V-/EPA
Agency
Solid Waste and Emergency Response (5305W)
Sensitive
Environments
and the Siting
of Hazardous Waste
Management
Facilities
-------
£
o
-------
Introduction
1 his publication discusses sensitive types of environments
that pose special challenges to the siting, expansion,
and operation of RCRA hazardous waste management
facilities. Locating hazardous waste management facilities
in certain areas - because of their soils, terrain, ground-
water, or weather conditions - may pose significant risks
of releases and possible exposures to humans and the
environment. The environmentally sensitive locations
addressed in this book are:
Floodplains
Wetlands
Groundwater
Earthquake Zones
Karst Soils
Unstable Terrain
Unfavorable Weather
Conditions
Incompatible Land
Use
In addition to these technical siting factors, there are social
concerns that affect the appropriateness of a hazardous
waste facility's location. These social concerns and related
evaluation factors will be addressed in a future EPA
guidance document.
-------
What Are Environmentally Sensitive
Locations and
Why Are They a Concern?
Sensitive environments are locations that, because of their
physical conditions, maybe disturbed or permanently
damaged by hazardous waste contamination. Wetlands, for
example, are especially sensitive to chemical contamination.
Sensitive environments are also locations that are physically
unstable and may change so greatly that they can cause the
release of a hazardous waste or complicate its cleanup.
...
Unfavorable
Weather
Conditions
Incompatible
Land Use
Locating hazardous waste facilities in the sensitive environments shown in this
figure increases the risk of contamination.
-------
For example, floodwaters spilling into floodplains may damage waste
management structures such as tanks or berms (walls of earth), causing
the release of hazardous waste to the environment. This brochure
provides additional information on wetlands and floodplains and
discusses other environments that are sensitive, particularly in relation
to hazardous waste management facilities.
Soil, groundwater, and weather conditions are important technical
factors in determining how environmentally sensitive a location is.
Knowing about environmentally sensitive areas helps ensure that a
hazardous waste management facility is sited at a location that is safe
for our health and our environment. For example, facilities constructed
on unstable ground or in floodplains are at greater risk for landslides or
floods, respectively, which could cause accidental hazardous waste
releases. Therefore, when selecting a
location for a hazardous waste facility,
such safety concerns must be considered.
Other nontechnical factors to consider in
locating a hazardous waste management
facility are the people living and working
around the facility, that is, the number of
people, their ages, and their health. Also,
hospitals and schools should be considered
because they may be difficult to evacuate
in the event of a hazardous waste spill.
This is why many states require
hazardous waste management facilities to
locate a safe distance from densely
populated areas, hospitals, schools, or
prisons. These issues will be discussed in
further detail in an upcoming
companion brochure on social factors.
-------
Companies that plan to construct and operate hazardous waste
management facilities should avoid siting their facilities in
environmentally sensitive areas. If a company does decide to locate a
facility in a sensitive area, its owner should design the facility to
minimize risks to people and the environment. By law, an owner's
approach to locating a safe hazardous waste management facility must
-------
include consideration of the physical site, the facility's design, and its
operating conditions. The facility's design includes such factors as
whether it is designed to protect surrounding soils and groundwaters.
Operating conditions may include how many hours each day an
incinerator may burn waste and how well a technology destroys or
treats waste.
The distribution of three of the types of sensitive
locations-wetlands, land use (population), and
major areas of karst-demonstrates the need to site
hazardous wastes carefully.
•ft • ^l
Population
• 50,000-100,000
Karst
Wetlands
100,001-500,000
• 500,001-1 Million
-------
Floodplains
Floodplains are lands that are subject to periodic flooding.
They are usually lowlands along rivers, streams, lakes, and
oceans. Often, they occur where annual water flow is low or
nonexistent, but they may also occur due to large amounts
of melting snow or rainfall that run off the land.
Facts About Floodplains
Floodplains act as natural storage areas, slowing down rushing
floodwaters and reducing downstream flooding. Floodplains also help
maintain the quality of rivers and streams by filtering eroded soils (also
known as sediments) and nutrients such as nitrogen and phosphorus.
To Learn Where
Floodplains are
Located...
Floodplain maps can be
obtained at no cost from the
Federal Emergency Man-
agement Agency's Flood
Map Distribution Center,
6930 (A-F) San Tomas
Road, Baltimore, MD 21227-
6227 or from the U.S. Army
Corps of Engineers, the Soil
Conservation Service, the
National Oceanic and Atmos-
pheric Administration, the
US Geological Survey, the
Bureau of Land Manage-
ment, the Bureau of Recla-
mation, the Tennessee Val-
ley Authority, and State and
local flood control agencies.
