A major project for SMI Services, LLC was restoration and stabilization of a 3,000-foot section of Brier Mill Run stream along New Carrollton Parkway in Prince George’s County.

SMI Services, LLC President Stephen G. Principe founded the company in 1997. He hopes to transition it to an employee-owned operation over the next five years.

When the rain comes down, say the folks at SMI Services, LLC (SMI), the water goes where it wants to go, taking soil and debris with it. Challenging this fact of nature is the mission of SMI’s stormwater management specialists, who work to control erosion, manage drainage systems, restore malfunctioning streams to health and make the environment a little bit better each time.

“We’re the guys who keep the dirt from getting where it’s not supposed to be, clean it up when it has gotten there and fix the channels that carry it,” says Stephen Principe, President of Bowie, Maryland-based SMI. “We do straightforward erosion and sediment control, waterway cleanup, stream stabilization, pond restoration and environmental interventions to deal with polluted surface water.”

Adds Senior Estimator Patrick McCall, “Sometimes we reconstruct a streambed to stabilize the slopes, slow the current down and give it a chance to settle its sediments naturally. With ponds, we often have to pump all the water out, clean out the accumulated muck and then reconfigure the way it handles water."

“We use an array of techniques to manage and filter water, from riprap constructions that filter sediments to bioretention systems that capture stormwater runoff pollutants.”

Says Stephen: “We’ve been doing these things for years, and we excel at it.”

From Construction to Stream Repair

Before and after a stint in the U.S. Air Force, Stephen worked in his family’s home-building company, Crown Homes LLC. It’s a three-generation family business—his parents started it and he grew up working in it. Today, his eldest son and youngest daughter are involved in the company, and since 2017, he’s served as President of Crown Homes as well as SMI. They’re headquartered together in Bowie, Maryland.

In the late 1990s, as federal and state environment regulations became increasingly stringent, he saw an opportunity for a business focusing on erosion prevention and stormwater control. He founded the company in 1997 as Site Maintenance, Inc.

“We started with three guys, a crew truck, a trailer and a skid steer,” he says. “In the beginning, we worked primarily for contractors building residential developments, doing mostly sediment and erosion control—the familiar black silt fences and other measures—and channeling the drainage off downspouts and gutters.”

When homebuilding crashed in the Great Recession of 2007-2009, the company shifted toward commercial projects like shopping centers, private business structures and government work including schools and road projects.

“With the increased emphasis on environmental regulation across the nation, stormwater management became very important in Maryland,” Stephen says. “We still do a lot of sediment and erosion control, but now about 50 percent of our work involves stormwater management, often related to environmental goals.”

As the scope of services evolved, in 2010 Stephen wanted a fresh look for the company. Site Maintenance, Inc. transitioned to SMI Services, LLC. Today, along with its main corporate offices in Bowie, it has branches in Mount Airy, Maryland, in Trenton, New Jersey, and in Selbyville and Smyrna, Delaware. Stephen emphasizes its status as a veteran-owned and minority-owned small business.

All told, the current SMI workforce numbers more than 100, whose steadfast dedication Stephen credits for the company’s success. “A lot of our folks have been with the company for years,” he says. “They’ve made the company what it is, and they’re like family.”

Slowing Down Stormwater

A key motivation for Maryland’s emphasis on stormwater management is concern for the delicate ecosystem of the Chesapeake Bay, which has at least 40 streams in six states flowing into it. Inevitably, the contaminants they carry end up in the bay, seriously disrupting its health. Agricultural runoff and other pollutants threaten not just the environment but economic drivers like commercial fisheries, recreational opportunities and tourism.

“Water is a natural eroder,” Patrick notes. “It moves through a stream and takes soil and stones with it, wears away the banks and widens the channel. In addition, brush, trash, stones and downed trees can block or impair the flow. Widening is a natural process, but if it happens too close to highways or buildings, it’s a problem. A stream remediation process is basically ‘mechanical.’ But sometimes it requires special soils.”

