For over 70 years, Parsons has planned, designed, engineered, built, and managed complex tunnels in challenging geologic environments, from transit to sewers and pipelines. Our underground construction experience ranges from small excavations to large underground transit systems, water and wastewater infrastructure, and hydroelectric projects. Our unmatched resume includes over 250 tunnels around the globe. Over the past year, we have provided advisory services, performed subway construction, and delivered major underground infrastructure/tunneling projects. Take a look into just a few of our recent and key successes!
Take a Look into a Recent Project Win:
Kensico Eastview Connection Tunnel, Westchester County, NY
The Kensico-Eastview Connection (KEC) Project would provide for the construction and operation of a new, additional water conveyance tunnel between Kensico Reservoir and the Catskill/Delaware Ultraviolet Disinfection (CDUV) Facility in Westchester County, NY. More than 90 percent of New York City’s drinking water is supplied by the Catskill and Delaware watersheds in upstate New York. The Catskill and Delaware aqueducts convey water by gravity from these upstate watersheds to Kensico Reservoir. The work related to this project will include the construction of new downtake and uptake shafts, an approximately 2-mile-long deep rock tunnel, a screen chamber, connection chamber, an improved Catskill Upper Effluent Chamber (UEC), a new electrical building and security for the Kensico site, and additional supporting facilities. The entire system will be designed to accommodate a maximum flow of 2,645mgd.
Completion of the KEC Project would increase flow to the CDUV Facility and improve NYCDEP’s ability to maintain Hillview Reservoir water surface levels within normal operating limits during single-basin operations at Hillview Reservoir during Hillview Cover construction in accordance with the Hillview Consent Decree and Judgment’s mandates. Major modifications to the 100-year-old UEC will increase the capacity of the existing structure from the current 800mgd to the new intake design flow of 2,645 mgd.
The Tunnel downtake shaft will have an overall depth of approximately 313 feet below the finished grade and a finished inner diameter of approximately 27 feet, while the uptake shaft will have an overall depth of approximately 425 feet below the finished grade and an inner diameter of approximately 32 feet. The KEC Conveyance Tunnel will have a finished inner diameter of approximately 27 feet with a cast-in-place concrete lining. In addition to the hard rock TBM tunnel, the work will also include the enlargement of more than 800 feet of an existing tunnel at the Kensico campus. The tunnel enlargement work will run from a new 80-foot-deep shaft behind the UEC to the new Screen Chamber Facility. To accommodate the large increase in flow, the 100-year-old hard rock tunnel will be enlarged from a 14.5-foot by 18-foot arch to a diameter of 27 feet.
Other work on this project will include relocating an existing public roadway to outside the Kensico campus, blasting and excavation support for the new screen chamber and connection chamber at the CDUV facility, dredging the Kensico Reservoir at the UEC intake, blasting for the structure foundations, and site work involving cuts and fills of over 230,000 cubic yards of soils and rock on site.
Parsons is a Joint Venture partner with AECOM for the Construction Management services on this 11-year project, which includes five construction contracts for more than $2 billion worth of work. The first, a site preparation contract, was given the Notice to Proceed on March 11, 2014. Vincent Sambrato is the Construction Manager, and Leif Stepakoff is the Resident Engineer for the CM JV.
Take A Look Into Some Of Our Tunneling Project Updates:
City of Fort Worth- Little Fossil Creek Interceptor, Fort Worth, TX
The City of Fort Worth selected Parsons to design the Little Fossil Creek Interceptor over ten years ago. The interceptor has been improved and replaced several distinct segments over the years. The most challenging section was left until the end. This segment included the need to cross a railroad track, a former freight line that now hosts the Trinity Rail Express commuter train between Fort Worth and Dallas.
Instead of relining the existing interceptor, the Owner decided to replace it with a larger diameter (48”), requiring a new pipeline under the railroad bed. Before designing the crossing, Parsons trenchless experts directed the geotechnical investigation. Interpreting the results received, Parsons tunneling experts designed the crossing using a cased 48” diameter fiberglass pipe inside a 60” ASTM A134 ¾” steel casing approximately 120 feet long. The design was performed according to American Railway Engineering and Maintenance of Way Association (AREMA) standards for utility crossings. Parsons designed a robust monitoring system at grade to ensure the railroad track is unaffected by the construction of the new pipe below it. Monitoring includes a web of inclinometers, ground monitoring points, and track monitoring points. The project includes a Geotechnical Baseline Report (GBR).
