&EPA
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 93478
Las Vegas NV 89193-3478
EPA/600/4-89/045A
November 1989
Research and Development
Proximity of Delaware
Sanitary Landfills
to Wetlands and
Deep water Habitats
Statewide Results
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EPA 600/4-89/045A
November 1989
OF DELAWARE SANITARY LANDFILLS TO WETLANDS AND
DEEPWATER HABITATS
Statewide Results
by
Robin L. Gebhard
National Wetlands Inventory
U.S. Fish and Wildlife Service
St. Petersburg, Florida 33702
Roy C. Herndon and John E. Moerlins
Center for Biomedical and Toxicological Research and
• Hazardous Waste Management
Florida State University
Tallahassee, Florida 32306-4016
and
Victor W. Lambou
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, Nevada 89193-3478
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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NOTICE
The information in this document has been funded wholly or
in part by the U.S. Environmental Protection Agency under
Grant No. CR-815139010 to the Florida State University. It
has been subject to the Agency's peer and administrative
review and it has been approved for publication as an EPA
document. Mention of trade names or commercial products
does not constitute endorsement or recommendation for use.
11
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ABSTRACT
Sanitary landfills can cause considerable harm to
sensitive ecosystems if they are not properly located,
designed, and managed. The purpose of this report is to
summarize the proximity of sanitary landfills in the state
of Delaware to wetlands and deepwater habitats (i.e.,
rivers, lakes, streams, bays, etc.); a companion report
presents data on individual landfills. 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. for use by the U.S.
Environmental Protection Agency's Office of Solid Waste in
its RCRA Subtitle D program. The sanitary landfills were
identified on U.S. Fish and Wildlife Service's National
Wetlands Inventory 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. All sanitary landfills in the state of Delaware are
located in or are close to either wetlands or deepwater
habitats. 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.
111
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CONTENTS
Abstract iii
Figures v
Tables vi
Introduction 1
Conclusions 1
Materials and Methods 2
Results and Discussion 5
Literature Cited 7
iv
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FIGURES
Number Page
1 Hypothetical sanitary landfill showing the point
(latitude and longitude coordinates) that
represents the location of the landfill, the
concentric regions used to determine the
nearness or proximity of the sanitary
landfill to wetlands and deepwater habitats,
and the boundary of an 100-acre sanitary
landfill distributed approximately evenly
around its point location (a 100-acre
landfill uniformly distributed around a point
will have a radius of approximately 1/4
mile). 8
2 Proximity of 3 Delaware sanitary landfills to
wetlands- 9
3 Distance of 3 Delaware sanitary landfills to the
closest wetland. 10
4 Proximity of 3 Delaware sanitary landfills to
deepwater habitats. 11
5 Distance of 3 Delaware sanitary landfills to the
closest deepwater habitat. 12
6 Proximity of 3 Delaware sanitary landfills to
either the closest wetland or deepwater
habitat. 13
7 Distance of 3 Delaware sanitary landfills to
either the closest wetland or deepwater
habitat. 14
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TABLES
Number Page
1 Definition of wetlands used by the U.S. Fish and
Wildlife Service 15
2 Definition of deepwater habitats used by the
U.S. Fish and Wildlife Service 17
3 Definitions of the five major systems used by
the U.S. Fish and Wildlife Service in
classifying wetlands and deepwater habitats 18
4 Number and percentage of sanitary landfills in
Delaware that are proximate to wetlands 23
5 Number and percentage of sanitary landfills in
Delaware that are proximate to deepwater
habitats 24
6 Number and percentage of sanitary landfills in
Delaware that are proximate to either
wetlands or deepwater habitats 25
VI
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INTRODUCTION
Sanitary landfills, as typically defined, are waste
management facilities regulated under Subtitle D of the
Resource Conservation and Hecovexy Act (RCKA). 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 hazardous waste from small
quantity generators 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 (U.S. EPA, 1987).
Sanitary landfills can cause considerable 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 this study is to document the proximity of sanitary
landfills in the state of Delaware to wetlands and deepwater
habitats (i.e., rivers, lakes, streams, bays, etc.). This
report gives statewide summary results; a companion report,
"Proximity of Delaware Sanitary Landfills to Wetlands and
Deepwater Habitats, Data on Individual Landfills," presents
data on the individual landfills.
