|
The justification
for poisoning people and contaminating the environment must be evaluated
against the availability of alternative materials and approaches that
may be safer. In the case of the hazardous materials used to treat utility
poles, alternative materials do exist. But, what are the hazards of
these alternative materials and do they offer a better approach?
The differences
in adverse impacts of materials is often difficult to compare. In
some cases, one material may represent a threat to air quality while
another represents a threat to water quality. In conducting life cycle
analyses, researchers have consis tently focused on energy consumption
associated with the production of various materials. However, the
analyses typically fall short of evaluating the total toxic trail
associated with the materials and practices that go into the production
of the end pro duct --in this case, a utility pole.
No comparative
analysis of products would be complete without consideration of the
cost differential among them. Sometimes the analysis is skewed by
its failure to consider the differential in the life span of a product.
It is also biased by a failure to consider external pollution costs
relating to chemical cleanup and health care associated with a wood
preservative-induced illness.
In the case of
wood, the utility industry expects 40 to 50 years of service (although
it has been found that a bad batch of wood can yield less than 35
years of service). The steel, concrete and fiberglass alternatives
yield a lifespan of 80 to 100 years. There are differences in maintenance
costs associated with different materials. Wood may require retreatment,
as some utilities do on a set cycle, while steel, concrete and fiberglass
do not. In addition, disposal costs for chemicals used in wood treatme
nt are high and growing, while steel is recycled.
Below is a discussion
of the major alternative materials to chemically treated wood utility
poles. It is important to consider these issues in the context of
making a choice that is better for the environment and public health.
Steel has been cited
as the most common alternative utility pole material in a Swedish report.
The same is true in the United States, although steel and all the alternatives
represent a small but growing alternative when compared with the use
of treated wood utility poles.
The steel industry
identifies steel as "the world's, as well as North America's, most
recycled material, and in the United States alone, over 70 million
tons of steel were recycled in 1995, resulting in an overall recycling
rate of 68.5 percent." The industry says that two out of every
three pounds of new steel are produced from old steel. Two processes
are used. The basic oxygen furnace (BOF) process or blast furnace,
which uses 28 percent scrap steel, and the electric arc furnace (EAF)
process, which uses 100 percent scrap metal. The steel for utility
poles are made with the electric arc furnace.3 According to the industry,
when one ton of steel is recycled the following is conserved: 2,500
pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone.
The Swedish report
indicates that air pollution associated with the processing phase
of steel is the predominant type of pollution in the processing life
cycle phase. The report identifies a drastic reduction in air
pollution from 1970 to 1988. Emissions to the air dropped in the following
ways: dust, containing a number of metals, such as lead, copper and
cadmium, went from 150,000 ton/year to 5,000; sulphur dioxide from
32,000 to 8,000 ton/year; nitrogen oxide from 4,400 to 3,700 a year
and carbon dioxide from 8.0x10-6 to 4.4 x 10-6. While steel production
has been cleaned up considerably over the past decade, environmental
concerns focus on air and water pollution. The electric arc furnace,
a cleaner process than the oxygen furnace, still produces dust contaminated
with metals that are classified and disposed as hazardous waste. The
production process also produces a sludge that can be landfilled and
discharge water that can be sent to a municipal water treatment facility.
Nucor, which uses EAF technology to produce new steel from recycled
scrap metal for at least two steel pole manufacturers, released less
than 100 pounds of lead in 1995 in producing approximately 1.5 million
tons of steel. While little research has been done o n U.S. steel
plants, there have been European studies that find airborne dioxin
emissions associated with steel product in iron sintering plants,
which are adjuncts to blast furnace operations. The contaminants are
tied to the use of chlorinated lubricant s in the operations and could
be eliminated with changes in practices.
The Swedish report
credits steel poles with a life of approximately 80 years and indicates
that the reuse rate "almost reaches 100 percent, resulting in a reduced
energy utilization in the processing phase from 10,000 kWh/ton to
1,700 kWh/ton.8 The steel utility poles are either galvanized or coated
with a sealant.
International
Utility Structures, Inc. (IUSI) in Baceville, AR and Valmont Industries
in Valley, NE have gotten into the steel utility pole business in
the last several years. For a 40 foot, class 3 pole, they both have
competitive pricing with IUSI pricing at $2659 and Valmont at $31510
(exclusive of freight). Valmont’s 40 foot, class 4 pole, which
has a thinner diameter than the class 3, is approximately $260.11
IUSI produces a 40 foot, class 5 pole and charges $215.12 The material
is lighter in weight than wood and the installation is similar.
