United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
Las Vegas, NV 89193-3478
Research and Development
EPA/600/S4-90/014Sept. 1990
&EPA Project Summary
Proximity of Texas Sanitary
Landfills to Wetlands and
Deepwater Habitats
V.W. Lambou, R.C. Herndon, J.E. Moerlins and R.L. Gebhard
Sanitary landfills can cause con-
siderable harm to sensitive ecosys-
tems if they are not properly located,
designed, and managed. The purpose
of these reports is to summarize the
proximity of 463 sanitary landfills in
Texas to wetlands and deepwater
habitats (i.e., rivers, lakes, streams,
bays, etc.); and to present data on
individual landfills. The sanitary
landfills were identified on U.S. Fish
and Wildlife Service's National Wet-
lands Inventory (NWi) maps. The
nearness or proximity of the sanitary
landfills to wetlands and deepwater
habitats was determined by drawing
three concentric regions around the
point representing the location of
each landfill. The radii of the
concentric regions were: 1/4 mile, 1/2
mile, and 1 mile. Due to the sig-
nificant variation in environmental
settings across Texas as well as the
availability of NWI maps, the state
was divided into 4 regions. Almost all
of the sanitary landfills included in
this study are located close to
wetlands and many of the sanitary
landfills are located close to deep-
water habitats. These facilities have
the potential to adversely affect
sensitive ecosystems, such as wet-
lands and deepwater habitats, either
through habitat alterations or through
the migration of contaminants from
sanitary landfills. There are other
considerations, besides the common-
ness of wetlands in an area, that
determine how close a sanitary land-
fill is located to wetlands.
This Project Summary was
developed by EPA's Environmental
Monitoring Systems Laboratory, Las
Vegas, NV, to announce key findings
of the research project that is fully
documented in two separate reports
of the sjme title (see Project Report
ordering information at back).
Introduction
Sanitary landfills, as typically defined,
are waste-management facilities regu-
lated under Subtitle D of the Resource
Conservation and Recovery Act (RCRA).
These facilities are commonly referred to
as municipal waste landfills and they are
primarily used to receive household
refuse and nonhazardous commercial
waste. However, sanitary landfills also
receive other types of Subtitle D waste,
such as sewage sludge and industrial
wastes. Sanitary landfills typically receive
some hazardous waste in the form of
household hazardous waste, and haz-
ardous waste from small-quantity gen-
erators as defined in 40 CFR Part 261.10
(Definitions). Depending upon the
definition of a sanitary landfill used by the
individual states, there are between 6,500
and 9,300 of these facilities permitted in
the United States.
Sanitary landfills can cause consid-
erable harm to sensitive ecosystems if
they are not properly located, designed,
and managed. These facilities have the
potential to adversely affect sensitive
ecosystems, such as wetlands and
deepwater habitats, either through habitat
alterations or through the migration of
contaminants from sanitary landfills. In
order to evaluate the seriousness of this
problem, information is needed on the
nearness of sanitary landfills to wetlands
and surface water bodies The purpose of
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this study is to document the proximity of
sanitary landfills in the state of Texas to
wetlands and deepwater habitats (i.e.,
rivers, lakes, streams, bays, etc.).
Materials and Methods
The source of data used to determine
the locations of the sanitary landfills was
the computer data file developed by
Development Planning and Research
Associates, Inc. (DPRA) for use by the
U.S. Environmental Protection Agency's
Office of Solid Waste in its RCRA Subtitle
D program. The DPRA data file includes
information on 7,683 sanitary landfills,
and 6,849 of these facilities have latitude
and longitude coordinates in degrees,
minutes, and seconds specified in the
data file. Each set of coordinates defines
a point which represents the geographic
location of a sanitary landfill. In addition,
the data file contains the names of the
landfills and data on the cities or counties
in which the landfills reside. Individual
states are responsible for permitting
sanitary landfills under Subtitle D of
RCRA and, since DPRA obtained the
information for the data file from state
sources, the site location information
varies in terms of accuracy and the point
chosen to represent the location of each
facility
Wetlands typically form part of a
continuous transition zone between
uplands and open water. Therefore, the
delineation of the upper and lower
boundaries in any wetland definition is
somewhat arbitrary. There are a number
of definitions of wetlands that have been
developed for use in classifying natural
environments or for regulatory purposes
While these definitions are not identical,
they are very similar. The selection of a
specific definition for use in this study
was determined by the availability of
national wetlands and deepwater habitats
geographic data.
