Three-year-old Sarah Pusey recently learned a new word.
"Stinky," she says, pointing her finger out the window of the house on Eastview Road southwest of Rock Hill where she attends day care.
When the smell hits, the children and their caregiver, Melanie Cook, run inside. Cook puts a red, construction paper frowny face on the door and locks it.
"For the past month we haven't taken a single walk in the wagon," said Cook, who along with several neighbors is trying to put an end to the odor.
The smell wafts across Cook's property from nearby farmland where the city of Rock Hill spreads biosolids, more commonly known as "sludge," from the city's Manchester Creek wastewater treatment facility.
Sludge is a solid byproduct of the wastewater treatment process. Residential and industrial waste comes into the plant. It is tested and treated, the liquid is squeezed out, and the remaining solids are pressed into sludge "cakes."
The cakes are then piled on a concrete slab underneath an open air awning until a company comes to pick them up.
Regulated in South Carolina by S.C. Department of Health and Environmental Control - which takes its guidelines from the U.S. Environmental Protection Agency - the sludge is disposed of in one of two ways: the city sends it to a landfill for about $70 per ton, or pays a company to spray it on farms for about $50 a ton.
Citing the EPA, DHEC and city officials say applying sludge to the land is more environmentally friendly than sending it to a landfill. It provides many essential nutrients for crops and replenishes depleted topsoil, they say.
It's a "green" practice, Assistant City Manager Jimmy Bagley said.
The city contracts with Synagro, a company that manages its sludge removal and land application programs. Synagro records where, how much, and when the sludge is applied.
Sludge samples are tested for a host of materials, including chemicals and metals, to make sure it meets toxicity standards.
Before DHEC grants a permit to apply sludge, each field must be checked for slope, soil quality and other characteristics, department officials said. There are also limits on how close to other properties the sludge can be applied and how much can be applied.
Some Rock Hill residents who have caught whiffs of the sludge aren't sold on the science or the regulatory process, and some want it stopped.
When Cook called the local DHEC office to complain about the odor, she said someone in the office told her it had an "earthy smell" that would eventually go away.
"It's not an earthy smell, not on any earth I've lived in," she said. "It can be fine for one minute and five minutes later you're gagging."
DHEC has received four complaints about the odor near Eastview Road, said Joe Faris, regional program manager for the department's regional environment quality control office in Lancaster.
These types of complaints are common, but odor is a reasonable concern, he said. DHEC can prevent the spread of sludge if the odor is a nuisance.
The city has an odor control plan in place, he said. If it is inadequate, "that would be something we would look at," he said.
Faris said DHEC would have more "conversations" with the city about its odor control plan.
In the future , the city wants to purchase an aerobic digester to help treat the sludge. Like a giant metal stomach, the digester will help break down the sludge, which will help reduce odor, said David Hancock, operations superintendent at the Manchester plant.
Neighbors want a fix now.
"It creates a quality of life issue for us," said Pete Treible, a resident of Holland Springs, a neighborhood that abuts farmland where sludge is being spread. Homes in Holland Springs are on large lots and are valued at more than $300,000.
Jerry Conway called it "a profound example between what is legal and what is right."
"It's not OK for these folks to have a privilege that infringes on my rights," he said.
Those rights include being able to spend time in their yards or cooking out, the neighbors said.
Many were upset they would not be able to cook out for Mother's Day or the Memorial Day weekend. Treible worries that no one will buy houses if "Holland Springs gets stamped with Holland Stinks."
In addition to the smell, residents are concerned about what's in sludge and whether it's safe. Holland Springs homes have wells and septic tanks. Residents see the sludge as a potential threat to their water source. Some plan to get their wells tested.
They're also worried that animals will track the sludge off the fields before it's safe.
Most of the sludge coming from Rock Hill's plant is treated at a "basic" level, which means after it is applied to the land, access must be restricted for about a month, according to DHEC.
Sludge treated at a higher level doesn't need to be managed in that way.
"If it's such great stuff," asked Cindy Hopkins, "then why aren't they using it in Cherry Park and Glencairn Gardens?"
Heightening their suspicion, the neighbors have been researching lawsuits alleging that land was ruined by sludge. They found some jurisdictions taking steps to ban it.
They are contacting local and state leaders to see what can be done to stop the spread of sludge, which "smells like there are 20,000 rotting buffalo carcasses in the yard next door," said Suzy Redd while addressing the York County Council this month.
Some farmers want the sludge, which the city provides for free.
"Fertilizer got so expensive," said Rebecca Borders, whose son now manages her farm off Eastview Road.
She said the smell hasn't bothered her. Synagro has spread sludge on her farm four times in December and twice in January. May's records are not available.
"You had to be outside to smell it," she said. "It's not as bad as cleaning out the barn."
When asked whether complaints would make her reconsider allowing sludge on her farm, she said it depends on fertilizer costs. She said people shouldn't complain "if they want good beef."
She and her husband have had the farm for 63 years. They started with cotton. Now cows graze the land, she said. She remembers when it was "all farmland," she said with a smile. "Now the town tries to come to the farm and take over."
Rock Hill sludge
The city has permission to spread sludge on more than 5,000 acres in York, Chester, Lancaster, and Fairfield counties, but mostly uses farms in Chester and York counties.
Application dates and locations vary from month to month. The amount of each application is usually in the hundreds of wet tons. Each month the amount of land-applied sludge ranges between 1,000 and 1,500 wet tons, according to data from the last 14 months.
In March 2010, Synagro applied more than 2,000 wet tons of sludge to farmland in Chester County alone.
Over the last 14 months, the sludge Synagro sent to landfills in North and South Carolina combined was about 3,000 wet tons.
Last year the city produced about 16,000 tons of sludge from May 2010 to April 2011, and about 19,000 tons the year before, Hancock said.
SOURCE: Synagro and the City of Rock Hill's 2010 annual report to the state's DHEC on its residuals land application program and Synagro's monthly monitoring reports for land application.