Reinforced concrete
is also identified as an alternative material to treated wood poles.
Centrifugal casting is used to produce concrete poles with natural gravel
or crushed stone with steel reinforcement. The environmental issues
related to cement, the & #147;glue” that holds concrete together,
raises serious environmental issues that must be added to the concerns
about steel raised above. The material’s longevity ranges from
80 to 100 years.
Cement is produced
in kilns that often burn hazardous waste. By 1994, 37 facilities out
of 111 plants in the U.S. were permitted to use hazardous waste as
a fuel to replace some or all of the large amounts of fuel required.
Cement is made
by heating limestone, clay, and other materials to very high temperatures
to form "clinker," which is cooled and ground with gypsum to make
cement. This is accomplished by circulating the combustion gas around
raw materials in a kiln. Many of the constituents of the vapor become
part of the dinker or cement kiln dust.
About 60 percent
of the five million tons of hazardous wastes incinerated annually
is burned in boilers and industrial furnaces, almost all of the cement
kilns or lightweight aggregate kilns. About 90 percent of all commercially
incinerated liquid hazardous waste in the U.S., as well as a growing
percentage of solid hazardous waste, is burned in cement kilns.
Some of the wastes
burned in cement kilns are destroyed, but some are indestructible
(heavy metals) and some are transformed into more toxic chemicals
like chlorinated benzenes and dioxins. Everything which is not destroyed
is released into the environment in some way. Some is released through
fugitive emissions from the stacks- in gaseous particulate form. Some
is adsorbed to cement kiln dust, which is typically piled on the ground
before being taken to conventional landfills. Some is left in the
ash, which also goes to landfills. And some becomes part of the cement-
to be breathed daily by those living near "ready-mix" plants, and
to be slowly released into the environment from concrete.
The disposal
of hazardous waste into the environment through the various products
of cement kilns results directly from incentives established by EPA.
By delaying regulations, writing loopholes into regulations, and failing
to apply their regulations, the agency has made cement kiln incineration
an attractive, cheap alternative to disposing of hazardous waste in
controlled facilities or reducing the production of hazardous wastes.
Therefore, while
concrete poles are an alternative that may be preferable to wood in
many cases, the current practice of producing cement through the burning
of hazardous waste raises serious environmental pollution problems.
Furthermore, concrete construction material is normally not used as
a raw material for another product, although techniques exist for
reuse.
StressCrete,
a company based in Burlington, Ontario, Canada (with a plant in Tuscaloosa,
AL) is a major producer of cement utility poles. It charges $375 for
a 40 foot, class 3 pole and $350 for a 40 foot, class 4 pole (exclusive
of freight). Because of i ts weight its installation costs tend to
be higher than other alternatives. However, its durability is proven,
having a track record of surviving hurricanes in the southeastern
U.S.
There are a number
of other materials that are available for poles as well as the option
of burying utility lines underground. The other pole material that most
commonly surfaces is made from fiberglass reinforced composite
(FRC). The manufacturing process is described by the major
manufacturer of the product, Shakespeare, in Newberry, South Carolina,
as follows:
These
new fiberglass reinforced composite utility poles are manufactured
using the filament winding process...Filament winding is accomplished
on a machine which winds glass fibers onto a mandrel in a prescribed
pattern to form the desired finished shape...For filament winding,
fiberglass is purchased in a yarn-like form called roving. This roving
is routed through a bath of liquid, catalyzed, pigmented, polyester
resin before it reaches the mandrel. After the fiberglass and resin
are in place, a surface of resin impregnated non-woven polyester fabric
is applied. Heat is then applied to initiate cross linking (hardening)
of the resin. After hardening, the tube is removed from the mandrel.
. .After the tube is removed from the mandrel, it is t rimmed to length
and any required holes are drilled...the final step is the application
of a pigmented polyurethane topcoat.
Burying utility
lines is often considered as an option for aesthetic reasons
or in areas with utility or telephone companies are trying to avoid
severe weather conditions. Although cost is a major consideration, the
burying of lines is currently accompanied by the use of chemical treatments
to protect lines from decay and pest problems. In fact the only remaining
use of the insecticide chlordane is underground power transformers.
This chemical was banned for agricultural uses in the 1970' s along
with DDT and other organochlorine pesticides and had its remaining uses
forbidden, with this exception, in the later 1980's. The use of this
and other chemicals buried along rights of ways, over water tables and
in sensitive areas, represents a serious threat to environmental protection.
Shakespeare prices
its 40 foot, class 4 poles at $900.
