Things are getting crappier at a controversial migrant shelter in Staten Island.

The shuttered school in Arrochar that was transformed into a shelter is a 67-year-old structure that was never intended to be an around-the-clock residence, and bathroom, for up to 300 adults.

Its ejector pumps are incapable of moving so much raw sewage into the city’s sewers, so a septic-treatment company must come several times a day to pump the raw sewage that collects in a concrete pit and truck it away.

During the half-hour pumping operations, the odor of poop wafts through the neighborhood.

“It absolutely smells,” said Scott Herkert, who lives adjacent to the shelter on Landis Avenue. “It’s disgusting and nobody should be subject to that.”

Months before the building’s repurposing, the city had deemed the location “not viable” for a shelter, said Staten Island Borough President Vito Fossella.

“These residents now have to endure this on top of everything else,” he told The Post.

St. John Villa Academy closed in 2018 and was bought by the city soon after, with plans to create a 1,000-plus seat public school.

“There were going to be significant capital investments required to make it ready to become a school again,” said Councilman David Carr.

The stench is the latest in a long list of disturbances Herkert and his neighbors have had to deal with since the migrants moved in.

On the first day back to school on Thursday, his sons were woken up at 5 a.m. by inexplicable drilling at the shelter that shook his home.

A 24-hour generator, outdoor showers and a dumpster full of trash attracting rats were listed in the August lawsuit Herkert and Republican lawmakers filed to block the shelter.

A judge originally granted a temporary restraining order in their favor but the decision was later overturned.

This week, Mayor Eric Adams said the migrant crisis will “destroy” New York City.

“If he doesn’t know what to do, we’re in serious trouble,” said Herkert.