(Adds updated comment from Protect Colorado, price action, adds background)
By Liz Hampton
Aug 29 (Reuters) - A Colorado ballot initiative that would sharply increase the required distance between new oil wells and populated areas will go before voters in November, Colorado officials said on Wednesday.
The proposal, opposed as anti-fracking by oil and gas producers, would require new projects to be at least 2,500 feet (762 m) from buildings, parks and certain wildlife areas. The state currently requires as little as 500 feet (152 m) of separation.
A 2,500-foot setback would render about 85 percent of all new oil and gas development on non-federal lands in the state off-limits to drilling, according to a 2016 study by the state's oil and gas conservation commission.
Colorado Rising submitted 123,195 verified signatures to get the initiative on the ballot, above the 98,492 required, state officials said on Wednesday.
A similar initiative failed to get on the 2016 ballot. The following April, two men were killed in an explosion caused by gas from an abandoned well about 170 feet (52 m) from a Firestone, Colorado, home. Supporters of the initiative say there have been 13 explosions and fires since then.
"The climate in regards to oil and gas has really shifted quite a bit since the Firestone explosion," Anne Lee Foster, a volunteer with Colorado Rising, said on Wednesday.
Opponents argue the proposal would cost Colorado's economy between $169 billion and $217 billion over the next 12 years, and reduce state and local tax revenues by between $7 billion and $9 billion. It would also affect an estimated 147,800 jobs, a July 2018 report by free-enterprise group Common Sense Policy Roundtable said.
"The impact of the measure would ripple through the whole economy," said Karen Crummy, a spokeswoman for Protect Colorado, a group backed by the oil and gas industry.
"It's just hard to conceive that the intent of this is anything other than to get rid of oil and gas development," Crummy said.
Protect Colorado said it would fight the ballot initiative. Energy companies, including Anadarko Petroleum Corp and Liberty Oilfield Services Inc, helped it amass more than $5 million in funding, according to August campaign finance documents.
Colorado, the seventh largest U.S. oil and gas producer, has experienced an uptick in production. In May, its crude output was 447,000 barrels per day, up 30 percent from a year ago.
Shares of energy companies active in Colorado, including Anadarko and Noble Energy Inc, sold off on the ballot news on Wednesday, but retraced some of the drop. (Reporting by Liz Hampton in Houston; Editing by Peter Cooney)