Is there any scientific evidence or are there any health studies available that show that a 20% opacity limit is too high to be sufficiently protective of human health?  I think that this type of evidence should be the basis for a regulatory change of this nature rather than out of concern or just because other states have set a lower opacity standard. 

 

Is there any scientific evidence or air quality studies available that show that lowering the Virginia Opacity Standard from 20% to 10% opacity will result in a significant improvement in air quality.  I think that this type of evidence should be the basis for a regulatory change of this nature rather than out of concern or just because other states have set a lower opacity standard. 

 

Won't there be upcoming PM2.5 regulations that will address the issue of fine particulate emissions.  If so, then no reason to also lower the opacity standard. 

I urge the SAPCB to consider the financial burden that Virginia industry may have to bear to meet stricter opacity regulations.  Many existing sources in Virginia have permitted opacity limits above 10% and would likely have to install additional air pollution control equipment to meet a 10% opacity standard.  An analysis of the financial burden should be considered.

 

If the SAPCB does pursue a regulatory change to lower the Virginia opacity standard for existing sources from 20% to 10% , I suggest that there be some sort of "grandfathering clause" for existing sources that have permitted opacity limits above 10%.  For example, an older diesel emergency generator or diesel fire pump engine (with permitted 20% opacity limit) would likely not be able to meet a 10% opacity limit and would either have to be replaced with a brand new diesel engine or retrofited with some type of particulate filter.  Again, financial burden that should be analyzed before changing opacity standard.