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CRAPTERTHREE Atfecte,d Environment , time (USGS 1981). By comparison, noise levels measured on Colorado Highw~iy 13 (7 to 17 miles east of the proposed pipeline) and Colorado Highway 64 (11 to l6 miles north of the proposed pipeline) averaged 67 and 66 dB(A), respectively (BLM 1982). 3.7 VEGETATION The study azea for vegetation resources includes the entire lease area of the Pice~utce Site, a 400- foot wide corridor along the pipeline route, and portions of the Parachute Site not covered by existing facilities. Vegetation communities occurring within the study area were classified and mapped by BLM (1998c) for that portion of the study azea within BLM lands and private land to about 5 miles south of the Rio Blanco-Ga~eld County line. Vegetation data were mapped on USGS 7.5 minute quadrangles using Geographical Information System (GIS), and the maps were then used to identify vegetation communities and calculate acres of each type in the study azea. Figure 3.7-1 shows the vegetation communities at the Piceance Site. Similaz detailed information is not available for the rest of the study area that includes approximately the southern 11 miles of the pipeline route and the Parachute Site in Garfield County. Information on vegetation types occurring along the proposed project pipeline corridor not covered by BLM GIS mapping was taken from environmental assessments for two natural gas pipeline:. that the project pipeline comdor would lazgely pazallel (Barrett 1994, CIG 1995). Additional information on local plant communities is presented in the BLM's White River Resource Area Draft Resource Management Plan and Environmental Impact Statement (BLM 1994) and the Ph}rto-Edaphic Classification of the Piceance Basin in which plant communities aze described in terms of the overall ecosystem, including species composition, soil type, climate, and other iru.'ormation such as land use, reclamation limitations, and revegetation requirements (Tiedeman an~i Terwilliger 1978). For conciseness, the detailed classification scheme used for the GIS mapping and the somewhat broader classification scheme used by Tiedeman and Terwilliger (1478) have been summarized into the broader plant associations presented in BLM's Resource Management Plan (1994). For example, there aze 48 BLM GIS mapping classifications for apinyon-juniper-dominated community that includes variations in percent canopy cover and various subdominant cover types. Tiedeman and Terwilliger (1978) identify 3 classifications for a pinyon juruper- dominated community based on elevation, soil type, and dominant understory cover types. For this EIS, information from both sources is combined and summarized to describe, in general, the Pinyon-Juniper Association. The same was done for all other plant communities in the study azea. Table 3.7-1 provides a summary of acres by major vegetation association in the study azea. Threatened and Endangered plant species aze discussed in Section 3.10. 3.7.1 Piceance Site Dominant plant communities occurring at the Piceance Site include the Pinyon-Juniper Association, Chained Pinyon-Juniper Community, Sagebrush Association, Banren/Rock Outcrop Association, and Greasewood Association. These five major plant communities make up about 94 percent of the Piceance Site; the remaining 6 percent includes small azeas of mountain grasslands, Douglas-fir, irrigated agricultural land, and halophytic shnvblands. 3-26 Norse