CONCLUSIONS
1. All sanitary landfills in the state of Delaware are
located in or are close to either wetlands or deepwater
habitats.
2. 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.
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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 (DPRA, 1986).
The DPRA data file includes information on 1,683 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 (Figure 1) . 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.
Four types of errors or omissions were identified in
the DPRA data file. These errors and omissions include:
missing latitude and longitude, missing state code, wrong
state code, and erroneous latitude/longitude. The first two
items relate to data that were omitted in the facility
record. Facilities that did not have latitude and longitude
coordinates were not used in this study while facilities
that did not have a state code were assigned an appropriate
state code by comparing the latitude and longitude
coordinates for the facilities with maps of the various
states. The last two items relate to ' errors in the data
file. Facilities with the wrong state code were corrected
and included in the study. The last item relates to
erroneous latitude and/or longitude records. Where
discovered, the erroneous coordinate(s) were corrected, if
possible. Errors may still exist in the DPRA data file;
however, it is believed that the overall results and
conclusions contained in this report will not be
significantly affected, since the number of errors is
probably small.
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
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this study was determined by the availability of national
wetlands and deepwater habitats geographic data.
The most, extensive, consistent source of wetlands
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) (U.S. GS, 1979). 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 are 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 (contained in Tables 1
and 2) and the classification system (contained in Table 3)
for wetlands and deepwater habitats developed by the U.S.
Fish and Wildlife Service (Cowardin et al., 1979). Wetlands
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. For more
expansive definitions and an explanation of the definitions,
as well as the boundary limits, see Tables 1 and 2; for
further details see Cowardin et al. (1979). The U.S. Fish
and Wildlife Service's classification of wetlands and
deepwater habitats is hierarchical in nature proceeding from
general to specific (Cowardin et al., 1979). 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. The definitions as well as the
boundary limits of the five systems, i.e., Marine,
Estuarine, Riverine, Lacustrine, and Palustrine, are given
in Table 3; for further details see Cowardin et al. (1979) .
The first four systems, i.e., Marine, Estuarine, Riverine,
and Lacustrine, include both wetlands and deepwater habitats
whereas the Palustrine System includes only wetlands.
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In order to link the location of sanitary landfills in
the DPRA data file to the appropriate NWI maps, we used the
information on the T-70 computer tape obtained from the U.S.
Geological Survey (National Cartographic Information Center,
1987) . The NWI large-scale maps were developed using U.S.
Geological Survey's quadrangle maps as base maps. The T-70
computer tape contains 67 fields of information including
latitude and longitude that can be used for identifying the
1:24,000 scale maps, the map names, and the state codes
assigned to the maps. Sanitary landfill location data on
the DPRA computer file tape were matched by a computer
program against location data on the US Geological Survey T-
70 computer tape in order to identify the specific maps that
contain sanitary landfills and/or that would be needed to
evaluate the wetlands and deepwater habitats that are within
1 mile of each sanitary landfill. Sanitary landfills that
were located on the edge or in the corner of a map required
more than one map (i.e., two to four maps) to complete the
interpretation. The map names obtained from the computer
matching were sorted by state and compared with inventories
of available NWI maps.
Each sanitary landfill included in this study was
located on NWI large-scale maps using standard cartographic
techniques; Nearness or proximity of 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 (Figure 1) .
The occurrence or nonoccurrence of the wetland 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 (Figure 1). 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 consideration for determining adverse
impacts associated with these facilities, since contaminants
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can migrate off-site to affect wetlands and deepwater
habitats.
RESULTS AND DISCUSSION
We obtained data on the proximity of 3 sanitary
landfills in the state of Delaware to wetlands and deepwater
habitats. There are 3 sanitary landfills in the DPRA data
file for the state of Delaware and all of these facilities
have NWI maps available for site interpretation.
Approximately 67 percent of the sanitary landfills are
located in or within 1/4 mile of wetlands, while 100 percent
are located in or within 1/2 mile of wetlands, (Table 4 and
Figure 2) . None of the landfills are located more than a
mile from any type of wetland. All sanitary landfills are
located either in or are close to Palustrine wetlands
(approximately 33, and 100 percent are located in or within
1/4, and 1/2, respectively, of a Palustrine wetland) . None
of the sanitary landfills are located more than 1/2 mile
from a wetland (Figure 3).
