YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT SUMMARY OF SOCIOECONOMIC DATA ANALYSES CONDUCTED IN SUPPORT OF THE RADIOLOGICAL MONITORING PROGRAM FIRST QUARTER 1996 TO FIRST QUARTER 1997, JUNE 1, 1997 (C) Prepared for: U.S. Department of Energy Yucca Mountain Site Characterization Project Office P.O. Box 98608 Las Vegas, Nevada 89193-8608 Prepared by: TRW Environmental Safety Systems Inc. 1180 Town Center Drive Las Vegas, Nevada 89134 Under Contract Number DE-AC01-91RWO0134 INTRODUCTION This document is the seventh in a series of annual reports that provide information about the spatial distribution of population and agricultural activities within a 50-mile radius of Yucca Mountain. The objective of this report is to make available site-specific data for performing radiation dose and risk assessments related to the Yucca Mountain Site Characterization Project (YMP). This research is conducted in support of the Radiological Monitoring Plan (DOE, 1990) for the YMP. 1.1 BACKGROUND The Radiological Monitoring Plan (the controlling document for this report) is written in compliance with the Nuclear Waste Policy Act of 1982, as amended (NVYTA, 1982). In Title 10 Code of Federal Regulation Part 960 (IO CFR 960) General Guidelinesfor the Recommendation of Sitesfor Nuclear Waste Repositories, there are several specific references to population distributions and densities, to the socioeconomic conditions in the study area, and to the relative importance of these data. Based on the regulatory requirements, knowledge of the radiological pathways to man within the study area is essential to ensure adherence to the Federal standards. The objective of this guidance is to "minimize risk to the public and permit compliance with the EPA and NRC regulations" (10 CFR 960, p. 47741). These regulations require that protective measures be assessed and that exposure to members of the public in unrestricted areas not only be limited, but be "further reduced below the limits to the extent reasonably achievable ." (10 CFR 960, p. 47741). Based on the requirements set forth in the Radiological Monitoring Plan, the Radiological Monitoring Program (RadMP) was developed for the purpose of providing the data necessary for radiological impact analysis related to the YMP. The primary data required for the socioeconomic support of radiological impact analyses are those used in computer models that assess radiation dose estimates for an individual or a population (DOE, 1990). Models that describe the atmospheric human pathway incorporate various data, including demographic and agricultural characteristics, with factors such as distance from the source and meteorological data, to compute potential exposure doses to members of the public through atmospheric dispersion of radionuclide releases. An example of such a model is the Clean Air Act Assessment Package- 1988 for a personal computer (CAP88-PC). CAP88-PC allows users to perform dose and risk assessments for the purpose of demonstrating compliance with 40 CFR 61.93(a) and provides the methodology for "assessments of both collective populations and maximally-exposed individuals" (EPA, 1992, p I - 1). 1.2 THE RADMP SOCIOECONOMIC DATA REQUIREMENTS A principal issue regarding RadMP requirements is that the data must be site-specific. Technical guidance notes, "because of the and characteristics of the Yucca Mountain area, site-specific data are very important because most generic data were developed for non-arid environments" (DOE, 1990). The site-specific RadMP data requirements include characteristics of radioactive aerosols, meteorological factors, agricultural and cultural characteristics, population demographics, and general biota data (DOE, 1990). This report focuses on demographic and agricultural data required for the assessment of radiation dose and exposure estimates for individuals or populations. The Enviommental Protection Agency (EPA) states: "knowledge of population densities and spatial distribution of farm animals is necessary to assess protective measures required in the event of an accidental release of radioactivity ...... (EPA, 1990). As mentioned in the preceding section, another requirement is that the data must be suitable for use in computer models designed specifically to assess the health effects of low-level chronic (long term) exposures. This means that the population of interest consists of that segment at risk of long-term exposure. This segment, in turn, consists of two related but distinguishable components: (1) daytime populations; and (2) resident populations. For purposes of the RadMP, daytime populations are comprised of groups of employees and school age children who are repeatedly found at the same specific locations. Resident populations are consistent with census definitions. (U.S. Bureau of the Census, 199 1: B- I to D- 14). The population at risk of "short term" exposure includes persons visiting or residing in the area on a temporary basis, such as those staying in recreational vehicle parks or jail facilities. While knowledge of these populations is necessary to assess protective and emergency response measures, their inclusion in the population estimates would be inappropriate since the computer models used for radiological impact analyses "cannot be used for either short term or high-level radionuclide intakes" (EPA, 1992, p. 1-3). The agricultural data requirements of the RadMP are intended to identify sources of possible concentrations of radionuclides from local origins. The factors taken into consideration include the location and quantity of fruits and vegetables grown within the study area, the quantity of dairy products produced, and the number of meat-producing animals raised within the study area. Consideration is given to animals that graze. The EPA notes, "grazing animals ingest forage from large areas of ground surface and so represent a concentration mechanisrw' (EPA, 1990). Milk is perhaps the most significant source for possible concentration of radionuclides because of the relatively short time between the ingestion of feed by the milk cows to the time the milk appears on grocery shelves for human consumption. 