SCW given Rainbow MWD contract for Vista Valley Villas Pressure-reducing Station

SCW Contracting Corporation received the Rainbow Municipal Water District contract to install the new Vista Valley Villas Pressure-reducing Station and associated infrastructure.

The company based in the town of Rainbow was awarded the contract on a 5-0 vote by Rainbow Municipal Water District board members Tuesday, June 23. The contract value of $334,700 matches the SCW bid for the project. The Rainbow board action also found the work categorically exempt from California Environmental Quality Act review.

“This is part of our ongoing effort to reduce the pressures,” Tom Kennedy, Rainbow general manager, said. “It will benefit the people who live nearby.”

The topographic features of the Rainbow Municipal Water District area have caused significant issues regarding water system pressure, and a recent condition assessment study indicated that system pressure is one of the major factors for pipeline failures. Rainbow staff has been developing options to replace old pressure-reducing stations and to install new ones in crucial areas of the pipeline system. One of the most cost-effective methods is to install pre-manufactured stations which are housed in fiberglass “doghouse” structures. Last year Rainbow purchased 10 pre-manufactured pressure-reducing stations from Engineered Fluid Inc. for subsequent installation in various locations throughout the district. One of those pressure-reducing stations is custom designed for the Vista Valley Villas Homeowners Association.

The Vista Valley Villas Pressure-reducing Station has been planned since 2015, although various obstacles delayed the completion of the facility design. Not only did topography limit the potential locations but so did existing underground utilities. Once a specific location was identified, Rainbow needed to work with the homeowners association to obtain an easement for the pressure-reducing station. A geotechnical firm was hired to collect core samples by using a drill rig, but due to shallow bedrock, the drill rig had to be moved multiple times to collect a deep enough sample. The pressure reducing station will require rock excavation of an existing slope along with a concrete pad and construction of a retaining wall. A geotechnical report was required to complete the design of the retaining wall. The design phase for the retaining wall analyzed concrete pads 13 feet by 13 feet and 20 feet by 20 feet, and the larger pad was determined to be cost-prohibitive. A topographic survey was conducted for the base map and the design plans.

In addition to the pressure-reducing station, the work will include installing two new valves on existing water mains just north of the pressure-reducing station site. Those new valves would allow Rainbow to isolate smaller sections of pipe in the event of a leak, which would minimize the service interruption. The work will also remove an existing pipe cross and would connect two pipe runs, so a low pressure line could be fed from two directions and if one of the pressure-reducing stations is shut down for maintenance the other station could still provide service to customers without interrupting their supply.

Rainbow has a list of pre-qualified contractors, and district staff prepared a bid package and advertised the project for bid to those contractors May 14. Three firms responded by the June 4 deadline. The SCW bid was the lowest, and T.E. Roberts Inc. of Orange had the second-lowest bid at $345,200. The SCW bid was reviewed and deemed to be complete, and all required licenses and bonding are in place.

“They have a 60-day construction timeline,” Kennedy said. “I imagine that one will be done by October.”

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