PRESENTATION FOR CWEA TRAININGKeys to Successful Pipeline/Infrastructure ProjectsPipeline Flow Diversion

Presented by: Tom Epperson, PE, Tetra Tech

Pipeline Flow DiversionKeys to Successful Pipeline/Infrastructure Projects

Tom Epperson, PE, Tetra Tech

• Connections to Existing Sewer• Manhole Connections or Rehab Work• Rehabilitation – Bypass Pumping

Maintaining Sewage Flow During Construction

• Construct New MH over Existing Pipe• Keep Flow within Pipe• Modify Channel/Base• Cut and Remove Top of Existing Pipe

Connection to Existing Sewer – Maintain Sewage Flow

1. Existing Sewer Pipe

Connection to Existing Sewer – Maintain Sewage Flow

Connection to Existing Sewer – Maintain Sewage Flow

1. Existing Sewer Pipe2. Add Manhole Base

& Shaft

Connection to Existing Sewer – Maintain Sewage Flow

1. Existing Sewer Pipe2. Add Manhole Base

& Shaft3. Modify Channel &

Side Pipe

1. Existing Sewer Pipe2. Add Manhole Base

& Shaft3. Modify Channel &

Side Pipe4. Cut & Remove Top

of Pipe

Connection to Existing Sewer – Maintain Sewage Flow

Manhole Connections or Rehab Work

Key Issues:• MH Access (cover size)• Confined Space Entry• Sizing of Flow-thru Tubes• Confirmation of Back-up

Manhole Connections or Rehab Work

Flow-thru Tubing

Manhole Work

Flow-thru Tubing

Manhole Work

Key: No Sewer Spills

Rehabilitation – Bypass Pumping

• Bypass Pumps• Bypass Piping• Redundancy• Spill Prevention &

Response Plan• Noise Monitoring• Odor Monitoring• Monitoring Systems

Key Elements of Bypass Plan

• Capacity – Typical Sewage Flow & Peak Flow Rate

• Suction Supply• Pumping Equipment

(submersible, self-priming centrifugal)

• Valving

Bypass Pumps

Capacity – Typical Sewage Flow & Peak Flow Rate

Weekly Flow Trend

Bypass Pump Set Up

Bypass Piping

Spill/Response Plan; Noise; Odor; & Monitoring

• Confirm Capacity• Location of Bypass Pumping &

Piping• Traffic Control• Duration of Bypass• Contractor Submittals: bypass

plan, noise, odor, monitoring, and redundancy

Key Design Issues

QUESTIONSMaintaining Sewage Flow During Construction Activities