Approximately 33 percent (1 facility) of the sanitary
landfills are located in or within 1/4 mile of deepwater
habitats, while 33 and 67 percent are located in or within
1/2 and 1 mile of deepwater habitats, respectively (Table 5
and Figure 4). One (33 percent) of the landfills is located
more than a mile from any type of deepwater habitat. The
facilities that are located in or that are close to
deepwater habitats are in the vicinity of Estuarine or
Riverine deepwater habitats (i.e., 33 percent are located in
or within 1 mile of a Estuarine deepwater habitat and 67
percent are located in or within 1 mile of a Riverine
deepwater habitat). Approximately 33 percent are located
more than 1 mile from the closest deepwater habitat (Figure
5) , while 33 percent are located 1/2 to 1 mile from the
closest deepwater habitat.
Approximately 67 percent of the sanitary landfills are
located in or within 1/4 mile of either wetlands or
deepwater habitats, while all are located in or within 1/2
mile of either wetlands or deepwater habitats (Table 6 and
Figure 6). All of the sanitary landfills are located either
in or are close to Palustrine habitats (approximately 33,
and 100 percent are located in or within 1/4, and 1/2 mile,
respectively, of a Palustrine habitat) while more than half
of the sanitary landfills are located either in or are close
to Riverine habitats, (approximately 33, 33, and 67 percent
are located in or within 1/4, 1/2, and 1 mile, respectively,
of a Riverine habitat). None of the sanitary landfills are
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located more than 1/2 mile from either a wetland or
deepwater habitat (Figure 7).
All of the sanitary landfills included in this study in
the state of Delaware are located either in or are close to
wetlands. From this, we conclude that these facilities have
the potential to adversely affect sensitive ecosystems, such
as wetlands, either through habitat alterations or through
the migration of contaminants from sanitary landfills. In
addition, two-thirds of the sanitary landfills included in
this study in the state of Delaware are located either in or
close to deepwater habitats and they also have the potential
for adversely affecting these sensitive ecosystems.
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LITERATURE CITED
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe.
1979. Classification of wetlands anH cieep«ater
habitats of tne United States. FWS/OBS-79/31. 103 pp.
Development Planning and Research Associates, Inc. 1986.
U.S. Environmental Protection Agency list of municipal
waste landfills. Computer data file, U.S.
Environmental Protection Agency.
Florida Department of Environmental Regulation. 1987. CMS
25 data file. Computer data file, Florida Department
of Environmental Regulation.
Langbein, W.B. and K.T. Iseri. 1960. General introduction
and hydrologic definitions manual of hydrology. Part
I. General surface-water techniques. US Geol. Surv.
Water-Supply Paper 1541-A. 29 pp.
National Cartographic Information Center. 1987. T-70
computer tape. Computer data file, National Mapping
Division, U.S. Geological Survey.
U.S. EPA. 1987. Resource Conservation and Recovery Act
Subtitle D report to Congress. Final Draft Report, May
28, 1987.
U.S. GS. 1979. Maps for America, First Edition. U.S.
Geological Survey.
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Point Representing
Location of the
Landfill
Hypothetical
Landfill
Boundaries
Lacustrine Deepwater Habitat
Palustrme Wetland
(marsh)
Rgure 1. Hypothetical sanitary landfill showing the point (latitude and longitude coor-
dinates) that represents the location of the landfill, the concentric regions used
to determine the nearness or proximity of the sanitary landfill to wetlands and
deepwater habitats, and the boundary of a 100-acre sanitary landfill distrib-
uted approximately evenly around its point location (a 100-acre sanitary land-
fill uniformly distriubted around a point will have a radius of approximately
1/4 mile).
8
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Palustrine
Lacustrine
Riverine
Estuarine
Marine
All systems
In or within 1 mile
In or within 1/2 mile
In or within 1/4 mile
100
120
Percent
Figure 2. Proximity of 3 Delaware sanitary landfills to wetlands.
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>1mite
1/2 to 1 mile
1/4 to 1/2 mile
1/4 mile
0 20 40 60 80 100
Percent
Figure 3. Distance of 3 Delaware sanitary landfills to the closest wetland.
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Lacustrine
Riverine
Estuarine
Marine
All systems
40
In or within 1 mile
In or within 1/2 mile
In or within 1/4 mile
60
80
100
Percent
Figure 4. Proximity of 3 Delaware sanitary landfills to deepwater habitats.
