Overview
Prepare for and Comply with Air Emissions Residual Risk Ruling (2007-377)
Project Team:
- Concurrent Technologies Corporation (CTC)
- General Dynamics Bath Iron Works
- Puget Sound Naval Shipyard
- Atlantic Marine - Alabama
- Northrop Grumman Ship Systems
- General Dynamics NASSCO
- Norfolk Naval Shipyard
- BAE Systems Southeast Shipyards
- Northrop Grumman Shipbuilding
- Softek Systems
- Naval Surface Warfare Center - Carderock (NSWCC)
- Bollinger Shipyards
- Scientific Resources Associated
- Penn State University Applied Research Laboratory
- Kelley Drye Collier Shannon
- American Shipbuilding Association
- Shipbuilders Council of America
- ATC Associates
January 2007 - July 2008
NSRP ASE Investment: $668K
Industry Investment: $48K
Objective:
Prepare for cost-effective compliance with a future residual risk ruling.
Summary:
The Environmental Protection Agency (EPA) is currently examining the adequacy of the National Emission Standard for the shipbuilding and repair industry. If the EPA determines that existing standards fail to adequately protect human health and environmental quality, it will develop new risk-based standards, i.e., a Residual Risk Rule. With Concurrent Technologies Corporation as the lead, nine commercial and two Navy shipyards teamed to proactively engage in the rule making process to minimize the cost, production and organizational impact to commercial and Navy shipyards. To ensure consistency in emissions data reported to the EPA, the project team conducted a survey of the shipbuilding and ship repair industry, environmental regulators, consulting groups, and other related industries to determine how they calculated emissions from welding operations. Based on the research conducted during this project, the team recommended that shipyards use the equation listed in the AP42 (Compilation of Air Pollutant Emission Factors) to calculate emissions from welding. The team also evaluated commercial off–the-shelf welding emission control technologies applicable to a shipyard environment. Two weld fume control technologies were successfully demonstrated at Bath Iron Works and Atlantic Marine and evaluated for capture efficiency. The small, portable, low volume, high vacuum Miniflex was found to have a capture efficiency of approximately 60% with the EN20 nozzle fume capture attachment. The larger, but still portable, high volume, low vacuum Mobiflex 200-M was found to have a capture efficiency of approximately 95%.
A Hexavalent Chromium Study was conducted to evaluate the ratio of Cr(VI) to total Cr in weld fume and to determine the transformation rate of Cr(VI) to Cr(III) over a 24-hour period. The emission factors developed as a result of this study were compared to emission factors that were published in AP42 and to the emission factors that were developed and proposed by the EPA. As a result of this comparison, four of the seven developed emission factors were lower in terms of micrograms (μg) emitted per gram of electrode when compared to AP42. Additionally, 9 of the 12 developed emission factors were lower in terms of micrograms (μg) emitted per gram of electrode when compared to the EPA-proposed emission factors. The results from this study provided actual data, which can be used for future shipyard risk assessments. It is recommended that the methodologies and procedures developed during this study be leveraged for the evaluation of additional electrodes to develop a more comprehensive data set for the shipbuilding industry.
Key Deliverables:
Request Final Report from NSRP – Limited Distribution authorized to U.S. shipyards and NSRP ASE Program representatives
Point of Contact:
Tiffany Belz, Concurrent Technologies Corporation (CTC)