Coal Ash Disposal
27
By Nick Garlisch [email protected]
description
Coal Ash Disposal. By Nick Garlisch [email protected]. What is Coal Ash?. Coal ash is what remains after coal is burned When coal is burned, roughly 10% of the coal remains as ash Coal ash is comprised of several types of ash including fly ash, bottom ash, and boiler slag. - PowerPoint PPT Presentation
Transcript of Coal Ash Disposal
By Nick [email protected]
What is Coal Ash?Coal ash is what remains after coal is burnedWhen coal is burned, roughly 10% of the coal
remains as ashCoal ash is comprised of several
types of ash including fly ash, bottom ash, and boiler slag
Fly AshFly ash is the ash that rises up and is trapped
by the stack filtersAbout 74% of the ash generated is fly ashStack filtration devices such as scrubbers
reduce fly ash emissions by around 95%Around 5% of the fly ash
produced is released into the atmosphere
Bottom AshBottom ash is too heavy to rise so it settles at
the bottom of the boilerAbout 20% of the ash generated is bottom
ash
Boiler SlagBoiler slag is formed when the ash melts
under the intense heatIt is collected at the bottom of the boiler and
at the exhaust stack filtersAbout 6% of the ash
generated is boiler slag
Coal Ash ConstituentsCoal ash contains pollutants such as arsenic,
cadmium, lead, selenium, and other toxic metals that can cause cancer and neurological harm in humans
Other constituents of potential concern include mercury, aluminum, antimony, barium, boron, and thallium
Should We Be Concerned?Pollution from coal ash dumps significantly
increases both cancer and noncancer health risks and degrades water quality in groundwater supplies
Unlined coal ash waste ponds pose a cancer risk 900 times above what is defined as acceptable
At least 23 states have poisonedsurface or groundwater suppliesfrom improper disposal of coal ash
Magnitude of Ash GeneratedThe US derives over half its electricity from
coal fired power plantsBurning this much coal results in nearly 140
million tons of coal ash produced each year
What happens to all that ash?
Where it goesAround 40% of the ash is reused as an
additive in a variety of applications such as a cement substitute in concrete and a filler for asphalt
Coal ash is also used in construction projects to level out uneven terrain
The remaining 60% isdisposed of in landfills
Beneficial ReuseAllows for the ash to be recycled instead of
disposedDecreases demand for cement and overall
energy requirements for certainprojects
Recycling reduces waterconsumption and greenhousegas emissions
FGD GypsumOne way coal ash is reused is to make FGD
GypsumFGD Gypsum is a product produced from the
sulfur dioxide emissions control scrubbersFGD Gypsum has many
uses including agriculture, highway construction, cement production, water treatment, and glass making
Agriculture
Sham Recycling?Concerns that the industry is using the ash
improperly and labeling it recyclingConsumer products such as bowling balls and
carpetsGolf coursesPlacing the ash in
deserted mines whereit might leach into into groundwater-groundwater
RegulationsNo uniform federal standardsState by state regulationsEach state must meet baseline federal
standardsEPA does not currently
consider coal ash a hazardous waste
DisposalCoal ash is disposed of in surface
impoundments (aka coal ash pond) where the ash is suspended in water
There are up to 1,300 impoundments nationwide
Some states have recently started requiring liners for new impoundments scheduled to be built
Catastrophic spillshave occurred
TVA SpillA retention wall collapsed at a coal ash pond
at the Tennessee Valley Authority’s Kingston Plant
Around 5.4 million cubic yards of wet coal ash spilled out of the ash pond
The spill flooded more than 400 acres andentered water systemsused for drinking water
TVA SpillElevated levels of radiation from those typically
found in coal ashLevels of radium 228 and 226 around 8
picocuries per gram, most coal ash is around 5-6 Fears over exposure to airborne particulate
matterAn underwater dam was
constructed to prevent ash from moving further downstream
IllinoisIllinois EPA has required new surface
impoundments built after the early 1990’s to be lined
Groundwater monitoring wells have been installed at some but not all of these new impoundments
The following is a table of power plants with surface impoundments permitted under the NPDES program
Total impoundments
Active impoundments
Inactive impoundments
LinedImpoundments
ImpoundmentswithGroundwatermonitoring
83 68 15 31 28
IllinoisIllinois EPA Bureau of Water issues permits for
surface impoundments that recently have started to require liners and groundwater monitoring
Surface impoundments must be in compliance with Illinois groundwater and surface water quality standards
IEPA Bureau of Land can issue a permit for coal ash to be disposed in special waste landfills
Proposed RegulationThe EPA is currently engaged in a rule
making process to regulate coal ashEPA has proposed two separate options for
how it would regulate coal ashRegulation would be under the Resource
Conservation and Recovery Act (RCRA)subtitle C or subtitle D
Public comments were due November 19th
Subtitle CCoal ash would be considered a hazardous wasteState and federal enforcement Permits requirementsPhases out the use of existing and new surface
impoundmentsIndustry contends a hazardous label would end
beneficial reuse and cost 12-13 billion dollars more per year which would be pushed onto consumers
Industry contends coal ash is not a hazardous waste
Subtitle DCoal ash would not be considered a hazardous
wasteCitizen suit enforcement where states can act
as citizensNo permit requirementsSurface impoundments would
continue to be used but would require liners
Environmental groups think subtitle D regulation would be too weak
How a Waste Becomes HazardousUnder RCRA, a waste can become hazardous
two ways1) The EPA administrator can list it as
hazardous2) The waste can exhibit certain statutorily
defined characteristics such as ignitability or corrosivity
The characteristics are described in detail in40 CFR 261.4
Is Coal Ash Hazardous?Each quantity of coal ash generated is
different because different coal plants burn different kinds of coal
Testing is the only way to be sure if an individual amount of coal ash is hazardous
Although generators are obligated to test their waste to determine if it is hazardous, few coal ash generators actually test
What Will EPA Do?The public comment period ended November 19,
2010EPA must respond to the concerns in these commentsEPA’s final decision will not be overturned unless it is
found to be arbitrary and capriciousEnvironmental groups contend
subtitle D will continue to provide inadequate regulation
Industry contends subtitle C will endbeneficial reuse and cost consumersmore money
What will EPA choose?
