(1) For real property having a rate category of light, moderate, heavy, or very heavy, the rate category shall be reduced one category if the storm water runoff discharges into an on-site storm and surface water management facility built to comply with the detention and water quality regulations and standards set forth in chapter 30.63A SCC, and said facility is adequately operated and maintained by the property owner.

(2) For real property located in the surface water management utility district, if all or any portion of the real property is regulated by a valid and active permit issued by the Washington State Department of Ecology or the federal Environmental Protection Agency pursuant to the National Pollutant Discharge Elimination System (NPDES) permit program established by the federal Clean Water Act, codified at 33 U.S.C. § 1251 et seq., then the portion of the annual service charges imposed pursuant to this chapter under authority of chapter 36.89 RCW shall be reduced by 35 percent. This rate adjustment shall not be available to real property that is a right-of-way owned by a municipality, the county, or the state subject to the rates provided in SCC 25.20.070(2) or (3). The property owner requesting a rate adjustment under this subsection (2) shall provide the director with sufficient documentation to verify that the real property at issue is subject to a valid NPDES permit. The property owner shall also provide the director with written notice promptly upon the expiration of or other termination of coverage under the NPDES permit.

(3) Public and private schools that provide water quality or watershed instruction approved by the director shall be given credit equal to the dollar value of the instruction offered. This credit shall be applied against the annual service charge billed under the authority of chapter 36.89 RCW. This annual credit shall not exceed the annual service charge authorized by chapter 36.89 RCW.

(4) Pursuant to RCW 85.38.160, real property within diking, drainage, or flood control districts shall be given a credit equal to the dollar value of the annual special district assessment. This credit shall be applied against the annual service charge billed under the authority of chapter 36.89 RCW. This annual credit shall not exceed the annual service charge authorized by chapter 36.89 RCW. (Added by Amended Ord. 15-069, Nov. 16, 2015, Eff date Jan. 1, 2016; Amended by Ord. 17-008, Mar. 29, 2017, Eff date Apr. 10, 2017; Amended by Amended Ord. 17-020, July 5, 2017, Eff date July 21, 2017; Amended by Ord. 18-089 § 3, Nov. 19, 2018, Eff date Dec. 8, 2018; Amended by Amended Ord. 22-042, Nov. 23, 2022, Eff date Dec. 10, 2022; Amended by Ord. 23-019, Apr. 12, 2023, Eff date Apr. 22, 2023).