Silt fences and erosion control might not be the most exciting topics in construction, but they’re critical—especially if you want to avoid costly fines and environmental damage. Whether you’re new to the game or a seasoned pro, understanding how to manage runoff and erosion on your job site can save you a lot of headaches.
What Is Silt, and Why Should You Care?
Silt is essentially loose soil, often a mix of dirt and fine particles, that runs off your job site when you disturb the natural ground. When you’re grading land, clearing trees, or doing any type of earth-moving, the roots of plants and trees that normally hold the soil together get uprooted, making the ground more prone to erosion. The result? A muddy mess that can wreak havoc on nearby properties, streams, and even your project itself.
When heavy rain hits, all that loose dirt turns into what’s called siltation. The rainwater starts dragging this silt downhill, potentially onto neighboring properties or into nearby water sources like streams or rivers. That’s where a silt fence comes in.
The Basics of Silt Fences
A silt fence acts as a barrier, letting water pass through while trapping the silt and preventing it from washing away. It’s not rocket science, but installing one correctly makes all the difference. Here’s how it’s done:
- Trenching: You can’t just stick the fence in the ground and hope for the best. You need to dig a small trench, typically about six inches deep, where the fence will go.
- Securing the Fence: The fence is usually stapled to wooden posts and run along the length of the trench. You want the fence to stand firm against the water while letting the water flow through. Backfilling the trench around the bottom of the fence keeps the silt from sneaking under.
- Keeping It Up: Silt fences aren’t “set it and forget it” pieces of equipment. After a couple of big storms, the fence will accumulate a lot of silt and could even collapse under the pressure. You’ll either need to add a new fence behind the original one or clear out the collected silt.
Inspections and Compliance: Keeping Your Job Legal
If you think throwing up a silt fence is enough, think again. Inspections are a crucial part of erosion control. In many cases, an erosion control company will visit your job site regularly, often weekly, to make sure your barriers are still doing their job. If they find anything wrong—like a breach in the fence—they’ll notify you, giving you time to fix the problem before the next inspection.
And here’s the kicker: if you ignore those warnings and Mother Nature hits you with a big storm, the cleanup is on you. Worse yet, if that runoff finds its way into a stream, you’ll have more than just mud to worry about—the Environmental Protection Agency (EPA) could come knocking, and that’s when fines can start piling up.
What If You Don’t Fix It?
Let’s say your inspector has been telling you for a week that part of your silt fence is faulty, but you haven’t had a chance to address it. Then, a heavy rainstorm rolls through, and all that silt ends up breaching the fence and flows straight into a stream. Now, not only are you liable for the cleanup, but you also face potential fines from the EPA or state environmental agencies.
And cleaning up isn’t as easy as sending in a backhoe. If the silt made it into a stream, you’ll likely be restricted to using shovels and wheelbarrows. Imagine hauling out five or six dump truck loads worth of silt with just a shovel. It’s not a pretty picture, is it?
Different Types of Silt Fences
Not all silt fences are created equal. The most common is your basic fence: fabric attached to wooden posts. But on more demanding job sites, you might need something sturdier, like a silt fence with wire backing. This type has fencing wire zip-tied to the fabric for extra support, helping it withstand more pressure from accumulated silt.
Multiple Layers of Protection
Sometimes, one fence isn’t enough. On projects with significant elevation changes, or where a stream is nearby, it’s common to see multiple rows of silt fence. The idea is that if the first fence fails, the second or even third one will catch what’s left. It’s a bit like having a backup parachute—better safe than sorry.
Predicting the Worst: Planning for Major Weather Events
In construction, you can’t control Mother Nature, but you can plan for her worst moods. Projects are typically designed to handle what’s called a “100-year flood,” meaning the site should be able to withstand a massive flood that statistically happens once every 100 years. Of course, as many of us know, “100-year floods” seem to be happening a lot more often lately, so planning for these events is crucial.
Subcontracting Erosion Control
Many contractors prefer to subcontract the erosion control part of the job. It’s one less thing to worry about, and these subcontractors often have inspectors on staff who will visit the site, monitor the conditions, and provide you with compliance reports. If an inspector from an environmental agency shows up, you’ll have everything documented, showing that you’ve done your due diligence.
Final Thoughts: Don’t Let Erosion Control Catch You Off Guard
Erosion control isn’t glamorous, but it’s essential. Ignoring it or cutting corners can lead to significant problems, from hefty fines to labor-intensive cleanup jobs. If you’re new to the industry, it’s best to subcontract the erosion control portion of your project, so you can focus on the build itself while staying compliant with regulations.
So, next time you’re on a job site and someone mentions silt fences, you’ll know just how important they are—not just for keeping your site clean, but for protecting yourself and your business from avoidable headaches.