Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 5/117)
Character Range: 358782–362133

and uncertainty. Variability arises from true heterogeneity in the environment such as lateral variations in soil properties or lithology or changes in contaminant levels over time and space. Uncertainty represents lack of knowledge about factors, such as contaminant levels (which may be reduced with additional investigation).

The identification of data gaps should be carried out in a logical, structured manner, to facilitate the assessment of uncertainty and the significance of those data gaps to the assessment objectives. Subsequent investigative efforts should be focussed on addressing the critical data gaps in a manner that is proportional to the uncertainties identified and results in data which is representative of the assessment area.

A tool for assessing gaps and uncertainties in CSMs and assessing their level of significance can be found in Clements et al. (2009).

Further information about developing CSMs can be found in:
    * API 2005, Collecting and interpreting soil gas samples from the vadose zone, API Publication no. 4741, American Petroleum Institute.
    * ASTM E1689–95  (2008), Standard guide for developing conceptual site models for contaminated sites, ASTM International.
    * ASTM E2531–06 (2006), Standard guide for development of conceptual site models and remediation strategies for light non-aqueous-phase liquids released to the subsurface, ASTM International.
    * Clements et al. 2009, Characterisation of sites impacted by petroleum hydrocarbons: guideline document, CRC CARE Technical Report no. 11, CRC for Contamination Assessment and Remediation of the Environment, Adelaide, South Australia.
    * Davis et al. 2009a, Field assessment of vapours, CRC CARE Technical Report no.13, CRC for Contamination Assessment and Remediation of the Environment, Adelaide, South Australia.
    * EA 2000a, Guide to good practice for the development of conceptual models and the selection and application of mathematical models of contaminant transport processes in the subsurface, NC/99/38/3,  Environment Agency, England and Wales.
    * ITRC 2009, Evaluating natural source zone depletion at sites with LNAPL, LNAPL-1, LNAPL Team, Interstate Technology & Regulatory Council, Washington, DC.
    * ITRC 2007a, Vapor intrusion pathway: a practical guideline, VI-1, ITRC Vapor Intrusion Team, Interstate Technology & Regulatory Council, Washington, DC.
    * ITRC 2007b, 'Vapor intrusion pathway: investigative approaches for typical scenarios', a supplement to Vapor intrusion pathway: a practical guideline, Technical and regulatory guidance supplement prepared by the ITRC Vapor Intrusion Team, Interstate Technology & Regulatory Council, Washington, DC.
    * NJDEP 2005b, Vapor intrusion guidance, New Jersey Department of Environmental Protection, (Available online at www.nj.gov/dep/srp/guidance/vaporintrusion/
      vig.htm).
    * ODEQ 2010, Guidance for assessing and remediating vapor intrusion in buildings, Report no. 10-LQ-007, Oregon Department of Environmental Quality, Portland, USA.
    * SA EPA 2009, Site contamination: guidelines for the assessment and remediation of groundwater contamination, Environment Protection Authority, Adelaide, South Australia.

    5                   Systematic planning for collection of environmental data

5.1              Introduction
It is recommended