Clark, 36, formerly of Haddonfield, is vying for a chance with Tayshia Adams, 30.
The season started with Clare Crawley, 39, as the bachelorette, but she left after four episodes with contestant Dale Moss. The pair are now engaged.
Clark, a Philly sports fan and former college baseball player, was one of the first few men to pull Adams aside on her show debut Tuesday night. He hasn't shared his inspirational story on-air -- yet.
Clark was addicted to alcohol and pills as a teen, Reading Eagle reported in 2014.
His addiction worsened when he had a brain tumor removed and powerful narcotics became readily available, the article says. All he needed to do was call a doctor, and he had prescription.
As Clark's wedding approached, he worried how he'd get drugs while on his 10-day honeymoon in St. Thomas, Reading Eagle says. What ensued was an eight-month drug binge, in which the former athlete smoked crack, did whippets and was shooting up heroin, the report says.
It wasn't until he was arrested for crack possession and DWI that he was forced to get sober, in 2017, according to the article.
In 2017, Clark and Justin Gurland co-founded "Release Recovery," a program for people looking to get clean.
"When they met seven years ago, they discovered a shared conviction that the message of recovery is one best conveyed through simple language," the RR website says.
"Drawing from their years of experience in the recovery field—as well as from their own personal journeys in recovery—Zac and Justin have made it their life’s work to share the gift of recovery with as many people as possible."
"Bachelorette" host Chris Harrison during a "meet the men" live stream described Clark as a great guy with a heart of gold, who starts out slow but later warms up.
Last year, Clark ran the New York City marathon for the sixth time.
Clark was one of the first few men to meet Adams. He planned a coin-toss into a fountain, and had the bachelorette "pinky promise" that in 30 years, they'd tell each other what they wished.
Adams was beaming.
Click here to follow Daily Voice Highland Lakes-Vernon and receive free news updates.