Mattawa Dundas Sanitary Trunk Sewer Project, Region of Peel, Ontario, Canada
Parsons was retained by the Regional Municipality of Peel (Peel Region) to provide design and services during construction for the Mattawa Dundas Sanitary Trunk Sewer Project in the City of Mississauga, Ontario, Canada. Peel Region’s Water and Wastewater Master Plan (updated in 2013) identified the need for upgrades to the existing sanitary trunk sewers and watermains in the southeast area of the City of Mississauga to address forecasted long-term servicing needs in the Region to the Year 2031. Specifically, 650m of new 1200mm dia. sanitary trunk sewer was proposed to address the needed improvements at several locations within the existing sanitary trunk sewer network located near Dundas Street East and Mattawa Avenue, as well as to provide security and operational redundancy to the Region’s sanitary trunk sewer network.
As the existing sanitary sewer on Dundas Street East between Mattawa Avenue and Dixie Road is noted to have capacity limitations, particularly the inverted siphon passing underneath an existing watercourse, the proposed solution needed to address the requirement to provide sufficient capacity for the future rehabilitation of the existing sanitary trunk sewer, while continuing to maintain uninterrupted sewer services to the surrounding businesses and residents.
A new 1200mm dia. sanitary trunk sewer is proposed on Mattawa Ave to divert flows upstream of the existing siphon and divert them back to the existing sanitary trunk sewer downstream. A diversion chamber will be constructed to divert the existing flows from the existing trunk sewer to the proposed trunk sewer and down to the Region’s interceptor trunk sewer downstream.
The design and construction strategy minimized impacts to the public, minimized impacts to the environment within the regulatory boundary limits, and reduced the property acquisition requirements. The tunneling construction methods include approximately 650m of 1200mm dia. tunneling and four tunneling shafts, with the tunnel construction primarily located within a shale limestone formation. The tunnel construction is expected to utilize an open-face micro tunnel boring machine. The construction activities are expected to commence in September 2023 and are estimated to be completed in Spring 2025. The project’s total estimated construction cost is approximately $22 million.
Explore More Tunneling Project Updates
To see more of our featured tunneling projects and updates, check out our project page.
Take A Look Into A Publication By One Of Our Experts, Ibrahima:
Subway Ventilation System Design and The Importance of Predicting the Long-term Tunnel Wall Surface Temperature
When designing tunnel ventilation system (TVS) for subway projects, considering the tunnel wall surface temperature is very important to quantify the tunnel air temperature, in order to guarantee adequate tunnel equipment operation condition, thus their performance and lifecycle.
The thermal load within the subway due to the trains operation plays a key role in the long term behavior of the tunnel wall surface temperature. Typical Subway revenue hours period is about 20 hours a day, giving only few hours of rest for the subway without extensive thermal solicitation. The heat accumulated along the revenue hours is absorbed by the tunnel wall and its surrounding soil, preventing the heating of the tunnel environment. In the long term, the surrounding soil will reach its optimum geothermal heat absorption capacity. Consequently, the revenue hours heat not being absorbed by the tunnel wall surface temperature, the tunnel air temperature will be increasing, impacting the equipment operation condition.
It is major to predict the long-term tunnel wall surface temperature by means of extensive numerical simulations in order to identify the appropriate mitigation measures such as additional mechanical or passive means of cooling the subway and more stringent specifications on the exposed equipment regarding their operating environment.
