Jasper County approves seal coal and microsurfacing plans near Neal Smith

Plans to apply seal coat and microsurfacing to roads near Neal Smith National Wildlife Refuge were approved by the Jasper County Board of Supervisors last week, which is all part of the first phase of an accessibility project funded in large part through a Federal Lands Access Program (FLAP) Grant.

According to county documents, the affected roads include West 129th Street South from Iowa Highway 163 to South 96th Avenue West and South 96th Avenue West from West 129th Street South to Pacific Street. County Engineer Michael Frietsch said the streets will be undergoing major upgrades.

“We’re going to be taking the road and fixing some box culverts that have broken end sections in there,” Frietsch said. “We’ve got a lot of things that we gotta fix up around the toes and the slopes. We’re going to fix the embankments and put guard rail up and basically make safety improvements.”

Crews are also going to stabilize the top 12 inches with cement and then put a layer of millings down and a double layer of what is called Otta seal. Normally, when applying a seal coat, contractors put down a layer of oil and then chip. But chip is pricy. So, instead, the county will put down 3/4-inch road stone.

“We’re going to let that sit and cure out, and then two weeks later or so we’ll put another run of oil on it and we put another layer of 3/4-inch road stone on top of it. Shape it, compact it, get it all rolled in,” Frietsch said. “Then the final step beyond this is we’re going to put down what is called a microsurface.”

Frietsch described the microsurface as a polymer-modified asphalt mixed with some coarse and fine materials that get bladed onto the surface and seals it off.

“It gives it a nice sort of black color, sort of poor mans looking asphalt road, so to speak,” Frietsch said. “…This is a method I’ve seen. Johnson County has done Otta seals and there are other counties that have done Otta seals. They’re better than a plain old seal coat.”

If it wasn’t for all the embankment slope and culvert issues around these roads, Frietsch said this method would come in around $300,000 per mile.

“I think we’re probably going to be around the $400,000 to $500,000 per mile range with this project,” he said. “So similar to what the Lake Road was — or is.”

The second phase of the project includes curing West 129th Street South from South 96th Avenue West to South 102nd Avenue West, and then South 102nd Avenue West over to the Neal Smith National Wildlife Refuge’s maintenance shed. A bridge on South 88th Avenue West is also addressed in the third phase.