Neighborhood was built in the 1980s, and the sewer infrastructure has been in operation since. Aged pump station equipment – pumps, valves, fans, concrete, etc. This aging equipment has the potential of causing: Sanitary Sewer Overflows (SSO) Sewer back-ups into homes Environmental damages Maintenance problems

1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Oak Marr Pump Station Rehabilitation – Construction Project
Wastewater Project – Virtual Community Meeting
Microsoft Teams – December 7, 2021, at 6:30 p.m.
Fairfax County Project Manager: Christopher Mata, P.E.
Project Engineer: HDR & RK&K
December 2021

2. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Agenda
2
1. Project Team Introductions & Attendee Virtual Sign-In
2. Project Location
3. Project Background & Need
4. Study Phase
5. Design Phase
6. Construction Phase
7. Project Schedule
8. Questions and Answers

3. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Project Team Introductions & Attendee Virtual Sign-In
3
• Fairfax County Project Manager:
– Christopher Mata, P.E. – Senior Engineer III
• Department of Public Works and Environmental Services (DPWES) – Capital Facilities –
Wastewater Design and Construction Division – Wastewater Collection Branch
• HDR Project Team:
– Fady Afif, P.E. – Project Manager
– Badana Mohamadi – Project Engineer
• RK&K Project Team
– Mike Klevenz, P.E. – QA/QC

4. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Virtual Meeting Administrative Items
4
• Attendee Virtual Sign-In (2 options)
1. Private Message me on MS Teams – Name, Property Address, Email,
Phone Number
2. Email me @ cmata0@fairfaxcounty.gov - Name, Property Address,
Email, Phone Number
• To reduce feedback, please remain on mute until the end of the
presentation during the Q&A
• The chat board on the right-side of your screen is available
throughout the presentation

5. Oak Marr Pump Station Rehabilitate – Construction Project
Project Location
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 5
Project
Location
Flow Direction
Sewer service area
and project area

6. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Project Background & Need
6
• Neighborhood was built in the 1980s,
and the sewer infrastructure has been in
operation since.
• Aged pump station equipment – pumps,
valves, fans, concrete, etc.
• This aging equipment has the potential
of causing:
– Sanitary Sewer Overflows (SSO)
– Sewer back-ups into homes
– Environmental damages
– Maintenance problems

7. Oak Marr Pump Station Rehabilitate – Construction Project
Existing Conditions
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 7
Incoming Flows
Outgoing Flows
Pump
Station
Site

8. Oak Marr Pump Station Rehabilitate – Construction Project
Existing Conditions
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 8
Incoming Flows
Outgoing Flows
Pump
Station
Site
EXISTING
ACCESS
ROAD/ TRAIL
EXISTING
FENCE
EXISTING
BUILDING
EXISTING
MANHOLES
EXISTING
FUEL TANK

9. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Study Phase
9
• Fall 2020 study:
– Evaluated existing conditions – flow analysis, hydraulic
assessment, site & equipment assessment.
– Alternative analysis and recommendation to rehabilitate the
pump stations.
• Criteria: Community impacts, schedule, cost, constructability,
maintainability, operability, reliability
• Recommended Alternative:
– Construct a parallel pump station on the same parcel
– Repurposing 4 existing below-ground structures & installing 2
new below-ground structures
– Pump station building will remain & new generator to be
installed outside
– Sewer services will not be impacted

10. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Design Phase
10
• Includes Designing:
– Pumps and wet-well
– Permanent by-pass & meter vault
– New enclosed standby generator
– Re-routing of sewer force main
– Station fence (w/ slats) realignment
– Access road repaving and widening in
front of the pump station
– Adding another gate
– Miscellaneous concrete work

11. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Design Phase
11
EXPANDED ACCESS
ROAD
EXTENDED
FENCE
TEMPORARY
CONSTRUCTION
EASEMENT
STANDBY
GENERATOR
NEW
UNDERGROUND
STRUCTURES
TREE
REMOVAL
Repurposed below-
ground structures (x4)

12. Oak Marr Pump Station Rehabilitate – Construction Project
Proposed Changes
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 12
Proposed Tree Removal
These
trees to
remain
Proposed trimming of
branches
Pond

13. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
Construction Phase - What to expect
13
• Construction Activity:
– Construction entrance off of Elmesmeade
Ct. cul-de-sac.
– Some construction activity to take place
along trail pathway.
– Excavation for the new wet well and valve
vault
– Dewatering until excavation is complete and
new structures have been placed
– Installing precast structures for wet well and
valve vault
– Installing emergency generator
– Bypass pumping within project site.

14. Oak Marr Pump Station Rehabilitate – Construction Project
Construction Phase – Access Through the Community
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 14

15. Oak Marr Pump Station Rehabilitate – Construction Project
Project Schedule
15
Capital Facilities – Wastewater Design and Construction Division – Collections Branch
December 2019
Study Began
October
2020
Study
Complete
January 2022
Anticipate
Acquiring all
Land Rights
Summer 2022*
Construction
Beginning
December 2021
Public Meeting
Summer 2023*
Construction
Completion
March 2021
Design Began
*This was updated as of March 2022

16. Oak Marr Pump Station Rehabilitate – Construction Project
Capital Facilities – Wastewater Design and Construction Division – Collection Branch
Questions & Answers
16
Capital Facilities – Wastewater Design and Construction Division – Collections Branch

17. Additional Information
For additional information, please contact
www.fairfaxcounty.gov/publicworks
Oak Marr Pump Station Rehabilitate – Construction Project
Christopher Mata, P.E.
703-324-5111, TTY 711
cmata0@fairfaxcounty.gov
Capital Facilities – Wastewater Design and Construction Division – Collections Branch 17
Questions & Answers