Coachella Valley WD approves $700,000 contingency boost for WRP 7 aeration upgrade

Coachella Valley WD approves $700,000 contingency boost for WRP 7 aeration upgradeThe $30 million biological treatment upgrade, currently 50% complete, requires additional funds to mitigate soil voids beneath pump foundations and replace dilapidated equipment inside live aeration tanks.

The board unanimously approved a $700,000 contingency replenishment for the WRP 7 Aeration Improvements Project, awarded to Mountain Cascades in December 2024.

Construction crews discovered soil voids up to 10 feet long beneath existing foundations, requiring the removal of concrete, soil mitigation, and rebuilding of the foundations.

Unmapped underground utilities conflicted with new pipeline and conduit installations, forcing the district to negotiate daily change orders that depleted the original $1.5 million contingency.

The additional funds will also cover the replacement of deteriorated low-flow mixers and valves discovered after the live aeration tanks were drained.

The Coachella Valley Water District (CVWD) Board of Directors unanimously approved a $700,000 construction contingency increase for the Water Reclamation Plant (WRP) 7 Aeration Improvements Project on August 11. The project, located in the City of Indio, involves upgrading the biological treatment process by replacing 30-year-old, 4,160-volt aeration blowers with modern, scalable units housed in a new climate-controlled building. The district awarded the $30 million construction contract to Mountain Cascades in December 2024, alongside an initial $1.5 million contingency. With the project currently 50% complete, CVWD staff requested the contingency replenishment after encountering two primary unforeseen site conditions that depleted the original funds. First, excavation work revealed unmapped underground utilities and equipment that interfered with the planned installation of new pipelines and conduits. To avoid contractor claims and project delays, district staff negotiated daily change orders to relocate the conflicting infrastructure. Second, crews discovered significant soil voids beneath existing pump foundations, with some gaps measuring up to 10 feet long. Staff attributed the voids to stormwater flow carrying away fine soil particles over time. Mitigating the issue required removing the existing foundations, applying engineered fill, compacting the soil, and rebuilding the concrete structures. Staff noted that post-construction grading and paving will be implemented to prevent future stormwater pooling. The newly approved $700,000 contingency will fund the remaining 50% of the project, including the replacement of newly discovered dilapidated equipment inside the aeration tanks. Staff noted that the deteriorated condition of low-flow mixers and valves only became apparent after the live aeration tanks were drained and washed. A staff member told the board that replacing the equipment now, while the tanks are offline and the contractor is mobilized, is significantly more cost-effective than bidding the work separately and risking future service interruptions. The new 480-volt blowers and motor control center will allow the district to more efficiently match oxygen demand in the biological treatment process. Despite the underground challenges, staff reported that the project is progressing well, with long-lead equipment deliveries expected on-site by the end of August.