The city’s public housing agency, the New York City Housing Authority, has faced many systemic problems for decades.

And nearly four years after a court-appointed federal monitor was put in place to oversee NYCHA, a recent report from the monitor reveals that many of those problems persist.

Bart Schwartz, the federal monitor, joined Errol Louis on “Inside City Hall” Monday night to discuss the many problems NYCHA is facing, including mold, lead paint, rodents and air quality issues.

“In most buildings, the ducts had not been cleaned for 60 years,” Schwartz said.

But there is some encouraging news, including progress in removing lead paint from many apartments.

“A child under six whose brain is damaged by lead is irreversible. So the time element here — getting things done and getting it done quickly — may be more important than anything else that we’re doing. NYCHA has taken that up,” Schwartz said. “This is really a good story.”

Schwartz’s report also noted improvements to the agency’s use of data to help address apartment conditions. For example, data has helped elevators run more efficiently, according to Schwartz.

“From the beginning, the elevator department asked us to help them. They wanted us to come in and do analytics. They wanted to test some of their theories about caring for the elevators,” Schwartz said. “Then we did an analytical study, and it shows, not surprisingly, how much fewer outages there are in the elevators where they did some work.”

But Schwartz says the agency still has a lot of work to do.

“With NYCHA, something good always also shows you something bad,” Schwartz said.