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HomeMy WebLinkAbout06 - Section 5 Environmental Analysis - Century Plan - Airport Plan Element June 19985.0 ENVIRONMENTAL ANALYSIS 5.1 General This section of the master plan report for the Georgetown Municipal Airport (GMA) addresses various environmental aspects of the planning process. While not as comprehensive or as detailed as a full environmental assessment (EA), this analysis provides a basis for evaluating the environmental impacts of the master plan's proposed development program. The following topics are addressed. • Noise Impacts • General Ecology • Wetlands Impacts • Endangered and Threatened Species • Cultural Resources As with most general aviation airport projects, impacts from aircraft generated noise are of significant concern. Accordingly, this analysis includes the modeling of aircraft noise at GMA for each of the master planning periods, i.e., current, short term (2000), mid -term (2005) and long term (2015). The other areas of environmental interest were selected primarily on the basis of the greatest potential for adverse impacts from the proposed development plan. Further, according to the FAA's Airport Environmental Handbook, Order 5050.4A, no feature of the proposed development plan would, in and of itself, indicate the need for the preparation of an EA or an environmental impact statement (EIS). Order 5050.4A does, however, require the preparation of an EA if adverse impacts on endangered or threatened species, wetlands, floodplains, coastal zones, property included in the National Register of Historic Places or Section 4 (f) lands, i.e., parks or recreational areas, may occur. Acquisition of prime farm lands would also trigger an EA. Since the adverse impacts on prime farm lands, 4 (f) lands or floodplains is not contemplated by the development plan, and the coastal zone provisions are not applicable, only impacts on wetlands, cultural resources and threatened and endangered species were reviewed. The following subsections discuss potential impacts in each of the areas of environmental interest cited above. The final subsection provides conclusions and recommendations relative to further environmental studies during the development process. 5.2 Aviation Related Noise The FAA's Integrated Noise Model (INM), Version 5.0, was used to estimate noise impacts related to aviation activity. The INM produces a number of different noise metrics, however, the most commonly used is the Average Day -Night Sound Level (DNL). This measurement provides the average decibel level for a twenty-four hour period with the period between midnight and 7 AM weighted by a 10 decibel penalty. While other measurements of noise impacts are often used, DNL is the FAA standard for evaluating cumulative exposure of individuals to noise. Table 5 -1 shows land use compatibility with different noise levels expressed in DNL. The land use compatibility levels shown in Table 5 -1 are taken from FAA Advisory Circular 150/5020 -1 and are the basis for the assessments of aviation noise impacts shown in the following subsections. 17326/960507 5-1 TABLE 5-1 LAND USES NORMALLY COMPATIBLE WITH VARIOUS NOISE LEVELS 17326/960507 5 -2 DNL Below Over Land Uses 65 65-70 70 -75 75 -80 80 -85 85 RESIDENTIAL: Homes, apartments, group quarters, Y N' N' N N N residential hotels Mobile -home parks Y N N N N N Transient lodging Y N' N' N' N N PUBLIC USE: Schools, hospitals, nursing homes, churches, Y 25 30 N N N auditoriums, concert halls COMMERCIAL USE: Offices, business, professional, wholesale, retail Y Y 25 30 N N MANUFACTURING AND PRODUCTIONS General manufacturing and production Y Y YZ Y3 V N Agriculture and forestry Y Y6 Y7 Y8 Y8 Y8 Livestock farming and breeding Y Y6 Y7 N N N Mining and fishing Y Y Y Y Y Y RECREATION: Outdoor sports arenas and spectator sports Y Y5 Y5 N N N Outdoor music shells and amphitheaters Y N N N N N Nature exhibits and zoos Y Y N N N N Amusements, parks, resorts and camps Y Y Y N N N Golf courses, riding stables and water recreation Y Y 25 30 N N KEY TO TABLE Y (Yes) Land use and related structures compatible without restrictions. N (No) Land use and related structures are not compatible and should be prohibited. 