An ambitious proposal to bring ultra-fast broadband to Seattle’s neighborhoods has not only fizzled, as we reported last month, but it has resulted in an overdue bill of $52,250, owed to the city of Seattle by Gigabit Squared, the company behind the project.

Erin Devoto, the city’s chief technology officer, confirmed the situation this week after GeekWire obtained copies of the invoices as part of a larger public records request. Internal emails show city staff attempting repeatedly to get Gigabit Squared to address the issue as the balance grew over the past year.

The wrangling over the unpaid bill is noteworthy in part because the sum is so small — a tiny fraction of the many millions that would have been required to get the project off the ground, taking advantage of unused capacity in the city’s 500 miles of fiber-optic cabling.

In an initial engineering agreement, the company had agreed to compensate the city for preliminary work by city engineers and staff on the project, while the city and the company worked out a larger master agreement, which was ultimately never completed.

The city did receive a payment of $2,500 from Gigabit Squared at the beginning of November, but based on the lack of a timely payment for the remaining $52,250 balance, the issue has been referred to the city’s law department for collections or potential legal action, Devoto said.

Representatives of Gigabit Squared, including President Chris Vogt and former President Mark Ansboury, have not yet responded to our recent messages seeking comment on the unpaid bill and the status of the project.

Announcing the project with then-Mayor Mike McGinn in December 2012, representatives of Gigabit Squared said Seattle would be one of the first cities to take part in its broader $200 million program to bring high-speed broadband Internet access to communities around the country. But Gigabit Squared officials informed the city in November 2013 that they hadn’t been able to raise the funding as expected — leaving the project in limbo and presumed dead by many in the city.

Gigabit Squared’s leaders, including Ansboury, cite their past experience building community broadband projects in places including Cleveland, Ohio; Chattanooga, Tenn.; and Jackson, Miss.; among other cities. Gigabit Squared’s $200 million “Gigabit Neighborhood Gateway Program” was created in partnership with Gig.U, a group of research universities led by Blair Levin, a former top broadband official with the Federal Communications.

Still, Devoto likened the situation to placing a bet on a startup, saying that the city understood the risks going in, and that its costs have been relatively low.

“It was going to be a pretty heavily lift for (Gigabit Squared) to pull this off,” Devoto said of the ambitious project. “It would be a heavy lift for anybody. None of this is easy, and there’s a reason why people aren’t just doing this all over the place.”

With the new administration of Mayor Ed Murray still settling into office, it’s unclear where the city will go from here with the larger vision. The grand plan was to use the city’s excess fiber to increase broadband service and competition to benefit Seattle businesses and residents, ultimately making the region more competitive economically.

One possibility is to lease portions of the fiber to other companies that would use it to improve and expand their existing services, Devoto said, acknowledging that such a plan would be far smaller in scope (and benefit) than the original plan.

Gigabit Squared had announced the initial pricing structure for its Internet service, offering gigabit speeds for around the same price per month as what Comcast charges for much slower 50 Mbps download/10 Mbps upload. The company had been targeting an early 2014 rollout for two of the 14 “demonstration” areas — University District and Capitol Hill — with the rest slated to get access to Gigabit’s network by the end of 2014.

In a statement last month, Gigabit Squared said it had “completed several rounds of investment financing” and was “currently executing projects in Illinois and Florida with a combination of public and private funding.” The company noted that it was looking forward to “a dialogue regarding project possibilities” with Murray and his staff.