UB our lab was doing NAP/NAGs 20 years ago. It was the standard...

UB our lab was doing NAP/NAGs 20 years ago. It was the standard measure of acid producing potential. We also did sulphur and sulphate percentage as this also indicated how much SO4 can be produced over time. The interesting thing is these soils can not be allowed to dry out as once they start to oxidise they will continue oxidising even under water due to REDOX reactions (exchange of electrons - reduction/oxidation). This happened in the 50's in Cairns when they drained East Trinity. Up until recently at the start of every wet season there would be a flush of acid and heavy metals directly into the inlet resulting in fish kills. Once REDOX reactions begin they can't be easily stopped. Can then only try to neutralise the acid produced with lime, but massive amounts of lime would be needed as the acid potential of these silts and soils is great. The best plan of attack is to rebury these silts before the reactions begin. Notice how NAG said they will only take PASS and not ASS. ASS would require continuing treatment and monitoring well into the future and would be far more expensive to treat.