Preliminary Engineering / Environmental Impact Statement Northwest Corridor LRT Line to Irving and DFW Airport During the field surveys, several species of wading birds and ducks were observed using permanently ponded areas. Stations Specific field studies for wildlife and threatened and endangered species were not conducted at the station areas. The probability of occurrence of threatened, endangered, and rare species within the stations area is dependent upon the habitat present, but should be similar to the probability of occurrences for the corridor. Some protected species could occur transiently in riparian and wooded habitats if sufficient food resources are available..1 GEOLOGY AND SOILS.1.1 Geology The Study Area lies within the Blackland Prairie physiographic region. This category consists of low rolling terrain with chalk and marl bedrock tilting to the south and east. The bedrock of Dallas County is of Upper Cretaceous age. Thick sedimentary beds underlie the northwestern quadrant of Dallas County and are covered with Quaternary terrace deposits consisting of sand, gravel, silt and clay, but no rock outcroppings. Along the Trinity River, these Quaternary soils are Alluvium floodplain deposits and Fluviatile terrace deposits. The remainder of the project area contains the Cretaceous shale, sandstone, and limestone of the Eagle Ford Group (BEG, 197). Geologic information in the Project Corridor is shown in Figure -8. Fossils are common throughout Dallas County and include occasional gastropods (snails), pelecypods (clams and oysters), cephalopod (ammonite and squid) shells, crayfish, and shark and skate teeth..1. The Project Corridor traverses many distinct soil types with varying patterns of drainage and relief. The Soil Survey of Dallas County, Texas was used to identify and characterize the soils that occur in the Study Area (USDA, 19). A total of 16 soil types intersect the alignment, these are listed, along with characteristics, potential and limitations of each soil type in Table -7. information for the Project Corridor is shown in Figures -9 and -0. consist mainly of nearly level to gently sloping clay soils. The soils immediately intersecting the proposed alignment have varying potential for urban development. Seven of these 16 soil types are of high or moderate potential for urban uses, and the remaining nine are of low or very low potential. The soils of low and very low potential for urban development are the most common along the length of the alignment, covering over percent of the alignment. Limitations to development in these low potential soils most commonly include frequent flooding and severe erosion hazards. Prime Farmland Prime farmland is defined by the Department of Agriculture in Section 7 of CFR 658. as land that has the best combination of physical and chemical characteristics to support farming. Prime farmland within the study area was identified using the 19 Dallas County Soil Survey. Approximately percent of the study area contains prime farmland soils, consisting of Houston black clay, Burleson clay, Frio silty clay, Silawa fine sandy loam, Trinity clay (occasionally ), and Heiden clay. Not all of these soils intersect the alignment, but all are found within the study area. Draft Environmental Impact Statement - 99 Chapter Affected Environment
Source: Geologic Atlas of Texas, 1986 Geology Figure -8 NW Corridor LRT Line to Irving/DFW Environmental Impact Statement 0 Proposed Station,000,000 8,000 Feet Study Area Proposed LRT Line to Irving/DFW Kef Eagle Ford Formation Fluviatile Terrace Deposits Qt Qal Alluvium and Quaternary Geologic Formations Legend
