“It’s very dirty here, all the apartments have rats,” says Catalina Espinosa, 34, who opens her door on the fifth floor carrying an infant son with one arm while a daughter peeks out from behind her.

Three stories below, Tino Torres, 40, has lived with rodents for all his five years in this building at 1985 Amsterdam in Washington Heights. “The rats crawl from the kitchen into my bedroom,” he says.

For many uptown immigrants, coming to America hasn’t meant an upgrade in housing. “In the last five years, it’s one of the worst buildings I have seen,” Luis Manuel Tejada, executive director of the community nonprofit Mirabal Sisters, says about 1985 Amsterdam.

Eighty percent of its residents are illegal immigrants, says Tejada, and the landlord has threatened to report them to immigration authorities if they complain about conditions there. In practice, illegal immigrants can’t be deported if they don’t break the law, but since few are aware of their rights, this kind of harassment has become common.

“Being undocumented is like living in the dark,” says Tejada. “They don’t want to be exposed.”

The residents of 1985 Amsterdam are among the few uptown resident who have mounted a campaign to improve their living conditions. For a year, they’ve worked with the Mirabal Sisters to force the landlord, Moshe Samouha, to maintain the building. Tenants tell stories of uncollected trash, cracked floors, exposed electrical wires in apartments and defective heaters. Samouha ranks 37th on NYC’s Worst Landlords Watchlist, compiled by Public Advocate Bill de Blasio, with 226 reported infractions in this one building.

All conversation in 1985 Amsterdam takes place in Spanish, and Mexican banda music seeps through the doorways and makes the otherwise decaying building feel alive. But there may be too much life in the hallways. In the stairwell a rancid whiff of urine is evidence of unwelcome intruders and on the sixth floor Nantes Rosario, 36, mother of three, has installed a surveillance camera outside her door.

“A lot of dirty people come into the building,” she says, nodding towards to the staircase. “They often sleep up there.” She keeps her own staircase swept, a spotless patch amidst the grime. “A super should at least clean, but ours doesn’t,” she laments. “We have families with children living here.”

“There is prostitution inside the building,” Tejada says. “People are smoking marijuana and crack under the stairs.”

In August Samouha allegedly assaulted Maria Montealegre who was organizing the tenants, and then evicted her and her four children. When taken to court, Samouha harassed tenants to prevent them from testifying, says Tejada of Mirabal Sisters, adding that around 20 families have since moved out, and that the campaign against the landlord has faltered. Mirabal Sisters doesn’t represent individual tenants, says Tejada, so if they don’t organize, “I don’t think they can do anything.”

Montealegre says she had been complaining that her boilers didn’t work. “I told the landlord, and he said, ‘You are Mexican. In Mexico they don’t even have these things,’” says Montealegre, visibly emotional.

She was gathering tenants for a meeting at her apartment, she says, when Samouha burst in, stumbling against her then 13-year-old daughter in the hallway. “He tried to hit her, but I got in the way, so he hit me instead,” Montealegre recounts in Spanish, touching her chin where she says the landlord struck her. The punch caused an infection, and she eventually had to have a tooth pulled, she says.

The landlord was detained but released shortly after. “There was no charge against him. The police didn’t do their job,” Tejada says.

Tenants say Samouha collects rent in cash and uses pressure, including fiddling with boilers and threatening to report tenants to the Immigration and Customs Enforcement (ICE), if they refuse. He issues unofficial receipts, if any, the reason Montealegre says he could evict her on allegations of not paying rent. Mirabal Sisters and several of the remaining tenants at 1985 Amsterdam back up her account.

The landlord, however, denies that version of events. “She’s a crazy woman,” says Samouha, who rarely speaks to the press but agreed to a phone call with The Uptowner. During the year Montealegre and her children lived in the apartment, Samouha claims, they broke the sink, the windows, the boiler and scratched the floor, amounting to more than 160 violations. She owed him $13,000 in rent, and when he came to change her boiler, he says, she attacked him, not the other way around.

