The search continues for affordable, long-lasting dust control methods.

By Paul Hull

My father had a friend whose response to any question about his general well-being was always “Oh, not so dusty!” by which he meant that everything was bearable and manageable and he would not complain. Keeping our ground “not so dusty” has been a challenge for many years as well, and we have seen different remedies recommended, tried, and used. From talking to those who could suffer in health (and bank balance) from too much dust, it seems we may at last be winning the battle. The solutions are scientific, as they are for many of today’s problems. One of the key words heard is polymer. Few of us are scientists, and we might not be able to come up with a quick definition of polymer, but most of us have heard of the Stone Age, the Bronze Age, the Iron Age, and the Steel Age for the human race; our times may be called the Polymer Age.

A polymer is defined in one dictionary as “a compound composed of one or more large molecules that are formed from repeated units of smaller molecules.” That may not help us too much, but let’s add that polymers have been in nature since the beginning (in such things as rubber, starch, and cellulose). One analogy is that a polymer-based product is like a cake; it combines many little ingredients to make one, big delicious result. Human attempts to create polymers are comparatively new, but they have been most successful and the polymer industry is said to be bigger now than the steel, aluminum, and copper industries combined. Some of the names may be familiar: Teflon, Dacron, Kevlar, polyethylene, and polyurethane. You use plastic bags and containers? They rely on polymers to make them lightweight, strong, and economical. Clothes, packaging, and floor coverings rely on polymers. They have improved the quality and affordability of products as diverse as pipes and adhesives, windshields and insulation, golf clubs and playground equipment. So don’t shake your head in disbelief when somebody tells you polymers may help you solve your dust problems.

While users will naturally have their favorite solutions for dust control, the one fact accepted by most people working on sites where the soil is disturbed is that water can be the least effective and most expensive method. If you live in a community where the summers are hot and dry, you will probably have witnessed an application of water to the ground that disappeared within minutes, leaving the dusty surface ready for the next gust of wind or rolling wheels. The momentum for developing polymer-based solutions for dust control came from the failure of water to satisfy users with areas larger than a few square yards to manage.

Along with the polymer-based solutions we find others, such as those that involve calcium chloride. There have been some that showed promise as dust controllers but have been banned because of their harm to the rest of the environment. In this article we present some dust control products, with comments from their producers about advantages and disadvantages of various solutions. There may be more than one acceptable solution for our dust problems; our homework and research can tell us which is most appropriate. It’s rather like selecting the right brand of vehicle or construction equipment. There are several good choices available and we have the luxury of picking the ones we like.

Emulsions That Bond
“DirtGlue Light polymer emulsion is typically used for soil stabilization encompassing dust control as well as stormwater control, sediment controls, and SWPPPs [stormwater pollution prevention plans],” observes Chris Rider for DirtGlue Enterprises, based in Amesbury, MA. “It functions by bonding the individual soil particles together to prevent them from moving. Erosion control for embankment stabilization is one use, and we have used it for capping stockpiles and controlling sediment to eliminate TSS [total suspended solids] in stormwater runoff.” DirtGlue is a water-based, biodegradable polymer-based emulsion. It is a liquid soil stabilizer designed to protect seed and soil from wind and water erosion. The rates of application will depend on your specific site, of course, but (when correctly applied) it forms a three-dimensional matrix in or on the soil and acts as a semi-permeable, membrane-like structure that can hold seeds and soil in place but still allows oxygen and water to penetrate. DirtGlue is rated as non-hazardous by the EPA.

If there are three priorities for dust control solutions, they are that the products used must be affordable, long-lasting, and environmentally friendly. These priorities are given different levels of emphasis as local regulations are developed or enforced or become more stringent. In some states, for example, many petroleum-based products have been banned because of their harmful effect on neighboring land and waterways. The cost of labor to apply the products is also a consideration that should never be neglected; it affects affordability.

Repairing the damage of wind and water erosion is expensive. “Prevention is a more efficient and economic solution,” notes Rider. “DirtGlue offers a long-term [three to 18 months] and cost-efficient solution for dust control. Our company is a major contributor in our industry’s fight to become more environmentally friendly with less labor costs.” Is DirtGlue, then, just another polymer product? Yes and no. The manufacturer uses a proprietary polymer additive/mix but includes no vinyl acetate copolymers, as some other products do. “Our mix is several times more UV stable and shows excellent low-temperature application characteristics,” says Rider. “It also offers superior flexibility through a wide temperature range. It has much higher adhesive qualities, relative to the copolymers, so it has better bonding capabilities.” From the environmental perspective, the polymer emulsions from DirtGlue are non-corrosive and non-flammable, do not change the pH of the soil, contain no harmful chemical solvents, do not emit any volatile organic compounds (VOCs), and have shown no harmful effect on people, animals, plants, fish, or other aquatic life.

At first it seemed nonsensical that water—such an everyday item and so familiar to most people—has become the most expensive solution for most communities. But it is water + something else that is becoming the favorite solution for dust problems. As long as those “something elses” become more and more affordable, long-lasting, and environmentally safe, dust control will be a challenge that every community can face and solve.

Paul Hull writes on construction topics for several international magazines.

EC - July/August 2007

Originally published at http://www.gradingandexcavation.com/ecm_0707_not.html