PUBLIC HEALTH ASSESSMENT
CAL WEST METALS (USSBA)
LEMITAR, SOCORRO COUNTY, NEW MEXICO
Cal-West Metals (CWM) is a former secondary battery recycling facility in Lemitar, New Mexico. The company processed an estimated 20,000 automobile batteries between 1979 and 1981. Lead, plastics, and hard rubber components were recycled from the used batteries. Contaminants from this process and crushed battery components were discarded on-site. After 1981, batteries were no longer accepted at the facility. Battery recycling research was continued at CWM from 1982-1984. In 1985, the Small Business Administration (SBA) foreclosed on the property. Following several studies by the US Environmental Protection Agency (EPA) and the New Mexico Environment Department (NMED), the site was officially listed on EPA's National Priorities List (NPL) on March 31, 1989.
Lead, antimony, arsenic, and polyaromatic hydrocarbons (PAHs) were detected in soil on site at levels that could cause health problems if people were repeatedly exposed to them over a long period of time. The only contaminant found off site at concentrations above levels of possible health concern was lead. Lead was detected in arroyos (surface water drainages) approximately 200 feet outside the site fence. Groundwater was not found to be contaminated with any substances from CWM.
Site cleanup was completed in spring 1995; no environmental pathways pose a human health threat. There were two potential exposure pathways in the past. Trespassers at CWM could have been exposed to on-site contamination if they inhaled, ingested, or had skin contact with contaminated media; people could have also been exposed to contaminated soils in the off-site drainage areas. Because of the site's isolated location, only repeated contact with contaminants over a long period of time could have produced adverse health effects, and it is highly unlikely that such exposures occurred. The cleanup plan carried out by EPA reduced average soil lead levels on site low enough to allow the land to be used for residential purposes without producing harmful health effects in future residents.
The Cal-West Metals site presents no apparent past or present public health hazard because past human exposures, if any, would have been intermittent at worst and highly unlikely to result in harmful health effects. The soil both on site and off site has been cleaned up, and all chemical and physical hazards have been removed from the site.
Information for this section was attained from the September 1992 Record of Decision (ROD) for CWM (1) unless otherwise noted. A ROD is a site evaluation through which the best cleanup method for a site is selected.
Cal-West Metals (CWM) was a battery recycling facility. The site had been used as a cotton gin prior to the CWM battery operation. Aerial photographs by the New Mexico State Highway Department indicate that the cotton gin was active between 1961 and 1972.
The property is located in Lemitar, 8 miles north of Socorro in Socorro County, New Mexico (Figure 1). As a result of foreclosure in 1985, CWM currently belongs to the Small Business Administration. The property covers 43.8 acres, 12.5 of which are enclosed by a fence. Before remediation, the site consisted of two evaporation ponds, soil and battery waste piles, earth berms, a concrete surface pad, three buildings, and a salvage area (Figure 2). The northernmost building was used for research and development activities. The central building was used for the battery separation process, and was later used as a storage area for crushed battery components (plastics, hard rubber, and lead oxides). Those battery components have since been removed as part of site cleanup. The south building was used for smelting processes, to store and repair equipment, and as offices. The earthen berms were created by surface soil grading on the site. The larger evaporation pond was lined, and the smaller one was unlined.
There are currently nine monitoring wells and two supply wells on site. The monitoring wells are sampled quarterly. The supply wells are used for monitoring at this time and may be closed in the future (2).
An estimated 20,000 automobile batteries were processed to recycle lead, plastics, and hard rubber components from 1979 to 1981. The lead, plastics, and hard rubber were separated by flotation and centrifugation in a separator drum. Water was recycled through the separator drum, and was eventually discharged into the lined pond. Once the discharge lines became clogged, the sludges were discarded onto the concrete pad. It has been reported that battery acid was neutralized with calcium hydroxide, and was then disposed into the lined pond or onto the concrete pad. Crushed battery components were stored outdoors uncovered from the beginning of the operation until 1989 or 1990, when they were moved inside one of the buildings. The battery components have been removed from the site.
Batteries were no longer accepted at the facility after 1981, but the owners continued to research recovery methods for old automobile batteries from 1982-1984. Work was decreased after 1984, and in 1985 the SBA foreclosed on the property.
The CWM site has been studied by state and federal authorities numerous times since 1979. From 1981 to 1989, initial investigations were undertaken by the New Mexico Environmental Improvement Division, now the New Mexico Environment Department (NMED), EPA, and the owners. On June 24, 1988, the site was proposed for inclusion on EPA's National Priorities List (NPL). The site was officially listed on March 31, 1989. The extent and types of environmental contamination were studied, and the ROD was signed in September 1992. As a result of the ROD, all contaminated soil was mixed with concrete and buried and covered with a layer of concrete, a 12-inch layer of clean topsoil, and vegetation. All physical and chemical hazards were removed from the site and all buildings were cleaned and secured. Site cleanup was completed in spring 1995 (2).
