TEWKSBURY - They know pigs smell. They know farms smell.

But Tewksbury, Andover and Wilmington residents say the smell coming from Krochmal Farm just isn't normal.

"This isn't a neighborhood issue," said Phaedra D'Ambrosio, who moved to Sunset Circle in Tewksbury, about a half-mile from the farm, four years ago. "This is a three-town-wide problem. We cannot enjoy our property."

The stench from the farm, which is near Interstate 93 between exits 41 and 42, has wafted across the town line to Andover. Andover Public Health Officer Thomas Carbone started getting complaints about it a few weeks ago. So did Wilmington Public Health Officer Gregory Erickson.

Residents said the smell this past summer was the worst yet from the family-owned farm. The stench stirred up Dave Powers, a South Street resident who lives about a half-mile from the farm, enough that he started a movement to stop it.

"A (dirty) diaper is a rose compared to what this smell is," the father of two babies said.

He started a Web site, Tewksburyodor.org, this summer. Within a week, dozens of people had found his site. They asked how they, too, could help get the stink out.

One of those people was Bryan Delonais. He's lived on Jennie's Way in Tewksbury, the same street as the farm, since 2003. Shannon O'Brien was another. For more than 20 years she has visited her grandparents, who live about a quarter-mile from the farm's entrance.

"I never remember it smelling like this," the 25-year-old said.

Despite the stench, these residents don't want the piggery to go away, just the smell.

The problem is the farm isn't doing anything illegal, according to the state Department of Agricultural Resources.

In response to complaints the department has received, an inspector has been out to the farm several times in the past few weeks. He has found that the farm is following "generally acceptable agricultural practices," according to Lisa Capone, spokeswoman for the department.

"It's all following within the realm of what would normally be expected in a pig farm," Capone said. "The farmer has a manure storage system being used. There's nothing there that looks out of the ordinary for how a farm should be run."

There are state regulations for the storage of manure and disposal of waste, but most other regulations of pig farms are left up to towns.

Capone said the exact number of pigs on the farm couldn't be released for bioterrorism security reasons.

Tewksbury's health officer was out of town and couldn't be reached for comment.

The owners of the farm declined to comment when a reporter visited last week, saying their attorney advised them not to.

But they sent a written statement: "Here at Krochmal Farms we are proud long standing members of the farming and agricultural community and have been for well over sixty years. Krochmal Farms is currently in compliance and operating pursuant to the applicable laws and regulations of the Federal, State and Local governing bodies."

Making matters more difficult is a state law that prohibits a small farm from being cited as a nuisance for odors, said Carbone, Andover's public health officer.

But that doesn't change the fact that the smell is really ruining their quality of life, residents say. They just want the farm to be a good neighbor.

Powers said they started a smell tracker on the Web site. From Aug. 23 to Oct. 10, there have been 89 different households tracking the smell, ranking it from unbearable to mild. There were 56 different streets in the Lowell Junction area affected by the odor, from Gillette Way to Burtt Road and Ballardvale Street in Wilmington.

"Out of 48 days, we only had six that were odor free," D'Ambrosio said.

The Board of Health in Tewksbury is looking into the problem and will have an answer by Nov. 9, neighbors have been told. And they're hopeful that the outcome will be positive.

"We fully expect once in a while it will smell like a farm," Powers said. "There are pig farms that have happy neighbors. There are farms around that don't smell like this."