Is the US Facing a Road Dust Crisis?
What is Road Dust?
Road dust is composed of pulverized loose particles of sand, rock, and other
earthen material that become air borne, mainly due to the interaction of vehicular
traffic on unpaved roads.
A study completed before the turn of the century, nearly 50 percent of America’s
public roads remained unpaved (EPA 1993), and an even larger percentage of
private roads and parking lots. Furthermore, many of these roads are located
near agriculture sites where dust can travel hundreds of feet through the air,
covering crops with debris, contaminating local streams, and causing a nuisance
to local communities.
What are the Potential Hazards of Road Dust?
- Obscures the vision of drivers, dust clouds are traffic hazards.
- Dust particulate can be carried several hundreds of feet, penetrating nearbyhomes and covering crops. Crop growth can be stunted due to the shading effectand clogged plant pores.
- In human health dust is a common cause of allergies and hay fever and aconveyor of diseases according to a United Nation study (United Nations, 1979).
- The fine dust particles can be abrasive and therefore greatly increase wear ofmoving parts of vehicles.
- The losses of fines (road binder), as dust, represent a significant material andeconomic loss (Colorado Transportation Information Center. #3, 1989).
- The fine dust particles are washed off during precipitation and carried intostreams, creeks and lakes increasing their respective turbidities.
Common Dust Abatement Practices
There are several common practices for reducing road dust. This process
is called dust abatement. Unpaved roads can be sealed with chemical dust
suppressants made out of synthetic oil based products, molasses and corrosive
rock salts like Sodium Chloride and Magnesium Chloride. It is estimated that the
chemical dust suppressant industry costs road managers $300,000,000 annually.
This is because chemicals must be manufactured, reduced to a concentrate,
shipped, diluted, and sprayed sometimes as often as 3 times per year,
indefinitely.
The EPA recommends that unpaved roads be paved in order to reduce
road dust. TRUEGRID is a proven dust abatement technology. Our permeable
surface captures dust within loose aggregate rock that is then contained within
super tough plastic cells aligned in a grid. When heavy trucks and cars drive on
TRUEGRID, the grid system itself and not the aggregate rock provides virtually
all the load bearing capacity.What that means is that cars and trucks never fully pulverize the
aggregate rock within TRUEGRID, reducing the creation of road dust. Unpaved
roads do nothing to stop turning gravel into air-borne dust from tire traffic.
TRUEGRID stops this process and effectively minimizes dust.
In addition, a TRUEGRID lot can last up to 60+ years and proper
installation ensures virtually no maintenance after TRUEGRID is placed on the
ground. See how easy it is to install TRUEGRID.
What is the Real Danger of Chemical Dust
Suppressants?
In 2002, the EPA released a report calling for more research into the
potential environmental and human health risks of chemical dust suppressants.
Their investigation revealed an almost complete absence of scientific studies into
the effect these chemicals have on the environment. The only studies they could
find were industry performed and focused mainly on the performance of chemical
dust suppressants and not on their effect on humans and the environment.
It is known that chemical dust suppressants have a significant negative
impact on surrounding plant life. Remember that literally tons of dust
suppressants are sprayed on the millions of square kilometers of unpaved farm
roads where food is grown. Dust suppressants can also cause runoff into water
supplies, and could potentially carry other contaminating debris into local streams
and eventually the water table.
Is the US Facing a Dust Crisis?
While a crisis might be an overstatement, we are talking about millions of
square miles of roads pouring dust into the air every day. Add in the tons of
chemicals poured on these roads to reduce the dust problem, and we now have
a problem solved with another problem.
Times Beach, Missouri was a middle class industrial town up until 1982.
Nearby manufacturing and industry plagued the small Missouri Township for
decades. In the early 70s a private contractor was hired by the city to spray a
chemical dust suppressant on the mainly unpaved roads. This went on for years
as residents complained about funny tasting water, and an increase in respiratory
diseases in the town. Eventually it was discovered that the chemicals used
contained lethal levels of dioxin, a then known neurotoxin. This quickly became a
crisis, then an emergency, then a disaster. The federal government sued the
contractor, and eventually had to evacuate and permanently close the town,
which wasn’t reopened to the public until 1999.
Currently water supplies in Flint, Michigan are at toxic levels due to
chemical runoff into local water supplies. Water supplies have been
contaminated with lead from industrial waste poisoning the drinking water of
residents. Flint, Michigan is an echo of Times Beach. Though the chemicals
involved and the mechanism of contamination are different, both municipalities
are paying a heavy price in human health, and actual dollars due to
mismanagement of chemicals in the environment.
These are not isolated incidents either. Just last year, a contractor to the
EPA contaminated the Colorado River with millions of tons of metals, and
wastewater from an abandoned gold mine. The list goes on. More than a dust
crisis, the US is facing a chemical crisis, and somehow chemicals are still being
used to control dust when there are viable and cost efficient alternatives that
involve no spraying of chemicals. Right now we have an opportunity to learn from
the past and choose a better path for Flint and for America. The eco-friendly
solution that will save lives and money is TRUEGRID.
