NEWBURYPORT — The commissioners of Moseley Woods have done the spade work on a program to make the 16-acre park litter-free.

They've removed the trash barrels and put up two stations to dispense bags for collecting dog waste. They've made Moseley Woods, at the intersection of Spofford and Merrimac streets, a pack-it-in, pack-it-out facility.

Now comes the hard part: getting the public to cooperate.

Local business owner and South End resident Mark Emmith is the chairman of the commissioners and president of a group called the Friends of Moseley Woods.

He said most people respect the principle "Always leave the park as you found it. Leave no trace." But not everybody does.

"It's just typical," he said. "About 10 percent of the people have issues."

On a recent weekday afternoon, with dozens of kids and families enjoying the park, Emmith showed a visitor a bag of trash, mostly empty bottles, he had found in the restroom.

At least the debris wasn't stuffed into the toilet, which interferes with the process of pumping it out. That happens, too, Emmith said.

Emmith said some dog walkers are the most persistent offenders. They are required by local ordinance to dispose of dog waste in their own receptacles, but not all do, he said. Even if they take the free bags, the dog walkers leave them in the park, rather than take them home.

"Our caretaker finds them in bushes, in trees, wherever a person decides to leave them," Emmith said.

Emmith said the city's leash law remains in force within the park, but people sometimes let their dogs run free. That practice is particularly troubling in the children's playground area, he said.

While he was talking, Emmith was presented with a good-news, bad-news scenario.

He watched with approval as a woman drove out of the park with a bag of dog waste tied to the rear windshield wiper of her minivan.

A few minutes later, however, an apparently unsupervised dog wandered out of the nearby woods and into the playground area, first stopping to urinate against a tree. Emmith identified the dog as belonging to a neighbor of the park who declines to leash it.

The seven-member commission decided to make the park a carry-in, carry-out facility after analyzing the work schedule of its part-time caretaker.

They found that he spent the bulk of his time emptying trash barrels and otherwise cleaning up, instead of working on projects to maintain and improve the park.

Moseley Woods, which was established as a city park in 1921, underwent a $440,000 rehab and renovation in 2004, Emmith said, and the commission was appointed to oversee it. In addition to Emmith, current members are James Farrell, Kathleen Latawiec, Tom Farrell, Linda Knight and Kim Kudym.

The park receives a small annual appropriation from the city. It was $8,000 in the current budget, reduced to $7,500 for the fiscal year that begins in less than three weeks on July 1.

Emmith said the Friends of Moseley Woods raise money and obtain donations to help maintain the park.

The commission also rents out the pavilion that overlooks the Merrimack River for functions and stages summer concerts there to earn money.

Moseley Woods also has five sponsor organizations: the Newburyport Five Cents Savings Bank, The Natural Dog (which supplies the waste bags), Custodial Partners (which contributes cleaning supplies and paper products), the Newburyport Community Website and Germinara Biofuels.