A nine-page letter signed by more than 300 people objecting to St. Paul’s design plans for the $54 million Lowertown ballpark arrived Wednesday at City Hall, but officials said the petition was too late to impede the project.

Organizers said that the letter required a response from the city because it was submitted within 30 days of the date when the ballpark’s environmental assessment work sheet was completed, on April 23.

However, city attorney Sara Grewing said the comment period actually ran from March 4, when the work sheet draft was first released to the public, through April 3.

“We will certainly review the petition for any new information, but at this time the decision remains and construction of the ballpark is moving forward,” she said.

In the letter, opponents of the city’s ballpark plans call for the city to seek an environmental impact statement for the project, a more thorough review that would cost more money and force a construction delay.

Signers of the letter are described as Lowertown residents, property and business owners, workers and visitors who believe that the city’s ballpark plans will strip them of convenient parking, make the neighborhood too noisy and lower property values.

They want the city to build the ballpark in the shell of the Gillette/Diamond Products building, which they say would effectively wall off highway noise and provide parking space for 585 vehicles.

The city plans to begin demolition of the Gillette building next month. The ballpark will be built with state, city and private funding.