1.3 REPORT ORGANIZATION Section 2.0 of this document provides a brief description of the methods and procedures used to compile information about the distribution of population and agricultural activities in the 50-mile radius of Yucca Mountain. A summary of housing, population, employment, enrollment, and agricultural data is presented in Section 3.0. Document references are shown in Section 4.0, and Appendix A provides a description of the RadMP grid. 1.4 CHANGES FROM PREVIOUS REPORTS There have been methodological and data improvements in the development of population estimates within the RadMP since the previous report (DOE, 1996). These improvements have been sufficient to warrant the development of a revised set of Ist Quarter 1996 (IQ/96) estimates to maintain consistency with subsequent estimates. One of the improvements involved the use of Global Positioning System (GPS) technology to more accurately identify the grid cell locations of housing units and population between Beatty and Scotty's Junction, Nevada and in Inyo County, California (Death Valley). This survey was done on April 17, 1997. Fieldwork in 1997 also revealed that the Mt. Charleston Elementary School, located in Pahrurnp, Nevada, is actually outside the grid. In 1996, this school was believed to be within the grid. Thus, this report provides enrollment figures for 1996 and 1997 that reflect this correction. Other improvements include: (1) the availability of current information on the number of persons per household; (2) an automated system for allocating Val-ley Electric Association (VEA) electric meter data into grid cells; (3) increased accuracy in the geographic information system (GIS) overlay between the grid cells and other coverages, including streets; and (4) more precise information for placing VEA meters within grid cells. Even though there have been improvements in both the coverage of the VEA utility data used to generate housing unit estimates and the classification of these estimates by grid cell, the basic method for estimating population has not changed; namely, the Housing Unit Method, (HUM), which is described in Section 2.2. 1, below. Neither has there been a change in the "population" being estimated. Its definition also has not changed: namely, the definition used by the U.S. Bureau of the Census for its enumeration and estimation programs (U.S. Bureau of the Census, 1991: B-I to D-14.). The definitions of housing unit and household used in this report also are consistent with past practice and, in addition, in conformance with the concepts and definitions.used by the U.S. Bureau of the Census (1993: B-14 to B-19). Another change from the previous report is that population estimates by race and Hispanic origin for the I st Quarter of 1997 (I Q/97), are provided for the main communities within the grid: Amargosa Valley, Beatty, Indian Springs, and Pahrump. These estimates are derived from the "biosphere" survey conducted in the spring of 1997 (UNLV, 1997). In July 1995, a change was made in the reporting of on-site employment for the Nevada Test Site (NTS) and the YMP, which affects Table 3-6 in this report. Prior to July 1995, employment for both sites was reported in a single category, while subsequent NTS and YMP employment figures are reported separately (DOE/NV, 1995). As a consequence of this change, employment data for the NTS and the YMP prior to December 1996, are not reported in Table 3-6. 2.1 THE RADMP GRID AND STUDY AREA The RadMP grid circle is defined in the YMP Radiological Monitoring Plan (DOE, 1990) as an area with a radius of 84 kilometers (1cm) (approximately 50 miles) of Yucca Mountain. The grid is centered on a point on the western side of Exile Hill at the Yucca Mountain site with the coordinates of Easting 551135.7, Northing 4078351.6 on the Universal Transverse Mercator (UTM) Projection Grid Zone I I of the North American continent (Figure 2-1). Although the grid itself has not changed, there have been improvements in the overlay between the grid and other information, including streets. This, along with the improvements described in the previous section, led to the creation of revised estimates for IQ/96 in order to have consistency with subsequent estimates through I Q/97. Figure 2-2 shows the community boundaries within the RadMP grid area. The study area includes the communities of Amargosa Valley, Beatty, and Pahrump in southern Nye County, Nevada; and Indian Springs in Clark County, Nevada. The boundaries shown in Figure 2-2 for Arnargosa Valley, Beatty, and Pahrump are the tax boundaries specified by the Nye County Board of Commissioners. The boundary for Indian Springs is the legal description specified for the unincorporated