Oil and Gas at Your Door? (2005 Edition) - Earthworks

Oil and Gas Development and Impacts
and vegetation near unpaved roads can be covered with the airborne dust stunting
their growth due to the shading effect and clogging of the plant's pores. As a result,
cattle and wildlife may avoid this vegetation. For motorists using the unpaved roads
the traffic-generated dust can reduce visibility and cause driving hazards.
Dust Suppression
WATER is probably the oldest of all dust suppressants. Typically, it is applied by spraying it over the road surface.
Drawbacks: Water’s dust suppressing capacity is very temporary because of evaporation. Heavy applications of water
can create soft mud or penetrate the road to the sub-base and causing major road failure. Consequently, several light
applications are preferable to one heavy application.
CHLORIDE COMPOUNDS such as calcium chloride (CaCl 2 ), magnesium chloride (MgCl 2 ) and the less popular sodium
chloride (NaCl 2 ) are used because they attract and absorb moisture from the atmosphere and retain it for extended
length of time, which significantly reduce the evaporation of moisture from the road surface. Thus, they are more
effective dust suppressants than plain water.
Drawbacks: Chloride compounds have the disadvantage of dissolving in water, and therefore can be washed out during
wet weather conditions. They are also corrosive.
LIGNIN DERIVATIVES include a variety of industrial waste products, animal fats, and vegetable oils; the most popular is
ligninsulfonate, which is a waste product from the paper-making industry. When used as dust suppressant, the lignin
polymers act as glue binding the soil particles together. According to the New Mexico State University Molecular
Biologic Program, a by-product of the soybean crushing process, called soapstock, is now being used as dust suppressant
on dirt and gravel roads throughout the Midwest. This alternative is said to be more environmentally safe in
places where runoff is a concern, and supposedly lasts longer than most other alternatives. 248
Drawbacks: Ligninsulfonate dissolves in water, and so it is easily washed away during wet weather conditions.
Dust can affect human
health, and the health of
crops, livestock and
wildlife.
RESINOUS ADHESIVES include waste oils, tars, bitumen, and by-products from the plastic industry. Of all these products,
cutback asphalt and asphalt emulsions are most widely used as dust suppressants.
Drawbacks: According to the Minnesota Pollution Control Agency, “When applied to roads, waste oil can seep into
groundwater, runoff into surface waters or spread into the air with dust particles. Once in ground or surface waters
even small amounts of used oil can contaminate large quantities of drinking water. . . Used oil reduces the amount
of oxygen in water, damaging fish and other aquatic life.” 249 Consequently, waste oils are prohibited from use as a dust
suppressant in Minnesota.Very little quantitative information currently exists on the environmental impacts from the
use of dust suppressants (other than water). Landowners should be aware that the application of dust suppressants
has been noted to cause slipperiness on unpaved roads in wet weather conditions. The water quality effects of the
use of dust suppressants are still not entirely known, however the chloride compounds and the lignin additives commonly
used contain contaminants such as chlorides, heavy metals and organic compounds that are regulated by the
U.S. Environmental Protection Agency. 250
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ALTERNATIVES TO WATER AND CHEMICAL DUST SUPPRESSANTS 251
LOWERING SPEED LIMITS will decrease the amount of dust stirred up from unpaved roads and pads. Lowering the speed
of a vehicle from 45 miles per hour to 35 miles per hour can reduce emissions by up to 22 %. Installation of speed
bumps can reduce vehicle speeds.
UPGRADING UNPAVED ROADS (e.g., by improving particle size, shape, and mineral types that make up the surface and
base materials) will increase a road’s surface strength, and reduce dust emissions. Adding surface gravel can reduce
the source of dust emission, but if gravel is added the amount of fine particles (i.e., those smaller than 0.075 mm)
should be limited to 10 to 20 %. Also, improving drainage and crown can reduce dust emissions. Paving is the most
expensive, but most effective road upgrade option.
3. The flaring of natural gas produced from the oil or gas wells may release carbon monoxide,
nitrogen oxides, sulfur dioxide, benzene, toluene, ethylbenzene and xylene, polycyclic
aromatic hydrocarbons (PAHs) and, in the case of sour gas, hydrogen sulfide and carbon
disulfide.
• Benzene and PAHs are carcinogenic (cancer-causing). Also, benzene has been shown
to cause various adverse health effects other than cancer, such as blood disorders,
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