Friday, January 24, 2014

New multi-million dollar Breckenridge water treatment plant in the works

#Breckenridge, Colorado.

The town of Breckenridge has spent the past few years filtering through possibilities to solve a predicted increase in water demand.
In 2011, a task force was formed to address water system issues in Breckenridge, including the existing Gary Roberts Water Treatment Plant. The Second Water Plant Feasibility Study, released Jan. 22, 2014, was conducted to better understand whether another plant is needed. The study looked at population growth projections, water quantity and quality, potential plant locations, water rights and estimated costs.
Originally constructed in 1971, with additions in 1974 and 1998, the Roberts plant is a conventional facility located below the Goose Pasture Tarn Reservoir. The expansions brought the total capacity of the plant to 5 million gallons per day (MGD). Breckenridge operated a second potable water treatment plant, located at Peak 7, until 2004 when it was taken offline, removing 0.5 MGD.
The study recommends a new 3 MGD conventional water treatment plant with raw water intake located near Lake Dillon along the Blue River.
Tom Daugherty, Breckenridge Public Works director, said research was necessary to establish a plan.
“When you put it all together, the report looks at population projections, the amount of treatment capacity in the existing plant, there will be a day in the future when we need more treatment,” he said.
Funding and finance
The estimated construction cost, including property purchase, equipment, buildings, new water delivery and site work, ranges between $21.5 million and $29 million for each of the five possible sites.
The cost to increase the capacity of the distribution system, to meet the demand from new customers, is $43.5 million.
The study names a worst-case scenario in which the project would have to be funded through a municipal revenue bond at a high interest rate. In the best-case scenario, the new treatment plant could be funded through a low-interest loan through the Drinking Water State Revolving Fund from the Colorado Water Resources and Power Development Authority. Existing rates will also likely need to increase between an estimated 50 to 100 percent.
Daugherty said he did not know when exactly the new plant would become a necessity, but signs point to increased demand.
“I’m not sure I know the answer,” he said. “It’s hard to predict the future, and difficult to understand what the actual increase in demand might be.”
Production capacity
The Roberts plant has an effective operational capacity of about 4 MGD during periods when the raw water is murky during late spring runoff. The town has plans to initiate an evaluation and rehabilitation of the current plant this year.
The peak of water demand was 3.41 MGD in July 2008. July has historically been a peak water demand month in Breckenridge, the study says. The findings reveal that since the existing plant has a summertime operational capacity of only 4 MGD, the peak demand day accounts for more than 80 percent of the plant’s production capacity.
“If you want to look into the future, expanding with this model, we should seriously start working on this in the next few years,” Daugherty said. “With the current demand on the system, we feel confident in the demand in the current boundary right now.”
The population forecasts addressed in the study indicate there will be a 10 percent chance for the 2015 peak day demand to exceed 5 MGD.
Daugherty said good practice suggests water systems should begin planning and designing capacity extension when the system reaches 80 percent of the rated capacity, because it takes several years of planning and construction to bring a new plant online. With the current schedule outlined by the study, the plant would be operational in 2020 and provide Breckenridge with enough water for the next 20 years.
“Essentially, what we’re saying is the plant could be up and running by 2020, treating water so people could drink it,” Daugherty said. “The real question is, do we need that by then?”
Operational flexibility
Repairs and improvements soon will be required at the existing plant to maintain functionality over the long term. The recommended 3 MGD water treatment plant will allow portions of the current plant to be taken offline for improvements, Daugherty said. It also provides a second source of supply in case of a wildfire in the upper Blue River watershed.
The study reports that because there is only a single source of raw water at the current plant, the option used by most utilities to survive the aftermath of wildfire — taking water from an unaffected watershed — is not currently an option for Breckenridge.
“The runoff can be untreatable, or at least very difficult to treat,” Daugherty said. “The capacity of the plant goes down, with all of the stuff in the water we’d have to get rid of. Then we could not longer treat at the capacity demand of our water users.”
The plant could be constructed in two 1.5 MGD increments, and the water demand would be managed by controlling the number of additional customers added into the system. The study recommends that the finished water from the new treatment plant be delivered to the town distribution system, without restricting the area the new plant can service.
Maximizing water rights
If the new water plant intake is located below the Blue River Gauge near Dillon, the study found construction of the new plant could also maximize the town’s water rights.
The combination of the 3 MGD second plant and the location of the intake has significant advantages for flexibility of water storage. Water taken from below the Blue River Gauge must be augmented at 5 percent. If water production from the second plant is maximized during periods when storage is desired, the overall water requirement is reduced.
Future planning
The findings indicate a conventional water treatment process would be best, due to reliability and operational flexibility. A number of the possible sites include private property not owned by the town; as a result, the detailed plant site analysis section was removed from the report because it contains confidential property information.
The Breckenridge Town Council will discuss the results of the study, including next steps for the project, at its upcoming Jan. 28 meeting.
Due to the concern over space requirements, one item up for debate will be a packaged treatment system or use of mechanical dewatering equipment. The study findings reveal the packaged plant option does not have a significant impact on the footprint required or equipment cost, but the mechanical dewatering equipment option does. However, the mechanical dewatering option saves an acre of space for triple the cost of drying beds.
“It’s not like the population projection is approaching a point where we have to make a decision right now this minute,” Daugherty said. “We’ve still got some growth to do.”
Courtesy of the Summit Daily News.