N.J. Stat. § 58:14-13
The cost of the construction of said sewer, plant and works shall in the contract be apportioned to the respective contracting municipalities in such proportion as the taxable property, real and personal, within so much of the municipality so contracting as is embraced in the sewerage district bears to the total amount of taxable property, real and personal, within so much of all the municipalities so contracting as is embraced within the sewerage district, as returned and certified by the respective taxing boards and taxing officers of the municipalities for the year one thousand nine hundred and seven. For said purpose, all taxable property, real and personal, shall be assessed at its true value and each assessor, taxing board and taxing officer for the several municipalities so contracting shall examine, compute and determine, and certify to the commissioners on or before the first day of October, one thousand nine hundred and seven, the amount of taxable property, real and personal, assessed for the year one thousand nine hundred and seven to and upon persons and property within so much of the several municipalities so contracting as lie within the district. The books of each of said assessors, taxing boards and taxing officers shall at all times be open for examination to the commissioners and to the contracting municipalities, and their officers and agents, for the purpose of examining, checking and verifying said certificates.
N.J.S. § 58:14-13