Weeks before the deadline for landlords and property owners to test rental units for radon, hundreds were calling the state office in charge of the program every day asking about how to test.

It’s two weeks past the deadline, and the calls are still coming in.

“We’re getting thousands and thousands and thousands of people trying to comply with the law at the same time,” said Bob Stilwell, head of the radon program for the state.

Lawmakers in 2011 pushed the deadline for testing the air, and the water if from private wells, in all residential rental buildings for radon from 2012 to March 1 of this year. The law, originally passed in 2009, was changed further last year to ease mitigation requirements for high levels of radon — a colorless, odorless gas that is the second-leading cause of lung cancer, after smoking.

There is no statewide database of residential rental properties, so it’s impossible to know how many landlords are not in compliance. Before the law was amended last year, only around 10 percent of the estimated number of rental units in the state had been tested for radon, Stilwell said.

However, based on the number of calls the department is receiving, it appears most landlords are trying to follow the law, Stilwell said. The radon section, which has only two full-time staffers, was getting hundreds of calls a day in February and the start of March, he said — more than the phone lines could handle.

Stilwell said calls with questions about the law have declined slightly in the last week or two. Around 1:30 p.m. last Wednesday, he said he had only had to return 50 calls so far that day.

“Most people seem to want to be complying with the law, and they’re doing what they can to get the testing done when possible,” Stilwell said.

Landlords are required to submit tests to the radiation control program in the Division of Environmental Health, part of the Department of Health and Human Services. But because of the sudden rush of landlords testing and limited staffing, Stilwell said it’s impossible to keep up with recording all the test results, many of which come in paper form. Without more staff, he said, they may be able to record around a quarter of the test results by this time next year.

“The people we’re not hearing from are the landlords that aren’t going to do anything about it,” Stilwell said. “We’ve heard from some tenants saying the landlords have told that they’re not going to do the radon testing.”

Landlords or their representatives are required to notify current tenants within 30 days of receiving the test results and new tenants before signing a lease. If high levels of radon are found, the landlord or tenant can terminate the lease with a minimum of 30 days of notice if the landlord can’t or won’t mitigate the problem.

Landlords can be fined $250 per violation of the law, although it’s not yet clear who will enforce the penalties. Falsifying the results or not notifying the tenants, which also could include not doing the test at all, Stilwell said, is a breach of the implied warranty of fitness for human habitation, according to the law.

It’s the responsibility of the department to enforce the penalties, said Linda Conti, an assistant attorney general in the consumer division of the Maine Office of the Attorney General.

The attorney general’s office probably would not get involved in a case unless, possibly, it was a landlord with a large number of tenants violating the law, she said.

Conti said she hasn’t received any complaints from tenants about the law, but she advised renters whose landlords are refusing to test to do the test themselves and deduct the cost from the rent.

A request for comment about enforcement from the spokesman of the department wasn’t returned.

Breaching the warranty of habitability allows tenants to file civil suits against landlords or property owners, but Pine Tree Legal Assistance, a free legal service for people with low incomes, advises consulting a lawyer before taking that step.

According to a guide from the legal assistance service, a judge in a warranty of habitability suit can order that a landlord fix the apartment, lower the rent until repairs are made or pay back some of the rent that has been paid.

The executive director of Pine Tree Legal Assistance, Nan Heald, said the organization hasn’t heard yet from any tenants seeking assistance in regard to the testing law.

Lindsey Burrill, president of the Central Maine Apartment Owners Association, in Waterville, said landlords she’s spoken with are trying to comply with the law. She said landlords have been able to work with Stilwell and the department to get extensions to finish the tests.

“As long as you’ve solicited a tester, you’ll be fine. If you’ve made a good-faith attempt, there shouldn’t be any issues,” Burrill said.

She said a reason landlords waited so long is the department didn’t issue testing protocols until the last minute, but Stilwell said that’s not the case. He said the different protocols for radon testing have been in place since at least 2010, and he informed lawmakers and stakeholders about the protocols during the various amendment processes.

Radon is produced by the breakdown of uranium in soil, rocks and water, and can rise into homes through cracks and holes in the foundation.

Testing of buildings of fewer than 10 units that don’t have an elevator shaft, forced hot-air heat or a central air-conditioning system can be done by landlords or their representatives using kits that cost as little as $30. For all other buildings, landlord must contract with a testing company certified by the state.

How much testing companies charge depends on the number of buildings and the characteristics of the buildings. A single-family home could cost around $150 to test, Stilwell said. Landlords or property management companies with a large number of buildings could pay thousands of dollars for companies to conduct the tests.

Landlords or tenants with questions about the law should contact the state’s radiation control program at 287-5676.

Paul Koenig — 621-5663[email protected]Twitter: @paul_koenig