The city has agreed to a $1.2 billion settlement to reform NYCHA buildings throughout the Big Apple and address chronic public housing problems.

Tenants have complained for years of inadequate services and unsafe living conditions, and prosecutors backed their claims in a federal lawsuit. An 80-page federal complaint released Monday outlines issues ranging from mold and vermin infestations to inadequate heat and hot water.

Investigators found that NYCHA's failures put some families at risk — accusations they highlighted with the housing authority's lead-paint scandal and attempted cover-up. For years, investigators say, NYCHA failed to comply with lead-paint safety regulations by not inspecting apartments and by failing to remove peeling lead paint from its housing units. Lead is toxic, especially to children.

After the reports surfaced in April, Shola Olatoye resigned as housing commissioner.

If approved by the court, settlement will give NYCHA five years to make sweeping reforms in all of its 326 developments. A federal monitoring board will also oversee the housing authority for the next 10 years.

There are about 400,000 people living in NYCHA housing.

"I wanna be honest with my 400,000 New Yorkers," Mayor Bill de Blasio said Monday. "You will see changes each year, and you will see improvements each year."

But, he added, complete fixes will take years -- and many resources.