town by the Clark County Commissioners. Also contained within the study area are portions of Death Valley National Park (DVNP), the NTS, and the Nellis Air Force Range (NAFR). Figure 2- 1. Radiological Monitoring Program Grid (RadMP Grid) Figure 2-2. BOUIRIMICS fOr the ConinlUnities Within Ilic Ra('-MP Grid Taxation boundaries and town boundaries do not correspond directly to the RadMP grid cell boundaries. Often, the community boundaries encompass partial grid cells and, in the case of Pahrump, may extend beyond the 84-km grid delineation. It is also important to note that the community of Pahrump includes areas both within and outside the RadMP grid. As a consequence, Section 3.2 provides information not only for the portion of Pahrump that is within the grid, but also for: (1) an area outside the grid but within the town tax boundary; and (2) for the portion of Pahrump that corresponds to the VEA service area, but includes areas outside both the tax boundary and the grid. 2.2 DATA COLLECTION PROCEDURES 2.2.1. Population The estimates of daytime populations were obtained by collecting employment and enrollment information for locations within the grid. The sources of this employment and enrollment infon-nation are described in Tables 3-6 to 3-7 and 3-8 to 3-9, respectively. The resident population estimates primarily were developed using the housing unit method (HUM). This procedure, which is used by nearly 90 percent of the state and local agencies responsible for preparing population estimates, is dependent on four variables: housing units, occupancy rates, population per household; and the population in group quarters (Byerly, 1990; Roe, Carlson and Swanson 1992). The HUM equation is as follows: P =[(H)*(OR)*(PPMI+GQ where P total population H total housing units OR = occupancy rate (occupied units/total units) PPH = population per occupied household GQ = population in group quarters As mentioned earlier, the housing and population data follow the same concepts and definitions used by the U.S. Bureau of the Census. In terms of group quarters, it is important to note that all persons not living in households are classified by the Census Bureau as living in group quarters. Two general categories of persons in group quarters are recognized: (1) institutionalized persons; and (2) other persons in group quarters (also referred to as "noninstitutional group quarters" (U.S. Bureau of the Census, 1993: B-1 to D-5). Clark County- The Clark County Department of Comprehensive Planning produces annual population estimates for small areas (census tracts) in the county based on two data sources: (1) building permits; and (2) historical census data describing each census tract's population per household and occupancy rates. The Clark County estimates were used for Indian Springs for I Q/96. The HUM was used for I Q/97, with housing unit and household estimates taken directly from a survey of Indian Springs and a PPH value taken from the "biosphere" survey (UNLV, 1997). Information obtained from military and civilian respondents during the survey verified that there is no group quarters population in Indian Springs in 1997. The HUM also was used for Cold Creek, which is in Clark County and approximately ten miles southwest of Indian Springs (Grid Cell IO 1 1). The V]EA supplies power to Cold Creek and provides a source of data for the number of housing units in Cold Creek. However, experience has shown that there are many vacation homes in this area, which means that there are many fewer units occupied by those who would be considered a resident according to the criteria used by the U.S. Bureau of the Census. Thus, a "windshield survey" was conducted on June 14, 1997, to count housing units that could be compared with the estimates based on the VEA data. The results of the windshield survey were consistent with the VEA estimate. The Indian Springs PPH value was applied to Cold Creek. There is no group-quarters population in the Cold Creek area. Esmeralda County - Neither a resident nor daytime population is in the portion of the RadMP grid circle (cell 1004, and portions of grid cells 904 and 1003) within Esmeralda County. This was confirmed by field work, most recently in April 1997. Lincoln County - Neither a resident nor daytime population is in the part of the RadMP grid circle (cells 915 and 1015) within the portion of Lincoln County that is outside of the Nellis Air Force Range. This was confirmed by field work, most recently in June 1997. Nye County - There are both resident and daytime populations in the portion of Nye County covered by the RadMP grid circle. For the most part, these populations are found in Beatty, Amargosa Valley, and Pahrump. The sources of the daytime population estimates are described in Tables 3-6 through 3-9. The resident population estimates were developed using the HUM. In the case of Beatty, it is known that the VEA data underestimate both the total number of housing units and occupied housing units, because of the high proportion of "master meters" (DOE, 1996). Thus, a 100 percent count of housing units and occupied units was done for Beatty in February 1997. This is consistent with past practice (DOE, 1996). As verification of the presence of master meters in Beatty, note that for IQ/97 the VEA shows 707 active residential meters, Iwhich is 44 less than the 751 occupied housing units counted in the survey. The estimate for the number of housing