Police seized 542 labs for the year as of September, the most recent numbers available — an increase of more than 21 percent compared to the same period in 2007.

At the seizure rate of 60 labs per month, Tennessee would exceed the 2007 total of 587 labs by November, according to Tommy Farmer, director of the Tennessee Methamphetamine Task Force.

Farmer said the manufacturing of meth has changed as drug makers have had to find alternative ways of producing the substance because of increased legislative and police controls.

In 2005, many laws took effect limiting the purchase of pseudoephedrine, an ingredient in cold remedies and a primary component of meth.

Meth production then shifted to Mexico, and the drug was shipped north through marijuana and cocaine networks, Farmer said. Other changes in laws and stricter enforcement on the U.S. border cut off most foreign meth and pseudoephedrine supply.

'Smurfers' go shopping

Now, local manufacturers are making meth often by using "smurfers," meth users who shop in groups at multiple pharmacies, often across state lines, buying enough pseudoephedrine to make the meth they use. New techniques also mean less elaborate devices, and smaller labs mean more labs, Farmer said.

Most arrests still come from pseudoephedrine sales, said Mike Hall, director of the Tennessee 10th Judicial District Drug Task Force.

The group talks to local pharmacists and checks a statewide database that tracks pseudoephedrine sales. Police spot names of frequent or quantity buyers. Purchase of just 9 grams of the product in an allotted time is enough to charge someone with intent to manufacture meth.