Your county or city planning
office should also have
floodplain maps. Know your
local zoning laws!
What is a 100-Year Floodplain?
A 100-year floodplain is any land area that
is subject to a 1 percent or greater chance
of flooding in any given year from any
source.
The Problem with Locating
a Facility in a Floodplain
Industry considers floodplains as valuable
locations for development because they
are often flat and near water and
transportation routes. However, EPA has
recently seen the damage that flooding can
cause at hazardous waste management
facilities (for example, the 100-year and
500-year floods that have occurred along
-------
the Mississippi River). In some cases, floodwaters have floated
hazardous waste storage tanks off their foundations and floodwaters
have flowed into waste ponds, carrying their hazardous contents
downstream.
The speed of flood waters is also a concern because high flow rates can
erode wastepiles, berms, landfills, or other types of waste management
structures.
=teod;isJn
Floodplains are typically lands along waterways that may flood.
Facility Siting Recommendations
Facilities should avoid building in floodplains. Existing regulations
require hazardous waste management structures built in a 100-year
floodplain to be built above the 100-year flood level or built to
withstand the flooding event. See Title 40 of the Code of Federal
Regulations, Section 264.18 (40 CFR 264.18).
Facilities can be declared exempt from this regulation if they prove
(1) that they can remove all waste before the flood or (2) no harm
will come to human health or the environment when the flood
occurs. Regulations also allow facilities to locate in 100-year
floodplains if owners can prove that the facility can withstand a
washout in the event of a flood (40 CFR 270.14(b)(11)(iv)). In
addition, all facilities should have detailed, up-to-date emergency
response plans that can be put into action before and during floods.
Check your state and local regulations; they may have more
stringent requirements that also have to be met.
-------
Wetlands
Wetlands are areas that are waterlogged for an extended
period of time and include a variety of fish and wildlife
habitats. Swamps, marshes, bayous, bogs, and Arctic tundra
are wetlands. Wetlands are highly sensitive areas that are
among the most productive ecosystems in the world.
Interesting Facts about Wetlands
• One-third of all bird species appear in wetlands, which serve as
vital migratory resting, staging, and nesting areas for waterfowl
and other species.
• 96 percent of all fish species caught by commercial fishers depend
upon wetlands for part of their life-cycle.
• Wetlands control shoreline erosion, which protects other
ecosystems from storms, improves water quality, supplies water,
and regulates climates.
The Problem with Locating
a Facility In or Near Wetlands
Construction or expansion of hazardous waste management facilities
directly in and near wetlands can destroy fish and/or wildlife habitats.
In addition, the high amounts of unstable soils and water in wetlands
make them poor areas for land-based hazardous waste structures such
as landfills.
Any hazardous wastes spilled on wetlands can spread faster through the
groundwater and surface water. Such contamination may harm
commercial and recreational fisheries and shellfish harvesting. Eating
finfish and shellfish that have accumulated toxic substances can be
-------
dangerous to human health. Hazardous waste releases into wetlands can
also reduce the variety and reproduction of species living in wetlands.
One of the most serious consequences of a hazardous waste spill or
leak in a wetland can occur in the process of restoring the wetland.
Removing the contaminated sediments can be very costly and may even
destroy the wetland. Because wetlands are typically found at the
headwaters of rivers, lakes, and streams, removal of contaminated
bottom sediments in wetlands could unintentionally release contami-
nants downstream to unsuspecting human, fish, and wildlife
populations.
Facility Siting Recommendations
Hazardous waste management facilities should not be located in
wetlands. This strategy of no construction in wetlands supports the
EPA's goal of no net loss of this important resource. Facilities planning
to locate near wetlands should also take special protective steps.
They should (1) investigate how the soil and groundwater would be
affected by spilled hazardous wastes, and
(2) design the facility to prevent spills.
Wetlands are often assigned to
three categories. Swamps are
dominated by trees, marshes by
grasses, and bogs by mosses.
Swamp
Marsh
Highlights
of Wetlands
Protection Laws
Section 404 of the Clean
Water Act (CWA) requires
permits from the Army Corps
of Engineers for activities
involving the discharge of
dredged or fill materials into
"waters of the United States,"
which include wetlands.
