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NEWS RELEASE · 30th April 2015
Northwest Institute

VICTORIA – 3rd Floor 747 Fort Street, Victoria BC V8W 9V1

Days two and three (April 28-29) of the hearings included witness testimony on the effects of acid rain on forests and on Rio Tinto Alcan’s (RTA’s) dispersion modeling. Rock Ouimet, the Quebec government’s expert on the effects of acid rain on forests, provided a critique of Rio Tinto Alcan’s reports on this topic. He made three main points:

1. When assessing the effects of acid rain, it is essential to know how much acid rain is going to fall and the neutralizing capacity of the soil. The criterion that RTA chose to balance acidification versus neutralization would only protect the roots of the trees, notthe long-term fertility of the soil. Therefore, although trees could look healthy according to RTA’s criterion, a reduction in soil fertility would impede future tree growth—which would have implications for the forestry industry—and increase susceptibility to collateral damage such as insect attacks.

2. RTA used simplified models to determine soil neutralizing capacity. For example, theyused a uniform 50 cm depth of soil over the Kitimat Valley despite the fact that many soils there are much shallower.

3. RTA used average values for their parameters used to predict the post-KMP acidification and neutralization of various sites. By using average values, the long-term harm to those sites that receive above average acidification is not considered.

The witness for April 29, Douw Steyn, a renowned meteorologist, provided very persuasive testimony that cast doubt on the approach that RTA’s analysis took to measure pollutant dispersion and determine what the predicted impacts would be.

April 28 – 29, 2015 Witnesses:

• Rick Ouimet, Quebec Natural Resource Ministry

• Douw Steyn, Meteorologist, UBC Department of Earth, Ocean and Atmospheric Sciences (Dr. Steyn also provided testimony on April 27)