DOCS II is the second generation Digital Opacity Compliance System (DOCS) utilized for EPA Method 9 and EPA Method 22 for Visual Emissions Observation. DOCS II is developed by Virtual Technology, LLC located in Rio Rico, Arizona.

Plume opacity emission standards have been essential for decades in the enforcement of air pollution regulations at the federal, state and local level. Failure to adhere to these regulations is very costly, as violations of opacity limits for air permits result in fines as much as $25,000 per source, per day. The most common methods to monitor opacity levels is the EPA Method 9 and EPA Method 22.

Virtual Technology LLC was founded in 2006 by Shawn Dolan. Over his career, Mr. Dolan has been involved with many enterprise-level Environmental, Safety, and Occupational Health solutions known throughout the DoD. Mr. Dolan pioneered the concepts of integrating regional monitoring data with reported emissions data to find opportunities to reduce pollution.