Growth spurs need for additional water infrastructure

The prospect of Hutto's future growth has created the need for new treatment plants to continue meeting the city's wastewater demand.

Hutto City Council approved a plan at its Feb. 7 meeting to build one plant that will pump 2 million gallons per day (mgd) of wastewater, followed by an expansion to pump a total of 4 mgd. The project will be done in two phases.

The city plans to begin construction on the first plant—expected to be online by June 2015—as soon as possible, Hutto City Engineer Matt Bushak said.

"We know that the city is growing," he said. "We know we've got developable land, and Hutto has been one of the fastest-growing cities in the nation over the past 10 years. There's going to be wastewater generated, and there's a need to treat it."

A growing need

The city first pinpointed a need for additional wastewater services in 2006, but a slowdown in population growth stalled construction. Now that population numbers and development are picking up again, the need has resurfaced, Hutto Assistant City Manager Micah Grau said.

"We see more interest not only in residential growth ... but also commercial sites, [and] that next wave of growth is occurring right now," Grau said.

The city is already running at 75 percent to 80 percent capacity with its current wastewater plant, which has a capacity of 1.5 mgd. The city has predicted its growth will meet or exceed the current plant's capacity by 2015.

"It's something we can't completely predict because we don't know when the growth is necessarily going to happen, but builders are continuing to build on lots that they actually platted and got on the books back in 2004 [and] 2005," Grau said.

The additional wastewater services will also allow the city to prepare for expected growth in the next several decades.

"You don't want to be in a city where it's not in a position to grow," Grau said. "[The plants are] going to give us more capacity to treat the wastewater not only of new residents, but new businesses."

However, Councilman Paul Prince spoke against the approved plans and said a smaller project would cover the city's needs without overspeculating on growth. Past public construction projects such as the building of Veterans' Hill Elementary School have overshot growth projections.

"My worry is that what will happen ... is what's happened over the past five years, which is that we've had growth, but it's been more of a plateau than a curve," Prince said. "I just think that building a [2 million-gallon-per-day] plant maybe is too much. ... Let's build a 1 million-gallon-per-day plant now and see where we are in a couple years. If we have the growth, we can push that up; if we don't, we can put that off a little bit."

Financial considerations

Initial funding for the projects will probably come from city-issued bonds, paid for with impact fees and increased utility rates, Grau said. Customers could see an additional $2 per month on their bills next year with additional increases in following years. The increase, however, will allow additional development in the area, and growth could ease customers' financial burdens.

"Getting new businesses and residents to use up that water is going to decrease the rate pressure for the rest of our citizens, as well as bring in additional tax revenue," Grau said.

The Brazos River Authority runs the current plant, and Bushak said the city plans to continue having the BRA carry out maintenance and operations. The city could be charged more in fees for the personnel needed for the new plants.

"[The BRA has] the expertise in operating those plants," Bushak said.

Construction plans

The city explored three expansion options, including expanding the existing plant, a three-phase project that would produce two plants pumping 1 mgd each and one plant pumping 2 mgd, and the approved two-phase project.

Austin-based engineering consulting firm K Friese & Associates Inc. reported expansion to the current site would cost approximately $8.4 million but would require buying additional property and would limit any further expansion.

"If we were to expand the existing plant, then we'd need to acquire some additional property, and even then, we'd have a really hard time expanding in the future," K Friese Professional Engineer Tom Owens said.

Building pipes to pump wastewater from throughout the city is an additional consideration.

"Because of the topography in the city, you would have to pump 70 percent of the flow in 2040 to get it to the existing plant," Owens said. "So if we build [a] new plant on [a] new site, 97 percent of the flow can gravity flow to the new site, and that's just a much more reliable way to convey that wastewater."

The council voted 5-1 to approve the two-phase plan, which K Friese estimated will cost $21.3 million and calls for a 2 mgd plant to be built immediately, followed by another 2 mgd plant in 2026. The plants will be built on the Saul property at 10700 FM 1660, which the city already owns.

Cost and infrastructure considerations factored into the vote. While the three-phase plan could save money initially by calling for a 1 mgd plant, Owens said it could have been more expensive than the two-phase plan, costing approximately $24.4 million overall. The city would also have little time between the first 1 mgd plant going online before it is slated to need the second plant, Owens said.

"If we were to build just a 1 million-gallon-per-day facility, about five years later we would need to have the second phase online," he said. "Considering that it takes [approximately three years to design and construct] the treatment plant ... it's almost like you finish the first phase and you immediately have to start into the second phase. Then, if growth were to accelerate in that period, you could have an issue."

Noise, light and odor are other considerations the city will have to factor in during construction. Bushak said the city is working with engineers to make sure lights are not pointed toward neighboring subdivisions and odor is minimized. A line of trees is also planned for the southern side of the plant to block views of the plant.

"When we put out the requests for qualifications, those were three things that we asked [applicants] to address. We want to minimize those impacts as much as possible," Bushak said.

Another consideration includes installing a pipe to connect flow from the current plant to the new plant, a project that is expected to cost approximately $3.75 million.

"We have a lot of infrastructure that collects, and interceptors already in place, so this is basically a new pipe connecting into our current system and taking it to the [other] treatment plant," Grau said.

A contract with K Friese for plant design was approved by City Council on Feb. 28. Owens said he expects construction plans to be completed in a year, with construction to begin immediately after. The council will also discuss issuing bonds and funding for the project in March, Grau said.