The proposal is to raise the application rate for total nitrogen from 106 to 150 kg/ha/y to the area of irrigated trees on the tree farm. Inquiry under s46 into changes to Ministerial Statement 287.
The original proposal, assessed in 1992, calculated nitrogen loadings in the wastewater applied to the grass bays and the irrigated trees at the wastewater disposal site. The projected loadings were based on the wastewater treatment plant being upgraded to reduce nitrogen concentrations in the wastewater in 2000, when volume flows were projected to increase. The upgrade of the wastewater treatment plant has not occurred, resulting in higher concentrations of nitrogen in the wastewater than originally allowed for and larger tonnages per year of nitrogen going to the wastewater disposal site.