13.46.120 Best management practices (BMPs) required.
A. Application. Existing development, current activities, and new development activities that are not listed in the exemptions of this section are required to apply storm water BMPs listed in the current Department of Ecology Storm Water Management Manual for Western Washington, Volume IV. A BMP not included in this manual may be approved by the director if the proponent demonstrates that it provides equivalent effectiveness. An exemption from the requirement to use BMPs does not provide an exemption allowing prohibited discharges.
B. Implementation. In applying the current Department of Ecology Storm Water Management Manual for Western Washington for existing development, the director shall first require the implementation of nonstructural source control BMPs. If these are not sufficient to prevent contaminants from entering surface and storm water or ground water, the director may require implementation of structural source control BMPs or treatment BMPs, using AKART.
C. Inspections. The city shall have the ability to inspect private property to monitor for proper implementation of storm water BMPs pursuant to AMC 13.46.340.
D. Exemptions. The following persons or entities are exempt from the provisions of this section unless the director determines the alternative BMPs to be ineffective at reducing the discharge of contaminants or activities are causing a prohibited discharge:
1. Persons implementing BMPs through another federal or state regulatory or resource management program; provided the director may perform inspections to ensure compliance with this chapter. If the other program requires the development of a best management practices plan, the person shall make that plan available to the city upon request;
2. Persons engaged in forest practices regulated under WAC Title 222, except for Class IV general forest practices as defined under Chapter 222-16 WAC; and
3. Persons conducting normal residential activities at property containing a single-family detached dwelling, duplex or triplex and modifications to it on a lot approved for such use, unless the director determines that these activities pose a hazard to public health, safety or welfare; endanger any property; or adversely affect the safety and operation of city rights-of-way, utilities, and/or other property owned or maintained by the county. (Ord. 1205-22 § 5, 2022).