Neal Bolton

By Neal Bolton

For most landfills, litter control is an ongoing process. For the job, litter fences are the most effective and usually the most economical means. However, many landfills skimp when it comes to installing fences.

Litter fences come in various types, depending upon their location and purpose. Here's a rundown on what landfills have to choose from. The list includes portable fences at the tipping area and face, semi-permanent fences downwind of the active landfill, and permanent fences along the perimeter of the landfill.

Portable Fence. The most common type of fence is a series of portable litter fences placed directly downwind of the unloading area and the active face. These fences should be slanted-frame fences placed end-to-end, immediately downwind of the active landfill area.

The primary point of containment should be as near to the active face as possible ... and immediately downwind. It is important that these fences be relocated as needed to contain litter blowing directly from the face. For them to work properly they should be erected close together without large gaps between the panels. Otherwise, once the panels plug up with litter, the gaps will act as "leaks," focusing litter through the gaps and away.

Semi-Permanent. Semi-permanent fences represent a secondary level of litter containment. These typically consist of metal fence posts and wire mesh (i.e., chicken wire) 4 to 6 feet in height. An alternative uses geotextile fencing instead of chicken wire. In any event, temporary fences should be constructed downwind of the active landfill, in areas where the fence will be undisturbed for as long as possible (i.e., at least a year).

It is important that the temporary fences be placed between the active landfill area and drainages, ridges, vegetation, or other features so that the litter is contained before it can become hooked on trees and brush.

Permanent. The third type is a permanent fence. Probably the most common type is a 6-foot-high chainlink fence along the boundary of the landfill. These fences provide an excellent "last shot" at litter that may be blowing off-site. But remember, these fences alone do not offer good litter control.

Looking for Innovations

The Ventura Regional Sanitation District owns and operates the Toland Road Landfill (TRL) near Ventura, CA. Over the years it has tried a variety of litter-fence systems. For several years, it used portable metal (i.e., backstop-style) screens, but eventually the screens became bent beyond repair. It has also tried setting steel poles in concrete-filled scraper tires Ö but the poles bent. TRL found that a netting fence on 8- to 10-foot poles mounted on concrete "K-Rail" worked "OK" but weren't very mobile. Do these guys have a problem making up their mind? Nope, but they do have the persistence to keep looking for something that works.

You may be asking yourself, "What's the point of all this experimenting? Where are the results? It seems like they are experts on things that don't work." Exactly. Just like Thomas Edison. And here's the point.

Thomas Edison was a genius. In his lifetime, he patented about 1,100 inventions. While working on one of his most famous inventions (the lightbulb), and after trying several thousand different materials without finding one that would work for the filament, someone asked him, "After thousands of failures, aren't you discouraged by the lack of results?" Edison replied, "Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work." And as we know, he went on to find what did work.

So when it comes to litter control, what's working?

TRL Manager Raymel Lloyd says, "I like the Wind Patrol systems. We purchased them about 10 months ago. They are built tough and the panels are easy to fix when damaged." As for mobility, he adds that "they [the screens] are built to be moved with a D6 dozer. So the engineer and I worked on some alterations to allow them to also be moved with a D7 or D8 dozer equipped with a trash blade." He goes on to say, "I'm still making some changes, but they [the screens] will be very mobile."

These guys know what they're talking about. In 2000, the TRL was presented with the 2000 SWANA Landfill Excellence Bronze Award. The annual award is given to landfills that demonstrate excellence in the areas of operation, design, efficiency, and overall integrated solid-waste management system. Among other things, TRLwas commended on its comprehensive dust and litter abatement.

Here's more on the Wind Patrol screens. Developed by Abletech Inc., they are unique in that their interchangeable panels can be used either to catch litter downwind or reduce wind speed and turbulence by being placed upwind of the active tipping area. The downwind panels are made of expanded steel that allows wind to pass freely through while stopping litter. The upwind panels are made of perforated steel that reduces wind speed and turbulence upwind of the tipping area.

This idea of reducing wind speed by placing fences upwind is a relatively new application of old science. Highway engineers have been using snowdrift fences for decades to reduce wind speed upwind of highways. Why? Because if they can reduce wind speed, snow particles will settle (into drifts) before they reach the roadway. Applying that science to create a calm area for the tipping area is logical Ö and it's working.

Removing Litter

For every landfill, the goal is to prevent, minimize, and contain litter. Yet despite one's best efforts to contain windblown litter using the various methods described earlier, litter will still blow and have to be removed, either by vacuum trucks or hand-picking litter crews.

