The board shall hold meetings regularly at least twice each month and shall designate the time and place thereof. The board shall adopt its own rules of procedure and keep a record of its proceedings. All meetings, records and accounts of the board shall be public. Three (3) members shall constitute a quorum for the transaction of business. Members of the waterworks board shall be persons of business experience and shall not be less than thirty (30) years of age, citizens of the United States, and for five (5) years immediately preceding their election, residents of such city.