PDFWAC 51-50-3109
Section 3109—Swimming pools, spas and other water recreation devices.
3109.1 General. The design and construction of swimming pools, spas and other aquatic recreation facilities shall comply with the International Swimming Pool and Spa Code, where the facility is one of the following:
1. For the sole use of residents and invited guests at a single-family dwelling;
2. For the sole use of residents and invited guests of a duplex owned by the residents; or
3. Operated exclusively for physical therapy or rehabilitation and under the supervision of a licensed medical practitioner.