July 16, 2012 04:11

Inlet Drain Protection

Remember when your dad cut the lawn on Saturdays and when he was done, he turned on the hose and washed all the clippings down the sidewalk and into the gutter? How about when the construction crews had those giant hoses snaking down the street that pumped dirt and debris from the jobsite into the storm drains? I know, it was a long time ago, but for years no one really minded what went down our drains.

With all the new single-family homes that were being built back in the late 1940s and early ’50s, work on those construction sites caused soil compaction, destruction of ground cover, and topsoil stripping. In addition, when it rained, all the oil, sediment, and toxins flowed into storm drains. We could see the debris, trash, and organic solids. What we didn’t see were the pesticides, herbicides, and dangerous chemicals that came along for the ride.

All of a sudden, we began to realize that these contaminants and debris were turning up in our lakes and rivers. So, to address water pollution, the Federal Water Pollution Control Act of 1948 was the first major U.S. law to be passed.

In the 1970s, new regulations were enacted by the Environmental Protection Agency to help control what went down our drains and into our waterways. However, over time, urban development led to more construction. Soon, public awareness led to growing concerns about the environment. So, in 1972, major changes were made to the law and it was renamed the Clean Water Act. The EPA began enforcing stricter guidelines concerning inlet drain protection.

Pollution creates a dangerous environment for aquatic life, as well as for humans. Soil that is free of pollutants still dirties the water, making it hard for fish to breathe, and even leaves and grass clippings begin to release harmful nutrients within hours of being submerged in water. That’s why it’s important to protect our inlet drains and control what flows into them.

Storm drain inlet protectors (SDIPs) are your last chance to capture debris before it gets to a waterway. Although no one product is perfect for every job, there are several options available to protect both drop inlets and curb inlets.

Some devices are meant to be temporary, for use during construction. Industry standards include sandbags, straw wattles and socks, and gravel bags which are placed around inlet curbs.

In addition, there are several types of domes or pyramids that sit on top of the grates of these drains. They are usually made of layers of fabric-like material that filter the water that passes through it. They are usually attached with hooks to hold them in place.

Mats made of rubber or fibrous material are also an option for protecting grates. They are also capable of holding 30 percent more water than gravel, making them a great filtering material for different types of mats and grate covers.

These devices filter and block dirt and other pollutants while still allowing water to flow into the drain freely. The key here is that the device not only be efficient, but also economical. They need to be easy to install and maintain, as well as be removable and reusable.

In addition, some manufacturers have also developed special fabrics that seal themselves to the pavement when they become wet.

These fabrics are now being used in mats and grate covers and, once wet, they ensure that silt is not able to seep under the edges of the mat.

Coconut fiber (or coir fiber) is also beginning to replace both sandbags and straw in protection devices. The coir fiber has an extremely high wet tensile strength, so it is much stronger and performs better than straw wattles. It also does not break down or fall apart like more traditional materials. But it’s 100 percent biodegradable and completely safe for the environment. And because of its slow composition rate, products made with coconut fiber are reusable. Coir is now being used as mats for covering storm grates.

Different parts of the country seem to prefer various types of devices. In some areas, contractors use large wattles, socks, and sandbags. In other areas, they may prefer to use gravel barriers, straw bales, or filter fences. The device you choose is going to depend largely on the environment you’re working in and what is appropriate for the area.

Over the years, contractors have often developed a number of new devices to make their jobs easier. Some have tried to sell their idea to a manufacturer. Others decided to go into the business themselves. For example, Stuart Horner worked as a paving contractor in Texas and got tired of seeing sandbags washed down the inlets after heavy rains.

In 2009, he designed a metal grate that is installed over the opening of curb inlets to trap debris. He calls his product the Curb Companion. He got a patent and has set up a company, Inlet Protection Company, in Gonzales, Texas, to market his product. Horner introduced his product to the City of Austin, Texas, to try out. Since then, Austin has changed its manual on environmental criteria and no longer uses sandbags around their curbs.

There are also some protection devices that are permanent. For example, skimmer boxes, which are used for catching soil and trash from drop inlets. They are usually installed just under the ground level and are able to catch ongoing debris in high traffic areas.