Preliminary Engineering / Environmental Impact Statement Northwest Corridor LRT Line to Irving and DFW Airport TABLE -7 SOIL TYPES INTERSECTING THE ALIGNMENT Soil Type Soil Characteristics Soil Potential and Limitations Arents (clayey, gently undulating) Bastsil- Urban land complex (0% to % Burleson clay (0% to 1% Ferris- Heiden complex (5% to 1% Consists of clayey soil material removed from nearby road cuts, borrow pits, or drainange ditches. The soil is typically dark brown, calcareous clay, containing many clods and bodies of very dark brown and grayish brown fragments of surface soil. Nearly level to gently sloping, well drained soils and areas of Urban land. The Bastsil soil comprises approximately 0 percent of the complex, while Urban land comprises approximately 5 percent. Typically, the surface layer is moderately acid, brown fine sandy loam to yellowish red to red sandy clay loam to a depth of about inches. To 68 inches, the soil is mottled dark red, yellowish red, and light gray sandy clay loam. Deep, nearly level, moderately well drained soils along old stream terraces. The surface layer, to a depth of inches, is typically neutral, very dark gray clay. To about 6 inches, the soil is slightly acid, very dark gray clay above a neutral layer of grayish brown clay to about 6 inches. To a depth of inches, the soil is moderately alkaline, grayish brown clay. Deep, well drained, gently rolling and rolling soils on hillsides. Ferris soil comprises about 60 percent of the complex and Heiden soils comprise about 0percent. The surface layer of the Ferris soil is moderately alkaline, light yellowish brown clay to inches. To 8 inches, the soil is moderately alkaline, olive clay over moderately alkaline, light brownish gray clay to inches. The soil is mottled light brownish gray, light olive brown, and gray shaly clay to about 7 inches. Heiden soils are moderately alkaline, dark grayish brown clay to 19 inches. To a depth of 5 inches, the soil is moderately alkaline, grayish brown clay above a layer of mottled brownish gray, olive yellow, and brownish yellow, moderately alkaline shaly clay to 78 inches. Permeability is slow to very slow, runoff is medium, and sloping areas erode easily. These soils have a very low potential for urban development. Limitations are a high content of clay, wet spots and ponding. Permeability is moderate, runoff is medium, and the hazard of erosion is moderate. These soils have a high potential for urban development. The only limitation is corrosivity to uncoated steel. capacity is high, runoff is slow, and the hazard of erosion is slight. The surface layer of these soils tends to crush. The soil has high potential for crop and pastureland and low potential for urban development. Limitations include high shrink-swell potential, corrosivity, and low strength of the soil. In the Ferris and Heiden soils, permeability is very slow, available water capacity is high, runoff is rapid, and the hazard of erosion is severe. The potential of this soil complex for urban uses is low. A very high shrink-swell potential, low strength, corrosivity, unstable slopes and erosion hazard are limitations to development. Frio silty clay, occasionally Heiden clay (1% to % Heiden clay (% to 5% slopes, eroded) Deep, well drained, nearly level soil on floodplains. The surface layer, to 7 inches, is moderately alkaline, very dark grayish brown silty clay. To a depth of inches, the soil is moderately alkaline, very dark grayish brown silty clay. In the lower layer to 7 inches, the soil is moderately alkaline, brown silty clay loam. Deep, well drained, gently sloping soil on uplands. Typically, the first 6 inches are a moderately alkaline, dark gray clay. To about 7 inches, the soil is very dark grayish brown clay progressing to grayish brown clay with gray and yellowish brown mottles to 56 inches. The bottom inches are composed of shaly clay mottled in shades of gray and yellow. Deep, well drained, gently sloping soils on uplands. Typically, the first 6 inches are a moderately alkaline, dark gray clay. To 56 inches, the soil is a dark grayish brown clay. The bottom inches are composed of shaly clay mottled in shades of gray and yellow. Permeability is moderately slow, available water capacity is high, runoff is slow, and the erosion hazard is slight. This soil has a low potential for urban use because of the hazard of flooding, low soil strength, and corrosivity. capacity is high, runoff is medium and the hazard of erosion is moderate. This soil has high potential for use as cropland and pastureland and low potential for urban uses. The very high shrink-swell potential, corrosivity, and low strength of the soil are its primary limitations. capacity is high, runoff is rapid and the hazard of erosion is severe. The soil has medium potential for pasture and low potential for urban uses. The very high shrink-swell potential, corrosivity, low strength of the soil, and severe hazard of erosion are limitations. Draft Environmental Impact Statement - 101 Chapter Affected Environment
