Village News Reporter
The Rainbow Municipal Water District awarded Anderson Burton the contract to design and build the battery backup system for Rainbow’s Sumac Communications Tower.
A 5-0 Rainbow board vote Tuesday, Oct. 25, awarded Anderson Burton, which is headquartered in Arroyo Grande, a $170,635.39 construction contract. The board action also established a total appropriations amount of $200,000 and found the project categorically exempt from California Environmental Quality Act review.
“The Sumac radio tower is a vital piece of equipment,” Rainbow general manager Tom Kennedy said. “This battery backup with solar power will allow that system to run indefinitely.”
The battery backup system will allow both Rainbow and the North County Fire Protection District to maintain voice and data communications capability during an outage. Rainbow owns the Sumac Communications Tower on the same property as the Sumac Reservoir in the 3000 block of Sumac Road and co-operates the tower along with the North County Fire Protection District. Electric power for the Sumac Communications Tower is currently provided by San Diego Gas & Electric and fully dependent on grid-supplied power.
On a districtwide basis between July 2019 and October 2020, the district experienced approximately 100 hours of power outage events, including 27 hours due to public safety power shutoffs when weather conditions increased the risk of a downed power line causing a wildfire.
Electricity for the Sumac Reservoir and communications tower was unavailable for approximately 68 hours during that period. If pump stations are shut down, Rainbow might not be able to provide potable water service and also might be unable to provide the fire hydrant flows needed to fight any wildfires or other blazes. Rainbow owns one portable generator which is positioned as needed to respond to power outages, but that single generator is not sufficient when more than one facility loses power.
The state Office of Emergency Services has a Community Power Resiliency Allocation to Cities Program, which aids cities and small districts with additional preparedness for a power outage. Rainbow applied for a grant through that program in October 2020 and was given a $300,000 grant to purchase two emergency generators and a solar-powered battery backup system. The 350-kilowatt generators will be used for the Gomez Pump Station and the Magee Pump Station.
The grant agreement required that the equipment be purchased and received into inventory before Oct. 31, 2021, although construction and actual installation did not need to be completed by that date. Rainbow acquired a ground-mounted solar power system with a 40-kilowatt battery pack to provide backup service to the Sumac site.
The solar-powered backup battery system would automatically switch to the redundant power source without interruption for up to seven days. Once power is restored and stabilized, the photovoltaic and backup battery system would automatically switch back to the permanent power source with supplemental energy being provided by the solar energy system without interruption.
Rainbow staff determined a design-build procurement method would be most appropriate for the Sumac communications project. District staff issued a request for proposals in June 2022. Anderson Burton submitted the only proposal before the Aug. 4 deadline.
The proposal was evaluated on technical approach, company qualifications, project experience, implementation schedule and cost. Each evaluator gave a score of up to 100 points, and the Anderson Burton proposal received between 92 and 96 points from each evaluator. The $170,635.29 proposal fee consists of $58,155 for project management and design engineering, $103,480 for permitting, construction and commissioning and $9,000 for three years of maintenance.
An ancillary structure to the existing communications tower will be constructed and minor grading will occur to install the solar panels. The grading will not impact mature trees, sensitive habitat or protected waterways.
The battery backup system is expected to be operational sometime during calendar year 2023.
Joe Naiman can be reached by email at [email protected].