At Parsons, we have been working on major road tunnel and metro (greenfield and brownfield) projects across the globe. Our team is fully versed in the application of NFPA 130 and NFPA 502 and we are pleased to provide the following services:
- Emergency and Normal Operations Ventilation 1D numerical studies such as Subway Environment Simulation (SES) studies;
- Fire and evacuation analysis 3D Computational Fluid Dynamics (CFD) studies;
- Space proofing for constructability, maintainability and future replacement;
- Electrical Power and Distribution interface;
- Communications and Controls meeting Safety Integrity Level 2 as a minimum (IEC 61508);
- Multi-disciplinary approach to mitigate the relevant hazards;
- Optimum design to fulfill Client’s requirements, NFPA standards and international standards, mitigating potential hazards while satisfying Client’s Operation, Maintenance and future proofing requirements
Take A Look Into Our Recent Awards:
- American Council of Engineering Companies (ACEC) California’s Engineering Excellence Merit Award – South Coast Water District (SCWD) Tunnel Stabilization and Sewer Replacement, Laguna Beach, CA (see photo on right).
- 2023 Project of the Year Award for Integrated Pipeline Project (IPL) – Phase 2, ASCE’s Utility Engineering and Surveying Institute
- 2023 American Shotcrete Association’s (ASA) Outstanding Shotcrete Project Award in the Underground Category for Delaware Aqueduct Bypass Tunnel
- Envision Platinum Award for Sustainable Infrastructure by Institute for Sustainable Infrastructure (ISI) for LA Metro’s Westside Subway Extension (Purple Line), Section 1
- Royal Society for the Prevention Accidents (RoSPa) Health and Safety Awards for Wakrah-Wukair Foul Sewage Conveyance System and TSE Return System Project (see photo below).
Women In Construction Week Award
Nancy Matteoni was highlighted and chosen for “Women in Construction Week: by the Civil, Architectural and Environmental Engineering Department at Missouri University of Science and Technology. She has over 30 years of experience in design of transportation infrastructure. She is currently managing design and post-design efforts for several sewer projects on the Deer Creek Sanitary System. Nancy is a new member to the Academy of Civil Engineers in 2021 and a great, engaged Miner alumna. She is also a Miner-Mom with a son who is a senior in civil engineering.
Take A Look Into Our Speaker Engagement:
Our team offers innovative solutions to some of the world’s largest, most complex tunnel and underground construction projects. We have had over a dozen recent publications and presentations at the following conferences:
| Conference | Publication(s)/Presentation(s) |
|---|---|
| World Tunnel Congress (WTC), April 19-25, 2024, Shenzhen, China | “Subway Ventilation System Design and the importance of predicting the long-term tunnel wall surface temperature” by Ibrahima Khalil Mbaye. |
| Rapid Excavation and Tunneling Conference (RETC), June 11-14, 2023, Boston, MA | “Gravity Sewer Tunnel Liner Corrosion Protection –Part Two” by Jon Kaneshiro, Pooyan Asadollahi, and Eric Dawson, “Evaluation of Long Term Loads on Freight Tunnels in Chicago” by Alireza Ayoubian. |
| CIC 2023: The 2nd International Conference on Civil Infrastructure and Construction, February 5-8, 2023, Doha, Qatar | “A Side by Side comparison of Shaft Excavation locally in Qatar” by John Brown and Sunit Saurabh. “Launching a 148m Long Tunnel Boring Machine from a 15m Diameter shaft” by Volkan Salepciler and John Brown. “Backfilling Manhole Surround Using Recycled Concrete Waste Material” by John Brown, Suvish Valsan and Nand K Vashisht. “Implementation of Odour Control Systems for Nuisance-free and Public friendly environment in Qatar” by Spyridon Trikis, Vaibhav Sumant, Muhammad Arshad, and John Brown. |
| Lecture at University of Chile, April 20, 2023, Santiago, Chile | “Tunnel Engineering in Countries Susceptible to Large Earthquakes” by Jon Kaneshiro. |
| European Tunnel Seminar #17, October 01- 07, 2023, London/York, United Kingdom: | “Update on the Delta Conveyance Project” by Steve Minassian. |
| Cutting Edge Conference, Advances in Tunneling Technology, November 13-15, 2023, Austin, TX | “Polymer Concrete in the Tunneling Industry: Applications and Benefits” by Jon Kaneshiro. |
| Geological Society of America (GSA) Cordilleran Section Meeting, May 17-19, 2023, Reno, NV | “Exotic Detrital Zircons from the Neoproterozoic Placerita Formation of San Gabriel Mountains Provide Clues to Identify of Conjugate Rodinia Rift Fragment(s)” by Scott Zylstra. |