Assessments shall be due and payable at such time as is fixed by the water pollution control authority, provided no assessment shall become due until the work or particular portion thereof for which such assessment was levied has been completed, except that when the work or particular portion thereof for which such assessment was levied is being performed by the water pollution control authority pursuant to an order of the Department of Energy and Environmental Protection, the entire assessment may be made due and payable, provided the portion of the total work bonded by the water pollution control authority, which directly benefits the particular property has been completed. The water pollution control authority shall give notice of the date when assessments are due and payable by publication at least twice within a period of fifteen days in a newspaper having a general circulation in the municipality and shall mail a copy of such notice to the owners of the property assessed at their last-known addresses. Such notice shall list the streets and describe the area within which are located any properties against which such assessments are due. No assessment shall be due and payable earlier than thirty days after the first publication of such notice.