Anne-Marie Cory and her partner spent the better part of a year looking for a dream home in Longmont, Colo., that fit their budget.
They had the property under contract when they discovered that a former occupant had been a methamphetamine smoker. Tests came back positive for the drug.
"We didn't want to bring a baby into a house contaminated with meth," said Cory, who was pregnant at the time.
Erik Nelson, then a real estate agent who had bought the home to fix up and sell, spent about $26,000 on meth testing, cleanup and then retesting to ensure it was safe for Cory to move in.
Other buyers have discovered such contamination too late, losing thousands of dollars and winding up with homes that had to be stripped to the studs.
"It is certainly a problem, how big it is is hard to quantify," said Colleen Brisnehan, an environmental protection specialist with the Colorado Department of Public Health and Environment.
No one knows how many homes in the United States are contaminated by meth, and there is no national requirement to test for it.
But state and industry officials say, as more testing is done, they are discovering more meth-contaminated properties, particularly among foreclosed or rental homes that are coming back on the market amid a housing recovery.
Not all of these homes are meth labs where the drug was cooked. Homes can be left toxic if someone has simply smoked methamphetamine a few times. The drug can leave behind toxins that cause respiratory and other illnesses.
"It is definitely buyer beware," said Timothy Gablehouse, a lawyer who handles environmental contamination cases. He recommends testing if there is anything about the home's history that raises alarms.
About half of the properties tested by Weecycle Environmental Consulting are positive for meth, said Judy Sawitsky, an industrial hygienist and president of the Boulder, Colo., firm. Weecycle tests for meth, asbestos and other contamination.
About one-third of properties that test positive have levels of contamination high enough to require some cleanup under state standards, she added.
The problem is greatest among rental properties, particularly those in the low- to average-cost ranges, said Jim Dennison, president of Century Environmental Hygiene in Fort Collins.
"Meth can be detected in homes after a small number of uses, and the residues persist in homes for many years, meaning that if anyone ever smoked meth there in the past, it may show up in a test. So, while most people do not use meth, many houses are still affected," Dennison said.
Foreclosures also test positive more often than homes occupied by the same owner for years, Dennison said.
Colorado's Neighborhood Stabilization Program operated in areas with high foreclosure rates, purchasing, renovating and selling 167 single-family homes and 139 multifamily rental units, according to Patrick Coyle, director of the Colorado Division of Housing.
Of those, 7 percent of the single-family properties were contaminated, and 11 percent of the multifamily units were, Coyle said.
Norris Minick, a buyer's agent, said his company, Agents for Homebuyers, tests all homes it handles, splitting the cost of screening with potential buyers.
But throughout the industry, Minick said, testing is infrequent.
Most agents believe contamination is rare, and few are willing to consider it might be common.
"It is such a frightful thing it is almost impossible to face," Minick said.
Most buyers are unaware of the potential for disaster in buying a contaminated home.
"I talk to all my friends who are buying houses, everybody says, 'You'll know, there will be some sign.' But you know what? You won't. This house was so clean," Cory said of her home.
Colorado requires sellers to disclose if a home has been contaminated by the drug, unless it has been cleaned up. But owners don't always know if meth, which can linger on surfaces, in carpets, drywall and duct work for years, has been used in the home.
There are often noticeable signs — people coming and going at all hours, strange smells, large amounts of trash — when a house or apartment is used to manufacture the drug. But it is harder to detect a user who smokes in private, Brisnehan said.
Law enforcement agencies report labs to county health departments when they find them, she said. "They say they find about 10 percent of the labs out there."
But there is no notification to health officials that would identify the homes of those busted for smoking meth.
"Most people don't let their neighbors know that they are meth users," Brisnehan said. "Often they are renters, sometimes a grandparent owns the home and the grandchild is the user."
Colorado law requires remediation for homes where testing finds more than .05 micrograms of meth in a space about 3.5 inches square.
The state labels any house where contamination is above state levels a meth lab. However, most homes that test above that level aren't labs at all, just places where the drug was smoked, Minick said.
Minick's agency splits the $375 cost of a basic screening that can detect the presence, but not the level of contamination in the home, with buyers, he said.
Sawitsky's firm charges $325 to screen for the drug's presence and from $1,400 to $2,200 to test for levels.
Once the house has been cleaned up, it must be tested again to be sure all traces are gone, said Lynda Fratis, office manager at Weecycle.
"If it has been freshly painted it has to be gutted, it can't be cleaned. You have encapsulated it in the paint, but it keeps seeping out," Fratis said.
Gablehouse said he hears from many people who find contamination in a home they bought and want to sue.
"Two-thirds of the time you can't make a case because it is clear that nobody had knowledge of the problem," he said.
Particularly in deals involving short sales and foreclosures, there can be a string of occupants in a home before meth is discovered.
"The real estate disclosure law is based on knowledge. When you do a lot of real estate flips there is enough distance between the person selling and the meth user," to make it impossible to place blame, Gablehouse said.
Most buyers find out they may have bought a contaminated home when they meet the neighbors, Gablehouse said.
"The classic scenario is the house is fixed up and on the market," he said. "They are in the process of moving in and a neighbor comes over with a fruit basket and says, 'Oh, by the way, did you know this is a meth house?' "