The following updates are from the August 2017 print issue of TBM: Tunnel Business Magazine.
Clearwater Program Effluent Outfall Tunnel
The Clearwater Program’s Joint Water Pollution Control Plant (JWPCP) Effluent Outfall Tunnel Project is part of an extensive effort by the Sanitation Districts of Los Angeles County to analyze the needs of its Joint Outfall System to the year 2050. The Effluent Outfall Tunnel is envisioned to enhance the existing 8- and 12-ft tunnels with a new 37,000-lf, 18-ft ID post-tensioned concrete segmented lined tunnel. All tunneling work will be done from a single shaft located at the Districts’ JWPCP located in the City of Carson. Structures located at the start and end of the tunnel will connect to the existing Ocean Outfall System facilities. Project advertising and bidding is anticipated to occur in the last quarter of 2017 or the first quarter of 2018..
The Interlake Tunnel for the Monterey County Water Resources Agency comprises an 11,000-ft long, 10-ft diameter, gravity-flow tunnel and related structures that would divert water from Lake Nacimiento (Nacimiemto Reservoir) to Lake San Antonio (San Antonio Reservoir). The benefits of the project include increased surface water supply and reduced flooding downstream of Lake Nacimiento by diverting water into Lake San Antonio that would otherwise flow out to the ocean. The project also includes a spillway modification at Lake San Antonio to add an additional 60,000 acre-feet of water storage. The engineering firm EPC Consultants has been hired by the agency as Program Manager for the project. McMillen Jacobs Associates and GEI, Inc have been retained for preliminary engineering and design services for the projects. Construction is scheduled to begin in early 2019. The estimated project cost is $76 million.
California Water Fix
The California Water Fix Program is a comprehensive effort to improve water conveyance in the Sacramento-San Joaquin Delta region. Key components of the program include a series of water conveyance tunnels that will allow for transport of up to 9,000 cfs of water directly from the Sacramento River to the major export pumping plants in the south end of the Delta. The components of this program will replace the current water diversion activities that rely on a series of improved channels and canals to move the water southward in the Delta. The program consists of three river intake structures, approximately 10 miles of 29-ft and 40-ft ID tunnels, and approximately 60 miles of 40-ft ID main conveyance tunnels, and a 9,000 cfs pumping facility located at the terminus of the main tunnels. The main conveyance tunnels will be configured in a parallel twin bore arrangement, with tunnel invert depth of averaging approximately 150 ft below ground surface. In addition to launching and receiving shafts, a series of ventilation/access shafts will be constructed along each tunnel reach. Current conceptual engineering efforts have been completed and the EIR/EIS were expected to be finalized at the end of June 2017. Tunnel design is anticipated to commence in mid-2019 with the first tunnel contracts being advertised for construction bids in mid/late-2020. Subsequent tunnel construction packages will be advertised on approximate 6-month intervals following the first contract award. Approximately five to six tunnel construction contracts will be awarded under this program. It is currently anticipated the facilities will be operational by 2033.
DISTRICT OF COLUMBIA
Northeast Boundary Tunnel
The Northeast Boundary Tunnel (NEBT) project is a major component of DC Water’s long-term control plan to meet court-ordered combined sewer overflow (CSO) control objectives, water quality standards, and provide flood relief. The NEBT would provide the last increment of CSO storage capacity for the Anacostia River required by the Consent Decree and would also serve to mitigate the occurrence of sewer flooding and basement backups in the Northeast Boundary drainage area.
Major characteristics of the NEBT include: Installation of 27,000-ft long, 23-ft diameter reinforced concrete tunnel; tunnel depths of 50-160 ft below the ground surface using a TBM; diversion facilities sited near chronic flood areas to relieve the existing sewer system and divert flows to the tunnel during storm events; and ventilation control facilities constructed to regulate air flow in the tunnel system.
In July, DC Water announced that the project was awarded to a joint venture of Salini Impregilo and S.A. Healy based on the highest technical score and lowest price proposal, therefore providing the best value. The $580 million bid is for design-build, a contract type adopted by DC Water in recent years.