Preliminary Engineering / Environmental Impact Statement Northwest Corridor LRT Line to Irving and DFW Airport TABLE -7 - continued SOIL TYPES INTERSECTING THE ALIGNMENT Soil Type Soil Characteristics Soil Potential and Limitations Normangee clay loam (1% to % Ovan clay, frequently Silawa fine sandy loam (1% to % Silawa Urban land complex (% to 6% Silstid loamy fine sand (0% to % Trinity clay, occasionally Trinity clay, frequently Urban land Wilson- Urban land complex (0% to % Deep, moderately well drained, gently sloping soil on uplands. The surface layer is typically neutral, dark grayish brown clay loam to a depth of 9 inches. To 1 inches, the soil is a dark brown clay. Slightly acid, grayish brown clay with light olive brown mottles is found to depths of 5 inches. To inches, the soil is olive clay with common yellowish brown mottles. To a depth of 66 inches, it is moderately alkaline clay, mottled with shades of brown, olive and gray over fine platy shale. Deep, moderately well drained, nearly level soils on floodplains. This soil is moderately alkaline, very dark grayish brown clay to 15 inches thick. Dark grayish brown clay is found to 5 inches with moderately alkaline, light olive brown clay to a depth of inches. Deep, well drained, gently sloping soil on uplands. Typically the surface layer is neutral, brown fine sandy loam 10 inches thick. To a depth of 19 inces, the soil is slightly acid, yellowish red sandy clay loam. To a depth of inches, it is medium acid, reddish yellow sandy clay loam. To a depth of inches, the soil is strongly acid, reddish yellow fine sandy loam, and to a depth of inches, it is medium acid, reddish yellow loamy fine sand. This complex is made up of deep, well drained, gently sloping and sloping soils and areas of Urban land. The Silawa soil makes up about 50% of this complex; Urban land makes up 5%. Typically, the surface layer of the Silawa soil is slightly acid, grayish brown fine sandy loam six inches thick. This is a deep, well drained, nearly level to gently sloping soil on uplands. Typically, the surface layer is neutral, brown loamy fine sand 10 inches thick. Deep, nearly level, somewhat poorly drained soil on floodplains. Typically, the surface layer is moderately alkaline, very dark grayish brown, very dark gray and black clay. Between 8 and 68 inches, the soil is black clay that has brownish mottles. Deep, nearly level, somewhat poorly drained soil on floodplains. Typically, the surface layer is moderately alkaline, dark gray, grayish brown and very dark gray clay. Extensively built up areas where 75 percent or more of the surface is covered with buildings and pavement. Native soils have been altered or covered by urban development. Nearly level to gently sloping, deep, somewhat poorly drained soils and areas of Urban land. The Wilson soil makes up about 60 percent of this complex and Urban land makes up about 0 percent. The surface layer of the Wilson soil is typically mildly to moderately alkaline, dark grayish brown clay loam, and dark gray and olive brown to light olive brown clay. Source: Soil Survey for Dallas County, Texas (NRCS, 19) capacity is high, runoff is medium, and the hazard of erosion is moderate. The soil has medium potential for urban development. Limitations include high shrink-swell potential, low strength, corrosivity, and the hazard of erosion. capacity is high, runoff is slow and there is a slight erosion hazard. This soil has a very low potential for urban uses due to frequent flooding, high shrink-swell potential, clayey texture and corrosivity