More Than One Way to Put Up a Fence

But while silt fence has always been the top option for sediment control, contractors today must pay even more attention to the proper installation of this erosion and sediment control standby. Federal and local regulations, not to mention good construction practices in general, have always required that contractors take measures to prevent silt and sediment from running off their construction sites during rainstorms or other forces. But in March 2003, the second phase of the National Pollutant Discharge Elimination System – a component of the federal Clean Water Act – took effect, extending rules that once applied to construction sites of more than 5 ac. to smaller ones as well, sites covering just 1-5 ac. Fines for not complying with these rules can be high. And the bad public relations that result from these fines can prove to be even more costly to developers and construction contractors.Because of this, contractors are paying more attention than ever to silt fence, largely because it still is overwhelmingly the top option that they turn to when it’s time to worry about controlling sediment runoff. In some areas, though, silt fence has gained a spotty reputation because crews often install it improperly or fail to maintain it once it is installed. Companies that offer alternatives to silt fence – drain inlet protection devices, for instance – often advertise their products as “better than silt fence.” Silt fence, however, despite the alternatives on the market, is still prevalent, and it’s important that crews know how to – and are willing to – install them properly. A fence not installed properly serves no purpose and does nothing to prevent silt or sediment from washing away during heavy rains. ESC experts around the country say many developers and contractors still don’t know exactly how to install silt fence. And those who don’t learn, they say, are only asking for trouble.“This is a huge problem,” says Tom Carpenter, owner of Carpenter Erosion Control. “The problem is that installing a silt fence is much more complex than contractors know. It’s not something that can be summarized by three or four bullet points in a set of instructions or a magazine story. There is so much to it. It’s like the chicken before the egg. It doesn’t do you any good to, for example, install the fence properly if it’s not placed on the right part of the construction site or if you don’t use enough of it.”Carpenter and several others recently talked about the steps developers and construction crews can take to make sure they install silt fence correctly. Here is what they had to say.The ProblemsSteve Lawko of Cleveland, OH’s Rhino Seed & Landscape, which sells silt fence, observes that contractors are slowly getting better at installing the product properly. “A few years ago a lot of the fence was put in incorrectly. I couldn’t give a percentage, but it was a significant amount. I could drive down the road and see under the fences. But just as with all other sediment control or erosion control products, people have learned more about them, how to work with them. There are full-time contractors out there now who do nothing but install silt fence for a living. They have to do it right to continue to earn their living.”Silt fence itself also has changed during the years, Lawko notes. Developers once installed it using any kind of stake available. They didn’t necessarily worry about spacing these stakes in a particular way either, he states. Today, though, contractors almost always are required to follow detailed specifications, laid out by counties, highway departments, environmental departments, or state regulatory agencies, when installing silt fence.This doesn’t mean, however, that every crew gets it right each time. The biggest problem Lawko sees is the failure to dig a deep-enough trench for the fence. “That’s a big one. If they don’t do that, there’s no chance the fence will work right. Crews will sometimes do a poor job. They’ll just trash the ground instead of building a real trench,” Lawko says.Billy Thompson with Birmingham, AL’s Nelson King Inc. also has seen improvements in silt fences over the years. Today Thompson’s company uses a variety of fabrics in the silt fence it installs, including high-flow fabrics designed specifically for areas featuring higher water flow. Thompson estimates that throughout the Birmingham area, contractors turn to silt fence about 90% of the time for sediment control.While most contractors install their fences properly, some do not, Thompson points out. “I’ve seen some where they haven’t anchored the bottom securely enough. They don’t get the fence down deep enough to keep blowout from happening. I think sometimes it’s just a failure to get their trench deep enough.”This isn’t surprising. Building a deep-enough trench – at least 6 in. deep, according to industry pros – is hard work. It’s why many companies turn to trenching machines. Nelson King crews, for instance, used a 24-in. trencher for the most recent silt fences they installed. But not all contractors refrain from hand-digging a trench. Craig Hammann, general manager of CEAttachments, recently drove home to his subdivision to find a crew of workers digging a trench around a water retention area and installing a silt fence. The crew was doing this entirely by hand.Hammann, of course, took the opportunity to talk to them about the EDGE Silt Fence Installer, which is an attachment that mounts onto trenchers and allows for up to 40 ft. of silt fence to be installed a minute. “The attachment is very new, so I wouldn’t say it is popular yet,” he says. “The task of installing silt fence, though, is popular. I don’t think any region of the country has the lock on how to install it. There are so many ways of installing it that no one way has ever been deemed the best. We offer an alternative.”Hammann agrees that the most common mistake crews make when installing a silt fence is that they fail to anchor it properly. “You can adjust the depth of the fence and get a taller silt fence and bury it deeper. But when the water is trying to pull this fence out of the ground and there is a tremendous amount of force there, just burying the fence in the ground is not the answer. With the anchoring our system provides, the fence material starts at the side of the fence and goes down. It’s more like a pocket of soil and fence. It then crosses over itself and locks it in place.”Since Phase II went into effect, Chris McCormick, owner of McCormick Equipment, has gotten more calls than ever about his silt fence plow. He explains that this is because his plow helps contractors reduce errors. With the plow, crews can install fence deeper and into a tighter slot. Too often, McCormick says, crews cheat when it comes to installing silt fence.“Guys just don’t put it in right,” he observes. “They try to cut corners and do it as quickly as they can. If they’re using a machine, it’s an easier job. They are more willing to do the job right because it’s not nearly as difficult as it once was.”Some certainly believe that part of the responsibility for improperly installed silt fences rests with regulatory agencies. Scott Forse with Bethel Park, PA­based JMD Company, which both manufactures and installs silt fence, says that contractors won’t truly become serious about properly installing fences until the agencies that regulate them get tougher.