TBM completed excavation of the 35,903 ft long tunnel on Oct. 18, 2024. The contractor has completed excavation of the adits and deaeration chambers and lining of the deaeration chambers. The carrier pipe installation started on March 18, 2025, and was approximately 15% complete on April 15, 2025. Final completion is anticipated by November 20, 2025.

This project is an extension of the previously constructed Baumgartner Tunnel Project which was 20,200 ft long with a 12.5 ft excavated diameter, 8-ft final diameter. Bedrock conditions encountered consisted of the Warsaw and Burlington-Keokuk Formations. The Warsaw Formation is composed primarily of limestone and shale with small amounts of chert. The Burlington-Keokuk Formation includes limestone and abrasive chert which, in places, comprises from 40% to 60% of the rock mass.

The Tunnel Designer is WSP as a subconsultant to HDR Engineering, Inc. The Construction Manager for the project is Black & Veatch. Major subcontractors include Williams Tunneling, Bates Construction, J&J Boring, Keller. TBM Manufacturer – Robbins.

Personnel: Metropolitan St. Louis Sewer District – Design Project Manager: Jerry Jung; Construction Project Manager: Ray Scherrer. Tunnel Design Manager: Everett Litton, WSP. Construction Manager: Clay Haynes, Black & Veatch: SAK Project Manager: Jim Buckley. Project Engineer: Patrick Niemuth. Tunnel Division Safety Manager – Jack Lynch. Safety Manager: Matt Muscarella. Project Superintendent: Christopher Gunter.

OHIO

Akron
Northside Interceptor Tunnel
Granite Construction
Granite was awarded an approximately $215 million contract by the City of Akron (OH) to construct the Northside Interceptor Tunnel Project (NSIT) in 2023. The aim of the project is to prevent combined sewer overflows from entering the Cuyahoga River during typical storms.

Key elements include 6,660 lf of precast-concrete-segmental-lined rock tunnel with a finished inside diameter of 16.5 ft, designed to accommodate both dry and wet-weather sewage flow, as well as store combined sewage. The project also features an array of control structures, flow drop shafts, connecting sewers, and overflow structures, all carefully integrated to optimize the system’s performance. The project also includes the 2,200-ft, 10-ft ID long Rack 32 ancillary tunnel to be mined with an EPB TBM.

On April 23, 2025, tunneling officially began with the Herrenknecht TBM. The drive is expected to take about 5 months to complete. Overall project completion is scheduled for 2027.

Cleveland
Shoreline Tunnel and Consolidation Project
McNally/Kiewit SST JV
This is part of the Northeast Ohio Regional Sewer District’s Project Clean Lake CSO program. The Shoreline Tunnel and Consolidation Project is a $201 million project that involves 14,100 ft of 23-ft ID soft ground tunnel using a 26-ft OD Herrenknecht EPB. NTP was issued in 2021. Mining was completed in May 2024. Final completion is expected this year.

Cleveland
Southerly Tunnel and Consolidation
McNally Tunneling Corp.
Another component of Project Clean Lake, the Southerly Tunnel is a $328 million project involving 18,060 ft of 23-ft ID tunnel using a TBM: 26-ft OD refurbished Herrenknecht EPB, which was lowered into the launch shaft in March 2025. The tunnel is anticipated to go online in 2029. With this project, six of the seven projects involving large tunnels are completed or are in construction.

Columbus
Lower Olentangy Tunnel
Granite Construction
The LOT main tunnel will require construction of approximately 17,000 ft of 12-ft diameter tunnel at an average depth of 50 ft. This portion will be mined with a Herrenknecht EPB tunnel boring machine (14-ft, 7-in. OD) and constructed of precast concrete segments. There are three main shafts (large manholes and other structures to provide access and tunnel controls) along LOT at Tuttle Park north of Lane Avenue, at Gowdy Field near Third Avenue & Olentangy River Road, and at Vine Street.

A 90-in. diameter microtunnel will also be constructed to relieve the OSIS near Second Avenue, built using a Herrenknecht AVN 2500 MTBM. The microtunnel will begin at the 2nd Avenue and Perry Street intersection and flow west into LOT at the Gowdy Field Shaft.

