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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
(in order of use on this page)
  • 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.)
  • personal air sampler
    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.
  • stationary air sampler
    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.
  • fixed air sampler
    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.
  • ambient air
    Generally, the surrounding air present throughout a vicinity.
  • 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.
  • infield skin
    The non-grass infield area of a baseball or softball field; also commonly referred to as infield “dirt” or “base pad”
  • QAPP
    Quality Assurance Project Plan
  • FSP
    Field Sampling Plan
  • DQO
    Data Quality Objective
  • SOW
    Statement of Work
  • QAO
    Quality Assurance Office
  • ERT
    U.S. EPA’s Environmental Response Team

5.0 Summary of Investigative Efforts

5.1 Objectives

As part of the El Dorado Hills Naturally Occurring Asbestos Multimedia Exposure Assessment, the START (Superfund Technical Assessment and Response Team) collected outdoor air and soil samples to assist the U.S. EPA in identifying and estimating associated exposure levels for locations in El Dorado Hills where there is a potential for exposure to asbestos from disturbed areas of naturally occurring asbestos.

  • The START collected activity-based outdoor air samples from the Community Park, the New York Creek Nature Trail, and three schools in El Dorado Hills. This was to document whether and at what concentrations asbestos fibers were present in outdoor air during activities conducted at sampled locations on the days of sampling. Activity-based outdoor air samples were collected under conditions ranging from minimal activity to dust generation activities while members of the sampling team wore personal sample pumps. In addition, stationary air samplers were set up in and around the activity areas during most of the activity-based sampling.
  • The START also set up fixed air samplers at the Community Park and schools to collect ambient outdoor air samples collected from outside activity areas to serve as reference samples.
  • The START collected surface soil samples at the Community Park, the Dirt Embankment, the Dirt Parking Area and the schools to document whether and at what concentrations asbestos fibers were present in soil at sampled locations. At the baseball playing fields at the Community Park, where the infield skin is imported material, the START also collected shallow subsurface soil samples from at and below the inter­face of the infield fill and the soil beneath (down to about 1½ to 2 feet below ground surface).

5.2 Scope of Work

The U.S. EPA directed the START to develop a Quality Assurance Project Plan (QAPP) and Field Sampling Plans (FSPs), conduct ambient outdoor air sampling, activity-based outdoor air sampling, dust monitoring, soil sampling, meteorological data collection, video monitoring of fugitive dust present during out­door air sampling, and limited video documentation of the soil sampling. The START assisted the U.S. EPA with the project objectives planning, including the development of data quality related objectives using the U.S. EPA’s Data Quality Objective (DQO) planning process. The START developed the El Dorado Hills Naturally Occurring Asbestos, Multimedia Exposure Assessment, El Dorado Hills, California, Quality Assurance Project Plan based upon the DQO planning process and developed supporting FSP and analytical Statement of Work (SOW) documents.

The START conducted ambient and activity-based air sampling for asbestos fibers in outdoor air, real-time air monitoring to measure total dust, soil sampling for asbestos fibers, meteorological data collection, and video monitoring to document dust generation and sampling. For logistical reasons, the START did not conduct video monitoring of the soil sampling effort, but photographed many of the locations of soil samples collected for asbestos analysis. The START procured subcontractors as needed to aid in the collection of the air samples, preparation and analysis of samples, and validation of generated data. The U.S. EPA Quality Assurance Office (QAO) is over-seeing the data validation of the analytical results.

The START is using the Scribe data management system to man­age asbestos and meteorological data generated as part of the project. Scribe is a software tool developed by the U.S. EPA's Environmental Response Team (ERT) to assist in the process of managing environmental data.

5.3 Schedule

Outdoor air sampling activities began in late September 2004. The START conducted ambient air reference sampling between September 27 and October 12, 2004. The activity-based air sampling took place between October 2 and October 10, 2004. The START collected soil samples for asbestos analysis between October 8 and October 11, 2004.

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