Spokane entrepreneurs pave the way to collect rain with porous bricks

Kevin Kunz, a young entrepreneur in Spokane, poured a bottle of water across the surface of a new type of paver brick that his startup company hopes to sell across the U.S.

Almost as fast as the water came out of the bottle, it disappeared into the bricks’ unique porous structure.

With the growing mandate to capture rainwater and snowmelt before it gets into sewer pipes and waterways, the value of this porous ceramic brick seems obvious. The water simply drains into the earth below.

“Our mission is to build materials for a resilient future,” said Kunz, 26.

He is in charge of product development and testing for a four-man company, Klorotech Inc., based in Spokane.

Kunz has been traveling around the country trying to get his unique brick – sold under the trade name KloroStone – accepted by public works officials and the construction industry as a useful pavement product.

The possibilities are immense since the U.S. Environmental Protection Agency is requiring state and local governments to clean up water bodies by cutting stormwater pollution under the Clean Water Act.

“There are many (potential) markets for this,” said CEO Jon Slizza.

KloroStone was chosen as one of three types of permeable paver bricks for a stormwater project at the new Olmsted Brothers Green park at Summit Parkway and Nettleton Street in the Kendall Yards development. Two other types allow water to seep into seams between the bricks. The blacktop trail there uses a permeable type of asphalt.

A portion of the park is being used to filter water, collected off Monroe Street and commercial sites on the east side of Kendall Yards, which is piped a mile west to the park.

The $1.6 million stormwater system includes small segments of the colorful KloroStone pavers. The project was financed in part by a state ecology grant.

Michael Terrell, who owns his own landscape architecture firm, helped plan the project for Kendall Yards developer Greenstone Corp.

He said company officials were insistent on finding new environmental solutions to dispose of stormwater.

Terrell said the construction industry is curious to see how the KloroStone pavers hold up to time and wear. “It’s a real interesting project,” he said.

KloroTech dates back several years to when Kunz became friends at Washington State University with fellow student and company partner Davy (Zihao) Mu, whose family operates a large paver brick manufacturing company in China.

Kunz grew up in Spokane and graduated from Gonzaga Prep. He has known Greg Johnson, also a Prep grad and a partner, since childhood.

Kunz said the Chinese have been using permeable pavers on a large scale. The KloroTech group thought the U.S. would be a likely place to introduce their own version of the product.

KloroTech worked in conjunction with the Chinese company to develop a proprietary process that turns clay into a ceramic brick through heat.

KloroTech owners declined to specify the manufacturing process or identify the Chinese company. The company has three patents and has applied for six others, Kunz said.

In the case of KloroStone, the manufacturing process creates tiny pores in the brick that range in size from 1 to 5 microns. A human hair is about 90 microns in diameter.

The pores soak up water and then let the excess seep downward, but leave dust, dirt and contaminants behind. As a result, the pores resist clogging, according to tests conducted by STRATA engineering in Spokane.

Here’s what STRATA found: “KloroStone pervious pavers demonstrate superior strength, durability and resistance to harsh winter conditions and de-icing chemicals.”

The report goes on to say that the pavers can absorb more than 2 inches of rain an hour, sending the water through the brick into a porous subgrade below. The absorption rate exceeds Washington state guidelines.

The testing also showed that the bricks removed key pollutants such as copper, zinc and oil from the water. The brick surface, with its baked-in color, is expected to not scratch or fade, Kunz said.

During the summer, the bricks allow ground moisture to escape into the air, reducing the heat-island effect of urban areas, he said.

A group of contractors and engineers gathered recently to view a presentation on the KloroStone test results.

“It’s time for these to get in the ground and get some (real-life) results,” said Tom Arnold, principal civil engineer for Coffman Engineers in Spokane.

So far, the number of installations is limited. The city of Redmond, Washington, is installing the pavers in a strip between a commercial street and sidewalk to absorb and filter stormwater.

Kunz is working to get the bricks approved for bidding on major projects throughout the country. The state of Oregon has approved the bricks for transportation projects, he said.

The cost runs from $7 to $10 a square foot, making the bricks more expensive than other paving materials, the owners said.

The owners are working off a startup investment of $500,000.