The Bronx landlord forcing tenants to share a single bathroom during renovations is doing the same thing at another property he is rehabbing — and those residents are so desperate that they’re tossing their waste out the windows.

Nearly a dozen units at 3115 Sedgwick Ave. are being upgraded at a time, and building’s owner Scott Morgan is making the affected occupants use one loo, they say.

That’s even worse than the conditions at his other property on East 196th Street, where — as The Post revealed Wednesday — Morgan admitted he shut off water to six units at a clip and made them share a communal bathroom.

Residents at the Sedgwick Avenue building have been spied defecating in plastic bags, either out of frustration or because the line is too long.

Sonia Perez, 48, feels like she’s living at “a gas station.”

“You go in there, and there is urine all over the floor, water, everyone is just doing their necessity in the same bathroom,” Perez said. “It was disgusting, extremely disgusting. People were becoming angry and desperate.” She said she spied at least one tenant from above throwing what appeared to be human waste in small bags “out of the window.”

Meanwhile, inspectors descended on the East 196th Street property Wednesday morning.

Plumbers were scrambling to speed through repair work, installing toilets and restoring water in “every unit under renovation,” said William Santiago of GSB Plumbing.

“I am so happy because they’re repairing my bathroom and toilet,” said resident Josephina Then, who had to use the communal bathroom for three weeks.

Another tenant, who is pregnant, said she’s at wit’s end. “I just want to have my apartment ready so I can bring my child here,” said Ingrid Acosda, 29, who is due next month but spent the last three weeks without water. “I tell my husband everyday I feel depressed. It’s really bad.”

Inspectors from the Department of Buildings, the Fire Department and the Department of Housing Preservation and Development were spotted at the 50-unit building.

One Buildings Department worker identified himself as part of a de Blasio administration task force on “tenant harassment.”

The bathroom nightmare inside the East 196th Street building began late this summer when the landlord cut the water flow to apartments so he could renovate bathrooms and kitchens. He asked tenants to share a single toilet and shower in vacant unit 4G, and now several families a day have to wait on line for up to 30 minutes to use the bathroom.

Morgan insisted to The Post he’s only cutting off water to six apartments at a time for between two and three weeks, but tenants claimed up to 14 units are currently without water.

The Fire Department on Wednesday issued Morgan a summons for “failing to provide/maintain required flame-resistant materials in the kitchens and bathrooms in every apartment” as well as for storing too many combustible materials in the basement. Morgan has to answer the summons by Dec. 14.

Additional reporting by Elizabeth Rosner