It is the big bet at Lawrence City Hall.

Someday the economy will improve, and builders will start constructing homes at a pace faster than they are today. And it is certain they’ll all want toilets that flush and sinks that drain.

But it also is a certainty that if the pace of home construction picks up significantly, the city’s lone sewage treatment plant won’t be able to handle all the toilets, sinks, showers, and, well, you get the picture.

None of that surprises city leaders. The city already has purchased a site south of the Wakarusa River to house a new $80 million to $90 million sewage treatment plant. What city leaders are trying to figure out now is when that plant should be built.

To answer that question, they are trying to figure out the answer to a question the whole world wants to know: When will the economy turn around? The only certainty in all of this is that if the city waits to build a plant until the economy really starts to hum again, it has waited too long.

“We think it will take four years to design and build the plant,” Mayor Aron Cromwell said. “If the economy really turns around before we complete the project, we’ll have people screaming at us that they can’t build out west.”

City commissioners don’t want that to happen.

But they also don’t want city residents screaming at them about high sewer bills, especially during a time when the economy is squeezing average households in many other ways. But that is certainly a possibility.

“If this is the year we start the planning for the wastewater plant, there will be a very significant increase in sewer rates,” Cromwell said.

Caution urged

A very significant increase means a jump in rates of 10 percent or more. How much more, though, is a number that city leaders have been reluctant to speculate on thus far.

Clearly, some city commissioners are leaning toward the idea that this year won’t be the year they have to start planning the plant.

“It is a tricky question because you don’t want to pick the wrong year and put yourself in a situation where you have to tell somebody to wait,” said City Commissioner Mike Amyx. “But based on the information we have right now, I just don’t see it for this year.”

Others, though, said there is a lot to think about. New City Commissioner Hugh Carter, for example, said it is possible that the final leg of the South Lawrence Trafficway could be completed by 2015. That could create a boon in building activity for the city. How bad would it be for the community not to be able to take advantage of that newfound interest in the community?

“We have to be thinking of the big picture,” Carter said. “The things we do right now, in what I believe are the early stages of a slow recovery but a long recovery, will be very important to how well we do in the future.”

Even if commissioners don’t start the planning for the sewer plant as part of this next budget — the 2012 budget — there could still be an increase in sewer rates. City commissioners last year went against the advice of staff and chose not to raise water and sewer rates for 2011. Both Cromwell and Carter expressed questions about whether that would be possible in 2012 as operational expenses rise and the need to maintain aging infrastructure increases.

But Amyx said it is too early to say that rates will have to rise in 2012. He said he will want more information about what the city can accomplish without a rate increase.

Water questions

Sewer rates are only part of the monthly bills residents receive from the city. Water rates also are creating questions at City Hall. But with the water system, the question isn’t when to start a major expansion, but rather how to keep up with the payments on an already-completed expansion.

The city completed an approximately $20 million expansion of the city’s Clinton Water Treatment plant in the late 2000s. The expansion gives the city far greater capacity to treat water, but the city has not been selling as much water as it used to.

In fact, numbers from City Hall show that Lawrence is selling less water now than it did in the 1990s. The numbers show water production peaked in 2002 and has declined by about 30 percent since then.

But costs have not been declining. Even though the city is producing less water, chemical costs to treat the water have nearly doubled in the last decade. In 2000, the city spent about $594,000 on chemical costs. In 2010, that total had grown to $917,000. Personnel costs also have increased, as most of the department’s employees aren’t responsible for treating water but rather maintaining the city’s waterlines and systems. Personnel costs were $2.3 million in 2000 and had grown to $4.1 million in 2010.

Cromwell and Amyx both said the city has to try to squeeze as much efficiency out of the system as it can.

“If there are increases that have to happen on water rates, I’m hoping they will be as little as possible,” Amyx said.

He also said he wants the city to continue with its efforts to lock wholesale water customers into longer-term contracts with the city. Currently, Lawrence treats the water for Baldwin City and a variety of rural water districts. But some of those major customers have been exploring other treatment options. Amyx said the city needs to be aggressive in keeping those customers.

“If we’re going to be in the water treatment business, we need to sell as much water as we can to as many customers as we can,” Amyx said.

Commissioners will set the water and sewer rates as part of the 2012 budget process. Commissioners began debating the budget last week and likely will finalize the budget by mid-August.