(1) In addition to the requirements of Parts 1 through 5 of chapter 246-290 WAC, Subpart B of Part 6 of chapter 246-290 WAC applies to purveyors of systems using surface or GWI sources and providing filtration, including:

(a) Systems with water treatment facilities that produced water served to the public before January 1, 1991;

(b) Unfiltered systems installing filtration, once the new water treatment facilities are online; and

(c) New systems using surface or GWI sources. For the purpose of the Part 6 chapter 246-290 WAC requirements, new systems are defined as systems first serving water to the public after December 31, 1990.

(2) The purveyor of a new system using a surface or GWI source shall comply with the requirements of Part 6 subparts A and B chapter 246-290 WAC and be subject to the treatment technique violations specified in WAC 246-290-632 beginning when the system first serves water to the public and thereafter.