Mechanical Cleaning. One of the most useful and cost-saving devices in terms of litter cleanup is a vacuum truck. Here are some suggestions for landfills considering the purchase of a vacuum truck:

• Install all litter fences with litter accumulation in mind. Vacuum trucks are most productive in areas where litter is dense. This means in "baskets," along the bottom of slanted fences, etc.P
• Provide all-weather access to areas where litter accumulates.
• Ensure that the vacuum truck provides the option of a handheld suction pipe. For safety's sake there should always be two people present when operating the suction pipe.
• Select a truck that has adequate storage capacity for collected litter. This minimizes travel time and cuts costs.
• Select a truck that has a clean, efficient dumping system for collected litter. It's pointless to vacuum up the litter around the landfill only to have it all blow away while trying to unload a poorly designed vacuum truck.
• Select a truck that has a good dust-containment system. A vacuum truck that makes lots of dust could become a problem in regard to air-quality compliance.
• Select a dealer with a proven track record at landfills. Many vacuum trucks work well in parks where the litter consists of pop cans and paper bags. However, at a landfill the truck must also be able to handle stiff paper, long pieces of stretch wrap, Styrofoam, garbage bags, etc.
• Select a truck that uses common, easily serviceable parts and components.

Hand Picking. Yes, the truth is that some litter will escape the fences and have to be picked up by hand. Manual labor to pick litter is required at virtually all landfills and is also (usually) the most costly part of litter control.

At many landfills, laborers work together, moving from one area to another picking up litter. Unfortunately, when litter pickers work in a group, it is difficult to know if they are being productive or not. One of the most difficult areas in which to measure productivity at a landfill is in regard to the litter-picking crew. Along those lines, it's suggested that the following procedure be implemented whenever a crew is assigned to pick up litter.

Crews should be split up so that no more than two people are working together, to prevent litter-picking from becoming a time of talking and strolling. In fact, unless there is an overriding reason (i.e., safety) for team picking, it's best that persons pick litter alone ... at least far enough apart to prevent continual conversation. Also, it's suggested that each person be assigned a particular area (i.e., a specific ridge, drainage, etc.) to clean. The goal is to establish a visible task that can be used to measure progress at the end of the day. Finally, by separating the litter-picking crew, it will become clearly obviousóby counting bags at the end of the day—who is working and who isn't.

Tracking Landfill Performance

To track your landfill's performance when it comes to litter production, set up a video camera and record one day's worth of blowing litter during a "high wind" day. Use time-lapse (or fast-forward) to gain a better understanding of what path most of the litter travels as it exits the site. This information helps pinpoint the most strategic location(s) for litter fences.

The camera may also be set up to view the tipping pad and the active face. This might provide additional insight into where the bulk of the litter is coming from. For example, if most of the litter occurs during the truck-dumping process, it may be best to set up a series of litter screens within the width of the tipping area to create two or three sheltered dumping areas, rather than a single dumping area the full width of the face.

Obtain a portable (handheld) wind meter and begin to develop a set of ISO maps showing how wind speed changes in relation to typical landfill structures such as litter fences, a typical cell, soil stockpiles, etc. Based on the data obtained from the wind-speed monitor (or from site-specific experience), it may be possible to highlight the time of day when wind is most likely to cause a litter problem. Once identified, the landfill's operating hours could be adjusted to shift as much tonnage as possible away from those "high wind" times.

The Economics of Litter Control

It costs money to control litter. Constructing litter fences can be time-consuming and costly. Vacuum trucks are expensive. Many landfills employ one or more full-time workers who are dedicated to litter control.

However, when viewed from the proper perspective, when it comes to litter control, an ounce of prevention is certainly worth a pound of cure. A landfill could build thousands of feet of litter fence in lieu of the cost of one full-time litter picker.

For the sake of comparison, consider the following two scenarios:

Landfill no. 1 has an aggressive array of litter fences. These include portable litter screens at the tipping area and at the active face, temporary litter fences constructed with poultry netting and metal "T" posts, and permanent fencing along the landfill property line.

Every litter fence on the landfill is accessible by truck. The two-man litter crew, using a vacuum truck, is able to control litter at the fences on all but the windiest of days. Because the litter is concentrated on the litter fences, the crew is able to spend more time picking and less time walking. Certainly, the vacuum truck increases their productivity as well. And because the fences are kept clean, they are more effective. It's a win-win situation.

Landfill no. 2 has no litter control fences. Litter is allowed to blow as it will and the litter crew is continually picking it up. This landfill is in a perpetual state of trying to keep up with a far-reaching and never-ending litter problem.

On a typical day, the six-person litter crew can be seen walking through the rugged grassland downwind of the landfill, picking litter as they go. The workers appear to be spending more time walking than picking litter. And, because the area is accessible only on foot, the workers spend lots of time carrying bags of litter back to the pickup. Unfortunately, every bit of blowing litter at this landfill must be picked up with this inefficient method.

Both landfills have a litter control program. Both work hard to control litter. On most days, landfill no. 1 looks clean and neat. But landfill no. 2 looks like a dump every day.

So, the question is, what kind of landfill do you want to have? I think the answer is obvious. If your site's image is being buried by litter, it's time to start taking control of the problem.

Author Neal Bolton is a consultant specializing in landfill operations and management. He is principal of Blue Ridge Services in Atascadero, CA, and author of The Handbook of Landfill Operations.

MSW - September/October 2004