Acid Rain Study Reveals "Silent Killer"


Acid Rain Study Reveals “Silent Killer”

Acid Rain Study Reveals “Silent Killer”


10/23/2000 — — Contact: Leon Szeptycki, TU Environmental Counsel, (703) 284-9411

October 23, 2000. Charlottesville, VAWater samples collected by 250 Virginia anglers from the state’s mountain streams have revealed that the “Silent Killer,” known as acid rain, continues to eat away at the streams, endangering the brook trout, Virginia’s state fish. Results of the sampling released this morning indicated that while acid rain is slowing down, it is not being stopped.

The massive volunteer effort, which collected 452 water samples across the state in April of this year, was part of the Virginia Trout Stream Sensitivity Study (VTSSS 2000), conducted by the University of Virginia’s (UVA) Department of Environmental Sciences. The Virginia Council of Trout Unlimited (VCTU) coordinated the on-the-ground volunteer effort.

“Its like death by a thousand cuts,” said Leon Szeptycki, Trout Unlimited’s Environmental Counsel. “We now have thirteen years of state-of-the-art, scientific data indicating that Virginia streams continue to be slowly eaten away by acid rain.”

Szeptycki said that in spite of slight water quality improvements on a minority of the streams sampled, the research suggests that acidification continues to cause biological harm for most Virginia trout streams. He said the harm has caused Virginia conservationists to question whether the 1990 Amendments to the Clean Air Act (CAA) are enough to protect the delicate ecosystem.

“While the 1990 Amendments to the Clean Air Act may have slowed acidification, it appears they cannot provide enough protection to stop the biological damage caused by acid rain. These results confirm that we will continue to lose streams in Virginia.”

The April 2000 stream monitoring results, released today by scientists at UVA, re-examined 344 Virginia brook trout streams sampled in 1987 to determine changes that have occurred in acidity levels. In addition, the UVA scientists compared the 2000 water samples to 48 quarterly samples collected over 12 years from a geographically distributed subset of sixty streams included in the 1987 and 2000 survey. Based on this data, UVA concluded the following:

  • Acidification is continuing in most Virginia brook trout streams. Among 58 of the long-term monitoring stream for which 12 years of quarterly sampling data are available, acid levels had decreased in only 15 streams. Acid levels increased in the remaining 43 streams.
  • A comparison of the 1987 and 2000 surveys, read in conjunction with long-term data, suggest that the recent reduction in sulfur dioxide has slowed the overall decline of mountain streams. However, the number of Virginia’s acidic streams (those in which lethal or sublethal effects on brook trout are expected) has increased.

Most of Virginia’s brook trout streams possess a limited capacity to neutralize acid formed by nitrogen oxides and sulfur dioxide. Watersheds on limestone bedrock have virtually unlimited Acid Neutralizing Capacity (ANC), but watersheds with other types of bedrock eventually use up their ANC when subjected to continued acid deposition. As the ANC (which has been compared to “Tums” in the soil) is used up, watersheds are subjected to “acid pulses” during rainstorms and snowmelt — water too acidic for the stream to neutralize quickly– that, in turn, kills trout and other fish, as well as insects and other components of the ecosystem. An apparently healthy stream can deteriorate rapidly once its ANC is used up.

Szpepycki said the loss of the St. Mary’s River 15 years ago to acid rain damage motivated many of the Trout Unlimited volunteers and others participating in the study. Located in the George Washington National Forest, this pristine river experienced dramatic losses of aquatic insects and trout. While pollution was the suspect, the cause was not as obvious to the eye as a chemical spill or pipe spewing sludge into the river. Instead, fishery biologists revealed that the St. Mary’s blue ribbon trout fishery had fallen prey to acid rain.

Acid rain is caused primarily by the burning of fossil fuels, such as coal, in power plants. The emissions from those fuels result in a reaction high in the atmosphere where the chemicals bind with moisture, creating a solution of sulfuric acid and nitric acid that then falls to earth as rain or snow.

The Clean Air Act Amendments of 1990 were designed to reduce acid rain by reducing emissions. However, a loophole in amendments allowed many older plants to be exempted from the stricter emissions standards because many believed those plants would be closed by now. However, most of these plants have exceeded their life expectancy and continue to operate without applying modern clean air standards. Although Congress failed to reauthorize the Clean Air Act in 2000, both the inability of the 1990 Amendments to provide enough protection to stop acid rain and the loophole are expected to be debated when the Act is revisited.

The Clean Air Act Amendments of 1990 include provisions for periodic measurements to evaluate the effectiveness of mandated emission reductions. The U.S. Environmental Protection Agency and the National Park Service funded VTSSS 2000. The study contributes critical and scientifically credible data that will help evaluate current environmental standards and whether the Clean Air Act Amendments of 1990 provide enough protection for acid-sensitive watersheds in western Virginia.

View the results of the VTSSS study.

Learn more about acid rain.

Trout Unlimited is the nation’s leading coldwater conservation organization with125,000 members and 500 chapters nationwide working to conserve, protect and restore trout and salmon watersheds throughout North America.

Date: 10/23/2000