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>1mite
1/2to1 mile
1/4 to 1/2 mile
<, 1/4 mile
33
0 20 40 60 80 100
Percent
Figure 5. Distance of 3 Delaware sanitary landfills to the closest deepwater habitat.
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Palustrine
Lacustrine
Riverine
Estuarine
Marine
All systems
20 40
In or within 1 mile
In or within 1/2 mite
In or within 1/4 mite
60
Percent
100 120
Figure 6. Proximity of 3 Delaware sanitary landfills to either closest wetland or deepwater habitat.
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>lmite
1/2 to 1 mile
1/4 to 1/2 mile
1/4 mile
Figure 7. Distance of 3 Delaware sanitary landfills to either the closest wetland or deepwater habitat.
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TABLE 1. DEFINITION OF WETLANDS USED BY THE U.S. FISH AND
WILDLIFE SERVICE FROM COWARDIN ET AL. (1979)
Definition:
Wetlands are 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. For
purposes of this classification wetlands must
have one or more of the following three
attributes: (1) at least periodically/ the
land supports predominantly hydrophytes; (2)
the substrate is predominantly undrained
hydric soil; and (3) the substrate is nonsoil
and is saturated with water or covered by
shallow water-at some time during the growing
season of each year.
Explanation:
The term wetland includes a variety of areas
that fall into one of five categories: (1)
areas with hydrophytes and hydric soils, such
as those commonly known as marshes, swamps,
and bogs; (2) areas without hydrophytes but
with hydric soils-for example, flats where
drastic fluctuation in water level, wave
action, turbidity, or high concentration of
salts may prevent the growth of hydrophytes;
(3) areas with hydrophytes but nonhydric
soils, such as margins of impoundments or
excavations where hydrophytes have become
established but hydric soils have not yet
developed; (4) areas without soils but with
hydrophytes such as the seaweed-covered
portion of rocky shores; and (5) wetlands
without soil and without hydrophytes, such as
gravel beaches or rocky shores without
vegetation.
15
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TABLE 1. (continued)
Limits:
The upland limit of wetland is designated as
(1) the boundary between land with
predominantly hydrophytic cover and land with
predominantly mesophytic or xerophytic cover;
(2) the boundary between soil that is
predominantly hydric and soil that is
predominantly nonhydric; or (3) in the case
of wetlands without vegetation or soil, the
boundary between land that is flooded or
saturated at some time each year and land
that is not. The boundary between wetland
and deepwater habitat in the Marine and
Estuarine systems coincides with the
elevation of the extreme low water of spring
tide; permanently flooded areas are
considered deepwater habitats in these
systems. The boundary between wetland and
deepwater habitat in the Riverine,
Lacustrine, and Palustrine systems lies at a
depth of 2 m (6.6 feet) below low water;
however, if emergents, shrubs, or trees grow
beyond this depth at any time, their
deepwater edge is the boundary.
16
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TABLE 2. DEFINITION OF DEEPWATER HABITATS USED BY THE U.S.
FISH AND WILDLIFE SERVICE FROM COWARDIN ET AL. (1979)
Definition:
Explanation:
Limits:
Deepwater Habitats are permanently flooded
lands lying below the deepwater boundary of
wetlands. Deepwater habitats include
environments where surface water is permanent
and often deep, so that water, rather than
air, is the principal medium within which the
dominant organisms live, whether or not they
are attached to the substrate. As in
wetlands, the dominant plants are
hydrophytes; however, the substrates are
considered nonsoil because the water is too
deep to support emergent vegetation.
Wetlands and Deepwater Habitats are defined
separately because traditionally the term
wetland has not included deep permanent
water; however, both must be considered in an
ecological approach to classification.
The boundary between wetland and deepwater
habitat in the Marine and Estuarine systems
coincides with the elevation of the extreme
low water of spring tide; permanently flooded
areas are considered deepwater habitats in
these systems. The boundary between wetland
and deepwater habitat in the Riverine,
Lacustrine, and Palustrine systems lies at a
depth of 2 m (6.6 feet) below low water;
however, if emergents, shrubs, or trees grow
beyond this depth at any time, their
deepwater edge is the boundary.
