Ashland water treatment plant project to go solar
Ashland City Council has given a green light to solar possibilities at the new water treatment plant as a means to improve the project’s rating through Envision, a certification program for sustainable infrastructure projects.
At a council study session Monday, Public Works Director Scott Fleury requested council direction as to whether to incorporate solar power into the new facility design, which currently sits at the 60% design and cost estimating phase. In discussion, the council considered funding changes and plant resizing associated with the project.
In the initial design, the water treatment plant was slated to handle 7.5 million gallons per day (the current plant rating), expandable to 10 million gallons per day. Finalization of the 2020 Water Master Plan updated demand projections based on population growth, reducing former projections for 2040 to 5.5-5.7 million gallons per day with conservation, or 6.5 MGD without, Fleury said.
Project consulting firm HDR reviewed the most recent data on water demand and climate change impacts pre- and post-Almeda fire, prompting a recommendation to downsize the plant design to 7 million gallons per day initially, expandable to 9 MGD in a 100-year time frame, and estimated project cost reduction of $2.5 million as a result, Fleury said.
City Council previously directed staff to work on raising the project’s status from silver to platinum within the Envision program, with focus on electrical energy consumption, reduction and offsets, he said. Staff looked at onsite solar to offset operational costs, including a rooftop system with 199-kilowatt power for $2 million or a ground-based array with 150-kilowatt potential for $1.7 million.
Because of a purchase agreement with the Bonneville Power Administration, a single-site solar facility can provide only up to 200 kilowatts without requiring battery storage, Fleury said.
“Part of our issue with the battery is the cost of the system now to drive the operation of the water treatment plant when we were trying to be cost efficient for the project in total,” Fleury said. “We’ve talked about managing it so it can be utilized in the future as part of an improvement to the system — to add battery storage on the site.”
Power demand for 1.5 MGD of water supply (average during winter) is around 167 kilowatts, growing to 250 kilowatts on an average day of 3 MGD, and 516 kilowatts at max capacity of 6.5 MGD.
Based on daytime net metering, the plant would run for 178 days using exclusively solar power, Fleury said. The remaining days would be subsidized with grid power.
Together, a small amount of battery storage and a diesel generator could form a resiliency strategy in the case of a major event with electrical grid failure, facilitating plant production to meet minimum community needs, he said.
With a 199-kilowatt system running year round, estimated net revenue to the city is $24,000, according to Pierre Kwan, HDR project manager.
Councilor Tonya Graham, in a motion to progress the Envision rating improvements, asked staff to investigate use of STrackers to achieve the “most economical” solar power system possible at the site.
According to STracker Solar founder Jeff Sharpe, the company’s dual-axis solar tracking systems allow the same solar panels to see 50%-70% more energy harvest than through fixed panels. Mounted on 20-foot posts, the elevated systems allow for continued use of the area below each installation.
Solar analysis at the site — with the new facility’s planned south-facing orientation and no trees or geographical impediments — modeled sunlight present for about 320-330 days per year, Kwan said.
Also included in the platinum-status Envision program estimate is $300,000 to increase storm drain retention and treatment, develop a sustainability management plan, prepare end-of-life analysis, and restart the Ashland Water Advisory Committee as a formal city commission.
In the final design phase, Fleury said, project managers will bring back recommendations as to the future of the old plant and its components. The new plant will cost about $1 less per thousand gallons treated, taking into account use of supplemental water sources, he said.
“If you were to invest in the existing plant and have to build a new plant in the future, you’ve stranded that asset and those monetary dollars into that moving forward,” Fleury said in response to questions about the cost to improve the old plant versus construct a new one. “You have a higher interim operational cost keeping the plant going versus building a new treatment plant.”
Construction of the new plant has the highest initial cost, greatest benefit to the city, and the lowest cumulative cost from years 26 to 100, according to HDR’s assessment.
“Deferring any attempts to meet seismic resiliency, reduce fire risks, address water quality issues, and provide any level of flood protection is the lowest cost option for the next 25 years,” according to HDR. “However, it still has a high annual cost due to the increasing need to maintain old equipment during this period.”
Graham made a motion to direct staff to move forward with Envision improvements, and investigate the possibility of using STrackers and the amount of battery storage needed for site resilience.
“We’ve been working on this for 20 years now, and I’m concerned that we do something before inflation hits us again with this,” Councilor Stefani Seffinger said in support of the motion. “This really impacts our ability to grow as a community, because if we don’t have enough water and we don't have safe water, that's going to affect our ability to be environmentally and economically relevant in this world.”
The motion passed 4-2, with Councilors Gina DuQuenne and Shaun Moran voting no. The issue will be brought back in front of the council at a future business meeting.
Also Monday, Fleury said Ashland’s water treatment project was one of 39 projects invited to apply for federal funding through the Small Cities Program under the Water Infrastructure Funding and Innovation Act, which would finance up to 80%.
The programs “combine state resources, annual capitalization grants, and the low-cost, flexible SWIFIA loans to accelerate investment in drinking water and wastewater infrastructure to modernize aging systems and tackle new contaminants,” according to the U.S. Environmental Protection Agency.
The city of Ashland is listed as a funding application invitee regarding $36 million for a 7 MGD capacity water treatment plant.
As of September 2020, with reductions to the new plant’s size, the project cost estimate dropped under $33 million — to be revised as the project nears 90% design to account for shifting inflation and labor issues during the pandemic, Fleury said.
On Tuesday, City Council unanimously approved a $99,636 contract for construction engineering and inspection services with Carollo Engineers, and a $1.6 million contract with HP Civil for the second phase of the wastewater treatment plant ultraviolet disinfection system upgrade.
The chosen low-pressure, high-output system costs more initially, Fleury said, but provides the long-term benefit of $20,000 in annual electricity consumption reductions.
Reach reporter Allayana Darrow at email@example.com or 541-776-4497.