La. R.S. 33:4114

Said certificates shall be sold by the sewerage and water board at public sale at not less than par and accrued interest after advertisement for bids published in two daily newspapers in New Orleans and one in New York, New York at least once a week for four successive weeks and awarded to the best responsible bidder. They shall bear interest at a rate not exceeding six percent per annum. Such certificates shall mature in not less than ten nor more than fifteen equal annual installments beginning not more than one year from their date, but the sewerage and water board may in said certificates reserve an option to redeem them prior to maturity at such time or times and in such manner as it shall determine.