25, 30 or 35 Land use and related structures generally compatible; measures to achieve Noise Level Reduction (NLR), outdoor to indoor, or 25, 30 or 35 must be incorporated into design and construction of structure. 17326/960507 5 -2 5.2.1 INM Input Following extensive discussions with the Master Plan Working Group, the input to the INM was formulated. The following is a synopsis of the INM inputs for the GMA Master Plan: • Aircraft operations in the base year were determined from TxDOT's most recent acoustic counter survey. Approximately 87,000 operations occurred in base year of 1995. • The aircraft mix from the aviation demand chapter were used in each planning period. • Various aircraft models are available in the RNM. The following aircraft models were used in the input. Single Engine Piston - Composite single engine piston - COMSEP Twin Engine Piston - Beechcraft Baron - BEC58P Turboprop - Mitsubishi MU - 2 and Swearingen Merlin, 40 percent and percent of turboprop operations, respectively Jet - Composite jet - COMJET and Cessna Citation 2 - CNA 500, 50 percent each for 1995 and 2000. CNA 500, Lear 35 and COMJET, 50 percent, 25percent and 25 percent, respectively for 2005. CNA 500 and Lear 35 for 2015, 50 percent each type • Touch and go (T &G) operations currently represent 40 percent of all airport operations however, this percentage declines to 30 percent by the year 2015. All T &G operations are conducted on Runway 18 -36 • Runway usage is split 70 percent to Runway 18 -36 and 30 percent to Runway 11 -29 except that all T &G operations and large aircraft operations are on Runway 18 -36. The actual operations split is, therefore, 83 percent to Runway 18 -36 and 17% to Runway 11 -29. • Approach flight tracks are as shown in Exhibit 5 -1. Runway 18 Track 18 -APP -0001, straight -in approach, used by all aircraft types Track 18 -APP -0002, 45° approach to the airport landing pattern, used by small aircraft only Track 18 -APP -0004, 45° approach to the airport landing pattern, used by turboprop and turbojet aircraft only Track 18 -TGO -0009, touch and go, used by only small aircraft 17326/960507 5 -3 Georgetown Municipal Airport Aircraft Noise Impacts r / 18—T n9� 36 —TOO -001a= is 1 /7, r 8— APP -0004 1S- P -0002 p �c. see r smug . ■■ am ll�.awwwrwr %' i «�,i uwwwaw■ Approach Tracks Exhibit 5 -1 E` 5 -4 ESPEY, RUSTON & ASSOMTES, HNBUPE WO a LWMNMWA MNSULTA Runway 36 Track 36 -APP -0001, straight - in approach, used by all aircraft types Track 36 -APP -0003, 45° approach to airport landing pattern, used by small aircraft only Track 36 -APP -0005, 45° approach to airport landing pattern, used by turboprop and jet aircraft only Track 36 -TGO -0010, touch and go, used by small aircraft only Runway 11 Track 11 -APP -0001, straight - in approach, used by small aircraft only Track 11 -APP -0002, 45° approach to airport landing pattern, used by small aircraft only Runway 29 Track 29 -APP -0001, straight - in approach, used by small aircraft only Track 29 -APP -0002, 45° approach to airport landing pattern, used by small aircraft only • Departure flights tracks are as shown in Exhibit 5 -2. The following usage percentages were used. All departures tracks are dispersed to cover a wider geographic area. Runway 18 Track 18 -DEP -0100, turn to the east 1 Nautical Mile (NM) from runway end, 80 percent of departures from Runway 18 Track 18 -DEP -0300, turn to the east 3/4 NM from the runway end, 10% of departures from Runway 18 Track 18 -DEP -0400, turn to the west 1 NM from runway end, 10% of departures from Runway 18 Runway 36 Track 36 -DEP -0100, turn to the west 1 NM from the runway end, 10% of departures from Runway 36 Track 36 -DEP -0200, turn to the east 1 NM from the runway end, 90% of departures from Runway 3 6 Runway 11 Track 11 -DEP -0100, turn to the north, 1 NM from the runway end, all departures from Runway 11 17326/960507 5 -5 Georgetown Municipal Airport Aircraft Noise Impacts 36— DEP —p100 , 36 D 0200 `(.ifs:^ ,�/ � ✓°'° �• '{/ ~ —DE —D 00 11— DEP -0 �•_-., � .;� \ : t;. .,�� - t.. � tai 8 —D —020 Departure Tracks Exhibit 5 -2 E �v� 5 -6 ESPEY, HUSTON & ASSOCIATES, "sr MMMC a LWMJVKWA CMUNY Runway 29 Track 29 -DEP -0100, turn to the south, 1 NM from the runway end, all departures from Runway 29 Engine runup operations were modeled in the designated maintenance runup area and at each runway end. Engine rnups in the maintenance area were conducted by turboprop aircraft for 10 minutes four times daily at 100% thrust. Runups at each runway end were modeled for single engine and twin engine piston aircraft at 50% power for 30 seconds prior to each departure. Runups for turboprop aircraft were modeled at 100% power for 30 seconds prior to each departure. 