units in the Amargosa Valley and Pahrump portions of the RadMP grid comes from the VEA. The specific data set obtained from the VEA for this purpose represents "active residential accounts." Unfortunately, there is no specific information that can determine the exact number of occupied housing units (households) from the VEA data for Amargosa Valley and Pahrump. In earlier reports, a 95-percent occupancy rate was applied to the VEA active residential meters to obtain an estimate of households for these two communities because, unlike the situation in Beatty, there are more active residential meters than households in both communities (DOE, 1996). Consistent with this practice, a 95-percent occuppcy rate was applied to the number of active residential meters reported for these two communities by the VEA for I Q/97. This adjustment also is consistent with the occupancy rate found for Beatty from the windshield survey, which revealed that 95.4 percent of the total units counted (787) were occupied. As was the case for Indian Springs, PPH values specific to Amargosa Valley, Beatty, and Pahrump were taken from the biosphere survey conducted in May 1997 (UNLV, 1997). Note that group quarters populations are extremely small or nonexistent in these communities. Thus, it was assumed that this component of the HUM for each community remained at the same level reported in the 1990 census (U.S. Bureau of the Census, 1992: 179). Inyo County, California - The portion of the Inyo County, California population contained in the RadMP is primarily situated in Death Valley National Park (DVNP). There are both daytime and resident populations in DVNP. Information on the sources of the estimates of the daytime population is provided in Tables 3-8 and 3-9. Administrative officials of governmental and private organizations operating in DVNP were contacted to obtain their counts of residential populations. This information was supplemented by a survey that supplied data needed for the HUM. AMFAC, Inc. provided information on the number of resident employees and their dependents at the Furnace Creek Inn and the Furnace Creek Ranch (AMFAC, personal communication, 1997). The Park Service Housing Officer provided information on the number of employees and their dependents living at Cow Creek, Stovepipe Wells, and Scotty's Castle (Death Valley National Park, personal communication, 1997) Information also was provided for the Grapevine Ranger Station housing area (Death Valley National Park, personal communication, 1997). However, the April 17, 1997 GPS survey determined that this housing area was outside of the Grid. Information also was obtained for the number of caretakers residing at the inactive Ryan Mine site (Grid Cell 808) and for the population living in Death Valley Junction (Grid Cell 809) (Furnace Creek Post Master, personal communication, 1997; Death Valley Junction, Amargosa Inn, personal communication, 1997). On-site work done on April 19-20, 1997, including a windshield survey, was used to develop the housing unit counts for the housing areas of Death Valley, including the Timbisha Village (Grid Cell 707), which is occupied by members of a Shoshone group. The population of the Timbisha Village was estimated by using the HUM in conjunction with the PPH value (2.45) used for Amargosa Valley. An estimate of the number of occupied units at Furnace Creek Inn and Ranch (Grid Cell 707) as well as at Cow Creek (Grid Cell 707), Stovepipe Wells (Grid Cell 906) and Scotty's Castle (Grid Cell 1004) was obtained by dividing the population data by this same PPH value (2.45). One of the Grid Cells in Death Valley (1004) has a substantial group-quarters population (48), because of the nature of housing for many of the resident employees working at Scotty's Castle, which is located in this cell. Race and Hispanic Origin Estimates - The population estimates by race and Hispanic origin for selected communities within the RadMP grid circle found in Table 3-5 were derived from the biosphere survey (UNLV, 1997). This survey was conducted in the spring of 1997 and covered the communities of Arnargosa Valley, Beatty, Indian Springs, and Pahrump. From it, the proportion of persons by race and Hispanic origin is available by community. These proportions were multiplied by the independently determined population estimates (Table 3-4) for each community to find the estimated number by race and Hispanic origin. 2.2.2 Agriculture Agriculture data for the spring of 1996 and 1997 were obtained by examination of the agricultural activities within the RadMP grid during the period from April to June of each year. The method used to compile agriculture data consisted of the following steps: (1) previously-collected information regarding agricultural activities within the RadMP grid was compiled and entered into a data base, including the type of agriculture (i.e., type of crop or livestock), the number of acres of cropland or number of animals, and the location of the agricultural activity; (2) location of the agricultural activities listed in the database (including the RadMP grid cell number) was identified on color aerial photographs of southern Nye County taken during 1997 (USDA, 1997); (3) field trips were conducted during May and June 1997 to verify the current existence of, or changes to previously observed agriculture, and to identify any agricultural activity not yet recorded. These data were verified, where possible, with the land owner or other individuals knowledgeable of local agricultural activities. GPS technology was utilized to accurately identify the grid cell location of cattle ranches and other agricultural activities between Beatty and Scotty's Junction. Additionally, all grid cell locations and previously recorded information were reviewed for accuracy and corrections were entered into the database. The data presented in Section 3.0 reflects all changes and corrections. 