The most extensive, consistent source
of wetlands and deepwater habitats
geographic data is the U.S. Fish and
Wildlife Service's National Wetlands
Inventory (NWI). The NWI has developed
detailed, large-scale maps for a
significant portion of the United States.
To date, wetland maps have been
developed for approximately 40 percent
of the contiguous 48 states, 10 percent of
Alaska, and all of Hawaii. Large-scale
NWI maps typically are either 1:24,000
scale or 1:63,360 scale U.S. Geological
Survey quadrangle maps, however, most
are 1:24,000 scale. Wetlands and
deepwater habitats are delineated on the
NWI maps. The delineation of wetlands
and deepwater habitats was developed
using remote sensing techniques and
field investigations. The NWI maps are
developed in accordance with the
National Map Accuracy Standard
(NMAS). The NWI 1:24,000 scale maps
used in this study are accurate,
according to the NMAS, to within 40 feet
of ground measurements. These maps
were particularly useful for plotting the
location of sanitary landfills and for
determining the proximity of these
facilities to wetlands and deepwater
habitats
The NWI maps use the definitions and
the classification system for wetlands and
deepwater habitats developed by the
U.S Fish and Wildlife Service (Cowardin
et al., 1979. Classification of Wetlands
and Deepwater Habitats of the United
States. FWS/OBS-79/31. 103 pp.). Wet-
lands are defined as lands transitional
between terrestrial and aquatic systems
where the water table is usually at or near
the surface, or the land is covered by
shallow water. Deepwater habitats are
defined as permanently flooded lands
lying below the deepwater boundary of
wetlands. See Cowardin et al. for more
expansive definitions and an explanation
of the definitions, as well as the boundary
limits.
The U.S. Fish and Wildlife Service's
classification of wetlands and deepwater
habitats is hierarchical in nature proceed-
ing from general to specific. There are 5
systems, 10 subsystems, and 55 classes.
In this study only the "system," i.e, the
complex of wetlands and deepwater
habitats that share the influence of similar
hydrologic, geomorphologic, chemical, or
biological factors, was used for
classification purposes.
Each sanitary landfill included in this
study was located on NWI large-scale
maps using standard cartographic tech-
niques. Nearness or proximity of sanitary
landfills to wetlands and deepwater hab-
itats was determined by drawing three
concentric regions around the point
representing the location of each landfill.
The radii of the concentric regions were:
1 4 mile, 1/2 mile, and 1 mile. The occur-
rence or nonoccurrence of the wetlands
and deepwater habitat systems in each
concentric region was then recorded.
Many sanitary landfills are typically of
the order of 100 acres in size. For
example, in the state of Florida about 35
percent of the active sanitary landfills are
between 50 and 150 acres in size, with
the average size being 110 acres (Florida
Department of Environmental Regulation,
1987). A landfill that is 100 acres in size
and uniformly distributed about its
latitude/longitude point designation will
have a radius of approximately 1/4 mile
and, therefore, will approximate the
boundary of the first concentric 1/4-mile
radius region. Undoubtedly, most of the
landfills located in a 1/4-mile radius
region containing either wetlands or
deepwater habitats should be considered
to be located in wetlands or deepwater
habitats. Since landfills vary considerably
in size and shape, some of the landfills
located in the 1/2-mile radius and 1-mile
radius regions containing wetlands or
deepwater habitats will probably also be
located in wetlands or deepwater
habitats. The exact geographic boundary
of the landfill is not the critical consid-
eration for determining adverse impacts
associated with these facilities, since
contaminants can migrate off-site to
affect wetlands and deepwater habitats.
Due to the significant variation in
environmental settings across Texas as
well as the availability of NWI maps, the
state was divided into regions: Region 1 -
Coastal, Region 2 - Northeastern, Region
3 - Panhandle, and Region 4 - Central.
Figure 1 identifies the four regions of the
state of Texas as delineated for this
report. Regions 1, 2, and 3 have been
completely mapped by the NWI and, as a
result data are presented on the sanitary
landfills located in these regions. Region
4 has not been mapped by the NWI and,
therefore, data are not presented for the
sanitary landfills located in this region.
Data are reported individually for Regions
1, 2, and 3 and are aggregated for the
entire state.
Region 1 (Coastal) consists of the
coastal areas of the state where the
greatest concentrations of wetlands oc-
cur. There are 119 sanitary landfills
included in Region 1. Region 2
(Northeastern) includes the eastern
portion of the state, while Region 3
(Panhandle) includes the Texas pan-
handle area and a small area in the west-
central portion of the state. There are 264
and 80 sanitary landfills in Regions 2 and
3, respectively. Region 4 (Central) in-
cludes the central and west-central
portions of the state. There are 463
sanitary landfills in Region 4.
