NORTH CONCORD -- Residents of a large mobile home park say they are experiencing sticker shock over a recent rent increase handed down by an administrative law judge -- a decision some City Council members say flies in the face of a new city rent control ordinance.

The residents of Dalis Gardens Mobile Home Park were ordered to pay an extra $57 in rent, plus a lump-sum payment of $471 to cover the period between a hearing date in February and the ruling by Judge James Trembath in October.

Residents took the issue to City Council, asserting the increases are hitting the pocketbooks of the many seniors or fixed-income residents who call the park home, including Theresa McCauley, who is disabled and cannot work.

"I had to take out a personal loan for this," McCauley said Thursday.

They are the first mobile home park residents in Concord to test the petition process under the city's mobile home rent control ordinance. The ordinance permits a hearing for residents of a mobile home park facing a special rent increase; at least 10 percent of a park's residents must petition for such a hearing.

The ordinance is designed to control rents at mobile home parks, and allows for automatic annual increases based on 80 percent of that year's inflation and for special rent increases, which was the case with Dalis Gardens Mobile Home Park. The mobile home park, with about 260 lots, sits near the interchange of Highways 4 and 242.

The retroactive payment of $471 angered many residents and frustrated city leaders, who said the judge's decision flew in the face of the city ordinance. The ordinance states that rent increases shall not take effect until the increase is allowed by the ruling. That provision would not allow the retroactive payment approved by Trembath in this case.

The ruling sparked the City Council to polish the ordinance in December and adopt the revisions in an unanimous vote this week to underscore the portion on retroactive pay.

"My heart goes out to you," Councilman Ron Leone said the December meeting. "I'm not a judge, but I think the judge erred."

Aimee Molsberry, president of Santiago Communities, which manages Dalis Gardens, did not return a call for comment on Thursday. Anthony Rodriguez, who represents Santiago Communities, also did not return a call for comment.

In a letter to the council in December, Rodriguez opposed the revisions to the ordinance and said approving them is "virtually certain to guarantee the return of the costly and contentious litigation that plagued the city before 2008."

He was referring to lawsuits against the city by his clients, Adobe and Diablo mobile home parks, which he said cost the city $1 million to defend. City Attorney Mark Coon said that figure was closer to $200,000.

Lawsuits appear likely again. Rodriguez has filed a petition against the city and Trembath that seeks to obtain the $63 special rent increase Santiago Communities initially sought and to make it retroactive to August 2011.

McCauley, a 25-year resident of Dalis Gardens, has threatened legal action as well to seek damages.

Resident Mark Feldberg said he moved there in October but nevertheless must be required to pay the retroactive lump sum from February. Coon said that is allowed under the law.

"The whole thing is creepy," Feldberg said Thursday. "It's certainly in bad taste even if it is legal."

David DeBolt covers Concord and Clayton. Contact him at 925-943-8048. Follow him at Twitter.com/daviddebolt.