Road Warriors

The hardworking crews at Selco Inc. pump restrooms throughout their Iowa hometown and place orange barrels along highways in three states
Road Warriors
Technician Steve Viertel of Selco Inc., washes a PolyJohn Enterprises Corp. restroom using a pressure washer built by Mi-T-M Corp. (Photos by Mark Hirsch)

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“There’s a lot more here than meets the eye,” says Clark Wolff with a sweep of his hand. Inside the shop at Selco Inc. are boxes filled with miles of reflective tape, hundreds of battery-powered amber blinkers, wiring for temporary traffic lights and stacks of bright orange highway construction signs.

Selco, a 38-year-old company based in Dubuque, Iowa, rents temporary signage, safety barriers, lighting, message boards and other traffic control paraphernalia used on road construction projects in parts of three states.

But the company is also a long-time portable sanitation operator, providing restrooms and sinks for construction sites and special events in the Dubuque area. The construction side of his traffic control business dovetails naturally with the portable restroom rentals.



Wolff, 67, was a backhoe operator making the top union scale of $6.30 per hour back in 1973 when he had the opportunity to purchase 200 wooden safety barricades that he could rent to local utility and concrete contractors.

“A light went on in my head. I thought this could be a good, little one-person business,” he says. “I already had an old pickup truck. So, I rented an old garage with a dirt floor and got started.”

Wolff named his new business Safety Equipment and Leasing Co., which was later shortened to Selco Inc.

Wolff used a $15,000 second mortgage on his home to launch the business and carry it through its first six months. The rental rate per barricade, including pickup and delivery, was 25 cents a day.

“You make it up on volume – just like McDonald’s hamburgers,” he says. “After a while, I was able to incrementally increase my prices up to 30 cents, then 35 cents, then 50 cents. I eventually moved into a shop and office as it kept growing.”

Ironically, a downturn in the U.S. economy spurred Selco into a different, faster-growing business direction.

“When interest rates skyrocketed in the 1980s, everything just died here. That’s when I made the switch from local rentals to bidding on state highway jobs,” Wolff says.

He became a subcontractor to highway paving and bridge contractors who needed someone to provide traffic control devices, including signs, signals, floodlights, message boards and the ubiquitous orange barrels. That business grew rapidly in the past two decades as state and federal budgets continued to fund the construction and repair of thousands of miles of highways.

Today, Selco operates in parts of Iowa, Illinois and Wisconsin. The company has 30 employees based at shops in Dubuque and Blue Grass, Iowa.



At the request of construction customers, Wolff diversified into portable restrooms in 1975 using a $2,000 loan from his father. While portable sanitation accounts for a small fraction of Selco’s annual sales, Wolff says it’s still an important part of the business mix.

Wolff believes in uniformity for the portable sanitation part of his business. Aside from a handful of trusty USANCO units from the 1980s, Selco has 400 portable restrooms from PolyJohn Enterprises and a selection of sinks, also from PolyJohn.

“I can’t see having a mish-mash of stuff,” he says. The inventory is kept clean with a power washer from Mi-T-M Corp.

In 2011, Wolff replaced his two service trucks with a pair of identical rigs painted to match the gray PolyJohn units. “We’ve spiffed up our image,” he says of the new service rigs.

Each of the service trucks was built out by Advance Pump & Equipment Inc. of Dubuque on a 2011 International TerraStar chassis. The twin rigs have Masport HXL 4V pumps and 800-gallon waste/300-gallon chemical/100-gallon freshwater stainless steel tanks.

Wolff says the three-compartment tanks were chosen so the trucks can easily fill sinks while servicing portable restrooms at weekend events.

Four home-built trailers, ranging from 20 feet to 24 feet and originally made to tote road barricades, are used to haul the restrooms and sinks.

Selco’s portable sanitation rentals have always been a strictly local affair. Wolff says it isn’t economically feasible for his company to service portable restrooms at highway construction sites 200 miles from Dubuque.

Instead, the company has a 50-50 mix of in-town construction and special event rentals within about a 30-mile radius. That’s enough to keep two service drivers busy, particularly from May through September, when church festivals and other events are held throughout the community.

Long-time connections with the local construction industry and event planners have helped Selco’s portable restrooms become commonplace around town. Riverfest, Dubuque’s annual July 4 weekend celebration, requires 80 units and is one of the company’s biggest annual events.



Selco has a direct link to portable sanitation industry history. Its first portable units were an early design, made of ABS plastic, from Aquazyme Industries of Minneapolis.

“We’d drive up there with a trailer and bring them back in parts. We’d hand-assemble them with a pop-rivet gun. Each one had 200 to 300 rivets,” he says.

The egg-shaped Aquazyme units were roomy and easy to handle, but the plastic became brittle after a few years of use. When Aquazyme ceased business, Wolff purchased the remaining inventory and molds and unsuccessfully tried to produce the units with more durable polyethylene plastic.

