This project obtained condition assessment information for approximately 47,000 feet of 18 to 42-inch diameter sanitary sewer pipes and 197 manholes located near Herndon, McLean, and Annandale. The inspections were performed using multi-sensor (Closed Circuit Television (CCTV), sonar, and laser) inspection technologies to identify internal defects. Defective sewers were identified for repair, replacement, or rehabilitation under future contracts. This project was substantially complete on January 15, 2021.

1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Project No. WW-000028-001
Supervisor Districts: Dranesville, Braddock
February 4, 2021
Large Diameter Sanitary Sewer Condition Assessment –
Package 5

2. Project Details
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Description:
This project obtained condition assessment information for approximately 47,000 ft of 18 to 42-inch diameter
sanitary sewer pipes and 197 manholes located near Herndon, McLean, and Annandale. The inspections were
performed using multi-sensor (Closed Circuit Television (CCTV), sonar, and laser) inspection technologies to identify
internal defects. Defective sewers were identified for repair, replacement, or rehabilitation under future contracts.
This project was substantially complete on January 15, 2021.
Project Overview:
• Public outreach
• Site access plans, including easement clearing
• Sewer Cleaning
• VDOT coordination
• Coordination with Fairfax County Park Authority
• No interruption of sewer service during inspections
• Deliverables: Manhole and Pipe inspections conforming to National Association of Sewer Service Companies
(NASSCO) standards
Project Team:
• Matthew Doyle, P.E., Wastewater Design and Construction Division
• Suzy Harding, P. E., Wastewater Design and Construction Division
• Junaid Malik, P.E., Wastewater Collection Division
• Greeley and Hansen, Consultant Engineer
• Redzone, Inspection Subcontractor

3. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Dranesville and Braddock Districts
Tax Maps
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4. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Sewer Inspection Equipment
Crawler Cam Truck Set up Multi-Scan Equipment Over Manhole

5. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Sewer Inspection Equipment
CCTV Crawler Parachute and Float to Propel
Equipment

6. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Example Site Conditions: Locating Manholes in Easements

7. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
NASSCO Condition Scoring (“Quick Score”) Method
• Operation and Maintenance (O&M) describe infiltration and foreign objects that may
interfere with the conveyance system
• Structural observations describe damaged or otherwise defective pipes
• Both are scored 1-5 where 5 is most severe
• Quick Scores are a shorthand way of expressing the number of occurrences for the
two highest severity grades using 4 characters, for example:
• In general, sewers with Quick Score > 4000 should be packaged into repair or
replacement projects. Sewers with Quick Score > 3000 should be scheduled for a
reinspection within 5 to 10 years as part of routine preventative maintenance.

8. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Condition Assessment Results – Structural Quick Score Summary
Quick Scores
(≥)
Number of
Manholes
5100 1
4100 0
3100 96
2100 0
1100 89
0000 3
Total 189
Not Inspected 8
Quick Scores
(≥)
Number of
Pipes
Length of
Pipe (ft)1
5100 0 -
4100 18 5,596
3100 118 30,689
2100 49 10,554
1100 2 109
0000 0 -
Total 187 46,948
Not Inspected 4 1,565
1) Based on Surveyed Length
Manholes Pipes

9. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Condition Assessment Results – Herndon
• 14 of the 78 Pipes in this
area have a Structural
QuickScore of at least 4000
• 13 Pipes in this area have
Surface Damage,
Reinforcement Visible
(Structural grade 4 defect)
• 7 Pipes in this area have
Continuous Surface Damage,
Reinforcement Visible
Broken

10. Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Condition Assessment Results – McLean
• 3 Pipes in this area have Surface
Damage Reinforcement Visible
(Structural grade 4 defect)

11. Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Condition Assessment Results – Annandale
• Installed 1954
• I-495
Construction
Began 1961
• 98 Foot
Continuous Sag
• Surface
Aggregate
Visible,
Continuous
• Infiltration
Prevalent
Surface Aggregate Visible

12. Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Potential Repair/Rehabilitation/Replacement Projects 1-3
Herndon McLean

13. Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Potential Repair/Rehabilitation/Replacement Project 4
Project 4 – Sewer Crossing I-495 in Annandale

14. Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Summary and Recommendations
• This project’s primary purpose was to collect condition information. Preliminary
recommendations for follow-up were made based on the deficiencies found. However,
recommended actions will be considered along with recommendations from other condition
assessment projects and re-prioritized in the County’s overall asset management program. The
timeline for follow-up actions will be based on risk the deficiencies pose to the County’s overall
wastewater system.
• Preliminary recommendations from this project include:
• Sewers That Could Not be Inspected (4 pipes and 8 manholes): Re-package for specialized
inspections.
• Sewers With Structural Quick Scores in 4000 Group (18 out of 187 pipes and 1 manhole):
Package into repair/rehabilitation/replacement projects for design and construction.
• Sewers With Structural Quick Scores in 3000 Group (118 out of 187 pipes and 96 out of 189
manholes): Reinspect in 5 to 10 years.
• Sewers with Structural Quick Scores in the 2000 and Lower Groups (2 out of 187 pipes and
92 out of 189 manholes): Reinspect in 10 to 15 years.

15. Additional Information
For additional Information, please call
www.fairfaxcounty.gov/publicworks
Large Diameter Sanitary Sewer Condition Assessment – Package 5
Capital Facilities/Wastewater Design and Construction Division/Collections Branch
Sharon North, M.A., Section Chief, Communications
703-324-8455, TTY 711
Sharon.North@fairfaxcounty.gov
or
Irene Haske, Communications Specialist
703-324-5821, TTY 711
Irene.Haske@fairfaxcounty.gov