Studies in Sediment Control

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When Nathan Stacy started Stacy’s ­Excavating in 2001, the Arcadia, IN-based company was bringing in less than $50,000 in revenues. The company is now pulling in more than $1 million.

The reason: an increasing amount of regulations is creating a greater demand for sediment control services.

With 10 employees, Stacy’s Excavating services mostly residential homebuilders such as Ryland Homes and Pulte Homes in a two-hour radius around Indianapolis.

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Stacy notes that the increased number of regulations among local municipalities and from EPA is creating more work for the company. The regulations have become stricter and demand more job site protections. Inspections to ensure compliance are becoming more frequent as well.

“Every city does it after every half-inch of rainfall around here,” says Stacy. “In the summer months when it’s not really raining, they’re required to do a weekly inspection on all of the job sites.

“A few cities in this area have their own stormwater inspector and that’s all they do—go around to inspect stormwater best management practices and silt fence,” he adds.

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In performing sediment control, the company typically uses silt fence, erosion logs, fabric mats, and inlet drain covers for its work. Among the items used are Blocksom and Co. products. The company’s Storm Water Inlet Filter serves as a sediment control solution for sewer inlets during the construction phase; it is constructed of 100% coir fiber bonded to a fiberglass mesh backing.

The mat is cut to allow a 3-inch overlap at each side of the grate and is attached to the top side of the inlet grate using cable ties. Maintenance includes cleaning silt from around the inlet mat after each rain and sweeping the top of the mat to clear built-up silt and solids.

Stacy has found using silt fence along a curb and filter mats on storm drains the two most effective methods of sediment control. Although some silt fence doesn’t stay up as long as he’d like it to, it works well in holding back the sediment, he says.

“The filter mats we use are inexpensive and easy to replace,” he adds.

Stacy also favors using erosion logs. “They don’t require much manual labor,” he says. “You just lay them on the ground and make sure they’re overlapped. They work really well.”

In addition to an increase in regulations, a mild winter has enabled Stacy’s Excavating crews to put in more work hours.

“We haven’t had a lot of snow here,” he says. “Usually we’re off for a few months in the winter with the ground freezing. It’s been a really mild winter and it’s been real wet and nasty. We have a couple of communities where we do the entire curb protection and silt fence. We’re having to maintain them through all of this rain and water, because they’re still enforcing the regulations.”

Looking ahead, Stacy believes regulations will become stricter and continue to increase in number. “I’m hiring more people and training more guys to do the sediment control,” he says.

In the Denver, CO, area, ever-evolving and stronger regulations are also keeping Down to Earth Compliance (DTEC) crews busy. The company provides a range of services related to stormwater management, sediment and erosion control, and revegetation for commercial and residential home construction sites in several western states with 26 field employees.

Brad Bierling, project manager and scheduler with DTEC, says the installation and maintenance crews use a variety of BMPs that may include inlet protection devices, erosion control blankets, silt fence, and heavyweight wattles from a variety of companies, including Gator Guard. The company’s reclamation division performs revegetation work.

One of the company’s biggest projects began in fall 2012 with the construction of the Leyden Rock community in Arvada, CO. The goal is to preserve the area’s natural attractiveness while constructing 1,439 homes over 1,033 acres, of which 600 are designated for open space. The project involves multiple homebuilders and includes construction of other facilities, such as schools.

The community is being constructed in six phases, with an anticipated completion date of 2018. DTEC was chosen as the sole erosion control company throughout the community’s construction for the project’s duration.

Each day, a DTEC team is onsite to perform silt fence installation and repair, installation of erosion control blankets where needed, reclamation and seeding projects, and sediment cleanup, among other tasks.

“We started on the project when it was just land and we’re doing initial installs,” says Bierling. “We’ve done some major seeding, grading diversion ditches, rock checks—pretty much an array of BMP work. We’ve been working on it for about two years, and it’s by far one of the biggest projects we have worked on.”

Generally, DTEC will choose a sediment control approach based on how much water flow comes through the site, the slope grade, and degree of erosion.

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Credit: STACY’S EXCAVATING
Silt fence and inlet protection are still two of the most effective ways to contrrol sediment.

Bierling, who has worked at DTEC for 14 years, says he has observed that more municipalities are getting stricter with their inspections, both in visiting sites and making people follow through with the regulations.

“Inspections are frequent, but a lot of times, they’ll check a site after big storms because that’s when you usually have the potential for most damage,” he adds.

Harsh weather can be one of the company’s biggest challenges. “We’ve had some inclement weather over the past year or two with some pretty good rainstorms and big gulley washers,” says Bierling. “We’ve had to do some extensive BMP work to get things back in order.”

FLS Energy is a full-service solar energy provider that owns and operates a portfolio of solar energy assets throughout the US. Its development team takes a project from conception to commissioning and offers complete in-house system design, engineering, construction, financing, and turnkey project development.

Norman G. Miller Jr. performs civil compliance for the company. “Our approved plans always contain a construction sequence,” he says. ­”Construction entrances, perimeter protection, and the protection of ­wetlands or streams are required straightaway. Clearing only enough to allow the installation of these ­measures is a requirement before any other land disturbing or construction activity is started.”

On the company’s larger projects, the North Carolina Department of Environmental Quality (NCDEQ) sometimes divides the project into smaller sections with a separate permit for each. Miller notes that the agency also requires phasing of the project. Cleared land for one phase must be stabilized before disturbing the next phase.

