Program Will Seek To Reverse Acid-rain Damage

Local lakes damaged by acid rain may benefit from a new program that aims to examine ways to restore Adirondack lakes and streams.

The Adirondack Acid Rain Recovery Program will look for new approaches to reversing the damage caused by acid-rain pollution, which affects hundreds of Adirondack water bodies.Acid rain is caused when air emissions of sulfur dioxide and nitrogen oxides, generated predominately by coal-fired power plants, interact in the atmosphere to form acid compounds that fall back to earth as acid rain.

The Adirondacks are particularly sensitive to acid rain. When acid rain falls on the Adirondacks, it acidifies forest soils, which reduce growth and survival of tree species. It also acidifies lakes and other water bodies, which can kill fish and water organisms or affect their growth.Some of the lakes in the area that have been affected severely by acid rain include Big Moose Lake, Brooktrout, Bellows, Stewart, Nine Corner and Jockeybush lakes.

Not all those lakes are to the point where they are lifeless because of acid rain, but the drop in pH levels have created problems for the marine life living there."Acid rain doesn't actually start doing a lot of damage right away; it takes a long time for the effects to accumulate, so places where the soil is the thinnest, you will notice the damage first," Sheehan said.He said to combat acid rain in the 1980s and '90s, lime and limestone was used to decrease the acidity of lakes. However, he said this also had a negative effect because it can make certain plants toxic to mammals.

"It is not good to just start spreading lime all over the forest in an effort to neutralize acid rain," Sheehan said. "Some of the things that were effective that I think this program can build on was placing limestone in the inlet streams to major lakes and ponds so that the water coming in will have a higher pH than it normally would. In other cases, placing lime on a frozen lake surface during the winter time also helped [lower acidity]."He said pollution is decreasing because of federal regulations on coal plants and automobiles."Pollution input is decreasing, and that is the first step you have to take in order for programs like this to really make a difference," Sheehan said. "The quicker we can get chemical recovery in the waters, the quicker we will see biological recovery. Once the pH levels are reduced to a livable level, some of the plants and life we had in the water will begin to return."

Sheehan said although acid rain won't hurt people swimming, it can contaminate fish with mercury, and if ingested after being caught, it can create serious health problems.Acid rain also can hurt the ability of maple trees to reproduce and destroy the commercial value of timber land, Sheehan said.Funding for the new program was obtained by the attorney general's office in a multi-state settlement with Cinergy Corp., now Duke Energy Corp., over violations of the federal Clean Air Act.

A news release said in addition to providing funds for the program, the settlement required Cinergy to control pollution.The program is intended to jump-start research projects for reducing the effects of acid rain pollution and advancing recovery in the Adirondacks."As progress is made in reducing acid-rain pollution, hundreds of lakes and streams in the Adirondacks are still struggling to recover from this pollution," Schneiderman said in the news release.Acid rain has decreased significantly in recent years as a result of federal and state efforts to limit air pollution, but parts of the Adirondacks have been slow to recover.

Simulating the Effects of Acid Rain

Materials Required:
 - Bottle of Vinegar (1/2 cup per group)
- Chalk (two to three pieces per group)
- Zip lock bags (2 per group)
- Droppers (2 per group)
- Plates (2 per group)
- Tap water (1/2 cup per group) 

Procedure:  

• Place one piece of chalk in each pan.
• Using the dropper drip vinegar onto the chalk on one of the plates in a constant stream.
• Using the dropper drip water onto the chalk on the second plate in a constant stream. 

Scientific Explanation: 

Acid rain is caused mostly by the combustion of fossil fuels containing sulfur and nitrogen. When sulphur and nitrogen are combusted, sulphur dioxide and nitrogen oxides are created and released into the atmosphere. Once these gases come in contact with water they become acids (Sulphuric acid and Nitric acid). This can happen either through wet deposition when rain, sleet or snow remove the gases from the air or through dry deposition when particles are deposited and absorbed into surfaces and later converted into acids when they come into contact with water. Coal power plants, electricity generation, driving a car, volcanoes and thunderstorms all contribute to acid rain. While there are natural causes of acid rain as mentioned, 90% of harmful emissions are a result of man-made sources. Acidity of rainwater is measured by the pH scale. It ranges from 0 which is highly acidic to 14 which is highly alkaline (basic). The scale point 7 is neutral. Clean rain measures at pH 5.6 while acid rain is anything measuring between pH 5 and pH 0. Acid rain has an adverse effect on the natural environment including forests, freshwaters and soils. It not only kills insect and aquatic life forms but also causes damage to buildings and has impacts on human health. Acid rain destroys the surface of trees and depletes essential nutrients in the soil greatly impacting plant germination and reproduction, causing vulnerability to disease and stunting its growth. It increases the level of acidity in water sources which inhibits the ability for natural mechanisms to cope. Gradually the most fragile creatures and life forms begin to die. Lastly, acid rain damages buildings through corrosion and fracturing.
 

Great structures such as the Taj Mahal and the Washington Monument buildings have all suffered the harmful effects of acid rain. Buildings made of limestone are particularly impacted.
In order to mimic the effect of acid rain on the environment specifically on rock (limestone) we used vinegar and chalk. It may take a considerable amount of time to see the visible effects of acid rain yet the reaction of vinegar and chalk is instant and illustrates the same concept. The reaction of vinegar and chalk is an example of an acid- base reaction (neutralization). Vinegar, the acid, has a pH level of 3 while the chalk also known as calcium carbonate is a base at pH 8. When they are combined the chalk starts to bubble and foam up. The acid breaks apart the calcium carbonate and produces calcium and carbon dioxide gas. The bubbles you see during the reaction are carbon dioxide. On the surface of the vinegar are small pieces of chalk which have been neutralized.

Acid Rain In Canada

Not all areas of Canada are affected equally by acid rain.This is because areas differ in their ability to offset or neutralize acidity. This is largely determined by the type and rate of weathering of the soils and bedrock in the region.A region’s underlying bedrock (the geologic deposit from which a soil is derived by weathering) is the most important factor on how sensitive an area will be to acid rain. Alkaline substances, such as calcium, magnesium and potassium (known as “base cations”), are found in the earth’s bedrock and soil.

 In essence, when an acid and a base combine, they cancel each other out, producing a neutral substance. When the rain is only mildly acidic, there are enough alkaline substances to balance the acidity and neutralize the effects on the soil and water. However, when the rain is highly acidic, these acid-buffering substances can become depleted. There may not be enough of them to continually offset the acid effect of the rain. When nature can no longer buffer the effect, the balance is lost. This is what has been slowly happening for the past 100 years in the natural environment due to acid rain. The areas most affected by acid rain are those with shallow soil cover on slowly weathering bedrock (since beneficial alkaline substances are released as the bedrock is weathered by incoming rain). 

For example, igneous bedrock (e.g., the granite bedrock of the Canadian Shield that covers almost half of Canada) has a very low alkaline content and, therefore, can’t buffer the effects of acid rain. On the other hand, regions that are formed on limestone or sedimentary bedrock (e.g., southern Ontario and parts of western Canada), which contain high levels of calcium, can tolerate fairly high acidic deposits over long periods of time. Limestone is very alkaline, and so it can maintain an acceptable balance despite increased acidity.