You are here: EPA Home Region 10 Air Page SIPs/SWCAA SIPSWCAA400040 

SIP - SWCAA - Section 400-040 

SWAPCA 400-040 GENERAL STANDARDS FOR MAXIMUM EMISSIONS

All sources and emissions units are required to meet the emission standards of this section. 

Where an emission standard listed in another section is applicable to a specific emissions 

unit, such standard shall take precedent over a general emission standard listed in this 

section. When two or more emissions units are connected to a common stack and the 

operator elects not to provide the means or facilities to sample emissions from the individual 

emissions units, and the relative contributions of the individual emissions units to the 

common discharge are not readily distinguishable, then the emissions of the common stack 

must meet the most restrictive standard of any of the connected emissions units. Further, all 

emissions units are required to use reasonably available control technology (RACT) which 

may be determined for some sources or source categories to be more stringent than the 

applicable emission limitations of this regulation or any chapter of Title 173 WAC. Where 

current controls are determined to be less than RACT, the Authority shall, as provided in RCW 

70.94.154, define RACT for each source or source category and issue a rule or regulatory 

order requiring the installation of RACT. 

(1) Visible emissions. No person shall cause or permit the emission for more than three 

minutes, in any one hour, of an air contaminant from any emissions unit which at the 

emission point, or within a reasonable distance of the emission point, exceeds twenty percent 

opacity as determined by certified observer in accordance with EPA Method 9 "Visual 

Determination of the Opacity of Emissions from Stationary Sources" as specified in 40 CFR 60 

Appendix A except: 

(a) When the emissions occur due to soot blowing/grate cleaning and the operator can 

demonstrate that the emissions will not exceed twenty percent opacity for more than 

fifteen minutes in any eight consecutive hours. The intent of this provision is to permit 

the soot blowing and grate cleaning necessary to the operation of boiler facilities. This 

practice, except for testing and trouble shooting, is to be scheduled for the same 

approximate times each day and the Authority shall be advised of the schedule. 

(b) When the owner or operator of a source supplies valid data to show that the 

presence of uncombined water is the only reason for the opacity to exceed twenty 

percent. 

(c) When two or more sources are connected to a common stack, the Authority may 

allow or require the use of an alternate time period if it is more representative of 

normal operations.

(d) When an alternate opacity limit has been established per RCW 70.94.331 (2)(c).

(2) Fallout. No person shall cause or permit the emission of particulate matter from any 

source to be deposited beyond the property under direct control of the owner(s) or operator

(s) of the source in sufficient quantity to interfere unreasonably with the use and enjoyment 

of the property upon which the material is deposited.

Region 10: the Pacific Northwest

Last updated on Saturday, March 12th, 2011.

URL: http://yosemite.epa.gov/r10/airpage.nsf/SIPs/SWCAA/SIPSWCAA400040

SIP - SWCAA - Section 400-040 Page 1 of 3

http://yosemite.epa.gov/r10/airpage.nsf/f3f22921988a261b882569e5005ee8bb/929313db2... 3/15/2011
(3) Fugitive emissions. The owner or operator of any emissions unit engaging in materials 

handling, construction, demolition or any other operation which is a source of emission: If 

located in an attainment area and not impacting any nonattainment area, shall take 

reasonable precautions to prevent the release of air contaminants from the operation. 

(a) If the emissions unit has been identified as a significant contributor to the 

nonattainment status of a designated nonattainment area, shall be required to use 

reasonable and available control methods, which shall include any necessary changes 

in technology, process, or other control strategies to control emissions of the 

contaminants for which nonattainment has been designated. 

(4) Odors.

(a) Any person who shall cause or allow the generation of any odor from any source, 

which may unreasonably interfere with any other property owner's use and enjoyment 

of his property must use recognized good practice and procedures to reduce these 

odors to a reasonable minimum.

(b) A scentometer No. 1 odor strength or equivalent dilution in residential and 

commercial areas shall not be exceeded.

(c) A scentometer No. 3 odor strength or equivalent dilution in all other land use areas 

shall not be exceeded.

Scentometer Readings

Scentometer Concentration Range

No. No. of Thresholds

0 1 to 2

1 2 to 8

2 8 to 32

3 32 to 128

4 128

(d) A violation of this section shall have occurred when two measurements made 

within a

period of one (1) hour, separated by at least fifteen (15) minutes, off the 

property 

surrounding the air contaminant source exceeds the scentometer limitations set

hereunder.

(e) When the source is a manufacturing process, no violation of this section shall have

occurred provided that Best Available Control Technology (BACT), Maximum

Available Control Technology (MACT), or Lowest Achievable Emission Rate

(LAER), as applicable for odor control and abatement, is provided and is 

operating in

compliance with other applicable regulations and emission limits.

(f) When the source is using "good agricultural practices", as provided in RCW 

70.94.640, no violation of this section shall have occurred.

(5) Emissions detrimental to persons or property. No person shall cause or permit the 

emission of any air contaminant from any source if it is detrimental to the health, safety, or 

welfare of any person, or causes damage to property or business. 

(6) Sulfur dioxide. No person shall cause or permit the emission of a gas containing sulfur 

dioxide from any emissions unit in excess of one thousand ppm of sulfur dioxide on a dry 

basis, corrected to seven percent oxygen or twelve percent CO2 as required by the applicable 

emission standard for combustion sources, and based on the average of any period of sixty 

consecutive minutes except: 

(a) When the owner or operator of an emissions unit supplies emission data and can 

demonstrate to the Authority that there is no feasible method of reducing the 

concentration to less than one thousand ppm (on a dry basis, corrected to seven 

percent oxygen for sulfur dioxide will not be exceeded. In such cases, the Authority 

may require specific ambient air monitoring stations be established, operated, and 

maintained by the owner or operator at mutually approved locations. All sampling 

results shall be made available upon request and a monthly summary shall be 

SIP - SWCAA - Section 400-040 Page 2 of 3

http://yosemite.epa.gov/r10/airpage.nsf/f3f22921988a261b882569e5005ee8bb/929313db2... 3/15/2011
submitted to the Authority. 

(b) When a source limits such emission by a combination of constant emission controls 

and dispersion techniques approved by the Authority. 

(7) Concealment and masking. No person shall cause or permit the installation or use of 

any means which conceals or masks an emission of an air contaminant which would 

otherwise violate any provisions of this section. 

(8) Fugitive dust sources.

(a) The owner or operator of a source of fugitive dust shall take reasonable 

precautions to prevent fugitive dust from becoming airborne and shall maintain and 

operate the source to minimize emissions. 

(b) The owner(s) or operator(s) of any existing source(s) of fugitive dust that has been 

identified as a significant contributor to a PM10 nonattainment area shall be required to 

use reasonably available control technology (RACT) to control emissions. Significance 

will be determined by the criteria found in SWAPCA 400-113(3). 

State effective: 9/21/95; EPA effective: 4/28/97

SIP - SWCAA - Section 400-040 Page 3 of 3

http://yosemite.epa.gov/r10/airpage.nsf/f3f22921988a261b882569e5005ee8bb/929313db2... 3/15/2011