Re: Another riding area bites the dust>> Mike this can't be so cause less sound = more ground and Cali has been
>> under the umbrella of 96db for a years now with riders spending all that
>> money on compliant exhaust systems.
>
> From what I'm reading, it's the EPA saying there is asbestos in the
> area and "it's not safe" to be there. A completely new tactic.
UGH!
Looking around the web:
"Where does asbestos come from?Asbestos minerals come from metamorphic
rocks. Significant deposits of asbestos are located in the western United
States. However, the mountains of North and South Carolina also have
extensive deposits of asbestos minerals. Some small deposits are found in
the Smoky Mountains of East Tennessee. There is currently no production of
asbestos in the United States. Most of the asbestos used here is imported
from Canada."
and some pictures of mines:
http :// www .health.state.mn.us/divs/eh/asbestos/#where1
getting specific about California:
from:
http :// pubs.usgs.gov/of/1995/ofr-95-0831/CHAP5.pdf
"Potential environmental considerations
(1) Most natural exposures of asbestos-bearing rock, particularly
serpentinite derived from ultramafic rocks, are
readily eroded by natural agents and the activities of man because most
serpentinite is composed of weak, highly
fractured rock; however, some serpentinite bodies are highly resistant to
erosion.
(2) Sedimentary deposits and debris slides derived from asbestos-bearing
rocks provide asbestos for redistribution
by water and wind.
(3) Vehicles driven across serpentinite and mine waste can dislodge
asbestos, adding it to dust or making it readily
available to surface drainage; roads also produce channels that aid run-off.
The surface area of roads in the southern
half of the chrysotile-bearing New Idria serpentinite in San Benito County,
Calif., exceeds the area disturbed by the
three largest asbestos mines in this area (Woodward-Clyde Associates, 1989).
(4) Waste generated from asbestos mining and milling operations exposes
asbestos to erosion by natural agents. The
U.S. Environmental Protection Agency (EPA) considers mine waste that
contains more than 1 volume percent
asbestos hazardous (Derkies, 1985, p. 4-34). The California Air Resources
Board considers asbestos contents of mine
waste greater than 5 volume percent as a potential toxic hazard (Resolution
91-27, April 1990).
(5) Asbestos fibers can be incorporated by surface drainage in areas of
asbestos-bearing rocks and mines. In central
California, water in the California Aqueduct System contains asbestos
(Kanarek and others, 1980; Coleman, in press).
However, the EPA has concluded that ingestion of asbestos fibers poses no
significant cancer risk (U.S.
Environmental Protection Agency, 1991).
(6) Chrysotile deposits may contain small amounts of fibrous tremolite,
which is classifiable by EPA as asbestos and
a risk to human health (U.S. Occupational Safety and Health Administration,
1975).
7) Health risks to humans from exposure to small quantities of chrysotile
asbestos in the environment are
controversial. The controversy results from the EPA assumption that any
amount of asbestos is potentially hazardous.
Oh, well, here you go:
http :// www .epa.gov/region09/toxic/noa/clearcreek/index.html
Introduction
Larger version | Closer look
The Clear Creek Management Area (CCMA) in San Benito and Fresno Counties is
located on one of the largest naturally occurring asbestos deposits in the
world. The rugged terrain overlaying this 31,000-acre serpentine deposit is
a popular and challenging riding spot for off-road motorcyclists. The
naturally barren slopes, bald ridges, chaparral and rare plants are also
enjoyed by rock collectors, botanists, hikers, hunters and campers,
including families with children. Thousands of visitors each year use
hundreds of miles of criss-crossing routes, a legacy of historic mining
activities in the area.
The CCMA is managed by the Department of the Interior's Bureau of Land
Management (BLM). Within the boundaries of the CCMA is the Atlas Asbestos
Mine Superfund site. In 1991, EPA signed the Record of Decision (ROD)
selecting the cleanup remedy for the Atlas Mine. In the ROD, EPA designated
the CCMA as one of four geographic areas that comprise the site, but did not
propose a cleanup action for the CCMA. Instead, EPA stated that it would
evaluate whether the BLM's plans for management of CCMA were adequate to
protect public health from exposure to asbestos found in the CCMA's soil and
air. BLM has designated the area as hazardous, and asbestos warning signs
are posted at entry points and on bulletin boards.
Map of study area.
Larger version
In 2004, as part of the evaluation of the Atlas Mine cleanup for possible
delisting of the site from the federal Superfund list, EPA initiated an
asbestos exposure and human health risk assessment for the CCMA. The goals
of the assessment were:
a.. To update the 1992 BLM Human Health Risk Assessment by using current
asbestos sampling and analytical techniques, and
b.. To evaluate risks to children because families are frequent visitors
to CCMA.