17
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TABLE 3. DEFINITIONS OF THE FIVE MAJOR SYSTEMS* (MARINE,
ESTUARINE, RIVERINE, LACUSTRINE, AND PALUSTRINE**) USED BY
THE U.S. FISH AND WILDLIFE SERVICE IN CLASSIFYING WETLANDS
AND DEEPWATER HABITATS FROM COWARDIN ET AL. (1979)
Marine:
Definition:
Limits:
The Marine System consists of the open ocean
overlying the continental shelf and its
associated high-energy coastline. Marine
habitats are exposed to the waves and
currents of the open ocean and the water
regimes are determined primarily by the ebb
and flow of oceanic tides. Salinities exceed
30 °/00 with little or no dilution except
outside the mouths of estuaries. Shallow
coastal indentations or bays without
appreciable freshwater inflow, and coasts
with exposed rocky islands that provide the
mainland with little or no shelter from wind
and waves, are also considered part of the
Marine System because they support typical
marine biota.
The Marine System extends from the outer edge
of the continental shelf shoreward to one of
three lines: (1) the landward limit of tidal
inundation (extreme high water of spring
tides), including the splash zone from
breaking waves; (2) the seaward limit of
wetland emergents, trees, or shrubs; or (3)
the seaward limit of the Estuarine System,
where this limit is determined by factors
other than vegetation.
The term system refers to a complex of wetlands and
deepwater habitats that shares the influence of similar
hydrologic, geomorphologic, chemical, or biological
factors.
**
The first four systems, i.e., Marine, Estuarine,
Riverine, and Lacustrine, include both wetland and
deepwater habitats whereas the Palustrine System
includes only wetland habitats.
18
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TABLE 3. (continued)
Estuarine:
Definition:
The Estuarine System consists of deepwater
tidal habitats and adjacent tidal wetlands
that are usually semienclosed by land but
have open, partly obstructed, or sporadic
access to the open ocean, and in which ocean
water is at least occasionally diluted by
freshwater runoff from the land. The
salinity may be periodically increased above
that of the open ocean by evaporation. Along
some low-energy coastlines there is
appreciable dilution of sea water. Offshore
areas with typical estuarine plants and
animals, such as red mangroves (Rhizophora
mangle) and eastern oysters (Crassostrea
virginica) , are also included in the
Estuarine System.
Limits:
The Estuarine System extends (I) upstream and
landward to where ocean-derived salts measure
less than 0.5 °/00 during the period of
average annual low flow; (2) to an imaginary
line closing the mouth of a river, bay, or
sound; and (3) to the seaward limit of
wetland emergents, shrubs, or trees where
they are not included in (2). The Estuarine
System also includes off-shore areas of
continuously diluted sea water.
19
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TABLE 3. (continued)
Riverine:
Definition:
Limits:
The Riverine System includes all wetlands and
deepwater habitats contained within a
channel, with two exceptions: (I) wetlands
dominated by trees, shrubs, persistent
emergents, emergent mosses, or lichens, and
(2) habitats with water containing ocean-
derived salts in excess of 0.5 °/0o- A
channel is "an open conduit either naturally
or artificially created which periodically or
continuously contains moving water, or which
forms a connecting link between two bodies of
standing water" (Langbein and Iseri, 1960).
The Riverine System is bounded on the
landward side by upland, by the channel bank
(including natural and man-made levees), or
by wetland dominated by trees, shrubs,
persistent emergents, emergent mosses, or
lichens. In braided streams, the system is
bounded by the banks forming the outer limits
of the depression within which the braiding
occurs. The Riverine System terminates at
the downstream end where the concentration of
ocean-derived salts in the water exceeds 0.5
°/00 during the period of annual average low
flow, or where the channel enters a lake. It
terminates at the upstream end where
tributary streams originate, or where the
channel leaves a lake. -Springs discharging
into a channel are considered part of the
Riverine System.
20
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TABLE 3. (continued)
Lacustrine:
Definition:
The Lacustrine System includes wetlands and
deepwater habitats with all of the following
characteristics: (1) situated in a
topographic depression or a dammed river
channel; (2) lacking trees, shrubs,
persistent emergents, emergent mosses or
lichens with greater than 30% areal coverage/-
and (3) total area exceeds 8 ha (20 acres).
Similar wetland and deepwater habitats
totaling less than 8 ha are also included in
the Lacustrine System if an active wave-
formed or bedrock shoreline feature makes up
all or part of the boundary, or if the water
depth in the deepest part of the basin
exceeds 2 m (6.6 feet) at low water.