5.2.2 Aircraft Noise Impacts 5.2.21 General Aircraft noise impacts were modeled for the base year, 1995, the short term period, 2000, the mid - term period, 2005, and the long term period, 2015. GMA is bounded on three sides by residential areas, all of which are subjected to some level of aircraft noise. The noise exposure in each planning period is discussed in the following paragraphs. 5.2.2.2 Base Year In the base year, 1995, the areas of the 55, 65 and 75 DNL contours, Exhibit 5 -3, are as follows: DNL Area -Acres 55 915 65 192 75 0 The 65 DNL contour is confined primarily within the airport's boundaries, however, on the south a small area of the contour extends south of Lakeway Drive. On the north, the 65 DNL extends to the airport boundary on the west. The 55 DNL contour extends substantially beyond the airport's boundaries to the south. 5.2.2.3 Short Term follows: In the short term, Year 2000, the areas of the 55, 65 and 75 DNL contours, Exhibit 5 -4, are as DNL Area -Acres 55 1,894 65 358 75 58 17326/960507 5 -7 f � /j X, v40 ♦ f 4v \\ tv 10: 8] a fill i� 1995 55 -60 DNL NEW "VILLAGE" ELEMENTARY 60 -65 DNL 65 -70 FUTURE ELEMENTARY SCHOOL DNL 70 -75 DNL BENOLD MIDDLE SCHOOL >75 DNL EXHIBIT 5 -3 1995 v0, NEW "VILLAGE" ELEMENTARY SCHOOL OPENS IN AUGUST 1998 © FUTURE ELEMENTARY SCHOOL OPENS AUGUST 2000 Q BENOLD MIDDLE SCHOOL EXHIBIT 5 -3 QD FROST ELEMENTARY SCHOOL 5 -8 EQ HIGH SCHOOL I vx% Q SCHOOL ESPEY, HUSTON & ASSOCIATES, . acumm & ramm m CONSUum Georgetown Municipal Airport Aircraft Noise Impacts �J / � � ter'— •'•l _• f v s k. l ----- 1'._ � tr r 1 LEGEND 2000 55 -60 DNL NEW "VILLAGE" ELEMENTARY 60 -65 DNL ❑ 65 -70 DNL E] 70 -75 DNL AUGUST 2000 >75 DNL © BENOLD MIDDLE SCHOOL 2000 O NEW "VILLAGE" ELEMENTARY SCHOOL OPENS IN AUGUST 1998 © FUTURE ELEMENTARY SCHOOL OPENS AUGUST 2000 © BENOLD MIDDLE SCHOOL EXHIBIT 5 -4 Q FROST ELEMENTARY SCHOOL 5 -9 Q HIGH SCHOOL Ek% © SCHOOL ESPEY, EUSTON & ®SSOMTES, Raerwu mrc r rfanxmM cnxeaMM The 65 and 75 DNL contours extend south of the airport boundary by approximately one mile. The 65 ! DNL contour also extends past the airport's boundary slightly to the north and more significantly to the northwest. The 75 DNL contour is, however,within the airport's boundary in this area. Residential areas to the south and north west are projected to experience average noise levels greater than recommended for such areas. 5.2.2.4 Mid -Term During the mid -term period, 2005, the areas of the 55, 65 and 75 DNL contours, Exhibit 5 -5, are as follow: DNL Area -Acres 55 2,074 65 390 75 70 The general shape of the noise contours for this period are much the same as seen in the short term period, although slightly larger. It should be noted that in this period half of the COMJET aircraft are replaced with the newer quieter Lear 35. This replacement reflects the aging of the COMJET type aircraft and their retirement from service. 5.2.2.5 Long Term During the long-term period, 2015, the areas of the 55, 65 and 75 DNL contours, Exhibit 5 -6, are as follow: DNL Area -Acres 55 1,651 65 281 75 26 It will be noted that the contour areas are actually smaller than in the previous period. This is due to the total replacement of the older COMJET with the Lear 35. Such a replacement is reasonable based on the age of the aircraft represented by the COMJET and the potential for government controls of general aviation aircraft noise. While there have been no initiatives in that direction to date, given the success of the noise control program in the air carrier industry, the assumption of a similar program applied to general aviation is not unrealistic. 