Other laws that provide some
protection to wetlands are:
the Wild and Scenic Rivers
Act, the Fish and Wildlife
Coordination Act, the Endan-
gered Species Act, and the
Coastal Zone Management
Act. In addition, some States
are now enacting wetlands
protection laws.
-------
Groundwater
Groundwater is a collection of water beneath the earth's
surface that is fed either by rainfall percolating through soil
and rock or by surface water. High-value groundwater is
(1) the sole source of drinking water available, or (2) the
water feeding into a sensitive environment such as a wetland.
Hydrogeology is the study of the interaction between groundwater and
its source (soil, surface water) along with its movement. A site's
hydrogeology is considered complex when scientists cannot accurately
characterize, monitor, or predict groundwater movement.
Interesting Facts About Groundwater
Over half the U.S. population
uses groundwater as its main
drinking water source.
95 percent of rural households
rely on groundwater for their
drinking water.
Groundwater is the only
source of drinking water
for people in some areas.
34 of the 100 largest U.S.
cities rely on groundwater for
drinking and commercial
purposes.
-------
The Problem with Locating a Facility
Near High-Value Groundwater
In certain parts of the country, contaminants can move quickly into
the groundwater. It can be very difficult and expensive, if not
impossible, to clean up this contamination. The underground soil and
rock in certain areas make it difficult for scientists to find out the
direction of groundwater flow, which further complicates cleanup.
Most of the time, groundwater cannot be cleaned for a reasonable cost
and within a reasonable time frame. Removing contamination from
groundwater may take hundreds of years.
Facility Siting Recommendations
Experts believe that hazardous waste management facilities should
not be located over high-value groundwater or areas where the
underground conditions are complex and not understood. If a facility
plans to locate in one of these areas, EPA requires several studies as part
of the groundwater investigation, such as (1) determining the
complexity and importance of the groundwater for drinking supplies,
(2) determining the direction of groundwater flow, (3) assessing the
ability of the groundwater to be replenished, and (4) determining
how other waters (e.g., rivers and wetlands) are connected to the
groundwater.
Facility owners should also take extra steps to make sure that no leaks
or spills will occur from structures that hold hazardous wastes.
They should use conservative assumptions when engineering waste
management structures such as adding more spill containment systems
around structures. Also, the number of monitoring wells used to detect
spills in these environments may need to be increased and samples
taken more frequently.
-------
Earthquake Zones
Earthquake zones are areas affected by earthquakes.
Earthquakes are a significant threat to public safety and
welfare over many parts of the United States, particularly
the West Coast, Alaska, parts of the Rocky Mountains, the
Mississippi Valley, and selected areas along the Eastern
Seaboard.
The Problem with Locating a Facility
in an Earthquake Zone
EPA is concerned about earthquakes affecting hazardous waste
management facilities because they can damage structures that hold
wastes and result in accidental releases to groundwater, surface water,
soil, and air. Damage can result from movement of large pieces of
ground or, more commonly, ground shaking. Because structures that
hold hazardous waste (e.g., landfills, ponds, or lagoons) are often made
of soil and rock, they can be damaged by earthquake activity.
Structures above the ground, such as tanks and incinerators can also
be damaged, toppled, or destroyed.
When is an Earthquake Zone a Siting Concern?
The magnitude or amount of ground shaking at a site is a good
measure for determining if a site is appropriate for a hazardous waste
management facility. To help determine the level of risk from shaking,
scientists have mapped out seismic impact zones. These zones measure
the amount that the ground could potentially shake during an
earthquake. The risk is based on the area's geology and past earthquake
activity. Maps of seismic impact zones are available to the public
through the U.S. Geological Survey (USGS) and state and local
governments.
-------
Facility Siting Recommendations
EPA currently has regulations designed to prevent damage to hazardous
waste management facilities in areas with earthquake activity. In Title 40
of the Code of Federal Regulations, Section 264.18 (a) bans facilities from
siting new hazardous waste management units within 200 feet of a
Holocene fault (that is, faults that have been active within the last 10,000
years). These faults are located in certain areas of the western United States.
And 40 CFR 270.14(b)(l 1) (ii) also requires owners and operators of
hazardous waste management facilities to investigate Holocene faults that
are within 3,000 feet of a facility.
