The Fairfax County Department of Public Works and Environmental Services repaired an 80-foot section of a failed 20-inch sanitary sewer line crossing Lake Thoreau. The project involved constructing an access road, installing an emergency bypass pumping system, cleaning and inspecting the sewer line, replacing 80 feet of pipe using scuba divers, anchoring the line to the lake bottom, lining the entire sewer run with cured-in-place pipe, rehabilitating manholes, and restoring the site. The project returned the sewer line to reliable service and is expected to reduce maintenance needs and odor complaints for the 300 homes and 3 commercial buildings it serves.

1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Emergency Repair of 20-Inch Sanitary Sewer Line Crossing
Lake Thoreau
Work Performed Under Emergency Purchase Order
Hunter Mill District
December 9, 2015

2. Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Pipe shown floating at surface of lake

3. Project Details
Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division/Wastewater Design and Construction Branch
Project Overview:
• Construction of access road and setup of emergency bypass pumping system
• Sewer cleaning and internal CCTV inspection
• Replacement of 80 feet of 20-inch DIP by scuba divers
• Correction of concrete anchor block elevations using hydraulic dredging equipment
• Installation of new stainless steel anchor and cradle straps
• Cured-in-place pipe lining from manhole to manhole
• Manhole rehabilitation
• Generate new as-builts
• Site cleanup and restoration
Project Team:
• Wastewater Collection Division – Jonathan Okafor, P.E., Russell Russell, Bobby White
• Utilities Design and Construction Division – Colleen Block, P.E., Jennifer Arias, Matt Doyle, P.E.
Project Description:
The Emergency Repair of a 20-Inch Sanitary Sewer Line Crossing Lake Thoreau Project returned a failed
20-inch ductile iron sewer pipe to a reliable level of service to prevent sanitary sewer overflows in the
residential neighborhood surrounding Lake Thoreau in Reston. The rehabilitated sewer pipe serves
approximately 300 residences and three commercial buildings. The improvements have secured the pipe
on the lake bottom and are expected to reduce the frequency of required preventative maintenance and
reduce odor complaints from residents. This project was substantially complete on November 13, 2015.

4. Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Hunter Mill District, Tax Map No. 026-2, Reston

5. Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Construction of Access Road and Setup of Bypass Pumping
Access road construction Bypass pumps
HDPE bypass pumping line installed across
lake
Installation of bypass pumping line
across lake

6. Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Replacement of 80 Feet of 20-inch DIP by Scuba Divers

7. Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Cured-in-Place Pipe Lining
Tracked equipment used for
sewer cleaning
Unloading liner material and positioning it along
the access road to reach the upstream manhole
Liner being inserted through the upstream
manhole next to the lake

8. Before After
Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Summary: Before and After Photos
Capital Facilities/Utilities Design and Construction Division/Wastewater Design and Construction Branch
Pipe shown floating at surface of lake Pipe shown submerged in the lake, strapped to
concrete anchor blocks on the lake bottom

9. Additional Information
For additional Information, please call
www.fairfaxcounty.gov/dpwes
Emergency Repair of 20-Inch Sanitary Sewer Line Crossing Lake Thoreau
Capital Facilities/Utilities Design and Construction Division /Wastewater Design and Construction Branch
Irene Haske
Public Information Officer
703-324-5821, TTY 711
SWPDmail@fairfaxcounty.gov