3.0 SUMMARY OF SOCIOECONOMIC DATA BY RadMP GRID CELL The socioeconomic data required for support of radiological impact analyses are presented in this section along with information that supplements the data collection procedures described in the preceding section. The data include information about the spatial distribution of population and agricultural activities within a 50-mile radius of Yucca Mountain. Population estimates are produced by federal, state, and local government agencies, universities, and private enterprises--often for widely different purposes. As mentioned earlier, one of the factors that complicates the comparison of various community characteristics is the lack of a common geographic definition. A community's name may be used to identify a variety of areas, including: those specified by the U.S. Bureau of the Census; the jurisdictional tax boundaries specified by state or local governments (either county or special district governing boards); and a utility company's service area. These differences, in turn, contribute to varying estimates of a community's population. In the community of Pahrump, for example, the 1990 U.S. Census Block Group aggregation of census blocks used for one set of population estimates represents an area larger than the tax boundary definition (PIC, 1996). Yet another population estimate, based upon VEA data, includes not only "Pahrump," but also Sandy Valley and Spring Mountain, an area that, in total, is similar to the census block group aggregation 9804-3 through 9804-6 (PIC, 1996). Because of these three different definitions, population estimates for Pahrurnp are provided in this report not only for the portion within the grid, but also for the other two areas. These data facilitate the comparison of population estimates of Pahrurnp done by different groups using these different geographic definitions. Note, however, the town boundaries shown on Figure 2-2 are the primary definitions of Pahrurnp. 3.1 HOUSING AND POPULATION Table 3-1 presents the estimated number of housing units by community and grid cell from I Q/96 to I Q/97. Table 3-2 provides similar geographic information on the number of occupied housing units (households) while Table 3-4 shows estimates of the resident population. Table 3-3 provides PPH estimates by community. Table 3-5 provides the distribution of the resident population by race and Hispanic origin. Estimates of Nye County's resident population by grid cell were computed using the HUM, as described in Section 2.2. 1. For Amargosa Valley and Pahrurnp, these estimates are based on the active residential accounts provided by the VEA. Within Amargosa Valley, Beatty, and Pahrump, the VEA residential accounts were allocated into grid cells using an automated system that associated VEA meter identifiers with grid cells. As stated earlier, a windshield survey was conducted to establish the baseline estimate of housing units for Beatty as of I Q/96 and I Q/97. The total housing unit and occupied unit counts for I Q/97 obtained from the windshield survey were allocated into grid cells using the proportion of meters by grid cell as reported by the VEA. This allocation was checked against the block-specific counts by grid cell. Estimates of Beatty's population for 2Q/96, 3Q/96, and 4Q/96 were obtained by interpolating between the estimates for 1Q/96 and I Q/97. Housing and population information on Indian Springs (Grid cell 912) for I Q/96 was provided by the Clark County Planning Commission (DOE 1996). The I Q/97 estimate for both Indian Springs and Cold Creek was taken from the windshield survey. Estimates of Indian Springs for 2Q/96, 3Q/96 and 4Q/96 were obtained by interpolating between I Q/96 and I Q/97. The estimate for Indian Springs includes 4 units counted in nearby Cactus Springs. A windshield survey was not done for Cold Creek in 1996. To maintain comparability for this area, the 1997 count of housing units was assumed to apply to each quarter in 1996. Also, as described earlier, an on-site survey also was used to obtain housing unit counts in Death Valley for IQ/97. This was supplemented by information gained from conversations with housing and other officials at Death Valley (AMFAC, 1997; Death Valley National Park, 1997). Comparable information for 1Q/96 to 4Q/96 is not available. To fill in this gap, the assumption was made that there was no change in data between I Q/96 and I Q/97. The data in Table 3-1 show that the largest absolute and relative increase in housing stock occurred in Pahrump. For the portion of Pahrump within grid cells, the increase in housing stock from I Q/96 to IQ/97 was 589 units (12.6-percent increase). The primary source of this increase was a gain of 405 units in grid cell 1010. The data for Beatty show a slight decline, from 792 units to 787 during the same period. Overall, housing stock in the grid increased from 6,949 to 7,556 units (8.7 percent). Table 3- 1. Estimates of Residential Housing Units