5.3 General Ecology 5.3.1 Vegetation Williamson County is located at the junction of the Blackland Prairies and Cross Timbers and Prairies vegetational areas, just north -east of the Edwards Plateau (Hatch et al., 1990) (Figure 5 -7 ). Thus, the study area represents a transitional zone with representative characteristics of all three regions. 17326/960507 5 -10 Georgetown Municipal Airport Aircraft Noise Impacts LEGEND t N } 1, :1 2005 55 -60 DNL NEW "VILLAGE" ELEMENTARY 60 -65 DNL F] 65 -70 DNL 0 70 -75 DNL 'AUGUST 2000 >75 DNL 0 BENOLD MIDDLE SCHOOL t N } 1, :1 2005 AO NEW "VILLAGE" ELEMENTARY SCHOOL OPENS IN AUGUST 1998 © FUTURE ELEMENTARY SCHOOL OPENS 'AUGUST 2000 Q BENOLD MIDDLE SCHOOL EXHIBIT 5 -5 QD FROST ELEMENTARY SCHOOL 5 -11 EQ HIGH SCHOOL am Q SCHOOL ESPEY, 1101I1 & ES, 1 .01,11A axenvsum ar rnruro A ca�s�Tw Georgetown Municipal Airport Aircraft Noise Impacts i�. LEGEND i in'w _ z3.4 _ ♦ e, 3-a � f�1 2015 55 -60 DNL 0 60 -65 DNL F] 65 -70 DNL 0 70 -75 DNL AUGUST 2000 >75 DNL 0 BENOLD MIDDLE SCHOOL i in'w _ z3.4 _ ♦ e, 3-a � f�1 2015 O NEW "VILLAGE" ELEMENTARY SCHOOL OPENS IN AUGUST 1998 © FUTURE ELEMENTARY SCHOOL OPENS AUGUST 2000 Q BENOLD MIDDLE SCHOOL EXHIBIT 5 -6 Q FROST ELEMENTARY SCHOOL 5 -12 Q HIGH SCHOOL Q SCHOOL ESPEY, RUSTON do ASSOCIATES lA'CIIIII n a INFB AYdM CUMT, 10 South Texas Plains Edwards Plateau Rolling Plains High Plains Trans -Pecos � /4_/� north 100 0 100 200 scale in miles Source: Hatchet al., 1990 5 -13 Characteristics of the Blackland Prairies include nearly level to rolling, well- dissected terrain. The soils of the Blackland Prairies are typically dark - colored calcareous clays interspersed with some gray acid sandy loams (Thomas, 1975). The once natural climax vegetation community of the Blackland Prairies was dominated by prairie grasses with a few species of trees scattered throughout. Dominants included little bluestem (Schizachyrium scoparium), big bluestem (Andropogon gerardii), Indiangrass (Sorghastrum nutans), and tall dropseed (Sporobolus asper) with minor grass species such as sideoats grama (Bouteloua curtipendula), hairy grama (B. hirsuta), and buffalograss (Buchloe dactyloides) (Hatch et al., 1990). Almost all of this region has been converted to cropland and domesticated pasture, thus little remains of the original native prairie vegetation. The Cross Timbers and Prairies region is rolling to hilly, with deeply dissected landforms and rapid surface runoff. Soils are occasionally stony and slightly acid sandy or clay loams. The vegetation cover is comprised of grasslands and savannahs with dense, invasive brushlands of post oak (Quercus stellata), blackjack oak (Q. marilandica), and honey mesquite (Prosopis glandulosa). The Edwards Plateau is characterized by shallow soils underlain by limestone and caliche on the plateau and with granite occurring within the Central Basin area. The region is a well drained, deeply dissected plain with characteristic savannah and dense juniper /oak woodlands. The once largely grassland or open savannah climax vegetation of the Edwards Plateau has had encroachment by brush and tree species. Now Ashe juniper (Juniperus ashei), plateau live oak (Quercus fusiformis), Texas oak (Q. buckleyi), and shin oak (Q. sinuata var. breviloba) typically dominate such sites. As suggested earlier, the study area is characteristic of a combination of all three vegetative types, but most closely resembles the Blackland Prairies. During EH &A's 15 October 1996 site visit, vegetation communities dominated by ashe juniper, live oak, cedar elm (Ulmus crassifolia), honey mesquite, elbow bush (Forestiera pubescens), prickly pear (Opuntia sp.), desert Christmas cactus (Opuntia leptocaulis), Texas grama (Bouteloua rigidiseta), King Ranch bluestem (Bothriochloa ischaemum), silver bluestem (Bothriochloa saccharoides), buffalograss and side oats grama were observed. Generally, the study area consists of large, open grassy areas intermixed with areas of clumped shrubs and trees. Average tree size within the forested areas ranges from 3 to 6 inch diameter-at-breast- height (dbh). One stand of live oaks ranged from 6 to 30 inches dbh. The entire property had been cleared during the initial airport construction. 