A 36-in. relief sewer will also be constructed to relieve a DSR in Third Avenue into LOT. This DSR is on the Kinnear Subtrunk Sewer which serves the Fifth by Northwest Blueprint area.

The LOT project was bid during the Summer of 2020. Construction began in early 2021 and is expected to be completed in September 2026.

Columbus
Moler Street Overflow Improvements
Turn – Key Tunneling, Inc.
The overall project of Moler Street Overflow Improvements consists of the installation of a 96-in. and 72-in. storm sewer and of the 72-in. Moler Street Overflow Intercepting Sewer (MSOIS). The existing Moler Street Regulator combined sewer will be connected to the OARS Approach Shaft 3 via the proposed Moler Street OIS. A 96-in. storm sewer discharging to the Scioto River will be constructed to divert storm flows from the combined sewer overflow pipe. Segments of the project along W Gates St will require trenchless sewer installation and a railroad crossing.

Complete General Construction Company (CGC) subcontracted Turn -Key Tunneling, Inc. (TKT) of Columbus to perform critical trenchless work as part of a larger infrastructure project. TKT was responsible for the installation of 196 linear feet of 18-in. diameter pipe using 36-in. jack and bore trenchless methods beneath several active railroad tracks. In addition, TKT constructed a 20-ft diameter access shaft at MH-300 and excavated a 30-ft tunnel using 96-in. liner plates to connect with the OARS Approach Shaft 3.

The owner is the City of Columbus. The construction manager is DLZ Ohio Inc. The initial bid was $1.3 million. Contract dates are from March 3, 2025, to May 30, 2025.

Personnel: Jaylen Reinhart – CGC PM; Jamie Pipes – CGC Supt.; Chris Leonard – TKT Senior PM; Clinton Hudkins – TKT Supt.

NEW YORK

New York
Gateway Program
The Gateway Program is a series of rail infrastructure projects that will improve the most congested 10-mile section of the Northeast Corridor. The centerpiece of the project is the construction of new twin tunnels underneath the Hudson River. Tunnels to the east and west and other projects are needed along the 10-mile corridor.

The Gateway projects closely tied to underground construction include the Palisades Tunnel, Hudson River Tunnel, Manhattan Tunnel, Hudson River Ground Stabilization, and Hudson Yards Concrete Casing – Section 3. The Hudson River Tunnel is in procurement while the other contracts have been awarded.
Palisades Tunnel: In August 2024, GDC awarded the Palisades Tunnel to Schiavone Dragados Lane JV for $465 million. This marks the first tunnel boring contract for the overall Hudson Tunnel Project. Work on the Palisades Tunnel is expected to be completed in 2027.

The Palisades Tunnel Project will construct the first mile of twin-tunnels on the New Jersey side of the Hudson River. It includes boring two tunnels approximately 5,100-ft long with an inside diameter of 25 ft, 2 inc., and six cross passages, as well as furnishing and installing a concrete tunnel lining with waterproofing membrane.

Manhattan Tunnel: On Feb. 3, GDC awarded a $1.18 billion contract to Frontier-Kemper-Tutor-Perini JV and authorized NTP. Construction of this portion of the Hudson Tunnel Project is expected to begin in the coming months, with substantial completion anticipated in 2029.

The Manhattan Tunnel Project will build the section of the new Hudson Tunnel Project tubes from the Manhattan Bulkhead in the Hudson River to the cut-and-cover Hudson Yards Concrete Casing east of 12th Avenue. In total, the Manhattan Tunnel Project will require designing and building approximately 700 ft of twin 30-ft diameter tunnels.

Hudson Yards Concrete Casing – Section 3 (HYCC-3): HYCC-3 is an essential rail right-of-way (ROW) preservation project on the west side of Manhattan that will enable the new Hudson River Tunnel to connect to New York Penn Station. Construction of HYCC-3 launched in November 2023, marking the start of work on the Hudson Tunnel Project in New York. Construction is expected to end in 2026.

Hudson River Ground Stabilization: The Hudson River Ground Stabilization Project involves injecting a mix of soil, concrete, and water into the riverbed in 1,200 ft of the shallow area on the Manhattan side of the Hudson River to ensure the TBMs can excavate the new tunnel and protect the riverbed from disruption. GDC awarded the contract for the HRGS Project to Weeks Marine, Inc. in February 2024. NTP was issued in August 2024. The project is expected to conclude in 2027.