Results and Discussion
We obtained data on the proximity o!
463 sanitary landfills located in Region 1
(Coastal), Region 2 (Northeastern), anc
Region 3 (Panhandle) of Texas to wet-
lands and deepwater habitats. This
includes all the sanitary landfills in these
regions for which location data are
available. We were not able to obtair
data on the proximity of the 463 sanitary
landfills located in Region 4 (Central) tc
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Regions
Coastal, Southeastern
1 = 119 landfills
NWI Maps Available
Northeastern
2 = 264 Landfills
NWI Maps Available
Panhandle, Westcentral
3 = 80 Landfills
NWI Maps Available
Central, Westcostal
4 = 463 Landfills
No NWI Maps Available
T
Figure 1. Four regions of Texas delineated for this report.
wetlands and deepwater habitats. There
are 926 sanitary landfills in the DPRA
data file for the state of Texas and 463
(50 percent) of these facilities have NWI
maps available for site interpretation. As
a result, 463 (50 percent) of the 926
sanitary landfills in the state of Texas are
not included in this study.
Approximately 73 percent of the san-
itary landfills are located in or within 1/4
mile of wetlands, while 93 and 99 percent
are located in or within 1/2 and 1 mile of
wetlands, respectively (Figure 2). Only
four (1 percent) of the landfills are located
more than a mile from any type of wet-
land. Most sanitary landfills are located
either in or are close to Palustrine wet-
lands (approximately 71, 92, and 99 per-
cent are located in or within 1/4, 1/2, and
1 mile, respectively, of a Palustrine wet-
land).
There are some differences among
the three regions of Texas in the relative
proximity of sanitary landfills to wetlands
(Figure 3); however, most of the differ-
ences are relatively small. It is surprising
that 83 percent of the sanitary landfills in
Texas Region 2 (Northeastern) are
located in or within 1/4 mile of wetlands
as compared to 64 percent in Texas
Region 1 (Coastal) with its large expanse
of coastal wetlands. It is also interesting
that 51 percent of the facilities are
located in or within 1/4 mile of wetlands
in Texas Region 3 (Panhandle) which is
located in the more inland and arid por-
tion of Texas. Only approximately one-
fourth of all the sanitary landfills are
located more than 1/4 mile from a
wetland. Twenty, 6 and 1 percent are
located 1/4 to 1/2, 1/2 to 1 mile, and more
than one mile, respectively, from the
closest wetland.
Approximately 12 percent of the
sanitary landfills are located in or within
1/4 mile of deepwater habitats, while 22
and 38 percent are located in or within
1/2 and 1 mile of deepwater habitats,
respectively (Figure 4). Approximately 62
percent (i.e., 289) of the landfills are
located more than a mile from any type
of deepwater habitat. Most of the facilities
that are located in or that are close to
deepwater habitats are in the vicinity of
Riverine or Lacustrine deepwater habitats
(i.e., 23 percent are located in or within 1
mile of a Riverine deepwater habitat and
21 percent are located in or within 1 mile
of a Lacustrine deepwater habitat).
There are some differences among
the three regions of Texas in the relative
proximity of sanitary landfills to deep-
water habitats (Figure 5). As expected,
Region 3 (Panhandle), located in the
more arid portion of Texas, has the
smallest percentage of facilities located
close to deepwater habitats. Region 1
(Coastal) and Region 2 (Northeastern) are
similar in the proximity of facilities to
deepwater habitats. Overall, relatively few
of the facilities are located less than 1
mile from a deepwater habitat; 12, 10,
and 16 percent are located less than 1/4
mile, 1/4 to 1/2 mile, and 1/2 to 1 mile,
respectively, from the closest deepwater
habitat.
Approximately 75 percent of the
sanitary landfills are located in or within
1/4 mile of either wetlands or deepwater
habitats, while 94 and 99 percent are
located in or within 1/2 and 1 mile of
either wetlands or deepwater habitats,
respectively (Figure 6). Only four (1
percent) of the landfills are located more
than a mile from either wetlands or
deepwater habitats. Most of the sanitary
landfills are located either in or are close
to Palustrine or Riverine habitats (approx-
imately 71, 92, and 99 percent are
located in or within 1/4, 1/2, and 1 mile,
respectively, of a Palustrine deepwater
habitat while approximately 10, 22, and
35 percent are located in or within 1/4,
1/2, and 1 mile, respectively, of a
Riverine habitat). Only approximately
one-fourth of the sanitary landfills are
located more than 1/4 mile from either a
wetland or deepwater habitat. Nineteen,
5, and 1 percent are located 1/4 to 1/2
mile, 1/2 to 1 mile, and more than 1 mile,
respectively, from either the closest
wetland or deepwater habitat.
