On a Wednesday afternoon at the Wilson Aquatic Center, about 30 people share the Olympic-size swimming pool that is the centerpiece of the still gleaming, two-year-old facility. Slower swimmers, mostly silver-haired retirees, largely stay on the right side. The faster swimmers and triathlete types stick to the far left.

They form a picture of peaceful coexistence.

But beneath the calm, chlorinated surface, there is conflict. A spat over the length of the lap lanes has roiled the waters.

On one end: swimmers who want shorter lanes to accommodate more people and different activities. On the other: a loose coalition led by competitive athletes who want to keep the status quo because Wilson is the city’s only indoor pool with the 50-meter lanes they consider ideal for training.

Both sides want to know: Whose pool is it, anyway?

It’s not the biggest issue in the city, by any stretch or butterfly stroke. But it does lead to another question: Should a public pool — and by extension the District government — serve the broadest range of residents or an underserved minority?

The Wilson Aquatic Center is considered by many to be the crown jewel of a massive overhaul of the District’s parks and recreation facilities launched during the tenure of former mayor Adrian M. Fenty (D), a triathlete who with each new bike lane seemed determined to make the city over in his uber-fit image.

The Wilson facility, where Fenty has trained, measures 54,765 square feet and sits just off Wisconsin Avenue, behind a Whole Foods Market and one block from the Tenleytown Metro stop. The old Wilson pool, built in 1978, was closed in July 2003 because of structural problems. After a series of hearings, the city and residents chose the Olympic-size pool. Two years and $34.7 million later, the new facility opened in August 2009.

The length of the lanes depends on where the lane dividers are placed. The pool is roughly twice as long as it is wide, so when the dividers are placed lengthwise, the lanes are 50 meters. When they are placed widthwise, the lanes are 25 yards, or roughly half of 50 meters.

With 50-meter lanes, “it becomes a facility for fewer people rather than more,” said Barbara Baldwin, 70, of the District’s Chevy Chase neighborhood, after she finished her swim the other day. “It’s a community facility. It should be able to accommodate a variety of swimmers.”

The Department of Parks and Recreation says it kept the lanes longer after a 2009 survey was inconclusive. (The exception is when 25-yard lanes are necessary for Wilson High School students.)

Some of the 50-meter advocates are competitive triathletes who need to pile up the miles. But, “even if you are swimming just to stay in shape, longer feels better,” says Michael Jacoby, 48, of Kent, a triathlete who trains at Wilson once a week.

“It’s a jewel,” he says of Wilson. “We can’t let it go.”

Some trace the current controversy — which has led to dueling petition drives — to Fenty’s defeat last fall. Shortly after the election, e-mails and phone calls requesting shorter lanes at Wilson started to trickle in to the recreation department. By June, debate was raging on neighborhood e-mail lists, and there were heated words.

Some blame the DPR for creating the mini-vortex.

“DPR is abdicating its responsibility to make a decision by politicizing it and dragging it out, pitting neighbor against neighbor,” says Mary Rowse of Chevy Chase.

The DPR is about to start another survey and will use the results to craft a compromise, says agency Director Jesus Aguirre. The petition most popular so far with the 50-meter camp would keep the status quo.

The school, scheduled to reopen in September after a massive renovation, is next to the pool. The swim team switches to shorter lanes for practice and for meets, as do swim classes. Wilson serves about 1,500 students.

The alternate proposal, backed by what some supporters refer to as “the slower swimmers,” calls for a 50-50 split, keeping the lanes at 50 meters for half the time and at 25 yards for the rest. The switch would likely occur weekday afternoons so that more Wilson students and other kids could use it.

“Go there at midday. There are no kids besides the ones in the toddler pool,” says Matthew Frumin, 52, of the American University Park area, who drafted the alternate petition. “There should not be a pile of flesh in the leisure pool and three people in my 50-meter lane.”

The 25-yarders also contend that shorter lanes open up the pool for activities that can’t be done otherwise, such as water polo, scuba lessons and even diving into the water for fun. When the lanes are set at 50 meters, it’s not practical to dive, because you would hit one of lane dividers. As a result, the diving boards, Frumin says, “are sculptures.”

The 50-meter folks argue the 25-yarders have six other indoor pools in the city to go to. They have only one. (The city has one outdoor pool with 50-meter lanes, East Potomac Park. The District operates 32 pools citywide, including five for children.)

Meredith Gardner, 41, of the District, another member of the triathlete group, says the flaw in the proposal to make the lanes 25 yards part of the time is how long it takes to rejigger everything — from 45 to 90 minutes, according to parks and recreation officials.

“We waited years for it to be rebuilt,” she says of the pool, and now that the long-lane swimmers finally have room to stretch out, they won’t go back so easily.

If 50 meters is too long for some people, Gardner says, “they could stop halfway and rest or hold their breath.”