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 ------- 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 ------- 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 ------- 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. ------- 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. ------- 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. ------- ------- 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 ------- |