To assist in planning the network of stock truck effluent disposal sites for the North Island, the NSEWG and Transit NZ (now the NZ Transport Agency) commissioned a study of livestock-carrier truck-movements.  The analysed data fed into the subsequent decisions on placement of disposal facilities.  Although stock movements will have changed over the intervening years, the 2003 Modelling Report from the study remains the primary source for data relating to livestock and stock effluent movements in the North Island.

As the current stock truck effluent disposal facilities are all located on state highways, the New Zealand Transport Agency has provided maps of the existing sites and of those under development or proposed for disposal facilities.

These maps are current as at June 2015.  See Map of Disposal Facilities.  See Map of Disposal Facilities being planned