St. Paul and Ryan Cos. have signed off on a $43.8 million contract to finally construct the St. Paul Saints' downtown ballpark, with Ryan responsible for any cost overruns involving labor or materials.

The agreement between the city and the builder was the final hurdle to be crossed before ground is broken this spring at the Lowertown site, where demolition is wrapping up on the former Gillette/Diamond Products factory.

The ballpark, to be owned by the city, is expected to be ready for the Saints' opening day in May 2015.

"This ensures the project will remain on schedule and on budget," said Brad Meyer, spokesman for the St. Paul Parks and Recreation Department.

The contract, finalized Wednesday, is the second phase of the city's two-part agreement with Ryan to design and build the 7,000-seat ballpark. The Minneapolis-based developer will be paid $3.48 million for overseeing the project.

"The execution of this contract puts us one step closer to bringing baseball to Lowertown, and includes important safeguards that protect St. Paul and Minnesota taxpayers," Mayor Chris Coleman said in a statement.

Although the Minnesota Twins covered cost overruns for Target Field, it's common for the general contractor to assume that risk with stadium projects. For instance, Mortenson Construction, which is building the new $1 billion Vikings stadium in downtown Minneapolis, will be responsible for cost overruns on that project.

The $63 million Saints' ballpark budget breaks down into three parts: $9.2 million for demolition, site preparation and most of the design work, under terms of a contract signed with Ryan last year; $43.8 million for construction and remaining design work, and $10 million for land acquisition, financial costs, contingency funds and legal and consulting fees.

Officials are confident that the budget will stay on track, despite the fact that the ballpark's price has steadily risen over the years.

In 2009, the estimated cost was placed at $25 million to $30 million; two years later, that estimate had grown to $50 million and then, in 2012, $54 million.

The project's price tag was finally placed at $63 million last summer, when city officials announced an $8.8 million shortfall due to environmental and design issues.

Meyer said the city will control any changes made to the current set of plans but doesn't anticipate any. If it happens, he said, "Ryan is now on the hook."

More than 80 percent of the ballpark's cost will be paid with public funding. The state is contributing $28 million in development and environmental grants and a $1 million loan.

St. Paul's contribution amounts to $23.25 million, including a $4.25 million balance on an internal loan which it hopes to pay off with county environmental grants and unspent contingency funds.

The Saints are kicking in $2.2 million in cash and will pay off $8.8 million in city bonding with regular rent payments to the city.

St. Paul awarded the project to Ryan in 2012 but then was forced to put it up for bid when Gov. Mark Dayton complained about the lack of competition. Ryan won the job anyway, submitting a lower bid and scoring a higher technical score than two competitors.

Originally, the agreement on cost overruns was supposed to be resolved last fall, followed by the start of construction. But the budget shortfall, plus unanticipated soil and pollution problems at the site, pushed the schedule back several months.

Meyer said construction cranes should be on the site next month.

Staff writer Paul Walsh contributed to this report.

Kevin Duchschere • 651-925-5035