City officials say the population is actually closer to 22,000. Officials challenged the interim census numbers back in April, citing utility connections to demonstrate the city's booming growth.

"The numbers they had for us were about 40 to 50 percent of what they really were," said City Administrator John Hendrickson. "Having those numbers reflect the true population helps people know the type of growth and size of city we really are.

The vast difference affects more than just statistics and bragging rights. For this city, located six miles west of Lehi, it could mean more cash - a welcome addition in a city looking to serve its booming number of young residents.

When the revised numbers come out next month, Eagle Mountain could get more state sales-tax dollars - perhaps in the six-figure range.

Hendrickson said he expects a boost of about $500,000, upping the city's income from sales-tax revenue from $1.2 million to about $1.75 million.

That money would go toward the city's general fund and could be used for park and infrastructure improvements, or boost police and firefighting forces.

"I would suspect the Council wants to look at resolving a couple issues that have to do with parks that have not been built in the downtown, or city-center, area," Hendrickson said. "We could possibly bring some additional personnel, but we'll have to see how it all works out."

And the new bucks won't stop there.

The adjustment might give the city funding toward transportation and capital projects from state and federal agencies that base their allotments on census figures.

Jonathan Takeuchi, a demographer at census headquarters in Maryland, said the bureau figures populations for cities and towns in a two-tier process.

First it works out the county population using birth, death and migration figures. Then, it distributes that figure to various towns according to the number of housing units in each.

Essentially, if a 10-city county - where each town has an equal population of 100 - grows by 10 residents, each town would officially gain one resident.

The challenge process looks specifically at the housing growth in a particular city. In Eagle Mountain's case, that was demonstrated by utility connections.

Takeuchi said the bureau's estimates use the once-per-decade census figures as a baseline, so the number of challenges around the nation increases as it gets further from the decade-mark - the last U.S. Census was in 2000. He added that the bureau gets a lot of challenges from Utah because funding is directly tied to the yearly estimate - not the case throughout the United States.

Mayor Don Richardson said the successful challenge "will provide much-needed funds for our rapidly growing city" and will open doors for other funding opportunities in Eagle Mountain.

sgehrke@sltrib.com