Date: February 13, 2018
Item No.: 8b

Terminal 18 Stormwater Outfall
Renewal and Replacement
Marine Stormwater Utility

Highlights
•

Marine Stormwater Utility formed in 2014 to protect water quality of the Puget
Sound
- Won AAPA Comprehensive Environmental Management Award
- Tenant fees about 15% lower compared to City's Utility fees

•

System assessment & rehabilitation

- Obtain baseline conditions of entire system, due to be completed end of 2019
- A dozen urgent repairs completed preventing safety & operational hazard

•

Investments in the stormwater system

- Green Stormwater Infrastructure such as oyster shell barrels & rain garden
- Installation of tide gates

•

Tenants expressed positive feedback on our efforts

Highlights of work accomplished
2

Utility Revenue & Goals
Utility Revenue Breakdown
NWSA
NWSA tenants
Port

Port tenants

• Collected $4.96 million in
2017, $5.33 million in 2018

• Assess all 78 miles of
infrastructure by 2019
• Invest in asset
rehabilitation to
improve water quality

Provide triple bottom line benefits
3

Terminal 18 Stormwater
• Drainage area roughly 175 acres
(nearly 9 Safeco Fields)
• Most site drainage enters Duwamish
East Waterway through 13 Portowned outfalls
• Outfalls were installed ~50 years ago
Largest active container terminal
4

T-18 Stormwater System

East Waterway Outfall Locations
5

Existing Outfall Conditions

Ponded water in the pipes
Missing tide gates

Broken Pipes

Visible conditions under the dock
6

Current Assessment / Scope of Work
•
•
•
•

Focus from last manhole to end of pipe
Repair broken and cracked pipe
Realign pipe grade or slope
Install new tide gate valves

New tide gate installation

Current Conditions and Repair
7

Project Schedule
• Commission Authorizations
- Design & partial construction authorization - Q2 2017
- Full Construction authorization - Q1 2018
• Construction Activities
- Non-disruptive activities postponed until 2018
- Repair and replacement construction phased between
2018 and 2020
Schedule phased over 4 years
8