He says that except for producing a few doors and roof sections, poly plastic just didn’t work with the molds. So after, using up the remaining parts, he discarded the molds and the rest of the units.

Another long-lost portable restroom brand – USANCO – survives at Selco. Wolff bought about 150 of these rotomolded units in the early 1980s. About three dozen are still in the inventory for construction site rentals.



Bidding on traffic safety rental contracts and then managing and maintaining equipment is a year-round proposition at Selco. Wolff handles the bidding and tracks the company’s construction rental jobs. His son Mark, 45, runs the day-to-day operations.

The company regularly receives bid packages for road and bridge projects from Iowa, Illinois and Wisconsin. Wolff then assembles bids for various combinations of barricades, signage, portable traffic lights, message boards and temporary striping. The Selco bids are then considered by the project’s general contractor.

As a subcontractor, Selco is awarded the business only if selected by a winning general contractor.

How are bid prices developed? “It’s called experience,” Wolff says. Among factors used to develop bids are travel distance, length of the rental period, type of equipment and the risk of loss and damage. Typical rental packages run from $5,000 to $50,000.

Wolff uses a decidedly low-tech – but effective – method to track his company’s project status. Huge roadmaps, speckled with colored pins, cover his office walls. The pins indicate the site, type and equipment in use at each project. For example, a set of blue pins might indicate the location of an asphalt road resurfacing job in western Illinois.

The system is helpful in determining bid rates. Wolff says by glancing at the wall maps, he can take the location of an existing job into consideration to help save on moving equipment from place to place.

Selco’s fleet includes about 20 stake-bed trucks to transport signs, barricades and other gear. Specialty vehicles, such as digger derricks, boom trucks and a rock auger, are used for tasks like setting temporary utility poles for traffic signals and installing overhead lights. One specialty vehicle, called an impact attenuator, is designed to serve as a temporary crash cushion in construction zones.

The boom trucks and augers were purchased from electric utility companies in the area while the crash cushion was home-built with components from Wanco Inc. and TraFix Devices Inc.

The company has been a heavy user of Chevrolet’s W4 series stub-nosed diesel models for its stake-bed trucks. More recent purchases include International TerraStar models for the stake-beds and Sterling, Peterbilt and Freightliner for specialty vehicles.



Mid-April through mid-November is the Midwest’s peak road and bridge construction and portable sanitation season. “It’s a lot like farming. You’ve gotta make hay while the sun shines,” Wolff says. But, the paperwork and equipment maintenance never ends.

“It used to be we would pretty much shut down from November until February, but that’s no longer the case,” he says. Instead, state road construction bids now trickle in from January through June. Selco’s crews, meanwhile, are kept busy repairing equipment much of the winter.

All but about five of the company’s employees work year-round. A complete equipment inventory is conducted each January. Wolff says an annual average loss rate of 10 to 20 percent is normal, as vehicle collisions and weather take a toll on traffic barrels and road signs.

“Plastic has made a big difference,” he says. “When everything was made of wood, our losses were closer to 40 percent.”

The lifespan for a traffic barrel is about three years while an electronic message sign is usually good for about 10 years. Today’s more sophisticated traffic safety devices are pricey. Wolff says new electronic arrow boards are $4,000 to $5,000, the message signs run about $20,000 and new portable traffic lights cost about $50,000 apiece. The more commonplace barrels and barricades run about $50 to $60.

Selco’s traffic control products come from a variety of sources, including Wanco Inc. (electronic message boards), Work Area Protection Corp. (arrow boards), TraFix Devices Inc. and Sun Safety Inc. (barricades, cones and barrels), Lyle Signs Inc. (traffic signs) and Tower Sign and Signal (portable traffic lights.)



Selco voluntarily became a union shop (Teamsters International) about 10 years ago to be compatible with the general contractors working on jobs in Illinois.

While two-thirds of the company’s employees are union members, all receive the prevailing wage rates in each state. The benefits package includes paid health insurance, paid vacation and five casual days each year.

“We don’t punch a clock here. It’s an honor system that uses time cards and it’s rarely abused,” Wolff says. “I’m about as easy to get along with as you can find because I’ve been on both sides of the fence.”

Selco’s employee turnover is fairly low. In fact, Wolff says that in recent years, two workers who left to take other jobs later returned to Selco.



Commercial and residential construction may have been knocked for a loop, but the U.S. recession didn’t touch road construction. Selco picked up some extra work in 2009-10 from asphalt repaving projects funded by federal stimulus money.

Wolff notes that road projects are part of long-term budgets, which are seldom amended by federal and state officials. Wolff doesn’t see a slowdown on the horizon. And, he personally doesn’t expect to slow down for the foreseeable future.

“I just have to say, it’s been a great run,” he says.


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