“Often the government regulatory agencies or the conservation districts themselves do not take silt fence seriously enough to have the contractor take it seriously,” Forse maintains. “On regular commercial projects, a lot of contractors know that they have to install silt fence, but they also know that no one is really checking it thoroughly. They just throw it up. A lot of times they may not even trench it because they don’t have a trencher. They pound it in and throw some material on the flap. When it gets wet, the front part of the flap gets saturated, and either it breaks down or the water goes underneath.”Forse believes the situation might be changing with the new federal regulations. JMD installs as much as 63 mi. of silt fence in a given year. It’s important to Forse, as an active participant in the industry, that the fence earns a more positive reputation. And if contractors and developers across the country spend more time installing the fences properly, much of the negative press the fences receive will surely disappear.“People are slowly getting better at this,” Forse believes. “The Phase II regulations have made a big difference. Agencies are starting to throw some fines around to let contractors know they are more serious about this than they once were. The federal government is saying take this seriously or they won’t fund your project. The states are finally getting off their butts and checking projects more seriously and throwing out fines of their own. That attitude trickles down to the contractor.”Still, Forse describes one local construction project that features absolutely no silt fence at all. “The project called for it, but the crews just didn’t use it,” he says. “You have a couple of people in every county where the guys who are supposed to enforce these regulations are just too busy to do it.”The Options“A proper silt fence installation is like a long chain,” relates Tom Carpenter. “If one link is broken, the whole system is worthless.” Carpenter literally wrote the book on silt fence – a manual called Silt Fence That Works that contains detailed instructions on how to properly install a fence. He has identified six major points concerning silt fences and their installation: placement, quantity, installation, compaction, posting, and attachment. “You cannot talk about effective silt fence without including all the elements,” he insists.Many contractors fail when it comes to the first element, proper placement of a silt fence, he notes. The goal of a fence is to pond and store water. If water runs around the fence’s end, the fence is worthless. Often contractors must install their fences in the shape of a smile or J-hook to create a water-storage area. There are times, however, when a construction site just doesn’t lend itself to silt fence, Carpenter points out. “Sometimes it is better to say, OThis is not the proper place for silt fence. XYZ is a better option,’ or to say, OSilt fence won’t work here; we need to move it somewhere else,’ or to tell the site manager, OYou must prepare the area so we can do a proper installation.'”Then there’s the issue of quantity. Carpenter recommends that contractors install 100 lin. ft. of fence per 10,000 ft.² of area. He also recommends that crews break large site areas into more manageable chunks of land by installing multiple runs of silt fence. Most contractors employ standard trenching when installing silt fence; Carpenter maintains that this method might not prove to be the most effective. Indeed, he notes, research conducted by the United States Environmental Protection Agency has shown that the less widely used method of static slicing is a more dependable installation method. The issue of compacting the soil obviously is important as well, and crews that provide a bare minimum of compaction risk having an underperforming silt fence. The reason? Compaction minimizes the amount of water that can saturate the base soil. Because of this, it stabilizes the installation and cuts down significantly on the possibility of washouts.Equally important is that contractors properly space their posts and dig them deep enough into the ground. Carpenter recommends that crews place posts 4-5 ft. apart where water concentrates and 6-7 ft. apart in low-stress areas. Workers should dig their posts as deep into the ground as high as the fabric above the ground stands. He also observes that steel posts, which are more durable, are preferable to wooden ones.Finally, there’s the attachment issue. Many crews fail to properly attach fabric to their posts; ideally the fabric will be able to support 18 in. of water and sediment. Contractors should use three plastic ties or wire installed diagonally within the top 8 in. of a steel post. Carpenter hopes that contractors, faced with changes brought about by National Pollutant Discharge Elimination System Phase II, now will do everything in their power to make sure their crews install silt fences properly. When fences are dug correctly, he says, they are an extremely effective method for controlling runoff.“Water, especially in volume, is a tremendous force. Because silt fence is mechanically installed in the soil and supported mechanically, it can detain hundreds of pounds of sediment and water, even a concentrated flow. Most other sediment retention devices rely on their weight alone to stop and retain water and therefore are woefully inadequate.”Not everyone, though, agrees that silt fence is the best way to stop runoff. Roger Singleton of Conyers, GA­based Silt-Saver, points out that contractors have options and alternatives to silt fence, such as the Silt-Saver storm drain inlet filter, which is marketed as a better option for controlling sediment or silt.“The industry considers silt fence the answer to all of our problems,” Singleton says. “Problem is, it is designed for one thing and used for everything. We’re trying to convince the industry that there are different tools to be used in erosion control. If each tool was used for what it was designed for, we’d have better erosion control.”The Silt-Saver, unlike silt fence, actually filters water, he explains, and features a frame that gives it the strength to not fall in. He realizes, however, that silt fence will remain the construction industry’s top choice because it is relatively inexpensive.“The problem with our industry is that performance doesn’t matter,” he says. “It’s the bid sheet that matters. People are more interested in using the cheapest product they can get in there regardless of performance. We are pushing the industry very hard for performance standards.” So far, the Silt-Saver has been approved by 10 states. But the product still has a long way to go before it becomes even a shade as popular as is silt fence.Just ask Mike Singleton (no relation to Roger Singleton). He knows that he will almost always turn to silt fence when it comes to sediment control. The project manager for Alton Industries in Pittsburgh reports that his company uses silt fence in almost every project it tackles.“These days we’re pretty well versed in it,” he says. “We’ve been using it for a long time, so we avoid the mistakes some people make. We do everything from clearing and grubbing to major earthwork. And on almost every project, we use silt fence.”