New floccing products are being used in inlet protection devices as well. FlocSnake, developed by ACF Environmental, is a long sock-like tube filled with flocculating agents that is placed around storm drains and grates. The agents in the tube separate dangerous solids from the storm water as it passes through to the drain.

As a companion product, ACF has also developed Floccin, which is a granular flocculating agent that can be sprinkled on wattles or rock check dams before or after a rain event. The granules are also safe to sprinkle into ditches, ponds, and streams.

Flocculation is a technique that has long been used in waste water treatment and swimming pool maintenance. Flocculation is a chemical process that separates solids from liquids and restores the pH balance of water. In this process, sediment, chemicals, hydrocarbons and heavy metals are filtered from the water; they then clump together so they can be easily removed.

Science takes center stage in the development of other products as well. New devices are now being designed that are able to degrade microbiologically instead of by photo-degeneration. After use, they can safely go to a landfill, or will simply biodegrade on the work site.

Many manufacturers are now using lighter weight materials and are adding handles to the apparatus for easier carrying and quick installation. You also want the devices to be highly visible for both your workers and others. Look for products that are painted in bright colors to help avoid these issues. Large wattles and gravel bags can cause costly damage to your vehicles and are a serious hazard to pedestrians. Eventually, someone is going to run over them, so look for durability as well.

Although SDIPs are effective tools for protecting our waterways, these devices can become overburdened, especially during a major storm. Keep in mind that this equipment will need to be maintained on the job. Inlet protection devices need to be cleaned, especially after heavy rains, so they do not become clogged up with sediment and debris. Some may need to be replaced or repaired. All should be inspected at regularly scheduled intervals.

Between new government regulations, technological advances, and the ever-growing concern for the environment, it is important that you stay up-to-date. It will also keep you ahead of your competition.

New stormwater guidelines developed by The Environmental Protection Agency are set to take effect over the next two years. Many of these new regulations will ultimately lead to national standards by superseding the ones some states already have in place. It’s important to know these regulations, and realize that they may vary from one jurisdiction to the next. Work with your city and county inspectors, as well as the watershed coordinators, so you know all the current guidelines.

For instance, in 2014, the Effluent Limitations Guidelines will enforce turbidity limitations on all construction sites that disturb ten or more acres of land at one time. The EPA says, “The rule requires certain construction site owners and operators to sample stormwater discharges and comply with a numeric standard for the pollutant turbidity in these discharges.”

While the EPA develops stricter regulations and we all work to reduce our own carbon footprint, manufacturers are working all the time to develop new products to help keep our waterways as clean as possible. Science and design are coming together to offer new devices that are stronger, greener, and more reliable.

It’s important to work with your city and county inspectors. You need to know the regulations and realize that they may vary from one jurisdiction to the next. You also need to keep them informed about what is working and what isn’t. Let them know which devices and practices are the most effective, economical, and easiest to maintain. Communication is a key factor in keeping everyone in compliance with the government and doing what is best for the environment.

Unfortunately, the red tape involved when working with these governmental offices can be exasperating. One manufacturer, who requested anonymity, spoke about the frustration of developing new products with new techniques and new technology, only to find that the cities, municipalities, etc., were very slow to accept them and incorporate them into their manuals and specs.

Another said that when a contractor bids on a project, let’s say for a Department of Transportation (DOT), to keep his bid low, he will continue to use the old products, rather than try to convince the DOT that by using the new technology, the environment would benefit. He said that some cities would rather pay the fines, if caught, than to spend a little more on the new products, because it will increase the cost of the project.

Water is our most basic need. We need it to live. We bathe our babies in it and teach our children to swim in it. Even our bones have water in them. Years ago, phrases like ‘eco-friendly’ and ‘going green’ were just buzzwords attached to a trend of reducing, reusing, and recycling. But our environmental concerns are no longer a trend, and we can no longer afford to purposely devastate our most precious resource. If we are serious about preserving our waterways and keeping them clean, then protecting our inlet drains must be a top priority.

Also in Soil Erosion News

In many ways, we are fortunate that, in our chosen profession, we are able to help people when certain disasters occur: the tornadoes in Missouri, Oklahoma, Louisiana and Georgia, the flooding in Louisiana, the snows in the northeastern part of the country, the rain in California, and the snow in Colorado....

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