(1) Odors or fugitive dust caused by agricultural activity consistent with good agricultural practices on agricultural land are exempt from the requirements of this chapter unless they have a substantial adverse effect on public health. In determining whether agricultural activity is consistent with good agricultural practices, the department of ecology or board of any authority shall consult with a recognized third-party expert in the activity prior to issuing any notice of violation.

(2) Any notice of violation issued under this chapter pertaining to odors or fugitive dust caused by agricultural activity shall include a detailed statement with evidence as to why the activity is inconsistent with good agricultural practices, or a detailed statement with evidence that the odors or fugitive dust have substantial adverse effect on public health.

(3) In any appeal to the pollution control hearings board or any judicial appeal, the agency issuing a final order pertaining to odors or fugitive dust caused by agricultural activity shall prove the activity is inconsistent with good agricultural practices or that the odors or fugitive dust have a substantial adverse impact on public health.

(4) If a person engaged in agricultural activity on a contiguous piece of agricultural land sells or has sold a portion of that land for residential purposes, the exemption of this section shall not apply.

(5) As used in this section:

(a) "Agricultural activity" means the growing, raising, or production of horticultural or viticultural crops, berries, poultry, livestock, shellfish, grain, mint, hay, and dairy products. "Agricultural activity" also includes the growing, raising, or production of cattle at cattle feedlots.

(b) "Good agricultural practices" means economically feasible practices which are customary among or appropriate to farms and ranches of a similar nature in the local area and for cattle feedlots means implementing best management practices pursuant to a fugitive dust control plan that conforms to the fugitive dust control guidelines for beef cattle feedlots, best management practices, and plan development and approval procedures that were approved by the department of ecology in December 1995 or in updates to those guidelines that are mutually agreed to by the department of ecology and by the Washington cattle feeders association or a successor organization on behalf of cattle feedlots.

(c) "Agricultural land" means at least five acres of land devoted primarily to the commercial production of livestock, agricultural commodities, or cultured aquatic products.

(d) "Fugitive dust" means a particulate emission made airborne by human activity, forces of wind, or both, and which do not pass through a stack, chimney, vent, or other functionally equivalent opening.

(6) The exemption for fugitive dust provided in subsection (1) of this section does not apply to facilities subject to RCW 70A.15.2200 as specified in WAC 173-400-100 as of July 24, 2005, 70A.15.2210, or 70A.15.2260. The exemption for fugitive dust provided in subsection (1) of this section applies to cattle feedlots with operational facilities which have an inventory of one thousand or more cattle in operation between June 1st and October 1st, where vegetation forage growth is not sustained over the majority of the lot during the normal growing season; except that the cattle feedlots must comply with applicable requirements included in the approved state implementation plan for air quality as of July 23, 2017; and except if an area in which a cattle feedlot is located is at any time in the future designated nonattainment for a national ambient air quality standard for particulate matter, additional control measures may be required for cattle feedlots as part of a state implementation plan's control strategy for that area and as necessary to ensure the area returns to attainment.

Legislative finding, intent—1981 c 297: "The legislature finds that agricultural land is essential to providing citizens with food and fiber and to insuring aesthetic values through the preservation of open spaces in our state. The legislature further finds that government regulations can cause agricultural land to be converted to nonagricultural uses. The legislature intends that agricultural activity consistent with good practices be protected from government over-regulation." [ 1981 c 297 § 29.]

Reviser's note: The above legislative finding and intent section apparently applies to sections 30 and 31 of chapter 297, Laws of 1981, which sections have been codified pursuant to legislative direction as RCW 70.94.640 and 90.48.450, respectively.

Severability—1981 c 297: See note following RCW 15.36.201.