5.3.2 Wildlife The study area lies on the western edge of the Texan Biotic Province and eastern edge of the Balconian Biotic Province as described by Blair (1950) and illustrated in Exhibit 5 -8. This transitional region is recognized as a broad ecotone between the forests of the Austroriparian and Carolinian provinces of eastern Texas and Oklahoma and the grasslands of the western parts of these states. The vertebrate fauna of these two provinces is represented by a mixture of species from the Austroriparian, Tamaulipan, Chihuahuan, Kansan, Balconian, and Texan biotic provinces. 17326/960507 5-14 5 -15 5 -16 D851 ...-- 'j(997 7 Gaging eta 80 803 797 'avel UN, CIPA 1` - AIRPORT •I I x756 'con 748 X78911 .�• I �, ; J / L / / •.. 71 \ / 1111122 729 /- - V 2339 750 V / %/) _� _ _\. •. __" - i-o�`1. 1 �hopping�o\ CeAkfer Rp ��. 754� / /" 1) % Q.�Hi G1 Sch \ ,;1 ZONE 1: Areas known to contain E.C.S. ZONE 3: Areas that probably do not contain E.C.S. ZONE 2: Areas having a high probability of suitable habitat for E.C.S. or other ZONE 4: Areas that do not contain E.C.S. endemic invertebrate cave fauna. EVRA—Engineering E Huston &Associates, Inc. &Environmental Consultants Exhibit 5 -9 north ZONES OF ENDANGERED 0 2000 4000 feet CAVE SPECIES (E.C.S.) IN RELATION TO GEORGETOWN Iv1UNIC!PAL AIRPORT Base Map: USGS 7.5' Quadrangle; Georgetown, Texas 5 -16 Mammals representative of the area potentially include the Virginia opossum (Didelphis virginiana), Brazilian free - tailed bat (Tadarida brasiliensis), black - tailed jackrabbit (Lepus californicus), deer mouse (Peromyscus maniculatus), coyote (Canis latrans), common raccoon (Procyon lotor), striped skunk (Mephitis mephitis) and the white - tailed deer (Odocoileus virginianus) (Davis and Schmidly, 1994). Representative herptofauna of the area includes the Gulf coast toad (Bufo valliceps), Blanchard's cricket frog (Acris crepitans crepitans), ornate box turtle (Terapene ornata), red -eared slider (Trachemys scripta), six -lined racerunner (Cnemidophorus sexlineatus), ground skink (Scincella lateralis), Texas spiny lizard (Sceloporus olivaceus), and the Texas rat snake (Elaphe obsoleta lindheimerii) (Dixon, 1987). Karst habitats are probable throughout the study area and may be seasonally important to species such as the Brazilian free - tailed bat, and cave myotis ( Myotis velifer). Karst features may also serve as hibernacula for several species of herptiles including the western diamondback rattlesnake (Crotalus atrox) and the cliff frog (Syrrhophus marnocki) as well providing important habitats for many troglobites. The aquatic habitats within the study area are limited tohydric areas associated with tributaries of Pecan Branch and related drainages. These areas are generally ephemeral in nature and under normal circumstances, do not provide year -round habitat for aquatic life forms. 5.4 Wetlands The study area lies within a subwatershed of the Brazos River Basin and drains to the south/southwest into unnamed tributaries to Pecan Branch. Pecan Branch is mapped as intermittent by the United States Geological Survey (USGS) (USGS, 1982). Areas of bottomland/riparian habitats (potential jurisdictional wetlands) observed were located in the southwest comer of the study area and are associated with an unnamed tributary to Pecan Branch. The U.S. Fish and Wildlife Service (FWS) has produced National Wetland Inventory (NWI) mapping for the area which is based upon 1982 aerial photography (FWS, 1993). The Georgetown, TX NWI map designates three areas of palustrine wetlands within the study area. These areas were not found during EH &A's site visit. Hydric habitats within the study area may be defined as jurisdictional wetlands by the U.S. Army Corps of Engineers (USCE). If these areas meet the criteria necessary to define them as jurisdictional wetlands pursuant to Section 404 of the Clean Water Act, certain activities (e.g., placement of fill) within these habitats are subject to regulation. 