Pat Walters grew up on the Allegheny River. She remembers a time when she swam the river every day.

As the public has become more aware of the river’s dangers, however, people don’t do that anymore.

Still, Walters is passionate about the river and about keeping it clean. She is secretary of Natrona Comes Together Association and organizer of Natrona’s river sweep.

On Saturday, she’ll be one of thousands of volunteers to participate in River Sweep. Volunteers will descend the banks of the Ohio River and its tributaries, spanning six states to the Ohio River’s end in Illinois, said Betsy Mallison, the state’s River Sweep coordinator. The Ohio River Sweep program began in 1989.

Over the years, Walters has noticed an improvement in the riverfront. Volunteers are keeping it clean, and they’re not finding tires, toilets, bicycles and shopping carts along the riverbank anymore.

Mallison said water quality has improved, fish have come back and more people are using the river.

But even today, she said, trash is left behind by people using the rivers and by contractors.

“While we’ve seem river conditions drastically improve over those 20 years,” Mallison said, “we still need to do some work out on the rivers and their banks.”

This year at the Natrona site, volunteers will paint guardrails, cut grass and pull weeds, Walters said. Volunteers with the Natrona Comes Together Association have already planted about a dozen wooden planters of flowers and shrubbery, she said.

Dennis Hawley, president of the Crooked Creek Watershed Association, said he’s found everything from car fenders to couches in his 10 years taking part in river sweep. His area covers Crooked Creek, a tributary of the Allegheny River, which is, in turn, a tributary of the Ohio River.

John Linkes, director of the Kiskiminetas Watershed and Roaring Run Watershed, said he began volunteering in 1999, after realizing how illegal dumping contaminated local waterways and well water. In his time volunteering, he’s seen tires and refrigerators dumped near local waterways.

But, he said, he has a sense of well-being after having contributed to cleaning up the environment.

“For that one shiny, bright moment, those four hours, we leave that area a little bit cleaner,” Linkes said. “And the sun seems to be shining a little bit more.”

Volunteers for the Ohio River Sweep on Saturday should wear old, comfortable clothes and shoes or boots that can get dirty, according to River Sweep’s website. Close-toed shoes are recommended. Trash bags and gloves will be provided.

No pre-registration is required, but volunteers must sign a waiver of liability to participate, and anyone younger than 18 must have parental permission to take part.

Refreshments and a T-shirt will be provided.

Here’s a list of River Sweeps in the Alle-Kiski Valley on Saturday. Refreshments and a T-shirt will be provided.

• Natrona section of Harrison: Meet at the pavilion on Veterans Way

9 a.m. to 2 p.m.

• Bethel Township: Crooked Creek site at Rosston Boat Launch, off of

Ross Avenue

8 a.m. to noon

• Parks Township: Garvers Ferry Road

8 a.m. to noon

• Braeburn section of Lower Burrell: Chartiers Run, Braeburn Road