-1- STATE OF CALIFORNIA

SUPPLEMENTAL INFORMATION FOR

RECOMMENDED LEAD NONATTAINMENT AREA

SOUTH COAST AIR BASIN PORTION OF LOS ANGELES COUNTY

EXCLUDING THE CHANNEL ISLANDS

EIGHT FACTOR ANALYSIS

INTRODUCTION

The Air Resources Board previously submitted justif ication for designating the South Coast portion of Los Angeles County as nonatt ainment for the 2008 lead national ambient air quality standard. This docume nt provides the justification for also excluding San Clemente and Santa Catalina isla nds from the nonattainment area, using the eight factors U.S. EPA recommends f or evaluating lead area designations.

ANALYSIS

Jurisdictional Boundaries

As shown in Figure 1, the southern two-thirds of Lo s Angeles County, including San Clemente and Santa Catalina islands, is located in the South Coast Air Basin and falls under the jurisdiction of the South Coast Air Quality Management District (South Coast AQMD or District). Pollutant concentrations are

FIGURE 1

LOS ANGELES COUNTY-2-

substantially higher in the mainland South Coast po rtion of the County because several significant lead-related stationary sources are located there, in the City of Commerce, the City of Industry, Santa Fe Springs, a nd Vernon. As a result, the South Coast AQMD has implemented rigorous, source-s pecific, emissions control requirements. Although the entire area is under the jurisdiction of a single control agency, the disparity among emissions sourc es justifies limiting the lead nonattainment area to the mainland South Coast port ion of Los Angeles County.

Air Quality Data

Lead concentrations are monitored at a number of si tes in the mainland South Coast portion of Los Angeles County. Some of these sites are located near lead-related stationary sources, while others are n eighborhood scale sites.

Based on data for the sites located near lead-relat ed sources, the design value for the South Coast portion of Los Angeles County i s 2.49 micrograms per cubic meter (μg/m 3 ), which exceeds the 2008 federal lead standard. T his value was measured near the Exide Technologies facility in Ve rnon. Values for the District’s other source-oriented sites surrounding the Exide facility are lower, with maximum 3-month averages ranging from 0.03 μg/m 3 to 0.55 μg/m 3

. Concentrations at sites surrounding the other lead- related facilities also show a

decrease in concentration with distance from the so urce, confirming the rapid drop in lead concentrations with distance. This re lationship provides additional support for limiting the size of the nonattainment area.

In addition to the source-related lead samplers, th e District maintains a network of neighborhood scale sites. Lead concentrations m easured at all of these sites are well below the federal standard, ranging from l ess than 0.01 μg/m 3 to 0.03 μg/m 3 . These values are based on data for 2005 through 2007, the most recent complete three-year period for which data ar e available. Although there are no monitoring data available for San Clemente o r Santa Catalina island, we expect concentrations there are even lower because of the differences in emissions and population, as well as the distance f rom the mainland County area and the rapid drop in lead concentration with dista nce from a source.

Emissions Data and Level of Emissions Control

There are significant differences between lead emis sions in the mainland and offshore South Coast portions of Los Angeles County . The mainland portion of the County contains one lead-related stationary sou rce (Exide Technologies) and one general aviation airport (Van Nuys Airport) tha t meet the 1 ton per year

current threshold of concern for lead. Several oth er facilities meet the 0.5 ton per year threshold being considered by U.S. EPA. The c losest of these facilities is

more than 25 miles from either island. In contrast to the mainland sources, no stationary source or general aviation airport that comes close to meeting the

lower threshold is found on either San Clemente Isl and or Santa Catalina Island.-3-

Given the rapid drop in lead concentration with dis tance from a source, the South Coast mainland facilities do not have any measurabl e impact on island

concentrations.

In September 1992, the South Coast District adopted Rule 1420, which is specifically aimed at reducing lead emissions from non-vehicular sources. Rule 1420 (Emissions Standard for Lead) applies to all facilities that use or process materials containing lead, including primar y or secondary lead smelters, foundries, lead-acid battery manufacturers or recyc lers, as well as facilities that produce lead-oxide, brass, and bronze. The South C oast District is planning to update Rule 1420 to be consistent with the revised federal lead standard. Therefore, the Rule will continue to be effective i n dealing with high, facility-related lead concentrations, and it forms the basis of the District’s lead attainment strategy.

Population Density, Degree of Urbanization, and Exp ected Growth

Similar to air quality and emissions, there are vas t differences between the population and degree of urbanization in the mainla nd and offshore portions of South Coast Los Angeles County. Based on estimates for 2010, the highly urbanized South Coast mainland portion of the Count y has a population of more than 10 million. The population of Santa Catalina Island is less than 5,000, while San Clemente Island, owned and operated by the Unit ed States Navy, is virtually uninhabited. This means that more than 99 percent of the population lives in the South Coast mainland portion of the County. In ter ms of size, the South Coast mainland portion of Los Angeles County is close to 20 times larger than both islands combined. However, the population density is 3,992 people per square mile, compared with about 50 people per square mile on Santa Catalina. Given

the limited size of Santa Catalina Island and the m ilitary function of San Clemente Island, this discrepancy in population between the mainland and island portions of South Coast Los Angeles County i s not expected to change.

Geography and Meteorology

Santa Catalina and San Clemente islands are isolate d areas surrounded by water. In contrast, the mainland portion of South Coast Los Angeles County is part of one of the nation’s largest metropolitan ar eas. Although an onshore/offshore air flow regime impacts both areas , the distance between the mainland South Coast portion of the County and the islands offshore precludes any significant contribution to lead concentrations from the mainland to the

islands.-4-

SUMMARY AND RECOMMENDATION

The mainland South Coast portion of Los Angeles Cou nty is distinctly different from the island portions of the County. The highly urbanized mainland South Coast portion is primarily a coastal area with a hi gh population density and a concentration of several lead-related processing fa cilities that have the potential to violate the federal lead standard. In contrast, the island portions of the County are sparsely populated areas that lack any notable lead emissions sources.

Because of these differences, the lead air quality problem in the South Coast mainland portion of the County is much more signifi cant. Even so, lead concentrations exceeding the federal standard are f ound only near lead-related

facilities. Lead measurements show these concentra tions decrease rapidly with distance from the source, and the transport of lead particles or pollutants from the South Coast mainland portion of the County to t he islands is not expected to occur. Although there are no physical barriers bet ween the mainland facilities and the offshore portions of the County, there is a significant distance (more than 25 miles). The heavy weight of lead particles and the quick decrease in

concentration with distance from the source make an y measurable offshore transport impact extremely unlikely.

In terms of air quality regulation, the South Coast portion of Los Angeles County, including both the mainland and island areas, falls under the jurisdiction of the South Coast AQMD. The District’s primary strategy for dealing with the high lead concentrations in the South Coast portion of the Co unty is their Rule 1420, which has been effective in reducing source-specific emis sions and resulting high concentrations. This strategy will continue to add ress violations of the federal

lead standard.

Based on the previous analyses, the Air Resources B oard recommends that

U.S. EPA limit the extent of the federal lead nonat tainment area to the mainland portion of Los Angeles County located in the South Coast Air Basin.