of the soil. Permeability is moderate, and the available water capacity is medium. Runoff is slow. Water and wind erosion are moderate hazards. The soil has high potential for pasture, medium potential for use as cropland, and high potential for urban uses. Permeability is moderate, and the available water capacity is medium. Runoff is medium. Water and wind erosion are moderate hazards. This soil has a high potential for urban uses. Permeability is moderate, and the available water capacity is low. Runoff is slow, and water erosion is a slight hazard. Wind erosion is a severe hazard if the surface is bare. The Silstid soil has medium potential for pasture, low potential for use as cropland, and high potential for urban uses. capacity is high, runoff is very slow, and the hazard of erosion is slight. This soil has a very low potential for urban uses. Limitations include the hazard of flooding and wetness, corrosivity, and very high shrink-swell potential. Permeability is very slow, runoff is slow, and the hazard of erosion is slight. This soil has a very low potential for urban use. Limitations include the frequent flooding and wetness, corrosivity, very high shrink-swell potential, and clayey texture of the soil. This mapping unit is extensively used for urban development. Permeability is very slow, runoff is slow, and the hazard of erosion is slight. The Wilson soil has medium potential for urban development. The high shrink-swell potential, corrosivity, and low strength of the soil are the main limitations to urban use. Draft Environmental Impact Statement - 10 Chapter Affected Environment
1 6 56 15 WEB CHAPEL RD 5 DENTON DR UV5 UV North Las Colinas &- 8 LUNA RD Legend Proposed Station Proposed LRT Line to Irving/DFW Carrollton-Farmers Branch LRT Line N O' CONNOR RD 7 JOHN CARPENTER FWY Lake Carolyn 6 UV11 ROCHELLE BLVD 7 CALIFORNIA CROSSING RD BNSF RR South Las Colinas (deferred) TOM BRANIFF DR NORTHWEST HWY 5E Dallas ") 1 ") 1 61 Joes Creek Study Area 65 1 7 5 60 Bachman NORTHGATE DR University of Dallas &- 8 Axtell-Urban (1) Bastsil-Urban (15) Burleson Clay (18) Arent Loamy () Arent Loamy Hilly () Ferris-Heiden () Ferris-Heiden () Frio Silty Clay (6) Frio Silty Clay (7) Arent Clayey () Heiden Clay () Heiden Clay () Houston Black Clay () Houston Black Clay () Houston Black-Urban (5) Source: Ssurgo Soil Data - USDA, 1975 Normangee Clay () Ovan Clay () Pits and Dumps (56) Silawa Fine Sand (60) Silawa Fine Sandy Loam (61) Silawa-Urban (6) Silstid Loamy Fine Sand (6) Silstid-Urban (65) Trinity Clay (7) Trinity Clay () Trinity-Urban (7) Urban Land (75) Vertel Clay (77) Wilson-Urban () Water (W) Irving 77 E AIRPORT FWY UV18 1 75 Loop 1 (deferred) 15 6 5 6 60 7 STOREY LN Elm Fork Trinity River REGAL ROW 5E HARRY HINES BLVD Figure -9 East Section 0 1,000,000,000 NW Corridor LRT Line to Irving/DFW Feet Environmental Impact Statement
MACARTHUR BLVD N MACARTHUR BLVD 7 LUNA RD DFW International Airport VALLEY VIEW LN Legend ESTERS RD 5 UV161 CARBON RD 5 Proposed Station BELT LINE RD 18 Belt Line Road WALNUT HILL LN Proposed LRT Line to Irving/DFW Study Area Source: Ssurgo Soil Data, USDA 1975 STORY RD HURD DR PRESIDENT GEORGE BUSH TPKE UV11 ROYAL LN WALNUT HILL LN North Lake College Irving HIDDEN RIDGE DR ch Cottonwood Bran LAS COLINAS B L VD Carpenter Ranch N O' CONNOR RD Hackberry Creek 7 JOHN CARPENTER FWY RIVERSIDE DR North Las Colinas Lake Carolyn 6 Dallas &- 8 ROCHELLE BLVD Figure -0 West Section 0 1,000,000,000 NW Corridor LRT Line to Irving/DFW Feet Environmental Impact Statement Axtell-Urban (1) Bastsil-Urban (15) Burleson Clay (18) Arent Loamy () Arent Loamy Hilly () Ferris-Heiden () Ferris-Heiden () Frio Silty Clay (6) Frio Silty Clay (7) Arent Clayey () Heiden Clay () Heiden Clay () Houston Black Clay () Houston Black Clay () Houston Black-Urban (5) Normangee Clay () Ovan Clay () Pits and Dumps (56) Silawa Fine Sand (60) Silawa Fine Sandy Loam (61) Silawa-Urban (6) Silstid Loamy Fine Sand (6) Silstid-Urban (65) Trinity Clay (7) Trinity Clay () Trinity-Urban (7) Urban Land (75) Vertel Clay (77) Wilson-Urban () Water (W)