Hennepin County still is on pace to pay off Target Field debt a decade ahead of schedule, officials said last week.

The $555 million ballpark and its surrounding infrastructure were built with $350 million in funding from the county, or $675 million total with interest. The county planned to pay it off in 30 years, or by 2037, but now expects to pay the debt by 2027 — a decade early.

Excess revenue from the ballpark sales tax, plus lower interest rates, have helped the county save money and pay off bonds sooner than anticipated.

The county paid off one of three series of bonds in November, 21 years sooner than the $75 million bond was initially due. And last week, the county refinanced $150 million in bonds, which could be paid off by 2032, five years early.

“We’re out to save as much as we can,” said Commissioner Mike Opat, the lead architect of the plan to build Target Field.

An early payoff on the debt would mean that taxpayers would see an early end to the sales tax, which equates to 3 cents on every $20 spent.

“The sales tax has done OK,” Opat said. “We are also making the move to prepay [rather] than put it in the bank.”

Hennepin County issued bonds and levied the 0.15 percent sales tax to cover its payments on the ballpark, which opened in 2010. When the economy dipped early on, revenue from the sales tax was below expectations. Since the economy rebounded, sales tax collections have risen.

So far, the county has saved $154 million in interest payments, Budget Director Dave Lawless said.

“We’re all collectively saving money,” Lawless added.

Of the $36 million a year that the countywide sales tax brings in, about $29 million goes to stadium debt. The rest goes toward operations of the Minnesota Ballpark Authority — the public body that manages the ballpark — as well as capital expenses and $4 million annually to maintain county libraries’ weekend hours and fund countywide youth sports grants.

The capital reserve fund has been used only once since the ballpark opened, to install LED lights for $1.6 million in 2016.

Since the youth sports grants program began in 2009, the county has awarded $17.6 million to 108 facilities, 200 small equipment projects, five playground projects and a swimming lesson pilot project. When the program ends, county officials estimate it will have funded $130 million for youth sports and library programs in the county’s suburbs and Minneapolis.

Hennepin County contributed nothing to the construction of the $1.1 billion U.S. Bank Stadium. The public contribution for that stadium, amounting to nearly $500 million, came from the state and the city of Minneapolis.