RMWD amends Rainbow Water Quality Improvement Project contract

Joe Naiman

Village News Reporter

The Rainbow Municipal Water District contract to relocate water mains and service laterals as part of the Rainbow Water Quality Improvement Project has been amended.

A 5-0 Rainbow board vote Tuesday, Feb. 28, authorized a $109,288.12 change order to the contract with Ortiz Corporation. The board action also authorized Rainbow general manager Tom Kennedy to approve change orders totaling $240,000 above the original $839,850 contract amount, which allows for small contingency situations to be handled without the need for additional board approval.

In June 2021, the San Diego County Board of Supervisors approved a project whose primary objective is to reduce nutrient discharge into Rainbow Creek and which will also provide flood control benefits and street improvements to some Rainbow roads. That action approved the advertisement for bid and award of a contract for the Rainbow Water Quality Improvement Project, appropriated $9,000,000 for the project, and adopted the environmental Mitigated Negative Declaration and the Mitigation Monitoring and Reporting Program.

The Rainbow Creek subwatershed covers approximately 7,000 acres in Rainbow Valley. Approximately 5% of that total acreage is currently being used by 37 nurseries and greenhouses which use fertilizer and irrigation water. Runoff from septic leach fields also flows into Rainbow Creek.

Excessive nitrogen and phosphorus levels in Rainbow Creek caused the Regional Water Quality Control Board to establish total maximum daily load contaminant levels in 2006. In 2013, the RWQCB issued a municipal separate stormwater sewer system permit to the county which has an enforceable TMDL reduction for Rainbow Creek.

The county evaluated the best way to reduce nutrients and also sought to identify how to fund the project. Rainbow Creek is within the Santa Margarita watershed, so the best management practices were also incorporated into the Water Quality Improvement Plan for the Santa Margarita Watershed which was finalized in 2018.

The project includes installation of approximately 3,400 feet of subsurface wetlands channels; adjacent road runoff will be conveyed through those channels which will deliver the water – minus whatever will be used for the vegetation or soil – to collection pipes and then to the discharge system at Rainbow Creek.

The channels will be installed in the roadway shoulders and will be approximately 4-5 feet deep and filled with treatment material and vegetation. The work also includes replacing other drainage channels to convey adjacent road runoff, and the county took the opportunity to add road and pedestrian safety improvements.

Capital improvements will take place along Huffstatler Street by Second Street, Huffstatler Street south of Fifth Street, Fifth Street between Huffstatler Street and Rainbow Valley Boulevard, Rainbow Valley Boulevard from Chica Road to Rainbow Creek Road and the northern part of Rainbow Valley Boulevard.

Some modifications to driveways will be necessary near Fifth Street and Huffstatler Street, on Rainbow Valley Boulevard between Chica Road and Rainbow Creek Road and along the 800-foot northern Rainbow Valley Boulevard segment.

The Rainbow Water Quality Improvement Project does not involve the water quality in the Rainbow Municipal Water District’s distribution system but rather surface water runoff from roads. However, the county’s improvements will create utility conflicts with water district facilities as well as San Diego Gas & Electric and AT&T facilities.

The county’s road easements predate Rainbow’s easements, so Rainbow is financially responsible for relocating the impacted water mains and laterals.

“We had to relocate some of our pipelines based on their project,” Kennedy said.

Approximately four Rainbow water main conflicts and 21 lateral conflicts were identified based on the county’s final design and multiple site visits. In addition to the estimated 21 service laterals Rainbow identified the need to relocate approximately 350 feet of 8-inch water main and 650 feet of 12-inch main and the need to remove three sections of 8-inch water main.

In June 2022, Rainbow’s board approved the $839,850 contract with Ortiz Corporation, which is headquartered in National City. The board action also acknowledged that the Rainbow board independently reviewed and considered the information of the mitigated negative declaration certified by San Diego County and that the Rainbow board reached its own conclusions that the mitigation monitoring program is adequately designed to ensure compliance with the mitigation measures during the project’s implementation and that the significant adverse impacts of the project have been reduced to below a level of significance.

The county issued the permits for the water main and lateral relocation work in October 2022. Ortiz began construction in November 2022. As of late February, Ortiz Construction had relocated five service laterals and approximately 650 feet of water main along Rainbow Valley Boulevard, but the company encountered delays due to the subsurface rock being harder than expected.

“It’s very hard rock. They’ve got some granite under there, which is very difficult to get through,” Kennedy said.

Ortiz Construction first encountered hard rock Dec. 15, 2022, and notified Rainbow staff. Ortiz recommended changing excavation equipment to a larger machine with a different bucket and proposed continuing the work with additional compensation on a time and materials basis. Rainbow agreed to those terms, and daily work tickets for additional labor and equipment were verified by Rainbow field staff each day.

Rainbow staff continued to monitor extra work tickets through December, which included four extra work tickets totaling $33,490.62. When work resumed in early January, the district and Ortiz continued to track hard rock excavation costs for the Rainbow Valley Boulevard North site. All rock excavation for that site was complete by Feb. 7, when Ortiz submitted tickets for work performed on three days in late January. The tickets exceeded Kennedy’s signing authority, and all of the extra work tickets totaled $109,288.12.

Ortiz Construction has completed the Rainbow Valley Boulevard North work and is currently at the Rainbow Valley Boulevard South site to relocate a water main in the roadway. Ortiz has relocated 625 feet of pipe and has not encountered any unexpected hard rock at the new work area.

Construction is approximately 30% complete and work outside of the roadway is still needed at the Huffstatler Street and Second Street site and the Huffstatler Street and Fifth Street site. The total $240,000 administrative authorization will allow $130,711.88 of contingency or approximately 15% of the total construction contract amount, for any unanticipated hard rock at any of the other sites.

Joe Naiman can be reached by email at [email protected].