=======================Electronic Edition========================
RACHEL’S HAZARDOUS WASTE NEWS #118
—February 28, 1989—
News and resources for environmental justice.
——
Environmental Research Foundation
P.O. Box 5036, Annapolis, MD 21403
Fax (410) 263-8944; Internet: erf@igc.apc.org
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NEW TECHNICAL STUDY CRITICIZES EPA’S INCINERATOR REGULATIONS.
A new technical paper presented at a recent meeting of the Air
Pollution Control Association (but not yet published) strongly
criticizes the U.S. Environmental Protection Agency’s (EPA’s)
budding effort to regulate garbage incinerators. The EPA
announced in August, 1987, that they plan to control air
pollution from garbage incinerators by requiring “dry” acid gas
scrubbers and fabric filters, to protect public health from the
mass burning of garbage. A “dry” acid gas scrubber tries to clean
smoke stack emissions without using liquids to wash them. A
fabric filter is a huge box (called a baghouse) containing an
enormous cloth filter; all the gases leaving the combustion
chamber pass through the baghouse before escaping up the smoke
stack. The fabric filter captures much of the sooty pollution,
which is then collected and buried in a landfill. “Dry” scrubbers
are much cheaper than the alternative, which is “wet” scrubbers.
The new paper, by Craig Volland, a Kansas City civil engineer,
argues that EPA’s proposal will not protect public health, and
will lock American incinerators into technologies that have
already been abandoned in Europe.
Mr. Volland attacks EPA’s proposal from many points of view,
among them:
EPA concluded incorrectly that dry scrubbers and baghouses would
protect public health because EPA used risk assessment that was
flawed in the following ways:
(a) EPA assumed that incinerators can be run for 20 years
emitting pollutants at the relatively low levels achieved by a
few brand-new incinerators operating under ideal conditions in
carefully-controlled tests. Mr. Volland says, “Those of us with
many years of experience in the pollution control industry know
it is foolhardy to assume that this incinerator [pollution
control] equipment will be consistently well operated and that it
will not deteriorate over time.” Mr. Volland argues that, as time
passes, the buildup of soot and “chloride-related deterioration
of the boiler tubes” will make it difficult for the incinerator
operator to maintain optimal conditions. Operator error and
carelessness are additional factors that will lead incinerators
to produce more pollution than was produced by the incinerators
the EPA studied in deciding that dry scrubbers and baghouses
would adequately control air pollution.
(b) EPA did not take into account the conditions knows as
“upsets,” “transient disturbances,” and “breakdowns.” These
events are any unusual condition that leads to abnormal emission
of pollutants; such conditions are readily caused by variations
in the fuel fed into the incinerator. Because garbage itself is
highly variable (some wet, some dry, some full of paper, some
not, some containing flammable materials such as paint and
gasoline, some not, etc.), it is common for garbage incinerators
to experience upsets and breakdowns regularly. Mr. Volland cites
evidence from Moody’s Bond Advisory Service indicating newer
incinerators are experience breakdowns more frequently than older
incinerators. EPA should take such data into consideration, Mr.
Volland argues.
(c) EPA selected dry gas scrubbers and baghouse filters on the
assumption that all incinerators will be operated to maintain a
temperature of 284 degrees Fahrenheit in the smoke stack. In
reality, because heating value of the fuel (garbage) varies
considerably from minute to minute, the temperatures in a garbage
incinerator vary up and down quite a bit. Consequently, Mr.
Volland argues, the temperature in an incinerator smoke stack may
often exceed 284 degrees, with heavy metals consequently turned
into a gaseous state not captured at all by dry scrubbers or
baghouses. Arsenic, selenium, and cadmium will be emitted in
gaseous form if the temperature reaches 392 degrees F., which
could readily occur because of operator inattention, or from
changes in the heat value of the fuel.
Even if the temperature never exceeds the standard operating
temperature of 284 degrees, mercury will be emitted into the
local environment continuously and in substantial quantities, Mr.
Volland shows. He presents data from seven modern incinerators
(built 1985 through 1987) showing that they emit an average of
3590 pounds of mercury for each million tons of garbage burned. A
thousand-ton-per-day incinerator will thus put out 1300 pounds of
mercury per year into the local environment. The toxicity of
mercury to humans is measured in micrograms, so the emission of
even a few pounds is a matter of public health concern. The dry
scrubber and the baghouse filter do not capture any of this
mercury, and it is emitted directly into the local environment.
To figure out whether this quantity of mercury is a lot or a
little, you can look at it in two different ways. The EPA looked
at it this way: they said, if this is emitted from the smoke
stack and begins to mix with clean air and becomes diluted, will
the resulting air be fit to breathe? They used a standard “air
dispersion” mathematical model (Turner’s) to figure out how the
mercury would mix with the fresh air. However, as Mr. Volland
points out, no one really knows how mercury moves when it is
released into the air. The standard air dispersion model may be
entirely inappropriate for estimating how the mercury will mix
with fresh air. In addition, the standard air dispersion model
assumes that the pollutant is being emitted into a rural
environment with level, open ground. The standard model does not
take into consideration the eddies and downdrafts in an urban
environment–and the majority of incinerators are being built in
urban environments. Additionally, Mr. Volland cites a recent
German study showing that fog droplets accumulate and concentrate
toxic heavy metals (such as mercury). Lastly, Mr. Volland argues
that dispersion models are not very accurate, even under ideal
conditions, and the wide variations in the characteristics of the
garbage entering an incinerator make air dispersion modeling
particularly subject to error. (The mercury in garbage will vary
with the number of batteries, fluorescent light bulbs, electrical
switches and so forth that local people have thrown away
recently.)
Mercury attacks the human central nervous system, particularly
the brain. It is a potent poison, the effects of which have been
well documented. It is therefore a matter of great importance if
the EPA’s air dispersion models are in error and local people are
exposed to mercury in greater concentrations than good health
will allow.
The second way to ask whether a given release of mercury is large
or small, is to look at the absolute amount released. Mercury
readily enters the food chain and accumulates in fish and other
wildlife. Many waters of the United States are already
contaminated with mercury at levels that have caused health
authorities to issue warnings and bans against eating fish from
those waters. The emission of tons of mercury into the atmosphere
by burning garbage represents a major new toxic assault upon the
nation’s environment, and one the EPA has so far evaluated by
inappropriate methods, Mr. Volland argues.
Send $3.00 for copying and handling to: Craig S. Volland,
President, Spectrum Technologists, 616 East 63rd St., Kansas
City, MO 64110; phone (816) 523-2525. Ask for: “A Critical Review
of EPA’s Plan to Establish A Dry Scrubber Technology Standard for
Municipal Solid waste Incinerators.”
–Peter Montague, Ph.D.
Descriptor terms: air pollution; air quality standards; epa
regulations; incineration; scrubbers; heavy metals; mercury;
health effects;