Evaluation of the Digital Opacity Compliance System at military and commercial industrial sites

Abstract

AbstractThe U.S. Environmental Protection Agency (EPA) has established EPA Reference Method 9 (Method 9) as the preferred enforcement approach for verifying compliance with federal visible opacity standards. The costs associated with maintaining Method 9 certification, including tuition fees, attendee's travel, and the three days of missed work every six months, supports the claim that the Method 9 program is expensive. Beyond the economic burden associated with Method 9 certification, its reliance on human observers to quantify visible opacity is inherently subjective, a characteristic that exposes the results to claims of inaccuracy, bias, and/or outright fraud.The Digital Opacity Compliance System (DOCS) has been proposed as a scientifically defensible alternative to Method 9. Field application of the DOCS at military and commercial industrial facilities has demonstrated that the accuracy of the DOCS in measuring plume opacity is not only comparable to Method 9–certified human observers but that the DOCS also provides a permanent digital image of the plume that can be easily referenced in challenging enforcement actions. © 2004 Wiley Periodicals, Inc.