by Grid Cell and Community, First Quarter 1996 to First Quarter 1997 Table 3-1. Estimates of Residential Housing Units by Grid Cell and Community, First Quarter 1996 to First Quarter 1997 (Continued) Table 3-2 shows the estimated number of households (occupied housing units) by community and grid cell from I Q/96 to I Q/97. For I Q/97, the data for Beatty, Indian Springs, and Cold Creek are taken from the windshield survey. For 2Q/96, 3Q/96, and 4Q/96, the data for Beatty, Indian Springs, and Cold Creek were developed using linear interpolation between I Q/96 and 1 Q/97. The stock of households within the grid changed in much the same manner as did the housing stock. As was found for housing units, the largest increase occurred in Pahrurnp, which fueled the increase in households for the grid as a whole. Overall, households increased from 6,527 to 7,099, an increase of 8.8 percent. Data on the number of persons per household (PPH) in each community for 1990 and 1997 are shown in Table 3-3. The 1990 data are from the U.S. Census, while the 1997 data are from the biosphere survey (UNLV, 1997). The table shows that PPH values increased for each community between 1990 and 1997. Table 3-4 provides estimates of the resident population by grid cell and community. To obtain the resident population estimates for Amargosa Valley, Cold Creek, Indian Springs, and Pahrump, the number of households (Table 3-2) was multiplied by the community-specific 1997 PPH value (Table 3-3) to produce the household population estimates by quarter. The group quarters population was added to the household population to get the total population by quarter. The group quarters population in Arnargosa Valley and Cold Creek is zero for the period in question; therefore, the total population in these communities is equal to the household population. For Pahrump, it is assumed that the group quarters population is the same as it was in 1990, 81 persons (Table 76, U.S. Bureau Table 3-2. Estimates of Occupied Housing Units by Grid Cell and Community, First Quarter 1996 to First Quarter 1097 (Image Only) Table 3-3. Resident Population Per Household (PPH) By Community, 1990 and 1997 of the Census, 1992). Note that the population figures shown in Table 3-4 for Pahrump, include the areas both within and outside of the grid cells, as was shown in Table 3-1 and Table 3-2 for housing units and households, respectively. For Indian Springs, 33 persons were counted in group quarters in 1996 (DOE, 1996). However, the 1997 survey revealed that no persons were in group quarters in 1997. For Beatty, the 1Q/97 resident population was estimated as follows. First, the estimated number of occupied units (Table 3-2) was multiplied by the community-specific PPH value (Table 3-3) to produce the household population estimate. Under the assumption that the group quarters population has been constant since 1990, seven persons assumed to be in group quarters were added to obtain the total population. The I Q/96 population was estimated in a similar manner. The estimates for 2Q/96, 3Q/96, and 4Q/96 were produced by linear interpolation between IQ/96 and IQ/97. To obtain the I Q/97 population by grid cell, the PPH value for Beatty was multiplied by the number of occupied housing units in each grid cell. As stated earlier, GPS measurements were used to allocate the housing units and population into grid cells for the area between Beatty and Scotty's Junction. Table 3-4. Resident Population by Grid Cell and Community, First Quarter 1996 to First Quarter 1997 A similar procedure was used to obtain the same information for Beatty for I Q/96. That is, the total housing units from the 1996 windshield survey were allocated into grid cells using the same proportion found for I Q/97. This was reasonable because there was very little change in housing stock. The 1997 PPH value was multiplied by the occupied housing units in each grid cell to obtain the estimated population in each grid cell for I Q/96. The housing and population information by grid cell for 2Q/96, 3Q/96, and 4Q/96 also was obtained by linear interpolation. An estimate of the number of individuals in group quarters in Nye County was added to grid cells 404, 405 and 1010, the only cells with group quarters population in both 1996 and 1997. Four of the seven persons in group quarters in Beatty were allocated to grid cell 405; the remaining three were allocated to grid cell 404. All 81 of Pahrump's group quarters population were allocated to grid cell 1010. Note also that the 48 resident employees at Scotty's Castle residing in group quarters are included in the population total shown for grid cell 1004. The grid cell showing the largest increase is 1010, which is in Pahrump. It gained 788 people, an increase of 10 percent over its IQ/96 population of 7,897. Overall, the population within the entire grid increased from 16,818 to 18,087, an increase of 7.5 percent. The estimated number of persons by race and Hispanic origin is shown in Table 3-5 for the primary communities within the grid. As of I Q/97, these communities, in total, comprise 96 percent of the grid's total population of 18,087. The racial categories shown in Table 3-5 conform to those used by the U.S. Bureau of the Census as does the "Hispanic origin" ethnic group (U.S. Bureau of the Census, 1992). Persons identifying themselves as belonging to the "other" racial category usually use terms such as multiracial, multiethnic, mixed, or