The federal Resource Conservation and Recovery Act (RCRA) is supposed
to regulate the generation and disposal of hazardous chemical wastes
"from cradle to grave."
Unfortunately, Congress built a feature into the law that EPA (U.S.
Environmental Protection Agency) has turned into a loophole. Today,
enormous quantities of hazardous waste are escaping regulation through
this loophole. Specifically, Congress exempted "recycled" chemical
wastes from control under RCRA, and EPA ruled that chemical wastes
burned as fuel in industrial boilers, industrial furnaces, aggregate
kilns and cement kilns are being "recycled" and are thus exempt from
According to Richard Fortuna, director of the Hazardous Waste Treatment
Council (an incinerator industry group in Washington, DC), 50 billion
pounds of chemical wastes are being burned in unregulated boilers and
kilns each year, compared to only 5 billion pounds (or less) being
burned in RCRA-regulated hazardous waste incinerators.
A recent report from Greenpeace describes the burning of chemical
wastes in aggregate kilns and cement kilns. Page numbers in our text,
below, refer to this report, SHAM RECYCLERS, PART 1: HAZARDOUS WASTE
INCINERATION IN CEMENT AND AGGREGATE KILNS.
Cement is the raw material from which concrete is made. In a cement
kiln, powdered limestone and clay are burned at high temperatures to
form a "clinker" that is later ground into a fine powder, which is
cement; when water is added to this powder, it hardens. Certain
"aggregates" can be added to cement to make mortar, plaster, concrete
or other similar materials. As with cement, aggregates are formed by
firing them in a hightemperature kiln. Thus aggregate kilns and cement
kilns seem ready-made for destroying hazardous wastes. They have to be
heated to high temperatures with fuel, so why not substitute hazardous
wastes for part of the fuel and burn up the wastes while making
aggregate or cement? Save on fuel and destroy wastes--what could be
better? This was the question Greenpeace's Science Director, Pat
Costner, and her colleague Joe Thornton, set out to answer.
There are at least 24 cement kilns and 17 aggregate kilns in the U.S.
burning hazardous wastes today (listed on pgs. 31-33). Together, they
burn approximately 3 billion pounds of hazardous wastes, and a recent
industry analysis says this amount could double between 1989 and by
1992 (pg. 8).
It is difficult to obtain data on destruction of wastes in kilns
precisely because kilns are exempt from RCRA; kilns are not required to
meet the permit requirements of regular hazardous waste incinerators,
nor are they subject to the operation and emissions standards that
control regular hazardous waste incinerators. So long as a company
claims to be using hazardous waste as a fuel or as a raw material, they
are classified as "recyclers," and there is essentially no review
process within EPA to check their claims or their operations. Thus a
fraudulent company, bent on unregulated waste disposal, has an easy
time exploiting this exemption within RCRA. Marine Shale Processors in
Amelia, Louisiana, which was recently closed down by EPA after national
TV threw a spotlight on them, is a notorious example of a fraudulent
waste hauler disguised as a kiln operator.
Even when the intention is not to defraud, destruction of wastes in
kilns is highly questionable. As Costner and Thornton make clear, there
are about a dozen good reasons for wanting to prevent wastes from
entering kilns. Here are some of them:
Typical wastes burned in kilns include paint, ink, and coatings
manufacturers' wastes, spent halogenated and non-halogenated solvents
generated by a wide variety of manufacturing processes, still bottoms
from solvent recovery operations, petroleum industry wastes, and waste
oils including crankcase oil, transmission fluid, hydraulic and
compressor fluids and coolants. Typically, 1.35% of these wastes are
metals (including cadmium, arsenic, chromium, lead, mercury, zinc, and
thallium). If 1.35% seems like a small amount, remember that 1.35% of 3
billion pounds is 40.5 million pounds of metals. Metals make trouble in
incinerators--they are not destroyed but instead pass through the
furnace into the outside environment, often in forms that make them
more dangerous than when they first entered the kiln (e.g., attached to
fine [extremely small] particles that can readily penetrate human lungs
or can leach into groundwater) [see RHWN #131, RHWN #132, RHWN #134,
RHWN #136, and RHWN #162].
Kilns burning hazardous wastes emit 66% more particles (soot, smoke,
haze) than kilns burning normal fuel. Kilns burning halogenated wastes
(containing chlorine, bromine, fluorine or iodine) emit 203% more
particles than kilns burning normal fuel (pgs. 12, 26). This increased
production of particles provides a pathway for metals to escape the
incinerator in a form that is particularly dangerous to humans. The
metals become attached to the outside of the fine particles and thus
become available for humans to breathe. Costner and Thornton estimate
that some 2 million pounds of metals may leave kilns attached to fine
particles each year (pg. 23). Measurements at one kiln in California
indicated it was releasing 15,000 pounds of metals into the local
environment via airborne particles each year; measurements at a Florida
kiln revealed airborne releases of 21,000 pounds of metals per year
(pg. 23). Tests at an Illinois kiln revealed that burning hazardous
wastes increased lead emissions 82%, chromium 167% and zinc 662%,
compared to the same kiln burning normal fuel (pg. 23).
The fly ash from kilns is loaded with metals if the kiln burns
hazardous wastes. Based on EPA data, Costner and Thornton estimate that
18.6 million pounds of metals enter the U.S. environment in fly ash
from kilns each year (pg. 25). These metals are in a particularly
leachable form, having a large surface area, and are thus available to
enter water and living things (see RHWN #162). The high alkalinity
(high pH) of kiln ash makes kiln ash even more leachable than ash from
normal hazardous waste incinerators (pg. 25). At least two ash disposal
sites for cement kilns are on the Superfund list, and neither kiln is
supposed to have burned hazardous waste (pg. 25).
Advocates of hazardous waste incineration in kilns often claim that
kilns destroy 100% of the wastes entering the furnace. Unfortunately,
available data reveal this is not true by a wide margin. Kilns do
operate at high temperatures (2000 to 3000 degrees Fahrenheit), but
metals are not destroyed at any temperature. Furthermore, a class of
chemicals called "products of incomplete combustion" (PICs, which
include dioxins, furans, and a broad range of other organic chemicals)
are created in a kiln, not in the furnace itself but in lower-
temperature parts of the machine (smoke stack, pollution control
devices, or ambient air outside the incinerator) (pgs. 18-21, 27-30).
The production of PICs is enhanced by "upsets," which occur in kilns
several times each month, when something goes wrong with the machine.
During these periods, puffs of hazardous chemicals are emitted into the
local environment (pg. 18).
Another source of problems may be chemical releases resulting from
transportation accidents. A typical kiln will burn 1,800 tank-truck
loads of hazardous wastes per year. Many such trucks operate
dangerously, in violation of applicable laws (pg. 18).
 Personal communication March 19, 1990, from Richard Fortuna,
executive director of Hazardous Waste Treatment Council, Washington,
DC; phone (202) 783-0870.
Get: Pat Costner and Joe Thornton, SHAM RECYCLERS, PART 1: HAZARDOUS
WASTE INCINERATION IN CEMENT AND AGGREGATE KILNS (Washington, DC:
Greenpeace [1436 U Street, NW, Washington, Dc 20009; phone (202) 462-
1177], November, 1989). Greenpeace asks a $5.00 donation to cover
printing and handling costs. Well worth the price.
Descriptor terms: rcra; epa; cement kilns; hazardous waste treatment
council; hazardous waste; marine shale processors; ash; heavy metals;