Organizers of a recall campaign against three Jefferson County school board members cleared a key hurdle Tuesday when the county clerk announced they had easily collected enough valid signatures to put the issue to voters.

Questions remain, however, about potential challenges and the timing of the recall if it is to proceed — with hundreds of thousands of dollars in taxpayer expense hanging the balance.

The group Jeffco United for Action collected more than 33,000 valid signatures per board member, the clerk’s office said. That’s more than double the amount they needed.

The clerk tossed about 4,000 signatures per board member from the petitions organizers turned in last month.

The recall campaign, which launched with much fanfare and hundreds of volunteers, paid $120,000 to canvassing firm Black Diamond Outreach to aid in collecting signatures.

Today’s announcement kicks off a 15-day window in which any Jefferson County resident can challenge the signatures validated by the clerk.

Supporters of the recall believe if there are no challenges, the recall election can be part of the November general election, which would mean only a nominal cost to Jeffco Public Schools. A special election would cost Jeffco schools about $500,000.

Because the laws governing general elections and recall elections differ on issues such as when ballots need to be finalized and mailed, it’s not certain when the recall election may take place.

That decision will rest with the county clerk’s office after the challenge period is complete.

The ambiguity around the election date isn’t slowing either side down.

Last week, recall organizers Jeffco United for Action posted large fundraising figures.

Both board president Ken Witt and fellow recall target Julie Williams have filed paperwork with the Secretary of State’s office that will allow them to raise money to fight the recall.

In a new development, former Jeffco school board member Paula Noonan filed paperwork to run for Witt’s seat, according to documents on the Secretary of State’s website. Under Colorado law, voters who choose to recall an elected official are asked on the same ballot to pick a replacement.

Noonan, who served one term between 2009 and 2013, did not immediately return requests for comment.

The Independence Institute, a libertarian-leaning think tank that formed a political committee last week to oppose the recall, followed up by launching a new website to support the school board majority. The website, KidsAreFirst.org, shares the same name as the committee.

Organizers behind the recall effort charge school board members Witt, Williams and John Newkirk with wasting taxpayer dollars, meeting in secret and disrespecting teachers and parents.

The board majority’s supporters claim the opposite is true: that the board is using existing dollars to fund a variety of needs without taking on more debt, increasing transparency by livestreaming board and committee meetings, and giving teachers raises.