State Dem big Farrell out in Sept.

ALBANY — One of the longest serving and most powerful state lawmakers is ready to call it quits.

Assemblyman Herman (Denny) Farrell (D-Manhattan) told the Daily News Tuesday that on Sept. 5 he will resign the seat he’s held the past 42 years.

Farrell, 85, cited age, health and the demands of the job as chairman of the Assembly Ways and Means Committee as key reasons for his decision to retire.

“The Ways and Means Committee is a lot of work, and it’s important,” Farrell (photo) said of the chairmanship he’s held since 1994. “I don’t want to embarrass myself by putting the ice cream in my ear. I want to leave the day before that, not the day after.”

Next month, upper Manhattan’s Riverbank State Park will be named after him.

“Denny taught me and an entire generation of New Yorkers the power government can have to serve the people and do good things for the community,” Gov. Cuomo told The News Tuesday.

First elected in 1974, Farrell, is the third-longest active member in the Assembly. He once headed the state and Manhattan Democratic committees and mounted an unsuccessful challenge in 1985 against then-Mayor Ed Koch.

Farrell in May told The News he would not seek reelection when his term is up in 2018. At the time he wouldn’t respond to talk that he was preparing to step down this year. That talk heated up again recently as it became clear he was pushing his longtime chief of staff, Al Taylor, to replace him.

Had he retired in June, a primary to fill his seat would have been held in November. But because he waited, the county committees from both parties will choose who appears on the ballot.