Washington Revised Code Title 80. Public Utilities § 80.28.050. Tariff schedules to be filed with commission--Public schedules

Every gas company, electrical company, wastewater company, and water company shall file with the commission and shall print and keep open to public inspection schedules in such form as the commission may prescribe, showing all rates and charges made, established or enforced, or to be charged or enforced, all forms of contract or agreement, all rules and regulations relating to rates, charges or service, used or to be used, and all general privileges and facilities granted or allowed by such gas company, electrical company, wastewater company, or water company.