Lacustrine waters may be tidal or nontidal,
but ocean-derived salinity is always less
than 0.5
00.
Limits:
The Lacustrine System is bounded by upland or
by wetland dominated by trees, shrubs,
persistent emergents, emergent mosses, or
lichens. Lacustrine systems formed by
damming a river channel are bounded by a
contour approximating the normal spillway
elevation or normal pool elevation, except
where Palustrine wetlands extend lakeward of
the boundary. Where a river enters a lake,
the extension of the Lacustrine shoreline
forms the Riverine-Lacustrine boundary.
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TABLE 3. (continued)
Palustrine:
Definition:
The Palustrine System includes all nontidal
wetlands dominated by trees, shrubs,
persistent emergents, emergent mosses or
lichens, and all such wetlands that occur in
tidal areas where salinity due to ocean-
derived salts is below 0.5 °/00. It also
includes wetlands lacking such vegetation,
but with all of the following four
characteristics: (1) area less than 8 ha (20
acres); (2) active wave-formed or bedrock
shoreline features lacking; (3) water depth
in the deepest part of basin less than 2 m at
low water; and (4) salinity due to ocean-
derived salts less than 0.5 °/00.
Limits:
The Palustrine System is bounded by uplands
or by any of the other four systems.
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TABLE 4. NUMBER AND PERCENTAGE OF SANITARY LANDFILLS IN
DELAWARE THAT ARE PROXIMATE TO WETLANDS*
Number and percentage of sanitary landfills
Located in Located in Located in
or within or within or within
1/4 mile 1/2 mile 1 mile
Wetland system No. % No. % No. %
All systems**
Marine
Estuarine
Riverine
Lacustrine
Palustrine
2
0
1
0
0
1
66.7
0.0
33.3
0.0
0.0
33.3
3
0
1
0
0
3
100.0
0.0
33.3
0.0
0.0
100.0
3
0
1
0
0
3
100.0
0.0
33.3
0.0
0.0
100.0
There are 3 sanitary landfills in the DPRA data file
for the state of Delaware and all of these facilities
have NWI maps available for site interpretation.
None of the 3 sanitary landfills included in this study
in the state of Delaware are located more than a mile
from any type of wetland.
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TABLE 5. NUMBER AND PERCENTAGE OF SANITARY LANDFILLS IN
DELAWARE THAT ARE PROXIMATE TO DEEPWATER HABITATS*
Number and percentage of sanitary landfills
Deepwater
habitat system
Located in
or within
1/4 mile
No.
Located in
or within
1/2 mile
No.
Located in
or within
1 mile
No.
All systems**
33.3
33.3
66.7
Marine
Estuarine
Riverine
Lacustrine
0
0
1
0
0.0
0.0
33.3
0.0
0
1
1
0
0.0
33.3
33.3
0.0
0
1
2
0
0.0
33.3
66.7
0.0
**
There are 3 sanitary landfills in the DPRA data file
for the state of Delaware and all of these facilities
have NWI maps available for site interpretation.
One (33.3 percent) of the 3 sanitary landfills included
in this study in the state of Delaware are located more
than a mile from any type of deepwater habitat.
24
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TABLE 6. NUMBER AND PERCENTAGE OF SANITARY LANDFILLS IN
DELAWARE THAT ARE PROXIMATE TO EITHER WETLANDS OR DEEPWATER
HABITATS*
Number and percentage of sanitary landfills
Located in
or within
1/4 mile
Located in
or within
1/2 mile
Located in
or within
1 mile
System
All systems**
No. %
2 66.7
No.
3
%
100.0
No. %
3 100.0
Marine
Estuarine
Riverine
Lacustrine
Palustrine***
0
1
1
0
1
0.0
33.3
33.3
0.0
33.3
0
1
1
0
3
0.0
33.3
33.3
0.0
100.0
0
1
2
0
3
0.0
33.3
66.7
0.0
100.0
There are 3 sanitary landfills in the DPRA data file
for the state of Delaware and all of these facilities
have NWI maps available for site interpretation.
**
***
None of the 3 sanitary landfills included in this study
in the state of Delaware are located more than a mile
from any type of wetland or deepwater habitat.
The Palustrine system includes only wetlands.
25
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