5.5 Endangered and Threatened Species 5.5.1 Vegetation Currently, 28 plant species are listed by the FWS as endangered or threatened in Texas (FWS, 1994 and Texas Natural Heritage Program (TXNHP), 1995). None of these species is known to exist within Williamson County. 17326/960507 5 -17 5.5.2 Wildlife Table 5 -2 lists wildlife species considered by the FWS, Texas Parks and Wildlife Department (TPWD), or Texas Organization for Endangered Species (TOES) to be endangered or threatened that are known to have occurred within Williamson County and could potentially occur within the study area. TABLE 5 -2 ENDANGERED OR THREATENED WILDLIFE OF POTENTIAL OCCURRENCE IN THE STUDY AREA Common Name FWS Status TPWD TOES Coffin Cave mold beetle E Tooth Cave ground beetle E Bone Cave harvestman E Timber rattlesnake -- T T Texas horned lizard -- T T Brown pelican E E E White -faced ibis -- T T Wood stork -- T T Swallow - tailed kite -- T T Bald eagle T T E American peregrine falcon E E E Arctic peregrine falcon E /SA T T Whooping crane E E E Interior least tern E E E Black - capped viero E E T Golden - Cheeked warbler E E E Four karst zones have been established in the Austin, Texas region based upon the potential for occurrence of endangered cave species (Veni & Associates, 1991). Zone 1 consists of areas known to contain endangered cave species. Zone 2 consists of areas having high probability of suitable habitat for endangered cave species or endemic invertebrate cave fauna. Zone 3 consists of areas that probably do not contain endangered cave species, and Zone 4 consists of areas that do not contain any endangered cave species. The study area contains areas of Zone 2 and 3 (Exhibit 5 -9). Three karst invertebrates currently listed by FWS as endangered have been found in Williamson County: the Coffin cave mold beetle (Batrisoides texanus), Tooth cave ground beetle (Rhadine persephone), and the Bone cave harvestman (Texella reyesi). Information from TPWD's Biological and Conservation Data system (BCD) reveals that two of these species, the Coffin cave mold beetle and Bone cave harvestman, have been observed within the boundaries of the Georgetown, Texas USGS topographic quadrangle map (BCD, 1996). During a limited field survey by EH &A personnel, no surface karst features, with the exception of a few minor sink holes, were observed within the airport boundaries; however, a more detailed field effort would be needed in order to determine the presence or absence of these features. 17326/960507 5-18 No current federally listed endangered reptiles occur within the study area; however, one state- listed threatened snake and one state- listed threatened lizard have been recorded from Williamson County. The timber rattlesnake (Crotalus horridus) inhabits wooded bottoms, and is more common in the eastern portion of Texas (Tennant, 1985). While it has been recorded from Williamson County (Dixon,1987), its presence within the study area is unlikely. The Texas horned lizard (Phrynosoma cornutum) was once common throughout Texas, and prefers open, flat terrain with scattered vegetation. It has been recorded from Williamson County (Dixon,1987), and its presence within the study area is possible but not probable. The Texas horned lizard is also a FWS Species of Concern (SOC). SOCs are species for which some evidence of vulnerability exists, but not enough to support listing at this time. These species have no legal protection under the Endangered Species Act. Apart from the Texas horned lizard, four other SOCs have been recorded from Williamson County and, therefore, may occur within the study area. These are the Texas garter snake (Thamnophis sirtalis annectens) and three salamanders (Eurycea sp.): the Buttercup salamander, the Georgetown salamander, and the Jollyville Plateau salamander. Eleven federally or state - listed endangered or threatened birds are of potential occurrence in Williamson County. Of these, the brown pelican (Pelecanus occidentalis), white -faced ibis (Pelegadis chihi), wood stork (Mycteria americana), swallow - tailed kite (Elanoides forfcatus), bald eagle (Haliaeetus leucocephalus), American peregrine falcon (Falco peregrinus anatum), arctic peregrine falcon (F. tundris), whooping