WAC 173-433-110
Opacity standards.
    
(1) A person shall not cause or allow emission of a smoke plume from any solid fuel burning device to exceed an average of twenty percent opacity for six consecutive minutes in any one-hour period.
(2) Statewide opacity standard. An authority shall not adopt or enforce an opacity level for solid fuel burning devices that is more stringent than the statewide standard.
(3) Test method and procedures. Methods and procedures specified by the EPA in "40 CFR 60 Appendix A reference method 9 - VISUAL DETERMINATION OF THE OPACITY OF EMISSIONS FROM STATIONARY SOURCES" as amended through July 1, 1990, shall be used to determine compliance with subsection (1) of this section.
(4) Enforcement. Smoke visible from a chimney, flue or exhaust duct in excess of the opacity standard shall constitute prima facie evidence of unlawful operation of an applicable solid fuel burning device. This presumption may be refuted by demonstration that the smoke was not caused by an applicable solid fuel burning device. The provisions of this requirement shall:
(a) Be enforceable on a complaint basis.
(b) Not apply during the starting of a new fire for a period not to exceed twenty minutes in any four-hour period.
(5) Education. Any person or retailer providing information on the operation of solid fuel burning devices, such as brochures, demonstrations, and public education programs, should include information that opacity levels of ten percent or less are attainable through proper operation.
http://apps.leg.wa.gov/WAC/default.aspx?cite=173-433-110
(broken link removed to http://www.pscleanair.org/actions/woodstoves/law.aspx)
	
		
			
		
		
	
				
			Opacity standards.
(1) A person shall not cause or allow emission of a smoke plume from any solid fuel burning device to exceed an average of twenty percent opacity for six consecutive minutes in any one-hour period.
(2) Statewide opacity standard. An authority shall not adopt or enforce an opacity level for solid fuel burning devices that is more stringent than the statewide standard.
(3) Test method and procedures. Methods and procedures specified by the EPA in "40 CFR 60 Appendix A reference method 9 - VISUAL DETERMINATION OF THE OPACITY OF EMISSIONS FROM STATIONARY SOURCES" as amended through July 1, 1990, shall be used to determine compliance with subsection (1) of this section.
(4) Enforcement. Smoke visible from a chimney, flue or exhaust duct in excess of the opacity standard shall constitute prima facie evidence of unlawful operation of an applicable solid fuel burning device. This presumption may be refuted by demonstration that the smoke was not caused by an applicable solid fuel burning device. The provisions of this requirement shall:
(a) Be enforceable on a complaint basis.
(b) Not apply during the starting of a new fire for a period not to exceed twenty minutes in any four-hour period.
(5) Education. Any person or retailer providing information on the operation of solid fuel burning devices, such as brochures, demonstrations, and public education programs, should include information that opacity levels of ten percent or less are attainable through proper operation.
http://apps.leg.wa.gov/WAC/default.aspx?cite=173-433-110
(broken link removed to http://www.pscleanair.org/actions/woodstoves/law.aspx)
 
	 
	 
 
		 
 
		 
 
		 
 
		 By the way, the regs specifically take condensed water vapor plumes out of the equation (i.e. detached plume).  Opacity can be read out of a 6" stack with no problem.  But imagine the nightmare instantly created for state EPA inspectors if they were suddenly faced with inspecting every wood-fired boiler
  By the way, the regs specifically take condensed water vapor plumes out of the equation (i.e. detached plume).  Opacity can be read out of a 6" stack with no problem.  But imagine the nightmare instantly created for state EPA inspectors if they were suddenly faced with inspecting every wood-fired boiler 
 
		 
 
		 
 
		
 
 
		