"We will go in on an area-by-area approach over the country. But it's a national plan and what we really ask Government is that, if we land this plan, we go hand-and-hand with Government on a national approach rather than a multi-council approach.
"Because the multi-council approach is going to kill us and it's going to kill growth because you have different debates all over the country and you need national ownership here."
Fonterra projections based on the 3 per cent compound average growth rate of the NZ milk pool over the past decade - and a projection of 2 per cent annual growth for the next seven years - suggest an extra 2.5 billion litres will be produced annually by 2020.
Spierings is upfront about some big and potentially controversial questions which need to be decided:
How much of the additional milk will come from greater productivity? Where will more land conversions take place? Where there should be higher stocking rates and whether higher stocking should be discouraged in some areas because the environment cannot take it.
He notes the environmental challenge is real, but maintains there is a "big risk" of sub-optimal outcomes from non-strategic local and regional interventions.
The Fonterra plan will spell out that dairy farmers supplying the co-operative have to be on top of effluent management to eliminate discharges to fresh water, ensure 100 per cent stock exclusion from waterways, reduce the nutrient leaching risk and use water more efficiently.
Every farm supplying Fonterra will be assessed every year and environment improvement plans will be agreed where needed. The final sanction is non-collection of the milk.
"We are very open but in order to supply Fonterra you need to step up. The farmers know it is coming," says Spierings.
"We are looking at each and every farm on effluent management. That is happening and at the end of the year we should be over 95 per cent stock exclusions."