Work on the project is expected to begin in September 2017 with completion in 2023, two years ahead of the schedule stipulated in the Consent Decree DC Water signed in 2005 with the U.S. Environmental Protection Agency and the Department of Justice. Once the NEBT is connected to the other tunnels already constructed, combined sewer overflows to the Anacostia River will be reduced by 98 percent. In addition to controlling combined sewer overflows, the construction of the NEBT will reduce the chance of flooding in the areas it serves from approximately 50 percent to 7 percent in any given year.
Potomac River Tunnel Project
The Potomac River Tunnel is a component of DC Water’s long-term control plan (LTCP), also known as the DC Clean Rivers Project. The Consent Decree establishes schedules for construction of the Potomac River Tunnel and other CSO control facilities under the DC Clean Rivers Project, including a 2025 deadline to implement the project in its entirety. The Potomac River Tunnel will be located approximately 100 ft below ground. CSOs captured by the Potomac River Tunnel would be conveyed to the Blue Plains Advanced Wastewater Treatment Plant.
The Three Rivers Protection and Overflow Reduction Tunnel (3RPORT) in Fort Wayne, Indiana – the city’s largest-ever public works project – was awarded to a joint venture of SA Healy–Salini Impregilo, the lowest of five bidders at $187,963,000. An official ground-breaking ceremony with city officials took place on June 15.
3RPORT is part of an EPA-mandated program to reduce combined sewer overflows into area waterways. The project includes a conveyance tunnel which will reduce the number of CSO occurrences from 71 down to 4 in a typical year. Bids were received on the project on February 16.
The City of Fort Wayne Utilities is currently evaluating bids for the construction of nearly 5 miles of 16-ft ID finished tunnel that is almost 220 feet deep, a pump station shaft, an upflow/working shaft, a retrieval shaft and nine drop shafts. Construction of the tunnel and shafts will begin in 2017 and be completed by 2021. The TBM is expected to be put into operation in 2018. Black & Veatch is currently working on the design of the pump station which will be bid in 2020.
Project Clear Tunnels
Metropolitan St. Louis Sewer District (MSD) has begun an ambitious program called Project Clear, a multi-billion dollar investment addressing wastewater overflows. The system improvements include construction of nine tunnels to control sewer overflows.
Project Clear reached a milestone in 2014 with the completion of the tunnel portion of the Lemay Redundant Force Main project (3,200 lf of 8-ft diameter tunnel). Currently under construction is the Maline Creek CSO Storage Facility, which includes 3,000 lf of 28-ft diameter tunnel. That project was awarded to SAK Construction/Goodwin Construction JV and given NTP in May 2016. The Jefferson Barracks Tunnel ($67 million) was awarded to SAK Construction. That project consists of 17,000 ft of 7-ft diameter tunnel. The Deer Creek Sanitary Tunnel has also been bid and is awaiting award. A joint venture of Jay Dee and Frontier-Kemper was low at $151 million for the 21,000-lf, 19-ft diameter tunnel.
Upcoming tunneling components of Project Clear include (Project, Construction Begin, Construction Cost Estimate, Tunnel Length, Tunnel Diameter):
- Lower & Middle Des Peres Storage Tunnel, 2019, $631,000,000, 9 miles, 30 ft dia
- University City Sanitary Storage Facility, 2018, $40,000,000, 1,250 ft, 30 ft dia
- Lower Meramec Tunnel, 2020, $170,000,000, 6.8 miles, 8 ft dia
- River Des Peres Tributaries CSO Tunnel, 2024, $375,000,000, 12,144 ft, 20 ft dia
- Upper River Des Peres CSO Storage Tunnel, 2028, $226,000,000, 8,976 ft, 24 ft dia
Hudson Tunnel Project/Gateway
The Hudson Tunnel Project is a new two-track heavy rail tunnel along the Northeast Corridor from the Bergen Palisades in New Jersey to Manhattan that will directly serve Penn Station New York. It consists of three major elements: the Hudson Yards right-of-way preservation project, the Hudson Tunnel, and the rehabilitation and modernization of the existing North River tunnel.
The Hudson Tunnel Project is part of the Northeast Corridor Gateway Program, a series of strategic rail infrastructure investments designed to improve current service and create new capacity. The Port Authority of New York and New Jersey (PANYNJ) currently serves as the project sponsor, but the project is a joint undertaking that also includes Amtrak and New Jersey Transit (NJ TRANSIT).
