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Miller Road Trench Soil Management Program

Miller Road Trench Soil Management Project

Miller Road Trench Soil Management Project

East Bay Municipal Utility District (EBMUD) provides water service to 20 incorporated cities and 15 unincorporated areas in Alameda and Contra Costa Counties. The water distribution system is comprised of 6 water treatment plants, 167 potable water reservoirs, 131 pumping plants, over 4,200 miles of potable (treated) water distribution and transmission pipelines, and numerous accessory structures that altogether provide water service to EBMUD’s approximately 1.4 million customers.

Program Objective 

EBMUD’s Miller Road Trench Soil Management Program (Program) involves the continued operation of the Miller Road trench soil stockpile and rock and sand stockpile sites; this includes the import, temporary storage, and periodic removal (off-haul events) of clean soil, rock, and sand to support the replacement of aging pipelines.

EBMUD estimates annual replacement of failing pipes will increase through 2030 leading to increased trench soil generation. EBMUD will conduct intermittent trench soil off-hauls to free space at the site. 

Program Description

Overview

EBMUD owns and operates the Miller Road stockpile site, which is located within EBMUD-owned watershed land southeast of EBMUD’s Upper San Leandro Reservoir in Castro Valley, in unincorporated Alameda County. The Miller Road stockpile site, which has been used by EBMUD for managing trench soil since 1975, is used to store excavated soil (sand, silt, and clay) generated by EBMUD pipeline construction and maintenance activities. The Miller Road stockpile site supports EBMUD’s efforts to proactively replace and rehabilitate critical water system infrastructure. Based on projected pipeline improvements required to address EBMUD’s aging infrastructure, EBMUD estimates annual pipeline replacement will increase from 20 to 25 miles per year to approximately 30 miles per year by 2030. 

This program involves the continued operation of the Miller Road stockpile site, including import, temporary storage, and periodic removal of trench soil. The program also includes continued operation of the rock and sand stockpile site approximately 1 mile south of the Miller Road soil stockpile site on EBMUD-owned property within the project site. Materials from the rock and sand stockpile site are used to backfill trenches from the pipeline construction and maintenance activities. Continued operation of the rock and sand stockpile site includes import, temporary storage, and removal of these backfill materials. 

The Miller Road trench soil and backfill stockpiles are necessary components of EBMUD's proactive efforts to replace and and repair water infrastructure. As the need for annual pipeline replacement increases as existing infrastructure ages, however, EBMUD is pursuing a long-term strategy to reduce reliance on temporary storage sites such as the Miller Road site. To support sustainable and cost-effective practices of maintaining the water system, EBMUD has begun direct hauling trench soil to permanent beneficial reuse sites, a practice that is expected to increase significantly. Other trench soil management strategies, including native slurry backfill (NSB) and trenchless construction, are being pursued where feasible. Overall, the use of the Miller Road site is expected to decrease while EBMUD continues to expand investment in infrastructure replacement.

Mitigated Negative Declaration (MND) Outreach

In accordance with the California Environmental Quality Act (CEQA), EBMUD released a Mitigated Negative Declaration (MND) for the program. The MND was presented to the Castro Valley Municipal Advisory Council (MAC) on March 24, 2025 with an additional virtual community meeting on April 3rd, 2025 to gather input from the Castro Valley community on this program.

Virtual Meeting. Please click on the link to view the Miller Road MND Public meeting held on 4/3/25.

The comment period for the Draft MND closed on May 19, 2025. 

About the Miller Road Site 

EBMUD owns and operates the existing Miller Road stockpile site at 17292 Redwood Road in unincorporated Alameda County. The site has stored excavated soil, sand, and rock (i.e., trench soils) generated by EBMUD pipeline construction and maintenance activities since 1975. The Miller Road stockpile site supports EBMUD’s efforts to proactively replace and rehabilitate critical water system infrastructure. The trench soils removed from the site are used for beneficial projects such as the restoration of Redwood Road after the 2022/2023 landslides. 

Contact

Community Affairs
Email: Construction-South@ebmud.com
Phone: 510-287-0140
Emergencies or after-hours, call EBMUD at 866-403-2683