Neighbours say they're sickened by the stink from Waterdown Garden Supplies' industrial-scale outdoor compost operation in rural Troy.

"It's a really, really bad smell. You come out in the morning and it makes you puke," says Gary Wallace, who houses nearly 200 racehorses at the Emerald Isle Standardbred Training Facility next to the compost operation on Highway 5.

Pat Pearson, who lives a little further away, said she had visitors last Sunday who left early because of the odour.

"My company was gagging as they left. They couldn't take it anymore."

Odour has been an issue since the site west of Peters Corners opened in 1996, but people living nearby say it's become worse in the past year. The Ministry of the Environment reports 33 complaints so far this year, 12 of them from July 1-17.

John Rocchi, an environmental consultant representing the company, says the owners reduced waste stockpiles on the property and are "trying desperately to identify the irritant odour and deal with it."

On a site tour, he said: "We are not denying we have an odour, but we are having real trouble picking up the source. We believe we are making a reasonable effort to make a difference. The long-term solution will probably be to do something indoors."

Hundreds of gulls, maybe thousands, cover long, 1 1/2-storey tall rows of slowly composting organic waste that Rocchi said comes from brand-name vegetable processors, pet food plants, even Tim Hortons. Large quantities also come partly processed from indoor plants that compost green-cart waste for the City of Toronto and Peel Region.

Rocchi said fresh, incoming material is quickly mixed with older compost and horse manure, then covered with dry material and allowed to sit for up to two years before being screened and sold.

Ministry spokesperson Jennifer Hall said the site "has been identified by the (Hamilton) district office as a high priority, subject to frequent inspections."

The company pleaded guilty last April to 10 violations of the Environmental Protection and Ontario Water Resources acts in a five-month period in 2006-07 and was fined $50,000, plus a $12,500 victim surcharge. It was given a year to pay.

It is also under order to conduct an odour assessment and produce an abatement plan. Rocchi said air sampling was carried out July 2-3.

Previous owners had a permit for up to 69,000 tonnes of material on-site, but the ministry found the limit had been exceeded and lowered it to 40,000 tonnes in 2005.

Company president Bill van Ravenswaay applied last December to restore the old limit, but the ministry refused, saying the odour issue must be resolved first.

The company is appealing, and Rocchi said he looks forward to presenting his case to the Environmental Review Tribunal. He said more income from tipping fees is needed to finance improvements.

emcguinness@thespec.com

905-526-4650