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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Naturally Occurring Asbestos

El Dorado Hills

Multimedia Exposure Assessment
Preliminary Assessment and Site Inspection Report Interim Final

El Dorado Hills Quick Finder
El Dorado Assessment Home 1.0 Introduction 2.0 Apparent Problem 3.0 Site Location, Description & History 4.0 Regulatory Involvement 5.0 Summary of Investigative Efforts 6.0 Hazard Ranking System Factors 7.0 Emergency Response Considerations 8.0 Summary Appendices References Acronyms Definitions Appendices & References


AAMS Ambient Air Monitoring Station

AHERA Asbestos Hazard Emergency Response Act

cc cubic centimeter

CARB California Air Resources Board

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information System

CoEMD El Dorado County Environmental Management Department

CSD El Dorado Hills Community Services District

DQO Data Quality Objective

DTSC California Department of Toxic Substances Control

E & E Ecology and Environment, Inc.

ERT Emergency Response Team

f/cc fibers per cubic centimeter

FSP Field Sampling Plan

HRS Hazard Ranking System

mg/m 3 milligrams per cubic meter

μ m micrometer or micron

NPL National Priorities List

NRA Northern Reference Area

PA preliminary assessment

PA/SI preliminary assessment/site inspection

PE performance evaluation

PCM phase contrast microscopy

PCME phase contrast microscopy equivalents

PLM polarized light microscopy

PPE personal protective equipment

QA quality assurance

QAO Quality Assurance Office

QAPP Quality Assurance Project Plan

QC quality control

SARA Superfund Amendments and Reauthorization Act

s/cc structures per cubic centimeter

SI site inspection

SOP standard operating procedure

SOW statement of work

SRA Southern Reference Area

START Superfund Technical Assessment and Response Team

STEL short-term exposure limit

TEM transmission electron microscopy

TWA time-weighted average

U.S. EPA U.S. Environmental Protection Agency


activity-based air sampling: Collecting air samples while engaging in dust generation activities (e.g., those that could disturb asbestos fibers and release them into the air).

ambient air: Generally, the surrounding air present throughout a vicinity. For the El Dorado Hills Naturally Occurring Asbestos Multimedia Exposure Assessment, ambient air is specifically defined as outdoor air (as opposed to indoor air) collected from the general vicinity of the various subject sites, and which may be used for reference samples. These samples may variably be upwind, downwind, or crosswind from locations that activity-based sampling scenarios are conducted, and they may or may not be influenced by sampling activities. In addition, some of the ambient air samples were collected under normal conditions (i.e., while no activity-based sampling was conducted).

amphibole: One of the two groups of minerals (serpentine and amphibole) that can crystallize as asbestos. The regulated asbestiform minerals of this group are crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos.

analytical sensitivity: The sample-specific lowest concentration of asbestos the laboratory can reliably detect.

asbestos: Asbestos is the generic name used for a group of naturally occurring mineral silicate fibers of the serpentine and amphibole series. Asbestos is composed of fiber bundles that are made up of extremely long and thin fibers that are easily separated from one another. For the purposes of this project, asbestos encompasses not only the six regulated varieties, but also the non-regulated asbestiform minerals.

asbestiform: Fibrous or tending to break into fibers.

aspect ratio: Length to width ratio.

breathing height: A height representing a typical height of a person = s nose/mouth area.

chrysotile: A regulated mineral in the serpentine group of minerals that can crystallize as asbestos. Chrysotile is also known as serpentine asbestos.

fixed sample pump: An air sample pump whose position is constant throughout the entire duration of the sampling effort. A fixed sample pump remains in its fixed location on a long-term basis over a period longer than 1 day. Typically a high-flow sample pump is used where a fixed sample pump is needed.

high-flow sample pump: Also known as a high-volume sample pump, this is an air sample pump that is capable of drawing up to about 30 liters per minute of air. This type of sample pump is not generally portable and is typically used for sampling from fixed and stationary positions.

hi-vol: Shorthand for high-volume or high-flow (sample pump).

infield skin: The non-grass infield area of a baseball or softball field; also commonly referred to as infield "dirt" or "base pad."

levels of personal protection: When sampling is conducted where contamination may exist, personal protective equipment (PPE) must be worn to prevent or reduce skin and eye contact, inhalation, and ingestion of the substance. Protective equipment to protect the body against contact with known or anticipated chemical hazards has been divided into four categories known as Levels A, B, C, and D:

  • Level A protection is worn when the highest level of respiratory, skin, eye and mucous membrane protection is needed. Level A protection includes a fully encapsulated suit for total skin, eye and mucous membrane protection and an SCBA for complete respiratory protection.
  • Level B protection is worn when the highest level of respiratory protection is needed, but a lesser level of skin and eye protection. Level B also generally includes everything used for Level D; and in addition includes appropriate chemical-resistant coveralls and gloves for dermal protection, and a full-faced mask and self-contained breathing apparatus (SCBA) or supplied air for eye protection and complete respiratory protection.
  • Level C protection is worn when the type of airborne substance is known, concentration measured, criteria for using air-purifying respirators (APR) met, and skin and eye exposure is unlikely. Level C generally includes everything used for Level D, with the addition of an APR or powered APR for inhalation protection.
  • Level D is primarily a work uniform and is used for nuisance contamination only. Level D generally includes basic work clothing with steel-toed and steel-shanked boots, and may include coveralls, a hard hat, gloves, ear plugs, and safety goggles.

naturally occurring asbestos: Asbestos minerals that occur in rock and soil as the result of natural geologic processes, often in veins near earthquake faults in the coast ranges and the foothills of the Sierra Nevada mountains and other areas of California.

personal sample pump: Also known as a low-flow or low-volume sample pump, this is an air sample pump that is portable so that it can be worn by a member of the sampling team during activity-based sample collection. The air flow for a personal sample pump is typically 1 to 5 liters per minute.

phase contrast microscopy (PCM): A light-enhancing microscope technology that employs an optical mechanism to translate small variations in phase into corresponding changes in amplitude, resulting in high-contrast images. This method was used traditionally to measure airborne fibers in occupational environments; however, it cannot distinguish between asbestos fibers and other fibers.

phase contrast microscopy equivalent (PCME): This refers to asbestiform structures identified through transmission electron microscopy (TEM) analysis that are equivalent to those that would be identified in the same sample through phase contrast microscopy analysis, with the main difference being that TEM additionally permits the specific identification of asbestos fibers. PCME structures are asbestiform structures greater than 5 microns in length having at least a 3 to 1 length to width (aspect) ratio.

polarized light microscopy (PLM): A microscope technology that uses the polarity (or orientation) of light waves to provide better images than a standard optical microscope.

reference sample: An ambient air sample from outside the specific area of concern collected concurrently with the activity-based samples; it is used as a reference for comparison with the activity-based air samples.

stationary sample pump: An air sample pump that is placed in a single location and is not moved during a sampling event. A stationary sample pump remains in its stationary location during one or more sample events. Typically a high-flow sample pump will be used where a stationary sample pump is needed.

transmission electron microscopy (TEM): A microscope technology that uses the properties of electrons to provide more detailed images than even polarized light microscopy.

ultramafic rock: An igneous rock containing mainly dark, ferromagnesian minerals (i.e., greater than 90% of olivine, pyroxene, or hornblende). Commercial deposits of asbestos have been associated with ultramafic rocks.

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