Lime treatment reverses acid rain effects
You can’t always believe what you see. The water in our mountain streams is sometimes polluted even though it appears crystal clear. And sometimes what looks like pollution is actually fighting the effects of pollution.
Acid rain looks just like regular rain. It occurs when rainwater falling through the sky picks up tiny pollutants like atmospheric sulfur from industrial plants. When acid rain makes its way into streams, it increases the acidity of the water, which can be harmful to fish.
Jason Farmer, U.S. Forest Service fisheries biologist, was part of a team that reversed the effects of acid rain on streams in the Upper Santeetlah watershed. Just like a gardener in Western North Carolina adds lime to naturally acidic soils, Farmer added limestone to neutralize the acidity of stream water. The streams were monitored to check the pH, a scale of acidity.
“After adding limestone to Sand Creek and Wolf Laurel Branch, our monitoring showed that pH levels were restored to pre-industrial conditions. This will help sustain a healthy population of brook trout, the only trout native to Western North Carolina,” said Farmer, who works on the Cheoah Ranger District of the Nantahala National Forest.
Farmer also monitored the physical attributes and fish and aquatic salamander habitat of the stream channel after liming and found no negative effects.
This was a cooperative project between the U.S. Forest Service and North Carolina Wildlife Resources Commission. It received significant financial assistance from the Tennessee Valley Authority and Duke Energy.
Farmer’s efforts recently earned him the North Carolina Council of Trout Unlimited President’s Award for Outstanding Work.
“We were impressed by this outside-the-box but simple common-sense solution,” said Rusty Berrier, NCTU’s National Leadership Representative. “The potential to fight acid deposition by targeting it just before it hits the stream — sort of like setting the hook right before the take — both struck a chord with us and is an example of the kind of work Jason has consistently presented at almost every meeting I’ve attended.”