YAKIMA, Wash. -- Do you know who the Rag Stuffer of Yakima is? If so, the good folks who operate the Regional Wastewater Plant would love to hear from you.

"We've never figured it out, but we'd love to know who it is," says Mike Price, a supervisor at the facility, which treats 13 million gallons of sewage a day.

For years, someone has been using the city's sewer system instead of the garbage to get rid of an unusual type of heavy-duty paper towel. Thousands of them show up at the plant, situated behind Kmart alongside Interstate 82.

Most people don't routinely flush regular paper towels down the toilet. There's a reason for that. Paper towels are thicker than toilet paper and can cause nasty clogs.

Although not cloth, the material being stuffed into the sewage system is sturdier than regular paper towels and remains intact upon arrival at the wastewater plant.

It's likely that the culprit is a business or group rather than an individual.

The towels arrive in such large batches that they overwhelm automated machinery designed to filter out hard objects.

That's why Wastewater staff would like to solve the case. You would too if you had to manually rake out the filtering machinery.

"I avoid the place, and I work here," says Price, referring to the influent building where raw sewage is initially filtered.

The rags are far from the oddest objects that get flushed down the drain in Yakima. A garbage bin attached to the filtering system has to be switched out once or twice a week.

Huge iron grates filter out objects down to 5/8 of an inch thick. The grates are necessary because people drop hard objects down the drain all the time.

"Huh, there's a disposable razor. Never seen that before," Price remarked during a recent tour of the influent building. Other objects in the garbage bin were easily identifiable, including a tiny orange toy basketball and large pieces of a Top Ramen-style noodle cup.

But the rags are the most annoying objects, both because of their volume and their ability to bind up a compactor that diverts large objects to the garbage bin.

"If they get through our first line of defense, they really wreck havoc on pumps" and other machinery further up the line in the treatment process, Price said.

In fact, the Wastewater staff keeps a supply of wood chips on hand to help push the rags through the screw and into the garbage bin. It's like fiber for the sewer plant.

Despite a fair amount of detective work over the years, Wastewater staff has never been able to figure out who is doing it and what the rags are used for.

Although the rags are small enough to be flushed down a toilet, given the volume, it's more likely the work of someone who has access to some type of large drain opening.

An aggressive pretreatment program launched in 2000 has enjoyed success at catching businesses, particularly restaurants, that dump too much grease down the drain.

But the pretreatment staff hasn't gotten lucky enough to narrow down the origination of rags within the 320 miles of sewer line that feed the plant, which also serves Union Gap, Terrace Heights and Moxee.

"Nothing's ever panned out," Price said. "It's impossible to backtrack. I wish the Rag Stuffer would print the business name on the towels."

Anyone with information can call 509-575-6077.

* Chris Bristol can be reached at 509-577-7748 or at cbristol@yakimaherald.com