The existing North River Tunnel, opened in 1910, is owned by Amtrak. NJ TRANSIT and Amtrak operate approximately 450 trains each weekday through the tunnel that carry over 200,000 daily passenger trips. The North River Tunnel presents reliability challenges due to damage from Superstorm Sandy in 2012, as well as the overall age the tunnel and the intensity of its current use. Significant delays to a large number of trains occur when problems arise.
The benefits of the Hudson Tunnel Project are twofold. First, the new tunnel will enable the closure of the existing tunnel for reconstruction without causing a significant reduction of capacity. Second, once renovations on the North River Tunnel are complete, its reopening will provide greater operational flexibility and system redundancy in the event of malfunction.
Preparation of an Environmental Impact Statement is currently underway, and is expected to be completed in March 2018. The selection of a locally preferred alternative and its incorporation into the region’s fiscally constrained long range plan is expected to occur in the first quarter of 2018. The current schedule anticipates the project will enter Engineering in the second quarter of 2018, receive a Full Funding Grant Agreement from FTA in spring 2019, and have both the new tunnel and the rehabilitated tunnel open for revenue service by 2028.
NEORSD Project Clean Lake
Project Clean Lake for the Northeast Ohio Regional Sewer District (NEORSD) includes several major tunnel components to store and convey combined sewer overflows. The projects include:
- Doan Valley Storage Tunnel – 10,000 ft of 18-ft diameter storage tunnel and two 8.5-ft diameter conveyance tunnels at 3,000- and 6,400-ft lengths. The project was awarded to the lowest and best team – McNally/Kiewit DVT JV on April 6, 2017 at $142,320,000. NTP was anticipated for July 10, 2017;
- Westerly Storage Tunnel – 9,600 ft of 25-ft diameter tunnel. The design contract for this approximately $160 million project was awarded to a joint venture Mott MacDonald and MWH in fall 2015 and also includes a $28 million 46-ft diameter, 200-ft deep submersible Tunnel Dewatering Pump Station. The Westerly Storage Tunnel is scheduled to advertise for bid in 2017, the Westerly Tunnel Dewatering Pump Station in 2019;
- Shoreline Storage Tunnel – 15,300 lf of 21-ft diameter soft ground CSO tunnel. It is anticipated to bid in 2021;
- Shoreline Consolidation Sewer – 11,700 lf of 9.5-ft diameter soft ground tunnel. It is anticipated to bid in 2021;
- Southerly Storage Tunnel – 18,340 lf of 23-ft diameter CSO tunnel. It is anticipated to bid in 2024;
- Big Creek Storage Tunnel – 22,400 lf of 18-ft diameter CSO tunnel. It is anticipated to bid in 2029.
ALCOSAN CSO Tunnels
The Allegheny County Sanitary Authority (ALCOSAN) is designing a tunnel program to control combined sewer overflows (CSOs) as part of a consent decree with EPA. The $2.8 billion system improvement program is expected to include tunnel segments to store and treat overflows. The improvements are slated to be complete by 2026. The tunnels include: Ohio River Segment (1.9 miles, 12-14 ft in diameter, $84 million); Allegheny River Segment (3.6 miles, 12-14 ft in diameter, $136 million); and Monongahela River Segment (4.5 miles, 12-14 ft in diameter, $152 million). Additionally the program will include interceptor and consolidation sewers, dewatering pump station and treatment plant improvements. To date, a formal agreement has not been reached, so plans are not finalized.
Lake Travis Intake
The Brushy Creek Regional Utility Authority (BCRUA) has embarked on a multiple year program to increase capacity and manage concerns associated with recent historic low water levels of Lake Travis. The program includes: a multiple level-screen deep water intake assembly and shaft extending about 70-ft below lake bottom; approximately 10,000-ft of 96-in. diameter tunnel to convey water by gravity from the intake to a new on-shore pump station (which will multiple raw water wet wells extending about 300 ft below grade); and 3,000-ft of 84-in. diameter pressurized transmission tunnel. Final design and construction are currently on hold. Final design could begin in 2019 or 2020. The authority is proceeding with right-of-way easement acquisition.