Mount Pleasant
Kensico-Eastview Connection
Frontier-Kemper Constructors
In fall 2024Frontier-Kemper Constructors was awarded a contract valued at approximately $1.1 billion by the New York City Department of Environmental Protection for the Kensico-Eastview Connection Tunnel Project.

The scope of work entails the construction of a new deep rock tunnel between the Kensico Reservoir and the Catskill/Delaware Ultraviolet (CDUV) Light Disinfection Facility, both in Westchester County, New York. The new tunnel will provide an additional means of conveying water between the Kensico Reservoir and the CDUV Facility, enhancing operational resiliency and redundancy for New York City’s water supply system.

The new tunnel will run approximately 500 ft below ground and extend approximately 2 miles. The finished tunnel will be 27 ft in diameter. Included in the project are two large shafts to accommodate TBM launch and retrieval. NTP was expected in early 2025 with substantial completion expected in 2030.

RHODE ISLAND

Pawtucket/East Providence
Pawtucket Tunnel
CB3A
The Narragansett Bay Commission is building the third and final phase of its Combined Sewer Overflow Program. Phase III includes the Pawtucket Tunnel, NBC’s second CSO storage tunnel.
The Pawtucket Tunnel is approximately 11,600 ft long, 30 ft in diameter and located in bedrock about 200 ft below the ground surface. The project includes the launch and recovery shafts (which will become permanent access shafts), four drop shafts with connecting adits at existing outfall locations, and an underground shaft- or cavern-style tunnel pump station.
Tunneling was started in September 2022 and was completed in February 2024. Final project completion was expected by 2028.

VIRGINIA

Alexandria
RiverRenew
Traylor-Shea
RiverRenew is $654 million clean water program for AlexRenew that includes a $454 million tunnel program. AlexRenew achieved several major milestones on the RiverRenew project in 2024, including the completion of the 2.2-mile Waterfront Tunnel and Hooffs Run Interceptor. The project is now 80% complete, as crews have shifted their focus to the construction of pumping stations, located at the heart of AlexRenew’s treatment plant.

The pumping stations are housed in a 12-story underground shaft along with critical support equipment. The facility is anticipated to meet silver Leadership in Energy and Environmental Design (LEED) certification requirements — making it the first of its kind in Virginia. When RiverRenew is completed in 2026, these new structures will capture and convey an estimated 120 million of gallons of combined sewage to AlexRenew for treatment each year.

Loudoun County
Milestone Reservoir and Pump Station
Drill Tech Drilling & Shoring
Drill Tech Drilling & Shoring, Inc. has been awarded this unique $42 million project which will ultimately allow Loudoun Water to temporarily store 1 billion gallons of raw water in an abandoned rock quarry prior to treatment.

Under contract with Clark Construction Group, LLC, Drill Tech will excavate and support a large diameter shaft and three separate intake tunnels utilizing drill and blast methods. Excavation of two of the three intake tunnels will start from within the shaft and will terminate into the abandoned quarry. The third tunnel will be excavated from a ledge within the quarry.

The Pump Station Shaft has been excavated and supported down to Tunnel B (El. 60) and excavation of Tunnel B is complete. Drill Tech personnel are currently installing the shotcrete liner and concrete invert within Tunnel B. Once complete, Pump Station Shaft excavation will resume down to final elevation -25 exposing the previously excavated Tunnel C at elevation -5.5.

Drill Tech personnel have also completed installation of the shotcrete liner and concrete invert within Tunnel C from the abandoned quarry. Installation of 36 inch diameter steel pipe within this tunnel will begin soon.

Raise bore excavation work is in progress and is expected to be completed by the end of May 2025. After completion, a 42 in. steel pipe will be grouted within the raise bore excavation.

NTP was issued March 30, 2024. Completion is expected in January 2026. The project is approximately 45% complete.

Owner: Loudoun Water; Tunnel & Shaft Designer: Arcadis; Construction Manager at Risk: Clark Construction Group, LLC; Major Subcontractors: Balter Company (geotechnical instrumentation and monitoring).