In terms of regulations, the NCDEQ in recent years has shifted its focus to customer service, notes Miller.

“The relationship has changed from compliance enforcement to compliance cooperation,” he says. “Still, the regulations stress that the permits are performance based. Measures need to be maintained, and ineffective measures have to be re-evaluated and redesigned to comply with the permit.”

Regulators can inspect the FLS Energy sites at any time and will also schedule inspections at the permit holders’ request, notes Miller.

“Permits require that the permit holder perform weekly inspections and after every half-inch rain event,” he says.

Terra Services’ 20 division employees provide erosion control and landscape services throughout the state of Minnesota to the commercial, residential, and government sectors, with heavy highway work at the core of its business model.

The company, a division of Hardrives Inc., is occasionally asked to pioneer new practices because a growing percentage of its work is design-build, notes Mark Jeffries, division manager for Terra Services.

On some projects, the prime contractor is responsible for designing the project, giving Terra Services the opportunity for input—as a subcontractor—as to how the design might evolve or change over the course of the project. “This creates opportunity for innovation and partnership,” says Jeffries.

Design-build projects—in contrast to bid-build projects—are becoming more common in Minnesota, with the state scoring contractors on their design, notes Jeffries.

“It’s not always just the low bid process,” he says. “It’s also part of a design process, and temporary erosion control is a big part of that. Quite often, as a subcontractor, we will partner along with the prime contractor to solve unforeseen erosion control issues that materialize on many projects. We also have the opportunity to field-test new products as potential solutions to erosion control challenges.”

Terra Services has been in business for 12 years; experience and the ability to try different approaches has led to Jeffries favoring the use of hydromulch for temporary erosion control.

“They’re the best thing on the market right now,” he says. “We still use straw and in some cases use blankets, but it seems like most of our temporary erosion control is concentrated on smaller areas, and hydromulches fit pretty well with that.”

Terra Services also uses a great deal of Silt Socks, a filter fabric sock typically filled with wood chips or compost for inlet protection, culvert protection, ditch checks, and perimeter control. “They’ve become a very useful, effective BMP for us,” notes Jeffries.

An important factor in using hydromulch is the rapidity with which the company can respond to emergency erosion control needs. “Someone calls in the morning and they need two loads of hydromulch, and if they’re close, we can get over and get an area covered for them before a rain event or a similar situation,” notes Jeffries.

Terra will often use an erosion control blanket to stabilize a ditch on a temporary basis to protect a regulated water body. In one example, the blanket is placed at the end of a culvert in the ditch if it is a conveyance system to a creek, river, lake, or pond.

“On many projects, you don’t have any latitude. They design the project and you bid it and build it accordingly,” says Jeffries. “When the contractor and owner add flexibility into the design, the results are often more successful, innovative, and cost effective.”

Of note, Minnesota is experimenting with some projects that include a lump-sum item for temporary erosion control, thus adding the potential for the erosion control contractor to have increased input in the temporary erosion control design of a project.

“That item becomes a design-build,” says Jeffries. “They are reminding the prime contractor it’s their responsibility to meet the permit requirements, and how they do it is up to them. We might get four or five prime contractors bidding a project, and in addition to a consulting firm that may be hired to prepare a SWPPP [stormwater pollution prevention plan], Terra often would be asked for input on what quantities and types of BMPs we think should go into that project. This results in a unique temporary erosion control design for each contractor on the same project.”

There is a lot of sandy soil that kicks up on the agricultural, railroad, and oil field job sites where Guy’s Seed Co. provides erosion control services in Oklahoma, Texas, and Kansas. Owner Rodney Guy says he finds the most effect erosion control approach to be mechanical seeding topped with shredded hay bales.

Guy also likes to use Triangular Silt Dike products, particularly the 10-inch barrier. “A lot of these oil field well sites have steep and long slopes around them, and because of the tendency of the soil to erode, we put them on there to divert the water,” he says.

Guy’s crews break the Triangular Silt Dike into sections and divert the water so it doesn’t gain momentum.

“Generally on those sites, you can’t get straw up there, so we use a hydroseeding machine to shoot the water mixed with the seed and fertilizer. We blow that up on the hill and then we put those dikes in, and they work very, very well,” says Guy.

“One thing about the Triangular Silt Dike that’s so good is we’ve got plastic flaps on the uphill side and the downhill. When the water runs down, it gets on that plastic flap that you put at a downhill angle runs off, and you can direct it anywhere you want to,” he says. “The result is that the water running off the side of the hill just runs a short way and is siphoned off instead of running all the way down the hill, gaining speed and momentum and volume. It prevents a wash-out.

“Another thing I like about the Triangular Silt Dike is that you can leave it there for a year and pull thing up and reuse it. I’ve seen ropes and all sorts of crud used for erosion control, but the problem is water rushes up and goes underneath it, whereas with the dike, it goes on that flap and rides off that flap.”

Guy notes that there are not as many regulations governing what he does as there are in some other states.

“The seed we put out has to be ­accurately labeled and has to be tested with a federally approved seed testing lab,” he says. “If there’s anyone who checks our work, it’s the oil company supervisors. They make sure it’s done the way they want it done or they make sure it’s approved.”  Ec Bug Web

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