Single-family homes and townhouses — Multipurpose fire sprinkler systems.
RCW 57.02.100
in effect(1) A water-sewer district may not prohibit the use of multipurpose fire sprinkler systems that are part of a structure's plumbing system for single-family homes and townhouses as defined by the state residential building code or require a separate water meter or backflow preventer for the multipurpose fire sprinkler system. (2) For the purposes of this section, "multipurpose fire sprinkler system" means a fire sprinkler system that: (a) Is supplied only by the purveyor's water; (b) Does not have a fire department pumper connection; (c) Is constructed of approved potable water piping and materials to which sprinkler heads are attached; and (d) Terminates at a connection to a toilet or other plumbing fixture to prevent stagnant water.
(1) A water-sewer district may not prohibit the use of multipurpose fire sprinkler systems that are part of a structure's plumbing system for single-family homes and townhouses as defined by the state residential building code or require a separate water meter or backflow preventer for the multipurpose fire sprinkler system.
(2) For the purposes of this section, "multipurpose fire sprinkler system" means a fire sprinkler system that:
(a) Is supplied only by the purveyor's water;
(b) Does not have a fire department pumper connection;
(c) Is constructed of approved potable water piping and materials to which sprinkler heads are attached; and
(d) Terminates at a connection to a toilet or other plumbing fixture to prevent stagnant water.
Source: WA Statutes (Official Site)URL: https://app.leg.wa.gov/RCW/default.aspx?cite=57.02&full=trueFetched: 6/29/2026