2012 Ocean Ranger Guidebook Revision 3-7-12 - Alaska ...

2012 Ocean Ranger Guidebook 3-7-12
In 2011 ADEC and its opacity contractor took 235 Method 9 readings of large and
small cruise ships and ferries. CPVEC also receives public complaints regarding cruise ships and
ferries. Eleven complaints were received in 2011. CPVEC also received 33 self-reports of excess
emissions (under 18 AAC 50.240) from cruise ships.
Ocean Rangers are not trained to perform opacity readings but have contributed
significantly to the cruise programs opacity monitoring by reporting cases of heavy smoke, soot,
and equipment failures. They have also documented many operators effectively and
successfully minimizing emissions to meet the opacity limits.
Opacity is a surrogate for air pollution. There are many types of air pollution, such as
oxides of nitrogen, sulfur, and carbon, particulates, volatile organic components, and
carcinogens. While it would be more difficult to measure all of these parameters, visible opacity
is used to
General opacity background information:
Opacity is the reduction of transmitted light caused by particles, mists, or gases. It can
be caused by partially burned fuel or ash from the combustion processes. Opacity was originally
measured using the Ringelmann scale which used grids to compare to the opacity of the smoke.
It only worked well with black smoke, and was replaced with EPA Method 9. The Ringelmann
method did introduce the 20% limit, which was based on increasing the efficiency of
combustion. The idea was that over 20% would show incomplete combustion.
Method 9 is a visual method that requires training and certification. The method
contains requirements that are designed to reduce potential bias. Because of the requirements
for angles and distances from the stack it would be difficult to have Ocean Rangers perform
opacity readings onboard. More information on opacity readings can be found in the reference
part of this section.
Subsection 1: Opacity (Visible Emissions); Air Quality
Job Aid Item: 4.1.a
Text: Stack emissions are minimized and monitored. Operational (combustion) procedures in place.
(18 AAC 50.070)
Background: Cruise Ships in Alaska often monitor air emissions using opacity meters (Continuous
Opacity Monitoring System (COMS)) and with visual checks by video camera located on the stack or in
person. Most ships have procedures on keeping emissions below the regulatory limit.
Please note that opacity meters can be useful onboard, but may not match the visible opacity as there
are many factors including calibration, equipment error, and levels alarms are set at.
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