There are some differences among
the three regions of Texas in the relative
proximity of sanitary landfills to either
wetlands or deepwater habitats (Figure
7); however, most of the differences are
relatively small. Region 2 (Northeastern)
has the largest percentage of facilities
located close to either wetlands or
deepwater habitats, while Region 3
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All Systems
Marine
Estuarine
Riverine
Lacustrine
Palustrine
40 60
Percent
Figure 2. Proximity of 463 sanitary landfills in Texas to wetlands.
Fi In or within 1 Mile
In or within 1/2 Mile
In or within 1/4 Mile
99
100
(Panhandle) has the smallest percentage
of facilities located close to either
wetlands or deepwater habitats. Region 2
(Northeastern) has the largest percentage
of facilities located close to either
Palustrine and Lacustrine wetlands or
deepwater habitats, and Region 1
(Coastal) has the largest percentage of
facilities located close to either Riverine
and Estuarine wetlands or deepwater
habitats.
Conclusions
Almost all of the sanitary landfills
included in this study are located in or
are close to wetlands and many of the
sanitary landfills are located close to
deepwater habitats. From this, we
conclude that these facilities have the
potential to adversely affect these sen-
sitive ecosystems, either through habitat
alterations or through the migration of
contaminants from sanitary landfills. This
study did not acquire data that would
elucidate why sanitary landfills are close
to wetlands. However, since a large
percentage of facilities in the more inland
and arid Region 3 (Panhandle) of Texas
are located in or are close to wetlands,
we conclude that there are considerations
other than the commonness of wetlands
in an area, that determine how close a
sanitary landfill is located to wetlands.
< 1/4 Mile
1/2-1 Mile
1/4-1/2 Mile
> 1 Mile
Whole State (463)
Region 1 (Coastal) (119)
Region 2 (Northeastern) (264)
Region 3 (Panhandle) (80)
0 20 40 60 80 100
Percent
Figure 3. Comparison of the distance of sanitary landfills to the closest wetland in the various regions in Texas.
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All Systems
Marine
Estuarine
Riverine
Lacustrine
21
11
In or within 1 Mile
In or within 1/2 Mile
In or within 1/4 Mile
0
20
40 60
Percent
Figure 4. Proximity of 463 sanitary landfills in Texas to deepwater habitats.
80
100
< 1/4 Mile
1/2-1 Mile
1/4 - 1/2 Mile
> 1 Mile
Whole State (463)
Region 1 (Coastal) (119)
Region 2 (Northeastern) (264)
Region 3 (Panhandle) (80)
20 40 60 80 100
Percent
Figure 5. Comparison of the distance of sanitary landfills to the closest deepwater habitat in the various regions.in Texas.
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All Systems
In or within 1 Mile
In or within 1/2 Mile
In or within 1/4 Mile
Lacustrine
Palustrine
99
20
40 60 80
Percent
100
Figure 6. Proximity of 463 sanitary landfills in Texas to either wetlands or deepwater habitats.
Whole State (463)
Region 1 (Coastal) (119)
Region 2 (Northeastern) (264)
Region 3 (Panhandle) (80)
< 1/4 Mile £31/4-1/2 Mile
1/2-1 Mile M > 1 Mile
80 100
0 20 40 60
Percent
Figure 7. Comparison of the distance of sanitary landfills to the closest wetland or deepwater habitat in the various regions in Texas.
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V.W. Lambou (also the EPA Project Officer see below), is with Environmental
Monitoring Systems Laboratory, Las Vegas, NV 27711; R.C. Herndon and
J.E. Moerlins are with State University, Tallahassee, FL 32306; and R.L.
Gebhard is with U.S. Fish and Wildlife, St. Petersburg, FL 33702.
The complete reports, entitled "Proximity of Texas Sanitary Landfills to Wetlands
and Deepwater Habitats: Data on Individual Landfills," (Order No. PB 90-
251 851/AS; Cost: $23.00, subject to change) and "Proximity of Texas
Sanitary Landfills to Wetlands and Deepwater Habitats: Statewide
Results," (Order No. PB 90-251 869/AS; Cost: $15.00, subject to change)
will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV 89193-3478
United States Center for Environmental Research
Environmental Protection Information
Agency Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S4-90/014
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