The RSIS governs in NJ as Trafficpro states. The ADT is 250 trips. Using the factor of 10.1 trips per single family home limits the total lots to 24. The length is dictated by the required zoning of the muncipality. If you want a copy the charge is $10.00 and write to New Jersey Department of...
Here in New Jersey the separation is 10ft. to a "Water Service Line,Pressure", for wells or suction lines its 100ft. and for a water course its 50 ft.