Although 60 percent of voters last week supported the tax, the "yes" votes didn't achieve the two-thirds threshold needed for passage.
So what's next for the library, its supporters and city officials?
The library won't be closing anytime soon, but there will be a wealth of analyzing and planning to determine its future.
Even though Measure X didn't pass, the results revealed something about the city's voters, said Marian Higgins, a Pomona resident and coordinator of the campaign to support Measure X.
"I think we feel like the library itself was validated," she said.
"We think there is support for the library, but we need to come at it from a different direction."
Had the group had additional time to campaign and get additional funds, it might have been able to garner the support of the 1,400 additional voters needed for passage, Higgins said.
John Clifford, who also worked on the campaign, said volunteers reached thousands of Pomona voters and explained the situation that the library faces and the need to pass Measure X.
In June, as part of a budget proposal, city administrators proposed temporarily closing the library for a year to reduce costs.
City Council members directed city staffers to find funds to keep the library open. Administrators suggested taking $400,000 to run the library during the 2012-13 fiscal year.
The money kept the library open, but the limited hours of service were cut further and library staff was slashed.
If Measure X had passed, owners of single-family home parcels would have paid $38 a year, generating about $1.5 million a year for library operations.
"Thirteen thousand people actually voted to tax themselves," Clifford said.
After going over election data, supporters of the measure found voters in City Council District 5, in southwestern Pomona, and District 6, in northern Pomona, showed the least support for Measure X.
Voters in those two council districts are closer to the Claremont, La Verne and Diamond Bar libraries than Pomona's, Clifford said.
Measure X supporters tried to reach voters there with signs, phone banks and other efforts.
"What we missed in those areas that we had in others was the personal contact," Clifford said.
Few people from those areas were involved in the campaign, Clifford said.
"If we had a year to put something together, or six months," things might have been different, Clifford said.
Efforts to place a measure on the November ballot in support of the library came about in July at the urging of residents and City Council members who approved placing it on the ballot in August.
Supporters moved quickly to launch a campaign for the measure knowing they had about three month to convince voters of the need for the parcel tax.
Additional time would have allowed supporters to develop a campaign strategy for districts 5 and 6, Clifford said.
It's too early to tell if supporters of the library will pursue another tax measure, Clifford said.
"Perhaps we can come back at a later time," he said.
It may be possible to pursue a general tax that would only require a simple majority to be approved, he said.
But Councilwoman Paula Lantz, who put out the call that drew residents and business people to brainstorm strategies to assist the library, said Measure X wouldn't have garnered as many votes if it had been a general tax.
Measure X "was guaranteed to increase (library) hours and maintain services," she said.
Clifford, who is also chairman of the Pomona Public Library Foundation, said, even before last week's election, foundation board members planned to meet with individual council members.
"We will meet with them and advocate on behalf of the library" in addition to offering assistance during the city's budgeting process, Clifford said.
Pomona Finance Director Paula Chamberlain said the city's 2012-13 budget, which includes funding for the library, is balanced and in place.
Next month, the process for developing a budget for the 2013-14 fiscal year will begin, she said.
Funding for the library and other services will hinge on various factors.
"It all depends on how we're doing with sales tax, property tax and development-related revenue," she said.
In October, the city organized a series of community meetings led by State Librarian Stacey Aldrich and members of her staff. The meetings were designed to collect opinions on a vision for the library.
The report with the result of the meetings is expected to be part of the City Council's Nov. 19 meeting, Deputy City Manager Mark Gluba said.
Lantz said that without a dramatic increase in sales tax or property tax, it's hard to say how the library will be funded during the coming fiscal year.
Lantz said the City Council will have two new members who may have ideas on how to address the library situation.
Before setting budget priorities, Lantz would like to hold a community meeting to show residents what the city's financial situation is like.
Lantz said the meeting would allow residents to see the city's revenues and expenses and offer their opinions about the programs and services they value most.
Lantz said she hopes those who came together to support the library continue to do so.
"One of the wonderful bright spots is lots and lots of people came together," she said. "I hope they remain engaged as far as the library is concerned."