EBMUD Inner Harbor Crossing Case Study

July 9, 2024

The East Bay Municipal Utility District (EBMUD) Inner Harbor Crossing project highlights a remarkable effort to upgrade aging water infrastructure in the Oakland area. They addressed the challenge of outdated and earthquake-vulnerable pipelines by implementing innovative solutions, ensuring dependable water service for residents of Alameda Island.

This case study highlights the challenges, strategic planning, advanced material used, and precise engineering that made this essential upgrade possible.

Infrastructure Challenges

EBMUD faced significant challenges with aging water infrastructure. In particular, the Oakland Inner Harbor crossings, which included multiple underwater pipelines, were susceptible to failure and liquefaction during earthquakes.

These infrastructures’ existing cast iron pipelines, installed in the 1940s, were outdated. They posed a risk of compromising water service and fire flow rates to the 40,000 Almeda customers, including the U.S. Naval Air Station. A pipeline failure in 2009 underscored the urgency of addressing these vulnerabilities to ensure reliable water service and public safety.

Strategic Solution: PE4710 Pipeline by WL Plastics

The following outlines the systematic approach taken by EBMUD, incorporating WL Plastics’ PE4710 pipeline, to address infrastructure challenges and enhance water distribution for Alameda Island:

Developing the Master Plan

To mitigate these risks, EBMUD developed the Alameda-North Bay Farm Island Master Plan in 2014. The plan aimed to reduce the number of water transmission lines serving Alameda from four to three, guaranteeing a more efficient water distribution network.

Environmental Impact Report

Following the master plan, an environmental impact report was completed in 2016. This report prioritized the replacement of the pipeline crossing between Alice Street in Oakland and Webster Street in Alameda. It ensured that environmental considerations were thoroughly addressed in the project planning process.

Awarding the Construction Contract

In 2022, EBMUD awarded a $25 million contract to Cratus Inc., a San Francisco-based construction company. This contract included the installation of a new 32-inch diameter PE4710 pipeline using Horizontal Directional Drilling (HDD) to guarantee minimal environmental disruption and maximum efficiency.

Selecting PE4710 Pipe Material

WL Plastics’ PE4710 pipe material was chosen for its flexibility, durability, and earthquake resistance. This selection was critical in ensuring the new pipeline would be reliable and resilient, particularly in an earthquake-prone region.

Implementation Process

These steps outline the implementation process for installing a large pipeline under the Oakland Harbor:

1. Planning and Preparation

The project commenced with extensive preparation to ensure a smooth execution. Detailed planning was essential for coordinating the logistics of installing a large pipeline under the Oakland Harbor.

2. Fusing the Pipe Sections

In Spring 2023, construction crews began fusing 63 50-foot-long sections of the PE4710 pipe along Mitchell Avenue in Alameda. This step involved precise welding to guarantee the pipeline’s integrity and durability.

3. Positioning the Pipe on Rollers

To facilitate the installation, the fused pipe sections were placed on rollers. This approach minimized friction during the pull-through process and ensured that the pipeline could be smoothly and efficiently maneuvered into place.

4. Pulling the Pipe Through the Bore Hole

On April 7-8, 2023, the fused pipe string was successfully pulled beneath the Oakland Harbor from north of Estuary Park. This complex operation required careful coordination and precise execution to avoid any damage to the pipe or surrounding environment.

5. Final Installation and Testing

Following the successful pull-through, the pipeline was secured and underwent rigorous testing to ensure its functionality and reliability. This final step confirmed that the new pipeline met all safety and operational standards before being serviced.

Choose WL Plastics for Reliable Water Infrastructure Solutions!

At WL Plastics, we understand the importance of superior quality and reliability in water infrastructure. The EBMUD Inner Harbor Crossing project demonstrates how our PE4710 pipe with its flexibility, durability, and earthquake resistance guarantees the success of critical infrastructure upgrades.

Contact us today for your next project and experience the benefits of cutting-edge pipeline solutions that stand the test of time!

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