It's often said that numbers speak for themselves. This has proven true in the culvert-cleaning industry, where a growing number of culverts have many contractors expanding their businesses to include a revolutionary new culvert-cleaning method that uses horizontal directional drilling (HDD) machines.

There are an estimated 563,000 drainage structures along railroad rights of way in the United States. And there will be more culverts added to that number as railroad companies expand the 583 railroads that already crisscross across the country. In fact, another 140,800 miles of track are currently in production, meaning there'll be more clogged culverts that will need cleaning.

One man keeping a close eye on these numbers is Bob Harr, owner and founder of Harr Technologies LLC in Mosca, Colo. Since Harr introduced culvert-cleaning attachments for HDD machines just a couple of years ago, contractors, railroad companies and government officials have taken notice.

"In the beginning, we were mainly doing work on railroads in the western part of the United States, but now we're also doing work on the East Coast," Harr says. "We've also started doing culvert-cleaning projects with the U.S. Department of Energy, and we've been expanding the work we do for states' Departments of Transportation."

Besides cleaning culverts along railroads and roadways, Harr says several waste management companies have also expressed interest in using the HDD culvert-cleaning attachments to clean the drainage pipes that run underneath their landfills. "Debris builds up inside the drainage pipe and in order for them to maintain their water quality permits, the pipes must adequately drain," Harr says.

Improved awareness of this new culvert-cleaning method and better availability of the attachments have been the biggest contributors to growth in this market. Last year, Harr aligned with Vermeer Manufacturing Company. Vermeer distributes the HDD culvert-cleaning attachment tools through its worldwide dealership network, and the company handles all aspects of manufacturing, sales support, service, and marketing. There are more than 50 varieties of the five different attachments, which range in size from 6 inches to 110 inches.

The first attachment used in Harr's patent-pending culvert-cleaning process is the barrel cutter, a round tool with fins and water jets. The barrel cutter rotates through the culvert pipe, mixing water with the debris inside. Harr says the tool allows the operator to evaluate the integrity of the culvert pipe and the type of debris inside. With the barrel cutter, the operator can decipher whether there are large rocks and tree debris or just dirt and sand clogging the pipe.

After running the barrel cutter, operators attach either the push bucket or pull bucket, depending on whether they must pull the material away from a wetland or creek. In environmentally protected areas, contractors must remove the material from the culvert and dispose of it properly. To do this, operators can attach the pull bucket, which rotates inside the culvert pipe, gathers the soil and debris, and pulls it back toward the drill. The push bucket also gathers soil and debris as it rotates, but it pushes the material out to the far side of the culvert.

While the push bucket and pull bucket are shaped like a half cylinder for round culvert pipes, Harr soon realized they would not sufficiently clean debris from culvert pipes with square sides. So Harr invented the square box bucket, which works the same as the pull bucket but can better clean the sides of box structures.

Harr says the metal barrel cutters and buckets are strong enough to cut through most tree roots and pick up large rocks, while sensitive enough to maintain the integrity of the culvert pipes. "Our tools are designed to help prevent damage to the culverts during the cleaning process, whether they are concrete, steel or plastic," he says.

As a finishing touch, Harr designed the brush attachment, which is used to clean the crevices and grooves of the culvert pipe after the soil and larger debris have been removed. "We use the brush to perform the final cleaning of the culvert," he says.

In addition to the barrel cutter, the buckets and brush also have water jets that are controlled by the drilling fluid system on the HDD machine. Unlike jetter cleaner trucks, which disperse a large amount of water into culverts to unplug pipes, Harr's attachments allow the operator to control the amount of water needed to clean the culvert. In fact, operators can opt not to use the water jets at all and just use the tools dry.

One company that's taken the plunge into the culvert-cleaning market is Leon E. Wintermyer, Inc., which was recently hired to clean three culverts, including a 180-foot-long, 18-inch culvert pipe for the Delaware Department of Transportation.

First, Wintermyer scheduled a site visit to inspect the culvert and determine if the HDD culvert-cleaning attachments would be the best solution to the problem. When he arrived at the site, he found that the upper end of the pipe was connected to a manhole and the lower end was connected to an end wall near a creek. Delaware DOT officials had twice attempted to clean the culvert pipe with a jetter cleaner truck, but were unsuccessful because the pipe was too clogged with sediment. Before Wintermyer contacted them, their only other alternative would have been to completely replace the culverts.

To begin cleaning the 180-foot culvert pipe, crewmembers set up their Vermeer NAVIGATOR® D24x40 Series II HDD machine on the opposite side of the creek to the outfall of the pipe. Wintermyer says they then extended about 20 feet of drill stem across the creek bed until the attachment was near the opening of the culvert pipe. The first attachment crews used was a 10-inch barrel cutter, which they rotated and pushed through the entire length of the pipe to evaluate its integrity, the type of debris inside, and whether there were any other obstructions. Once the barrel cutter attachment reached the inside of the manhole, Wintermyer says they were confident they would be able to adequately clean the entire culvert.

After the barrel cutter was pulled and rotated back to the HDD machine, crew members then attached a 14-inch push bucket. Their major challenge was controlling the amount of sediment that came out of the outfall of the pipe near the creek. To prevent the sediment from going into the creek, most of it was pushed up to the manhole, where Delaware DOT officials then used a vacuum system to remove it.

"We did not want the sediment getting into the creek because of environmental concerns," he says. "Our crew did a wonderful job of controlling and containing the sediment. We didn't even have a shovel full of sediment get into the creek as a result of our actions. This certainly proves the point that the process is environmentally friendly."

In fact, Wintermyer says the operator-controlled water jets on the culvert-cleaning attachments helped his crew better control how the sediment flowed, thus keeping it from going into the creek. "We used very little water, only about 100 to 150 gallons during the process," he says.

As a final measure, Wintermyer's crew attached a 15-inch brush to the D24x40 Series II HDD machine and pushed the brush attachment through the entire pipe to the inside of the manhole. As the brush attachment neared the manhole, a large amount of sediment was pushed into the manhole. So to clean the culvert pipe further, Wintermyer says they chose a 24-inch brush attachment to scour the pipe one final time.

"We removed about half of the bristle rings on the attachment so the bristles were able to somewhat collapse or bend inside the pipe," he says. "We wanted to scour the inside of the pipe and remove any loose debris that may have been still attached to the walls of the pipe.

"I believe everyone was amazed by the amount of material that continued to come out of the culvert as a result of the brush attachments," he adds.

In all, it took the three-man crew less than five hours to completely clean the culvert.

Provided By: Vermeer Manufacturing Company

Pella, Iowa

VERMEER and NAVIGATOR are registered trademarks of Vermeer Manufacturing Company in the United States and other countries.