Langley School Pump Station and Force Main Project – Phase 2 – Chain Bridge Road Gravity Sewer Capacity Improvements

Project Background

2011 Force Main Condition Assessment Report:

• The forcemain was identified in need of rehabilitation / replacement by a 2011 condition assessment. The pump station has pumps from 1994 that are corroded and are at the end of their useful life.

2019 Comparison of Alternative Force Main Alignments:

• In August 2019, DPWES completed a preliminary study to compare five (5) forcemain routes. Five (5) replacement alternatives were evaluated for Langley School forcemain which were based on using Horizontal Directional Drilling (HDD) or open cut. HDD is a trenchless form of pipeline replacement while open cut is the most common method of installing a new pipe.

2020 Preliminary Engineering Report:

• In June 2020, DPWES started looking at refining the recommended option to determine if this recommended route is feasible. If we find that this route is feasible, we will seek the community’s input in a virtual meeting.

Project Description

The overall project description will include the complete replacement of the existing 0.42 MGD pump station. Most all the mechanical equipment is over 20 years old and is highly corroded. The existing electrical building is a little undersized to hold the new modern-day mechanical equipment. We also are planning to install a new fence, repave the access road and plant some trees to help “hide” the pump station. The forcemain is quickly reaching the end of its useful life and needs to be replaced.

We are planning to abandon the old forcemain and install a new forcemain along the Fairfax County School Property, then along Georgetown pike and into Langley Lane to its new discharge point.

Project Location

The project is located to the east of Langley High School and extends along Georgetown Pike.

Project Phase

This is a multi-phase project planned to take place over several years.

Phase one consists of building the new force main and increasing the capacity of the gravity sewer on Langley Lane.

Phase two consists of updating the pumps at the pump station to ensure the capacity of the downstream gravity sewer is maintained, as well as gravity sewer improvements along Chain Bridge Rd and Ballantrae Ln. The objective is to replace the existing gravity sewer pipe that runs under sections of Chain Bridge Rd and Ballantrae Ln with a larger diameter pipe in the same location to accommodate higher flows. In addition, upon successful completion of the gravity sewer along Chain Bridge Road, the existing Force Main shall be abandoned in place.

Phase three consists of replacing the pump station and electrical buildings.The project is currently in phase one with construction of the force main and gravity sewer on Langley Lane expected to be complete Summer 2022.

Phase 2 has design plans ready for construction and public review, with a community meeting scheduled in June 2022.

Timeline

What to Expect

This project will be awarded to a qualified contractor through a competitive bidding process once design efforts are completed. Potential staging areas and access points off-site will be studied. All work will be supervised by Fairfax County staff. Every effort will be made to minimize disturbances and impacts to public and private areas. Careful consideration will be given to schedule construction activities to minimize interference with recreational activities. There will be no interruption to existing sanitary sewer service.

Project Cost and Funding Source

The total project estimate is expected to be approximately $3.4 million. As of January 25, 2019, funding in the amount of $9,631,000 is currently available in Fund 690C69300, Project Number WW-000001-024, to fund this project. The Langley School PS Project is included in the FY 2021 – FY 2025 Adopted Capital Improvement Program (with Future Fiscal Years to 2030) identified as the Sanitary Sewer Replacement, Rehabilitation and Reinvestment Program.

PRESENTATIONS TO THE COMMUNITY

Langley School Pump Station Community Meeting - October 22, 2020

Langley School Pump Station and Force Main Project - May 10, 2021

Chain Bridge Road Gravity Sewer Capacity Improvements Community Meeting - June 28, 2022

Contact

For more information, please email elizabeth.merin@fairfaxcounty.gov Engineer II, Wastewater Design and Construction Division, Department of Public Works and Environmental Services, or call 703-324-5111, TTY 711.