La. Stat. tit. 33 § 3690.8
The amounts assessed in the said local or special assessment ordinance shall be due and collectible immediately on its passage, and if not paid within ten (10) days from the date of publication of said ordinance, it will be conclusively presumed that any property owner whose property is affected thereby exercises the right and option, which is hereby authorized, to pay the amount due in equal semi-annual installments bearing interest at a rate not exceeding 6% per annum, payable semi-annually, and amortized over a period not exceeding two years, as provided for in the said local or special assessment ordinance and within the discretion of the Jefferson Parish council. The first installment shall become due on December 31st of the then current year and subsequent installments shall become due semi-annually thereafter. The failure to pay any installment or the interest thereon when due shall ipso facto cause all other installments and the interest thereon to become due and payable, and the Jefferson Parish council may within 30 days from the date of each default proceed, by an action either in rem against the property or in personam against the owner, or both, for the collection of the total amount due, including interest and 20% additional on principal and interest as attorney's fees.
La. R.S. § 33:3690.8