In addition to the regulatory requirements, earthquake experts
recommend a number of safety features for facilities in areas where
earthquake activity can cause ground shaking or ground rupture:
• Design structures at hazardous waste management facilities to resist
ground motion or shaking and withstand the maximum horizontal
acceleration - the highest acceleration value expected at the earth's
surface in that particular area. It has been found that the horizontal
direction of shaking is much more damaging to structures than the
vertical direction.
• Build structure containment systems to prevent spills in case of a failure.
• Pay special attention to site factors such as soil moisture and slope
stability, which may enhance ground shaking and lead to structural failure.
\
The side-to-side motion of the ground during earthquakes causes the most
damage to structures.
-------
Karst Terra in
Karst terrain consists of rock - such as limestone, dolomite, or
gypsum - that slowly dissolves when water passes through it.
The dissolving rock leaves underground voids, tunnels, and
caves. Sometimes these underground spaces can grow so large
that their "ceilings " will collapse, forming large sinkholes.
A karst sinkhole in east-central Missouri.
The Problem with Locating a Facility in Karst Terrain
Facilities located in karst areas may have an increased chance of
hazardous waste spills because sinkholes can form suddenly. These
spills can contaminate the groundwater and make it difficult to clean
up since the hydro geology is complex in these areas. Engineers do not
have good methods to protect hazardous waste management facilities
against sinkhole collapse.
-------
Sinkhole
Losing Stream
Cave
Deeply Weathered
Bedrock
Limestone and
Dolomite
Sandstone
Spring
Karst soils are poor foundations for any structure.
Facility Siting Recommendations
Hazardous waste management facilities should avoid locating in
"active" karst areas. Approximately 5 percent of the United States
has "active" karst, including Missouri, Kentucky, Florida, Indiana,
Arkansas, and Puerto Rico. Companies planning to locate facilities
in karst areas should demonstrate that they can (1) engineer a waste
management structure that protects against sinkhole formation
(e.g., additional foundation support) and, in turn, hazardous waste
spills, and (2) monitor and clean up groundwater contamination if it
occurs. It is important that companies conduct site characterization
studies in which they map sinkholes and underground caverns,
determine ground stability, and measure the speed and direction of
groundwater flow.
-------
Unstable Terrain
Unstable terrain is any area where movement of the land
surface can damage structures and buildings. Unstable
terrain is divided into two kinds of land movement:
(1) the movement of rock and soil on steep slopes by gravity
(e.g., landslides), and (2) rock and soil sinking, swelling,
or heaving.
The Problem with Locating a Facility
on Unstable Terrain
EPA is concerned that movement of unstable soils can damage
hazardous waste facilities and lead to spills and leaks. Mass movement
of rock and soil onto a hazardous waste facility can crush or destroy
buildings, puncture and bury drums of hazardous waste, and break
apart earthen structures containing liquid wastes. Poor foundation
conditions can:
• Cause buildings to shift and crack
• Disrupt landfill gas and leachate collection
• Rip landfill liner systems.
Damages such as these may cause hazardous waste spills that can be
difficult to clean up.
-------
Facility Siting Recommendations
Unstable terrain is found throughout the United States. Therefore,
companies seeking locations should check for past mining activities,
flood control, or groundwater withdrawal, which could cause the
ground to sink. Natural conditions, such as high water content in soil
and freezing temperatures that cause soil to heave or swell, should also
be identified along with slumping soils caused by steep slopes that have
high soil moisture, poor drainage, or weak soils.
It is possible to build a safe facility on unstable terrain; however,
construction and operating costs would increase considerably.
Although most of the risks to facilities in unstable terrains can be
addressed by good design and engineering, EPA recommends that
facilities perform geotechnical analyses of soil and geologic properties
to determine the extent of unstable conditions. This information will
help a facility decide if its unit should be located in another area
or if additional design and engineering measures are needed.
Building on unstable soils can lead to serious environmental consequences.
-------
Unfavorable Weather Conditions
Certain areas of the United States have atmospheric
conditions that increase the chance of breathing air
contaminants. Some parts of the country may have long
periods with little or no air movement (such as Los Angeles'
smog inversions). In these areas, air contaminants are not
easily dispersed. In mountainous areas, air contaminants can
also become trapped for a long time. This situation occurs
because mountains can affect regional wind patterns by
acting as barriers that reduce air flow.