Stream Stabilization Strategies

The SMI crews generally start work on a flowing waterway by taking in excavators and clearing the trash, silt and other sediments, as well as invasive plants. They regrade the slopes and armor the banks with rocks and vegetation to minimize erosion. They stabilize the channel with stones to filter the water and slow down the current. The slower the water moves through, the better it allows the silt to drop out rather than head for the nearest drainage area or waterway. At times, the team builds step pools and check dams to slow down the flow.

Retrofitting a pond involves similar work. The crew typically starts by “de-watering” the pond to facilitate removing accumulated mud and trash. If stream entrances and exits have riprap—constructions of stones massed together to filter the water—they may remove the stones by hand, wash them and resettle them.

They may create “gabion baskets,” steel and wire constructions filled with stones at the pond entrance to filter sediments and nutrients out of the inflowing water. “Gabion” is a term for stones 4 to 7 inches in length. Riprap is usually 8 to 12 inches in size.

Techniques commonly used include outfall protection (using riprap and/or vegetation to stabilize and filter water through the junction where a drainpipe or channel enters a pond); wet swales (broad, vegetative-lined ditches, often along the sides of roads, to carry runoff water to a natural body like a wetland, stream or pond); and submerged gravel wetlands (areas of wet or poor-draining soil filled with gravel and covered with soil in which native plants can grow and remove contaminants and sediments).

Bioretention Strategies

“A big concern,” Patrick adds, “is that stormwater often picks up environmentally harmful substances—nitrogen and phosphorus from fertilizer runoff, oil and grease from roadway spills, rubber from tire skids, tars from roof shingles. They aren’t filtered out by wet swales and the like, so we use engineered soils where we find particularly difficult problems.”

Engineered soils are systems that mix layers of topsoil, sand and compost, often several-feet deep. Combined with grasses and other plantings, they take up pollutants while the filtered water is returned to the groundwater.

In a bioretention situation, they’re likely to focus on constructing formations like bioswales (basically wet swales that channel water across engineered soils and plants); bioretention cells (large, in-ground structures that filter runoff from as much as 5 acres of paved area, like parking lots and buildings); micro-bioretention cells (smaller versions); and tree box filters (concrete boxes filled with engineered soil in which trees are planted to assist in filtering).

Partnering for Clean Water

Through its public-private Clean Water Partnership (CWP) program, Maryland’s Prince George’s County has been a leader in stormwater management. Established in 2015, the program partners with private contractors for stormwater control projects, emphasizing employment of local minority-owned small businesses. Today, other Maryland counties and mid-Atlantic states have similar programs.

Although the CWP is only a small part of SMI’s work, the company has completed more than 15 CWP projects since the program began.

One standout is the restoration of Brier Mill Run stream, a 3,000-foot channel along New Carrollton Parkway. Another is the retrofitting of Carol Pond at Maryvale, a large stormwater management pond. The latter work involved dewatering the pond, hauling out significant amounts of dirt, regrading it and installing a huge gabion basket wall.

“Both were challenging sites that we restored and stabilized in good time and on budget,” Stephen notes. “And, they both look gorgeous!”

A showcase assignment from the Maryland Department of Transportation State Highway Administration (SHA) was a design, build, operate and maintain project (DBOM) project in Charles County, involving 99 stormwater management facilities.

“We’re proud of this work,” Stephen says, “because we administered a program that had never been performed for the SHA before—a DBOM project. The entire process went very smoothly and showed the SHA that they can have contractors maintain their stormwater management facilities for them and not have to implement time-consuming programs internally.”

Two Goals, Five Years

With 100-plus employees, branches in three states and a strong skill set for environmental projects, Stephen hopes to accomplish two goals over the coming years.

One is expanding SMI’s scope of work in environmental projects. “In recent years,” he says, “many more techniques for managing pollutants have been developed. There’s so much more we can do in this area.”

The other involves his employees. He is emphatic that the success of SMI rests on the shoulders of the people who work for SMI, some of whom have been with the company since its beginning.

“I hope to transition the company to an employee-owned business within the next five years,” he says. “I’m not close to retirement and would remain involved. But I think they deserve ownership, and I know the company will be in good hands when it happens.”