Millbrae Retaining Wall Backfill Project

we take pride in delivering excavation and backfill projects that combine speed, accuracy, and unmatched professionalism. Our recent retaining wall backfill project in Millbrae, CA is a perfect example of how teamwork, equipment, and experience come together to achieve exceptional results.

Located on a multi-tiered site with limited access, the project required precise material placement, careful coordination, and a strong focus on safety. In just two days, our crew successfully placed more than 500 tons of drain rock—completing the task well ahead of schedule and meeting every geotechnical specification the first time, with no rework required.

A Strategic Approach to Retaining Wall Backfill

The Millbrae project involved backfilling behind three newly constructed retaining walls. Each wall area required elevation control and consistent compaction to ensure proper drainage and long-term stability. With extremely limited direct access to the wall areas, we deployed an equipment strategy capable of delivering our drain rock exactly where we needed it without putting equipment in the hole.

we deployed two pieces of specialized high-performance equipment:

• CAS AT7 Slinger – a 4 wheel drive aggregate placement system that allowed us to place our drain rock with pinpoint accuracy.
• CAS RL26HD Reloader – a powerful support conveyor system that kept the slinger continuously fed directly from our dump truck fleet, eliminating double handling material and keeping operations efficient.

This equipment combination allowed our crew to move massive volumes of material quickly and safely. By utilizing the slinger in a stationary area where it could reach out and touch the whole site, we reduced heavy equipment movement on-site and minimized the disruption to the surrounding neighborhood.

Efficiency That Saves Time and Money

One of the standout achievements of this project was completing it ahead of schedule—a direct result of our planning and state-of-the-art material-handling methods. In just 2 Days, our team placed and graded over 500 tons of drain rock across all tiers.

That level of productivity translates into significant cost savings for our clients. Faster execution means reduced equipment hours, less disruption to ongoing site work, and shorter project timelines overall.

At Harris Excavation, we believe efficiency doesn’t come from throwing more resources at a project, it comes from the precise application of specialty equipment to turbocharge our existing crews and turn them into superstars.

Communication at the Core

On every Harris Excavation Co. project, safety is a non-negotiable priority. The Millbrae retaining wall site included multiple elevated work areas, so we installed a temporary guardrail system to protect our team from fall hazards while maintaining full mobility across the workspace.

Just as important as physical barriers is communication. Throughout the project, we kept open lines of communication with the property owner, geotechnical engineer, and nearby neighbors. This collaborative approach ensured that everyone was informed about the schedule, noise expectations, and daily progress—allowing us to maintain professionalism and goodwill within the community.

Our dedication to clear communication and safe operations doesn’t just create a smooth work environment—it builds trust, which is why so many Bay Area clients continue to rely on our team for their excavation and backfill needs.