a Spanish/Hispanic origin group in describing themselves (U.S. Bureau of the Census, 1993). As can be seen in Table 3-5, the white population makes up about 95 percent of the racial composition. The largest single identified racial group after white is American Indian, with 286 persons, or about 1.6 percent of the population in these communities. Those of Hispanic origin represent about six percent of the population. Note that persons of Hispanic origin may be of any race. Most persons of Hispanic origin in this survey identified themselves as belonging to either the other" or "white" racial groups, which is consistent with the experience of the U.S. Bureau of the Census, as described in the preceding paragraph. Table 3-5. Resident Population By Race and Hispanic Origin, First Quarter 1997 3.2 DAYTIME POPULATION: EMPLOYMENT The major sources of daytime populations due to employment in the RadMP grid are the NTS, the YMP, and mines. Estimates of the employment in southern Nye County are provided for the NTS and the YMP site in Table 3-6 (DOE/NV, 1996). From January to December 1996, NTS employment levels decreased slightly from 1,393 to 1,382. Table 3-6 indicates that during 1996, YMP employment increased from 182 in January to 375 in December. 3-13 Table 3-6. Daytime Population: Nevada Test Site and YMP Monthly Employment (Number of Persons), January to December 1996 Table 3-7 provides estimates of the employment levels for the major mines in southern Nye County and indicates that overall employment levels declined from 509 in 1995 to 460 in 1996. The Bullfrog Mine, west of Beatty (grid cells 405 and 505), the single largest employer among these mines, showed a slight increase, from 372 in 1995 to 382 in 1996. 3.3 DAYTIME POPULATION: SCHOOL ENROLLMENT Primary concentrations of daytime populations also occur at the schools within the RadMP grid. Table 3-8 indicates the number of schools in particular grid cells. Within the RadMP grid there are six grid cells that include a total of ten schools, four of which are located in Pahrump. There is a fifth school in Pahrump, Mt. Charleston, but fieldwork determined that this school is outside of the grid. In 1996, this school was believed to be inside the grid and its enrollment was included in the 1996 report (DOE, 1996). Table 3-7. Daytime Population: Employment Figures for the Major Mines Within the RadMP Grid Table 3-8. Daytime Population: Public Schools by Grid Cell and Community Table 3-9 provides school enrollment estimates for the ten schools by grid cell from I Q/96 to I Q/97. During this period, school enrollment in the grid increased from 3,062 to 3,578, a gain of 516 students (16.8 percent). Virtually all of this was due to the increase of students (513) in the Pahrump Schools. Note that the data shown in Table 3-9 reflect the removal of enrollment for the Mt. Charleston school in Pahrump from the 1996 figures so that the change from 1996 to 1997 reflects enrollment only for the ten schools inside the grid. Table 3-9. Daytime Population: Public School Enrollments by Grid Cell and Community, First Quarter 1996 to First Quarter 1997 3.4 AGRICULTURAL CHARACTERISTICS Tables 3- 10 and 3-1 1 show estimates of livestock within the grid area for spring 1996 and 1997. The distribution of beef cattle reported in these tables includes cattle grazing on privately owned land and/or Bureau of Land Management (BLM) administered lands within the study area. The number of beef cattle decreased only slightly from 290 in spring 1996 to 275 in spring 1997. Notable Table 3-10. Estimates of Livestock by Grid Cell for 1996 Table 3-1 1. Estimates of Livestock by Grid Cell for 1997 changes in the livestock inventory from spring 1996 to spring 1997 include a 25-percent increase in the total number of milk cows, a 74-percent increase in total number of ostriches, and an 88-percent increase in the total number of catfish. Tables 3-12 and 3-13 provide estimates of the number of acres of agricultural crops by RadMP grid cell for spring 1996 and 1997. These data show an overall estimated increase from 2,787 to 3,004 acres of crop production from spring 1996 to spring 1997. This figure is largely a reflection of newly-identified areas of a riculture. 9 Table 3-14 provides estimates of agricultural yields by RadMP grid cell for 1996. The figures in this table are derived from estimates provided in Nevada Agricultural Statistics for 1995-1996; thus, they may not reflect actual yields. Table 3-12. Acres of Plant Agriculture by Grid Cell for Spring 1996 Table 3-13. Acres of Plant Agriculture by Grid Cell for Spring 1997 4.0 REFERENCES 10 CFR Part 960 1984. Title 10, "Energy," Part 960, "General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories," Washington, D.C.: U.S. Government Printing Office. AMFAC, Inc. 1997. Personal Conversation (30 May 1997) with M. Brady. Byerly, E. 1990. "State and Local Agencies Preparing Population and Housing Estimates." Current Population Reports Series P.25 No. 1063, U.S. Bureau of the Census. Death Valley Junction, Amargosa Inn 1997. Personal conversation (19 April 1997) with M. Brady. Death Valley National Park 1997. Personal Communication (29 April 1997) with M. Brady. DOE (U.S. Department of Energy) 1990. Yucca Mountain Site Characterization Project Radiological Monitoring Plan, Revision 1. Las Vegas, Nevada: U.S. Department of Energy, Yucca Mountain Site Characterization Project Office. DOE (U.S. Department