The Problem with Locating a Facility in an Area
with Unfavorable Weather Conditions
Hazardous waste management facilities increase the chance of exposing
people and the environment to air contaminants in areas where
stagnant weather conditions exist. Young and elderly people, along
with people suffering with respiratory ailments, are more susceptible to
extended exposures to air contaminants. In addition, eating food
produced in areas with air pollutants (e.g., meat, milk, and grains)
becomes a concern because these pollutants may be taken up by plant
or animal respiration or by contaminated rainfall. Hazardous waste
facilities that burn or incinerate waste (i.e., combustion facility,
incinerator) may cause unacceptable contamination and, in turn,
environmental exposures in these stagnant areas.
Facility Siting Recommendations
Facilities that burn hazardous wastes should avoid locating where
unfavorable weather conditions exist. Atmospheric conditions
in this type of area should be evaluated carefully by the facility.
Facilities should evaluate the distribution and age of the population
-------
and other vulnerability factors and the effects of land features on wind
patterns and pollutant mixing in the air. Seasonal effects on wind
patterns should also be evaluated. Special engineering and placement of
the facility at the site may be necessary to ensure acceptable dispersion
of air contaminants. The permit for the facility may also need to
restrict the operations of the facility to times when weather conditions
are favorable.
Regulations Controlling Air Emissions
from Hazardous Waste Management Facilities
Both the Clean Air Act and the Resource Conservation and Recovery
Act contain regulations on the control of air pollution from hazardous
waste facilities (40 CFR 264, Subparts I, J, K, and O and 40 CFR 266,
Subpart H). Combustion regulations address specific chemical
pollutants; tank, container, and waste pond regulations address volatile
organic pollutants as a class. However, both sets of regulations target
emission reduction. They do not address the siting of emission sources.
An inversion can be worsened by a mountain range forcing warm desert air to
move up and over cooler ocean air flowing in the opposite direction.
-------
Incompatible Land Use
Certain preexisting land uses may not be compatible with
the operation of a hazardous waste management facility.
For example, densely populated areas or facilities such as
hospitals, schools, and prisons are especially vulnerable to
hazardous waste exposures.
Human Exposure to Hazardous Wastes
People may become exposed to hazardous waste contaminants
by breathing, drinking water, eating food, eating dirt (children,
particularly), or by skin contact (with soil, air, or water).
The Problem with Locating a Facility
Near Sensitive Populations
Certain people may be more sensitive to exposure to hazardous waste
than the average person. Studies have shown that children and the
elderly may be more sensitive to certain toxic substance exposures.
Likewise, people who are sick can also be more vulnerable to toxic
exposures, and their illnesses may become worse.
Facility Siting Recommendations
Hazardous waste management facilities should avoid locating near
sensitive populations or in densely populated areas. Areas near schools,
nursing homes, day care centers, or hospitals should be avoided. Many
states have setback distances that prescribe the minimum distance a
hazardous waste facility can be from certain types of land use.
These minimum distances are meant to protect the public or
the environment from potential exposure to hazardous waste.
-------
EPA recommends NOT siting hazardous waste facilities in sensitive
locations for the following reasons:
Location
Environmental Consequences
Floodplains
Waste ponds may wash out.
Tanks may be moved from foundations.
Wetlands
Fish and wildlife are threatened.
Spills are spread to groundwater
and surface waters faster.
Cleanup is difficult, costly,
and sometimes more damaging.
Land Use
Sensitive populations such as the elderly,
children, and the sick are more affected
by toxic exposures.
High-Value
Groundwater
Contaminants are transported quickly.
Cleanup is costly and difficult.
Earthquake Zones
Ground fractures and shaking damage
structures, leading to spills.
Karst Terrain
Sinkholes may develop, leading to
structure failure and spills.
Unstable Terrain
Soil movement can shift and damage
structures causing waste releases.
Unfavorable
Weather Conditions
Stagnant air concentrates pollutants.
Mountains may block pollutant dispersion.
For Further Information...
For further information on sensitive environments, please contact
the RCRA hotline at 800-424-9349 orTDD-800-553-7672.
In the Washington, DC, area, call 703-412-9810.
This publication is also available on the Internet at
http://www.epa.gov/epaoswer/hazwaste.
-------
&> ~u o
GO CD 3»
O ffl Q!
T) 3'
3- CD
j5 w
CD ^
C^
il-
=^' CD
O Q_
O CD O SI
P CD 2. CD
r* 5T c/3
0> GO Si
OO5'
93§
CO
CD
O
------- |