(1) An adequate supply of cool drinking water must be made available to all employees wherever they may be working.

(2) Drinking water must meet all standards of the Washington state department of health.

(3) Containers used to furnish drinking water must meet all specifications of the Washington state department of health and must be sterilized as often as necessary to assure a sanitary water supply.

(4) The common drinking cup is prohibited.

(5) Cross-connections between potable and nonpotable water supplies are prohibited. Nonpotable water supplies must be clearly labeled as not fit for drinking or washing.