crane (Grus americana), and interior least tem (Sterna antillarum athalassos) are not known to reside in the study area, but could pass through during migration or post - breeding dispersal (Oberholser, 1974; FWS, 1992; TOS, 1995). The black- capped vireo (Vireo atricapillus), an endangered species, is a spring and summer resident of the Balcones Escarpment. It utilizes open, shrubby areas dominated by sumacs (Rhus spp.), shin oak (Quercus sinuata var. breviloba), ash juniper, and live oak (Marshall, Clapp and Grzybowski, 1985). There are no recorded sightings of the black- capped vireo within the study area; however, their presence is possible if suitable habitat exists. During the field investigation, areas with suitable habitat structure were observed; however, due to the small size of the areas and their species composition, it is unlikely that these birds would be found within the study area. The golden - cheeked warbler (Dendroica chrysoparia) is an endangered species of special concern because it has the distinction of being the only avian species that nests exclusively in Texas. Its nesting range comprises approximately the eastern one -third of the Edwards Plateau and the southwestern one - quarter of the Cross Timbers and Prairies. Its nesting habitat includes mature ash juniper, Texas oak, live oak, and various other deciduous trees, with a dense canopy cover (Oberholser, 1974; Pulich, 1976; FWS, 1992). BCD data shows recorded sightings of this species west of the airport, but none within the study area. The golden - cheeked warbler is unlikely to occur within the study area as preliminary observations by EH &A personnel failed to locate suitable habitat. 5.6 Cultural Resources A literature search and records review for the Georgetown Airport was conducted by EH &A in October 1996. The records of the National Register of Historic Places (NRHP) and the Texas Historical Commission (THC) were reviewed for the identification of sites on or determined eligible for inclusion on the NRHP. Research of available records and literature was conducted at the Texas Archeological Research Laboratory, J.J. Pickle Research Center, the University of Texas at Austin. 17326/960507 5-19 The review was conducted in compliance with the National Historic Preservation Act of 1966 (PL 89 -665) as amended by PL 94-442 (1974), the National Environmental Policy Act of 1969 (PL 91- 190), the Archaeological and Historic Preservation Act of 1974 (PL 93 -291), Procedures for the Protection of Historic and Cultural Properties (36 CFR 800), the Archaeological Resources Protection Act of 1979, and the National Preservation Amendment Act of 1980 (PL 96 -515). The literature /records review revealed that no previously recorded archaeological or historic sites are located within the airport property. However, there are eight archaeological sites recorded within a one -mile radius of the GMA boundaries. All of the sites are located to the south and the southeast of the airport. The eight sites are designated as 41WM378, 41WM379, 41WM430, 41WM783, and 41WM824 to 41WM827. Of these, information was available for only four sites: 41WM378 and 379, 41WM430 and 41WM783. According to the survey forms at TARL, sites 41WM378, 41WM379 and 41WM430 were all recorded during the LCRA's Pecan Branch Survey in 1979. Two of the sites (41WM378 and 379) are prehistoric sites described as lithic scatters. Site 41WM430 is also a prehistoric site. This site is a large lithic procurement area with chert outcrops and large cobbles and debitage on the surface. No temporal affiliation was made for any of the sites. A recommendation of no further work required was made by the recording archaeologist. Site 41WM783 is a prehistoric burned rock midden. The site was recorded in 1992 during a survey for the Texas Department of Transportation. Besides burned rock, the only other cultural materials observed were flakes. No recommendation was made by the recording archaeologist. The remaining four sites (41 WM824 -827) were recorded in 1995 during a survey for the Pecan Branch Wastewater Interceptor. No data on any of these sites is on file at TARL. 17326/960507 5 -20