Poor workmanship is threatening to further delay the opening of the new Mitchell Park Library and Community Center in Palo Alto, according to a letter released by the city Wednesday.

The five-page letter, which Public Works Director Michael Sartor sent to Flintco Pacific Inc. President and CEO Tom Maxwell on Nov. 7, outlines numerous problems with the project, including a fire alarm system that has failed testing three times and a pair of leaks in the roof.

“There is no excuse for Flintco’s lack of effort to correct these problems. Flintco’s current level of effort is unacceptable,” Sartor wrote.

The letter is similar to one City Manager James Keene sent Maxwell in May advising him to fix shoddy work and manage the project better.

Sartor’s letter says it appears unlikely the contractor will be able to fulfill its promise to obtain a temporary certificate of occupancy by Nov. 27. Missing the deadline will push back the opening of the library and community center well into 2014.

The now $28 million project is 96 percent complete but more than a year and a half behind schedule, according to a recent report from the city manager’s office.

The pace of construction has also slowed significantly in recent months, with the number of on-site workers falling from 15 or 16 to four or five. Many of those who show up do not stay for an entire shift, according to Sartor’s letter.

“There are many areas that Flintco and its subcontractors could be working on, but Flintco appears either unable or unwilling to commit an adequate amount of personnel to complete the project any time soon,” Sartor wrote.

The new letter calls on Flintco to fix all of the problems it has identified by Nov. 25 and to make a “firm” commitment to have buildings B and C of the community center ready for occupancy by the end of the year.

If Flintco fails to do any of those things, the city will find it in default, said City Attorney Molly Stump. A default notice would set the stage for another firm to take over the project.

“It is not a straightforward matter to replace a general contractor,” she said. “There are cost and schedule impacts. If we do that, we want to make sure it’s in the public’s best overall interest.”

In addition to getting the project back on track, the city wants some answers about changes in the structure of Flintco Pacific.

Workers at the site have started identifying themselves as employees of Flint Builders Inc. According to Flint Builders’ website, the firm was established this year when Flintco transferred its Pacific division to Vice President John Stump.

City Attorney Stump said the city needs to know whether Flint Builders is properly equipped to finish the project. Any transfer of the contract is also subject to city approval, she added.

“It appears that this is something that Flintco has been working on for some time, yet the city has never been notified,” Sartor wrote.

At 56,000 square feet, the new Mitchell Park Library and Community Center is the city’s largest construction project in four decades and the centerpiece of a $76 million overhaul of the library system. The funding was made possible by the passage of Measure N in 2008.

Email Jason Green at jgreen@dailynewsgroup.com; follow him at twitter.com/jgreendailynews.