of Energy) 199 1. Yucca Mountain Site Characterization Project Summary of Socioeconomic Data Analyses Conducted in Support of the Radiological Monitoring Program During Calendar Year 1990. Las Vegas, Nevada: U.S. Department of Energy, Yucca Mountain Site Characterization Project Office. DOE (U.S. Department of Energy) 1996. Yucca Mountain Site Characterization Project Summary of Socioeconomic Data Analyses Conducted in Support of the Radiological Monitoring Program During Calendar Year 19965. Las Vegas, Nevada: U.S. Department of Energy, Yucca Mountain Site Characterization Project Office. DOE/NV (U.S. Department of Energy/Nevada Operations) 1996. "Report of Nevada Test Site and Other Related Employment." Las Vegas, NV: Human Resources Division (since April, 1996; prior to April, 1996, reports were issued by the Industrial Relations Division), Nevada Operations Office, U.S. Department of Energy (monthly) 1996. U.S. Department of Energy. DOE/NV (T-J.S. Department of Energy/Nevada Operations) August, 1995. "Report of Nevada Test Site and Other Related Employment, July, 1995." Las Vegas, NV: Industrial Relations Division, Nevada Operations Office, U.S. Department of Energy (monthly). DOE (U.S. Department of Energy) 1996. Yucca Mountain Site Characterization Project Socioeconomic Monitoring Program Quarterly Employment Data Report, January 1997 through March 1996 Las Vegas, Nevada: U.S. Department of Energy, Yucca Mountain Site Characterization Project Office. EPA (Environmental Protection Agency) 1990. Radiation MonitoringAround UnitedStates Nuclear Test Areas, Calendar Year 1990, Las Vegas Nevada: U.S. Environmental Protection Agency. EPA (Environmental Protection Agency) 1992. User's Guidefor CAP88-PC, Revision 1, Las Vegas Nevada: U.S. Environmental Protection Agency. Furnace Creek Post Master 1997. Personal communication (29 April 97) with M. Brady. Nevada Bureau of Mines and Geology 1990-1996. Major Mines ofNevada, 1989 - 1995. Reno, Nevada: Nevada Bureau of Mines and Geology, Nevada Department of Minerals. Nevada Bureau of Mines and Geology 1997. Major Mines of Nevada, 1996. (World Wide Web Website http://www.nbmg.unr.edu/mm). Maintained by the Nevada Bureau of Mines and Geology, Nevada Division of Minerals. Reno, Nevada. NWPA (Nuclear Waste Policy Act) 1982. "Nuclear Waste Policy Act of 1982," [as amended by the Nuclear Waste Policy Amendments Act (NWPAA) of 1987], Public Law 97-425. Washington, D.C. Nye County, Nye County Assessor's Office 1988. "Resolution No. R88-38, Beatty Taxing District Boundaries." Information received from Robin Rivero, Chief Deputy, Tonopah, Nevada, October 1993. PIC (Planning Information Corporation) 1996. Draft Population Estimates Through the Fourth Quarter, 1996, prepared for the Nye County Board of Commissioners, Tonopah Nevada. Roe, L., J. Carlson, and D. Swanson 1992. "A Variation of The Housing Unit Method for Estimating the Population of small, rural areas: A case study of the local expert procedure"Survey Methodology 18: 155-163. SMPA (Security Milk Producers Association) 1996. Unpublished data provided by L. Sharfl, SMPA Accounting Coordinator, June 6 1997. Ontario, CA. State of Nevada 1996. Nevada Agricultural Statistics 1995-1996 Reno, Nevada: Nevada Agricultural Statistics Service. UNLV (University of Nevada, Las Vegas) 1997. " Summary Report on The 1997 Biosphere Survey." Las Vegas, NV: Cannon Center For Survey Research, UNLV U.S. Bureau of the Census 1993. Population and Housing Unit Counts, Nevada. 1990 Census of Population and Housing.'1990 CPH-2-30. Washington D.C.: U.S. Government Printing Office. U.S. Bureau of the Census 1992. General Population Characteristics, Nevada. 1990 Census of Population and Housing. 1990 CP- 1 -30. Washington D.C.: U.S. Government Printing Office. U.S. Bureau of the Census 199 1. Summary Population and Housing, Nevada. 1990 Census of Population and Housing. 1990 CPH- 1-30. Washington D.C.: U.S. Government Printing Office. USDA (U.S. Department of Agriculture) Farrn Se.rvice Agency 1990 and 1997 Aerial Photography. VEA (Valley Electric Association) 1997. Residential and Commercial Account Information, Pahrurnp, Nevada. APPENDIX A READING THE RadMP GRID Reading the RadMP Grid The RadMP grid is divided into 16 equal sections of 22.5 degree arcs. Beginning with an undivided 4-km circle at the center, there are ten concentric rings each 8-km in width. Including the center, there are 161 grid cells. The RadMP grid boundary is 84 kilometers from its center point, whose coordinates are defined as Easting 551135.7, Northing 4078351.6 Universal Transverse Mercator (UTM) Grid Zone 1 1. The grid data contained in Tables 3-1, 3-2, 3-5, and elsewhere where data are reported for grid cells are read as follows: 1. The center of the circle is grid cell 1. 2. Each concentric ring is numbered sequentially from 100 (the first ring surrounding the center grid cell) to I 000 (the last ring of the radiological circle). 3. The 16 sections are numbered sequentially beginning with number 1, which is centered on due north. Thereafter, each subsequent section is numbered counterclockwise, so that, Section 5 is due west, Section 9 is due south, and Section 13 is due east. 4. Grid cell identifiers consist of the number of the ring followed by the number of the section. For example (refer to Figure 1, p. 2-3), Death Valley Junction is found in Grid cell 809 and the community of Cold Creek is contained in grid cell IO 1 1.