The completion of a nearly $4.8 million renovation to New Brighton's Hansen Park has been delayed, and construction has left some residents dissatisfied.

The renovations are intended to improve flood control and water quality in the region. As part of the update, New Brighton and the Rice Creek Watershed District are dredging and expanding the park's man-made pond that runs to Pike and Long lakes.

"In addition to serving as an aesthetic amenity, it was created for stormwater management in terms of water quality and flood control," project manager Kyle Axtell said. "Over the last 45 years, the pond that once was once 4 to 5 feet deep was only maybe 6 inches deep. It filled in with sediment from urban runoff."

The park's renovations include a 2.25-acre expansion to the pond, an iron-enhanced sand filter to remove phosphorus from the water, revegetation and reconstruction of some park trails. Completion, scheduled for fall, has been pushed back a year. The delay was caused by last winter's atypical warmth, Axtell said, because the soft ground around the pond impedes dredging machines unless it's frozen.

Piles of dirt that were dredged and the removal of two baseball fields left some residents displeased.

"Nobody in the neighborhood realized they were going to pile that muck up there," said James Senden, a spokesman for disgruntled residents. "That's never going to settle out. It's going to be a decaying situation for years."

Some of the dirt will remain at the park to create the elevated area. "Construction isn't done," Axtell said. "It looks like a big pile of dirt. When it's done, it's going to be leveled off as a big, open play area."

The city received $200,000 from the Rice Creek Watershed District for removal of two baseball diamonds for the new area and will receive $125,000 to $150,000 for the on-site storage of the dirt.

Apart from the removal of the fields, some citizens are concerned because they think some of the remaining dirt may be contaminated. "We did find some contaminated areas out in the pond," Axtell said. "There were some areas that had polycyclic aromatic hydrocarbon contamination."

That contamination "include[s] hundreds of different chemicals that commonly occur as mixtures in the environment," according to the Minnesota Department of Health. The contaminated dirt was removed and trucked away, Axtell said. But residents are concerned because a 2015 conceptual report for the project said segregating sediment "can be challenging and may provide additional uncertainty or risk for both the contractor and disposal facility."

Representatives for the city of New Brighton could not be reached for comment.

Gabriel Sanchez is a University of Minnesota student on assignment for the Star Tribune.