[Posted on December 31st, 2015 by: Barry Stiles]
Today, most parking lots are made from either asphalt or concrete, which initially provide a smooth surface for parking , but are expensive to install and typically require periodic applications of sealant to keep them in good condition. Additionally, once constructed, an existing parking lot can be difficult and difficulty to modify as the parking needs for the facility change over time.
By using permeable pavers in place of conventional materials, the parking lot design process is much simpler, because complex drainage systems can be eliminated, the materials for filling the pavers are easy to acquire and the installation process is simple and quick compared to other materials. Thanks to the unique design of permeable pavers, parking lots built with them are also easy to modify or expand in the future, and if extra parking is ever needed, permeable pavers can be easily installed temporarily and removed at a later date.
Here are some of the most desirable benefits that permeable pavers have to offer in your parking lot design:
#1 Simple Installation
For parking lot applications, permeable pavers are very easy to install compared to asphalt or concrete surfaces. They require much less equipment, there is no curing time and the installation process is extremely fast.
First the site must be prepared, similarly to asphalt or concrete, by removing vegetation and grading the soil, followed by adding a layer of rock, in most cases, to create a stable base. Then the permeable paver installation begins by laying down the individual grids, which come in pallet-sized sections that can easily be maneuvered by a single person. Each grid covers a large area, making the process go quickly, and it has specially-designed tabs that lock it into neighboring grids, creating a single durable surface that still allows for expansion, contraction and other movement as temperatures change. Some of the grids may need to be trimmed to go around objects like light-posts or to conform to curves, landscaping, curbs or other features, and this can easily be done with either a manual saw or a power saw.
Once all the grids are in place, gravel, limestone or other materials are spread evenly over the tops of the grids, and compacted into place. Heavy equipment can be used throughout the installation process to make the job easier.
#2 No Complex Drainage Requirements
A concrete or asphalt parking lot is one contiguous, sealed surface. Without properly grading the subsurface, crowning the parking lot and installing drains and gutters, the parking lot will be prone to flooding, upheaval, cracking and damage from rushing water or moisture trapped beneath the surface.
Permeable pavers greatly reduce the drainage requirements in a typical parking lot design. Because water can move freely through the gravel or limestone surface, there is no flooding as long as the soil drains well, and there is no need for complex drain systems. A simple gravel drain or French drain will work well. In areas that freeze often, expansion and contraction from soil moisture will not cause the surface to crack or buckle, which happens often and causes significant damage in asphalt or concrete parking lots.
#3 Easy Parking Space Design
With asphalt or concrete parking lots, things like parking space width, length, orientation and number of lanes must be carefully planned during the construction process, and they are not easily changed afterwards without significant expenses. Once the lines are painted, the parking lot typically remains in a similar configuration throughout its useful life.
With a permeable paving system, you can easily create a parking lot design, and mark out parking areas, directional markers, lane markers and other elements using easy push-in plastic caps, which come in an assortment of colors. Should you determine that the design is inefficient or problematic, the caps can easily be removed and repositioned. With a bit of work, the entire parking lot can be redesigned, such as changing from a 60 degree parking layout with single-direction lanes, to a 90 degree layout with two-way lanes to maximize the number of available spaces. Lane widths can be changed, parking space dimensions, and nearly anything else, without incurring significant additional expenses.
#4 Creates A Durable Surface
Asphalt and concrete parking lots often have a set weight limit. Due to the expense of installing concrete or asphalt, the parking area is often rated for passenger vehicles, while main lanes are rated for heavy equipment. This reduces the cost of the installation, but it can result in damage if heavy equipment is driven over areas designed for passenger vehicles.
Once installed and filled with an appropriate material, permeable pavers can handle everything from small cars to heavy equipment like wheel loaders and fully-loaded 18-wheelers. The gravel fill provides an extremely durable surface that can easily withstand heavy loads, the elements and even snow removal equipment. When properly installed and compacted, very little maintenance is required to keep the surface in good condition.
#5 Temporary Parking Can Be Easily Added
If a facility’s need for parking suddenly increases, permeable pavers can easily be used to create additional temporary parking. The pavers can be laid down on the existing soil and filled with limestone, gravel or sod to create a temporary parking area. Once the parking area is no longer required, it can be removed with minimal effort and little disturbance to the underlying soil.
Permeable pavers can also be used to transform grassy areas into permanent parking, by filling them with soil and grass seed or sod, and allowing the grass to naturally grown in the pavers. The grass can then be trimmed by standard lawnmowers without damaging the pavers. Such parking areas are useful for parks, performing arts centers, fairgrounds or any other area that has an occasional need for an overflow parking.
In addition to being a good alternative to asphalt or concrete in parking lots, permeable pavers also work well for driveway surfaces, oil field roads, landscaping, erosion control, emergency access roads, fire lanes, and even helicopter pads. They are lightweight, self-anchoring, durable and very easy to install, use and maintain.
Sources:
http://truegrid2.jfcserver.de/
http://truegrid2.jfcserver.de/resources/installation/
http://truegrid2.jfcserver.de/parking-lot-design/
http://www.uh.edu/plantops/departments/fpc/design-guidelines/09_parking.pdf
http://www.vaasphalt.org/parking-lot-design/
