To meet DoD requirements and support the U.S. military range sustainability initiative, ORAs are conducted to determine whether a release or substantial threat-of-release of MC exists from an operational range to an off-range area, if that release exceeds state or federal screening criteria, and if it creates a potentially unacceptable risk to human health or the environment.
ORAs are aimed at collecting and assessing relevant data in order to develop a conceptual site model for potential source-pathway-receptor interactions. The approach to an ORA is primarily a two-phase process, consisting of an initial qualitative effort (Phase I ORA) and, if necessary, a follow-up quantitative effort (Phase II ORA) if further analysis is required (i.e., media sampling is necessary in order to quantitatively assess the potential off-range migration and risks). If deemed necessary, a Phase III ORA effort may be recommended to evaluate corrective measures and remedial options for addressing the off-range MC migration and associated risks to human and ecological receptors.
In concert with the ORA, EA also provides Best Management Practice recommendations for range areas in order to reduce the potential for MC migration to off-range areas.
EA refers to the following points of guidance in addition to DoD Directive 4715.11 and DoD Instruction 4715.14:
- U.S. Army, ORA Guidance, April 2010
- U.S. Air Force, ORA Plan, Version 3.0, December 2011
- DoD Directive Number 3200.15, Sustainment of Ranges and Operating Areas, 10 January 2000 (Certified Current as of 21 November 2003)
- DoD Directive Number 4715.11, Environmental and Explosives Safety Management on Operational Ranges Within the United States, 10 May 2004
- DoD Directive Number 4715.14, ORAs, 15 November 2018
- U.S. Army, Memorandum – Operational Range Assessments, 28 July 2008
- Office of the Secretary of Defense, Memorandum – DoD-Regulator Interactions for ORAs, 15 August 2006
- Office of the Secretary of Defense, Memorandum – ORAs – Supplemental Guidance, 18 December 2007
- U.S. Army, Memorandum – Army’s Operational Range Assessment Guidance, 21 April 2010
- Technical Outreach Guidance for the Operational Range Assessment Program, 19 February 2008