ATSDR personnel, accompanied by a representative of the NMED, conducted a site visit on May 10-15, 1992 (3). ATSDR health assessors met with officials from the NMED, the New Mexico Department of Health, the New Mexico Bureau of Mines, EPA, the city of Socorro, and the town of Lemitar. A meeting was also held with the petitioner for the site.
During the first site visit it was discovered that the fence was down in at least two locations, so the property was readily accessible. There was evidence of trespassing, such as graffiti on walls and smashed windows and locks. Heavy equipment that was on site was not secured. One of the buildings was unsecured; marked and unmarked containers of chemicals were found in that building. Acids and bases were stored together. Large piles of lead battery wastes were found on the concrete pad. Large quantities of a white crystalline material (later identified as calcium hydroxide) were found partially buried in a concrete trench (3).
ATSDR staff conducted a second site visit July 29-31, 1992 (4). The purpose of that visit was to attend a second public availability meeting in conjunction with EPA's presentation of the 1992 Remedial Investigation and Feasibility Study (RI/FS) (5,6). A representative of the New Mexico Health Department went along on the site visit. The perimeter fence had been repaired but trespassing on the site was still possible. The building was unsecured and still contained the chemicals seen on the first visit. Acids and bases were still stored together. Subsequent site remediation resulted in the removal of all chemical and physical hazards from the site.
Demographic data provide information on population and housing characteristics of communities living near hazardous waste sites. Demographic information from the 1990 Census relating to the population living in the CWM area are presented below for general information.
CWM is located in a rural area one-half mile northwest of Lemitar, the nearest village. The eastern boundary of the site is the frontage road for US Interstate 25. The interstate is approximately 250 feet from CWM. Cal West is two miles west of the Rio Grande and four miles east of the Lemitar Mountains. The site is located 8 miles north of Socorro.
The general area around the site is barren and very sparsely populated. Approximately 250 people live within one mile of the site. The nearest residences are across Interstate 25, 1000 feet to the northeast and to the southeast. There are at least three households 1100-1300 feet south of the fence at CWM (see Figure 3).
Data from the 1990 Census for the census blocks that extend out to approximately one-half mile east of the site and include most of Lemitar are presented in Tables 1 and 2; data for Socorro County are included in the tables for purposes of comparison. Only 201 persons lived in that area in 1990. Nearly the entire population was white and approximately two-thirds were of Hispanic origin; the Hispanic percentage was considerably higher than the county average. Almost 28% of the population was under age 18, which is relatively high but still under the county average. Over 80% of all households were owner occupied, which suggests a relatively nontransient population (i.e., renters tend to move much more frequently than do homeowners). The average value of owner-occupied households and average monthly rent paid for renter-occupied housing units are roughly the same as the county averages.
The privately owned land near the site is not irrigated. Agricultural land lies on the opposite side of Interstate 25. Land lying west and north of CWM is owned by the US Bureau of Land Management. That land is primarily grazing rangeland, which has been overgrazed by cattle. The soil in the area has been ranked by the US Soil Conservation Service as being fair to poor for a potential wildlife habitat (1). The types of wildlife that are expected to exist in the area are small to medium sized birds, birds of prey, and small mammals and reptiles.
The Rio Grande is two miles east of CWM, and is the only perennial (i.e., water is constantly flowing) stream within fifteen miles. The Rio Grande flows north to south. The Lemitar Mountains are drained by a number of ephemeral (i.e., water seldom flows in them) arroyos in the area. There are two west-east ephemeral arroyos located to the north and south of CWM within one-half mile of the site (Figure 5). Those arroyos flow into channelized irrigation ditches that eventually lead to the Rio Grande.
The Sierra Ladrones Formation and Quaternary deposits form the upper shallow groundwater aquifer in the Lemitar area (groundwater is defined as being water beneath the earth's surface that supplies springs and wells); that aquifer is the primary source of groundwater. No known private drinking water wells have been completed deeper than the shallow aquifer in the Socorro and La Jencia Basins (5). All residences in the area use the Polvadera municipal water supply as their potable water source, according to the most recent data. Polvadera is about seven miles north of the site; the municipal water comes from a deep groundwater aquifer. The shallow wells near CWM are now used mainly for irrigation (2). Groundwater surface contours indicate that groundwater beneath CWM flows predominately to the south-southwest (1).