Innovative Design of a Multiport Diffuser

Category:

Dredge Plant

Description:

Design of a 200-m-long (660-ft-long) multiport outfall diffuser to minimize environmental

impacts, costs, and permitting requirements. By placing the pipe on the seabed, dredging

(including possible rock excavation) and dredge material handling costs were reduced.

Displacement of surficial sediments by plowing will allow the creation of a suitable foundation

for the diffuser pipe. The plowing technique can also meet vertical tolerance requirements for

pipe placement, which will allow the diffuser to be hydraulically efficient. The use of heavy wall

(non float) pre-stressed concrete cylinder (PPC) will counter buoyancy and hydrodynamic forces.

Use of this pipe along the smooth profile of armor protection across the diffuser alignment will

also provide adequate protection from vessel anchors.

Surface bedding material was displaced with an underwater plow, which resulted in cost savings

and ease of permitting. The plow was pulled over the seabed by a barge at low speed, minimizing

turbidity.

Reviewer:

C. Woolley

Company / Organization(s):

Projects Completed:

South Essex Sewage District Outfall

Location:

Salem Harbor, Massachussetts

Information Sources:

Literature:

Title:

"Innovative Design of a Multiport Diffuser"

Author:

Mindy Roberts, Bernadette H. Kolb

Month:

Year:

1994

LitType:

Report/Proceedings

Publisher:

Dredging 94

Publication

ASCE, New York, New York

Address:

Page:

Interviews:

Interviewer:

John Lally

Interview Location: Telcon

Chapter 5 Other Technologies Reviewed