The owners of a Ukiah-area medical marijuana dispensary are scrambling to find a new home after their landlord received a letter from the U.S. Attorney's Office demanding they evict the business or risk losing the property.

The letter is part of a national wave of cease-and-desist notices sent by federal authorities to marijuana dispensaries and their landlords in California, Washington and Colorado. Marijuana remains an illegal drug under federal law.

"I'm afraid I have no choice," said property owner Ed Busch, 86, of Ukiah.

Busch has rented a 5,000-square-foot building to the Compassionate Heart dispensary for the past four years. After he received a certified letter Monday and consulted his attorney, Busch said reluctantly handed his tenant a notice of eviction. He is sending a copy of the eviction notice to U.S. Attorney Melinda Haag of California's northern district.

"I'm very sorry to do it because they're running a very legitimate business as far as the state of California is concerned," Busch said. "It's difficult for me to understand why we're living under two sets of laws."

<NO1><NO>The tenant declined to comment, saying he feared losing his bank account if he was identified.

<NO1><NO>A spokesman for Haag's office said he could not publicly discuss the letters.

A similar letter Haag sent to a San Jose dispensary warns a landlord that it is illegal to knowingly rent space for the purposes of "manufacturing, storing, distributing or using a controlled substance."

Many of the notices, like the letter sent to Ukiah, state that because the property is within 1,000 feet of a school, playground or day care center, which could bring stiffer penalties into play.

The Ukiah dispensary is around a rural block in unincorporated Ukiah from the Pinoleville Pomo Nation Head Start, which serves children from ages 3 to 5.

"Where is it? I'm not even aware that there is one," Jennifer McGowen, Head Start program director, said of the dispensary.

The day care program has been open since 2006 on the reservation.

Although she hadn't known the dispensary existed, McGowan said she didn't have concerns with its presence. The two locations are separated by trees and a hill, and the roads to the two sites don't connect.

"You can't see it from here," McGowan said.

Mendocino County Sheriff Tom Allman said he wasn't aware of law enforcement problems at the dispensary.

Ukiah Police Chief Chris Dewey also said he was unaware of any problems at the dispensary, which is just outside city limits. Still, said he is opposed to having medical marijuana dispensaries in or around the city.

"Anywhere we make it easy to obtain marijuana concerns me," Dewey said. "We've had such a problem with marijuana on our high school campus, we had to actually assign a drug dog fulltime."

The letter was among at least a half-dozen sent by Haag to dispensaries in San Jose and San Francisco.

Also this week, the U.S Drug Enforcement Administration sent cease-and-desist letters to about a dozen marijuana dispensaries in the Seattle area, although marijuana is legal in the state.

The agency sent similar letters to Colorado dispensaries, often noting the proximity to a school or other place serving children.

In California, federal prosecutors have have been shutting down dispensaries for two years by warning landlords they might lose their property if they're found to be in violation of federal law.

"They scare the landlord into kicking people out. It worked before and it will work again," said Oakland attorney Bill Panzer, who co-authored Proposition 215, the 1996 initiative that legalized medical marijuana in the state.

In 2011, Haag and the three other top federal prosecutors in the state announced a crackdown on marijuana dispensaries. During several speeches and interviews at the time, Haag explained that she would initially focus on dispensaries that sell marijuana close to schools, parks and other places where children learn and play.

Medical marijuana advocates have said it's unclear just how many letters have gone out since 2011 and how many dispensaries have closed as a result.

"It's got to be hundreds," said Sebastopol attorney Omar Figueroa, who co-wrote the Repeal Cannabis Prohibition Act of 2012.

And it appears to be a highly effective strategy, both Panzer and Figueroa said.

"It's a way to make it economically difficult for these nonprofit dispensaries to stay afloat by forcing them to try to relocate," Figueroa said.