“It’s a lie, it’s a lie,” he says, agitated about the assault allegations. “My people were in the apartment putting on the water heater for her. She attacked me, and I ran out of the apartment. I called the police. She cried to the police, and then they took me to the station,” he says, admitting that he was led away in handcuffs, as photos of the arrest confirm. But the police released him because they didn’t have a case, he says.

“I could sue the police department, I could sue her, but I’m not going to waste my time and energy and aggravate myself for a [expletive] like that,” he half-shouts in English on the phone. “She was a devil to me.”

Samouha denies accepting payment in cash in order to be able to evict tenants without receipts. He tells tenants to pay by money order, he says, but they refuse because they don’t want to pay the fee.

“I have owned the building for 27 – 28 years, I know what I’m doing,” he says, volunteering that he owns other buildings where tenants will swear to a good relationship with him, but refusing to say where those building are.

Samouha says he wants to change the population in 1985 Amsterdam, upgrading them with “couples and students.” Currently, “Most of them are Mexican, and they live 10 to 12 people in each apartment. They ruin the apartments,” he says.

For three months, Montealegre and her children, aged 19, 14, 13 and 10, have lived in a shelter in the Bronx, which for safety she’s asked to keep unidentified. While the landlord collects her welfare check, which the city still sends to her old apartment, she says the eviction and accusations have made it difficult to find a new home. “I now have a bad history on record, so I can’t get a new apartment.”

Other Washington Heights residents have been more successful in taking on their landlords, albeit one step at time. At 545 W. 146th Street, Maria Moina offers a quick handshake while two workers are repairing her bathroom. The landlord sent the workers after she took her complaints to the Department of Housing Preservation and Development.

“I have been without a toilet and water for five days,” she says in Spanish, her voice cracking. During that time she has used lavatories in neighborhood restaurants.

This property ranks No. 17 on De Blasio’s landlord watchlist, with 287 infractions. Leading the way through the apartment, Moina, 48, points to deep cracks in a floor she says was laid a few months ago, to moldy wooden panels in the bedroom, and to a radiator that works but remains unused because it leaks too much water through the floor into her downstairs neighbor’s apartment. At some point she’ll need to turn it on anyway.

“I don’t know where all the cold in the winter comes from, but it gets cold,” she says.

A native of Ecuador, she has stacked her bedroom with boxes and plastic containers of beads and stones for the South American handicraft she sells on the streets. She has challenged her landlord with help of P.A.’L.A.N.T.E., People Against Landlord Abuse and Tenant Exploitation, a Harlem nonprofit whose acronym in Caribbean slang means “moving forward”.

“We’re trying to build a tenants’ association, but some of the folks there are scared,” says president and founder Elsia Vasquez. The key to better living conditions for undocumented immigrants, she says, is to teach them their rights.

“Landlords think they’re above the law,” she says. “But undocumented immigrants are not as vulnerable as many think.”

Challenging the landlord has been a lonely task for Moina, who lives with five others, including her 7-year-old daughter, in a crammed three-bedroom apartment. Her neighbors, whose apartments are deteriorating as fast as hers, are unwilling to organize.

“People don’t complain because they’re afraid of being deported,” says Maria Palacios, a neighbor on her way to her daughter’s house, pestle and mortar in hand, to prepare a Mexican chili.

“We have many problems with our apartments. There’s no hot water, my bathroom ceiling is falling down, and the roof leaks water,” says Palacio. “The rent is too high for me.”

Some landlords jack up the rent beyond what’s legal, says Vasquez. In 545 W. 146th Street, a rent-stabilized building, the proprietor is allowed to raise the rent 15 percent annually without making improvements, Vasquez says, but in the past year, rents rose an average 70 percent, until P.A.’L.A.N.T.E. stepped in. In a few weeks, she says, the tenants will receive a rent reduction.

“If you stand up to the landlords, knowing your rights, they stop their intimidation tactics,” she says.

The Department of Housing Development and Preservation did not respond to multiple calls and emails for comment on the landlords’ multiple violations.