Impact fees and revenue bonds would fund $24.2 million facility
In preparing to meet the needs of a growing population, Boerne officials have mapped out a plan for a second water-treatment plant to deliver a combined 3 million gallons of water a day to residents.
Speaking to the City Council Nov. 18, Michael Mann, Boerne Utilities director, laid out the results of a pilot study addressing the city’s future water usage relative to a population that could soon approach 50,000.
Mann said the plant would be constructed near the current system at Boerne City Lake. The new system’s price tag is $24.2 million and would be paid by impact fees and revenue bonds.
“Our Capital Improvement Plan includes a new water plant,” Mann told the council. Members on the dais took no action because the agenda item was a study presentation only.
Bids for the project could go out in late spring or early summer. Construction could start in 2027 or 2028, with the plant being operational by 2030.
The current water-treatment plant can produce 1.3 million to 1.5 million gallons of water per day. The city’s future water model for 50,000 people “is going to need to be able to produce 3, 3.1 million gallons per day,” Mann said. “We need to augment that, and that’s what the second plant is for.”
The original plant was constructed at the lake in 1978 for flood control. Previously the city — with a population of just a few thousand people — was supplied by wells.
That original plant is still in operation.
“It does a great job,” Mann said. “ However, regulatory requirements have changed since that time.” In the late 1990s or early 2000s, Mann said, the Texas Commission on Environmental Quality started regulating disinfection byproducts — specifically compounds that form when chlorine comes into contact with microscopic organics.
“So that became regulated. Our plant was not designed specifically to treat that. It does, but it needs help,” Mann added.
Other incidents have popped up — the city added a potassium permanganate feed to help with oxidation after the 2002 summer floods. Recently, the city had to tackle a “geosmin” event where water from the lake had a “dirt” or damp earth smell and taste to it.
More important, the city needs water delivery help on “peaking days,” officials said.
Mann reviewed the city’s main sources of water: those overseen by the Guadalupe-Blanco River Authority, Boerne City Lake, groundwater wells and reclaimed water.
“What we did was create a water model,” Mann said, “for what we think our model demand would be with a population of 50,000.”
City officials used a formula equating 2023 usage with demands of a population of 50,000 and created a chart showing “water availability,” or water demand, in a normal year.
Mann explained how the current treatment plant pulls water from the lake and uses a “mixed-media filter” before the water is stored, ready to be shipped to town.
“It’s a filter just like you would have on your kitchen sink ... It still works,” he said. “But it doesn’t do the kind of job we need” when contaminants are present.
The proposed water treatment plant, he said, will rely on a granulated activated carbon filter that brings the city’s water treatment into the 21st century.
“Instead of having the mixed-media filter at the newer plant ... it would be a biologically active filter. It just does a better job of removing those things that cause us problems,” he said.
The addition of a calcium thiosulfate applicator will give the city better means of treating its water.
Once up and running, the new plant would be in continual use, with the older plant placed into service during peak periods when water consumption is at its highest, traditionally the summer months.
Councilman Joe Bateman asked about the life span of each plant.
“The 1978 plant probably has another 30, 35 years on it, Mann said.
“But it really becomes an efficiency thing,” Mann said. “How often do you have to replace pumps? How often do things corrode? When it gets to where it’s costing more money to maintain than replace, that’s when we would (replace it).”
“Our Capital Improvement Plan includes a new water plant.”
— Michael Mann, Boerne Utilities
Comment
Comments