Washington State rules on construction and maintenance of regulated recreational water facilities such as swimming pools, spas, water parks, and wading pools. Regulated facilities include pools at athletic or private clubs, municipal or park facilities, hotels, motels, apartments, condominiums, mobile home parks, RV parks, and homeowner association communities.
Pool operators need to be properly trained in water chemistry and mechanical components to effectively maintain pools. You can find resources for pool owners and operators at the Department of Health Water Recreation Facilities page.