Personnel: Drill Tech Drilling & Shoring, Inc. – Project Executive: Brent Duncan, PE; Project Manager: Kyle White & Alex Steadman; General Superintendent: Mike Belderrain; Site Superintendent: Travis Thomas; Project Engineer: Justin Bayer; Safety Manager: Dan Baldwin and Jim Goodson.

Norfolk
Hampton Roads Bridge-Tunnel }
Expansion Project
Hampton Roads Connector Partners
The Hampton Roads Bridge-Tunnel Expansion Project is a $3.9 billion project for the Virginia Department of Transportation that includes the construction of twin tunnels under the shipping channel that will carry traffic along I-64. The contractor is Hampton Roads Connector Partners (HRCP), a joint venture of Flatiron-Dragados, Vinci Grand Projets, and Dodin-Compenon. NTP was issued in September 2020. Substantial completion is scheduled for February 2027.

Each tunnel is 7,941 linear feet and the tunnel bore diameter is 46 ft. The depth of the tunnel is 173 ft below the river surface at its deepest point. There are two tunnel shafts. Ground conditions include various layers or soft soils, sands, clays, organics and portions of the Yorktown layer of soil are comprised mostly of sand, silt and shells. The tunnel construction method uses a Variable Density Tunnel Boring Machine method using slurry pumped to the TBM and back to the slurry treatment plant through 22-in. pipes.

The first bored tunnel completed its mining mission in April 2024. In June 2024, the project set a world record during its rotation of the 46-ft diameter 2,350 ton cutterhead and shield via use of a nitrogen table. Mining resumed on Oct. 17, 2024, when construction began on the second tunnel. Currently, the second tube is more than 45% complete. The second breakthrough is expected to occur in fall 2025. In May 2024 the North Trestle, the first new trestle in 50 years at the Hampton Roads Bridge-Tunnel, opened. In Summer 2025 two lanes of eastbound traffic will be shifted to the new eight-lane South Trestle Bridge, which will carry both east and westbound traffic on an elevated superstructure.

Special/unique Features of the Job:
The Project’s funding is largely (92%) through the creation of a local tax district managed by the Hampton Roads Transportation Accountability Commission (HRTAC). Through HRTAC’s stewardship, this project that has been studied since 1990, is finally coming to fruition.

The HRBT Expansion is just one phase of a larger 45 mile express lanes network that will be operated and maintained by VDOT. Upon completion of the HRBT, the Hampton Roads Express Lanes network will increase capacity, ease congestion, and enhance travel time reliability across the region’s most traveled corridor.

“Mary” the project’s TBM is the second largest diameter TBM ever used in North America (46 ft) and the largest variable density machine ever fabricated. It will dig twin tunnels each more than 7,940 ft in length. The tunnels will be the 3rd and 5th ever mined in the United States for vehicular traffic (Seattle, Port of Miami, HRBT HOT tunnel, CBBT, HRBT General Purpose tunnel).

Project Designer: Mott MacDonald, HDR; Owner’s representative: WSP; TBM Manufacturer: Herrenknecth; Slurry Treatment Plant Manufacturer: MS; Tunnel segment supplier: Technopref

Personnel: Ryan Banas, PE, CCM (HNTB) – Project Director for VDOT; Claudio Cimiotti – Project Executive – HRCP.

Norfolk
Parallel Thimble Shoal Tunnel
Dragados USA/Schiavone Construction
The $756 million project entails the construction of a 5,700-ft bored tunnel connecting two southbound trestles of the existing Chesapeake Bay Bridge and Tunnel, a 17.6-mile structure connecting the Norfolk/Virginia Beach areas to Virginia’s eastern shore. When complete, the new tunnel will carry two lanes of traffic southbound and the existing tunnel will carry two lanes of traffic northbound.

The 43.5-ft diameter TBM began mining in February 2023 and completed the drive in January 2025, after being shut down for about a year due to encountering an unexpected obstruction in the seabed. The TBM averaged about 50 ft per day after mining resumed in April 2024.

Looking ahead, the contractor will begin to construct the roadway inside the tunnel, install the electrical/mechanical systems and construct the support buildings. Once complete, the new tunnel will carry two lanes of traffic southbound and the existing tunnel will carry two lanes of traffic northbound. Current forecast for project completion is early 2028.