MELBOURNE, Fla. — More help, in a big way, for the struggling Indian River Lagoon is coming to Melbourne.

It's a baffle box that will stifle more than 4,000 pounds of harmful pollution from seeping into the lagoon every year.

Wednesday, six of the large pieces, each weighing 43,000 pounds, were installed in the drainage basin surrounding the Cliff Creek neighborhood.

The underground structure is filled with debris trapping chambers and keeps pollution from flowing into waterways like the lagoon.

And at 26 feet by 22 feet, 15 feet-deep, it's the largest such box east of the Mississippi.

“It's one of those goals that we have to treat the lagoon and the water before it gets there, and make it healthier,” said Danni Straub, Engineering Project Manager.

Brent Neubauer with Old Castle Infrastructure added, “So for us to be part of this, not only to have the product here, but to be part of the bigger picture is really exciting.”

Officials say the boxes have an add-on that removes nitrogen and phosphorous, the pair of damaging, harmful pollutants running into the water.

More than half of the $700,000 cost is funded by the 1/2 cent lagoon restoration sales tax voters approved back in 2016.