Electromagnetic
Field
The jury may still
be out on the dangers associated with electromagnetic fields (EMFs),
but there is sufficient evidence that the EMFs generated by utility
lines are hazardous enough to cause utilities to consider options that
increase the distance between the lines and human habitation. Among
those options are burying lines and increasing the height of poles.
Both options --which compare differently in different situations-- favor
moving away from treated wood wood poles. Steel poles are more easily
upgraded to taller poles by inserting a new section.
Cost
Comparisons
It is difficult to
compare costs of treated wood poles and the principal competition, steel,
because of a number of factors that vary, including the type of wood
utilized, maintenance practices, and length of service. Although Southern
Yellow Pine is the most common wood utilized, Douglas Fir and Western
Red Cedar are used in the west. Utilities use different average size
poles, most ranging between 40 foot poles with differing thickness that
are generally either class 3 or class 4. In addition, pole prices vary
according to a number of factors including volume purchases, contract
agreements and volatility of the market.
Nonetheless,
the purpose of this section is to generate a cost comparison between
chemically treated wood poles to provide a context for evaluating
the competitiveness of the alternatives.
Tillamook People's Utility District, Tillamook, OR 97141
This utility
service areas covers 60 miles of Pacific coastline and 24,000 poles.
The utility uses coastal Douglas Fir, with an average pole size of
40 foot, class 4. It pays $271 for its penta-treated wood poles and
approximately $70 more for steel poles . The utility district is purchasing
steel poles currently for aesthetic reasons and to use in high traffic
areas where it is expected that they will have less maintenance requirements.
The utility indicates that there is some maintenance savings associated
with the steel poles because they can discontinue the wood pole retreatment
program which cost the utility $30 to $35 a pole. The utility retreats
poles on a ten-year rotational cycle, treating the poles with additional
chemicals (chloropicrin) as a preventive measure to stop decay before
it starts. The utility believes that steel provides a long-term savings
because its lifespan, estimated at 80 years, is double that of wood.
They base this estimate on their experience with galvanized steel
substations, transmission towers and fences. They also believe that
they will recoup some of the cost of the steel pole through salvage
at the end of the life of the pole.
Public Utility District of Douglas County, East Wenatchee,
WA 98802
This utility
services north central Washington state. The utility uses on average
a 40 foot, class 3, Western Red Cedar pole that is treated with penta
only on the portion of the pole that is submerged underground. The
cedar is naturally resistant to insects and decay. An inspection program
is conducted on a 10-year cycle with treatment on an as needed basis.
The utility has begun using steel poles. It pays $360 for wood poles
and $383 for steel.
Eastern Utility Association, West Bridgewater, MA 02379
The utility covers
a 599 square mile area in Massachusetts. The utility uses on average
a 40 foot, class 4, Southern Yellow Pine pole, full length treated
with pentachlorophenol. It pays on average $213 a pole and does not
purchase any other alternative materials.
Pennsylvania Power & Light, Allentown, PA 18101
This public utility
has a service area that includes 23 counties in northeastern Pennsylvania,
10,000 square miles and 54,000 miles in their distribution system.
The company uses full length creosote-treated Southern Yellow Pine
poles. It pays $249 for it s standard 45 foot, class 3 pole. The utility
discontinued its retreatment program as part of a budgetary move.
However, previously the utility conducted a pole retreatment program
every five years, treating poles from three feet above groundline
to the base.
City of Alliance, Alliance, NE 69301
This municipal
utility covers 140 square miles in west central Nebraska. The area
takes in 250 miles of primary distribution line. The utility is currently
using full length penta-treated Douglas Fir for which it is paying
$312 for its average 40 foot class 3 pole. It also uses full length
penta treated Western Red Cedar, depending on the price. The company
does not have a retreatment program.
Conclusion
From a cost perspective,
alternatives to treated wood poles have become more competitive in recent
years. Steel and concrete appear to be more cost competitive at this
time than fiberglass. Longer transportation distances for wood pole
alternatives add an additional front end cost to the alternative materials.
However, savings in maintenance, longer in service lifespan and salvage
value (of steel in particular) levels the cost playing field over the
long-term.
Cost issues aside,
there are numerous compelling reasons for shifting away from the hazardous
chemicals used in treating utility poles and moving to alternative
pole materials. While there are a range of considerations that should
be brought into play, as indicated in this chapter, there is every
reason to begin moving away from the use of pentachlorophenol, creosote,
copper chromated arsenate and other wood preservatives.
Back
to Regulatory History
| Ccontents | On
to Conclusion
|
