Acid Rain Facts

Rain or other types of precipitation that contain elevated hydrogen ion levels, making it acidic, are referred to as acid rain. Elevated levels of hydrogen ions cause the rain to have a low pH, making it damaging to aquatic animals and plants and it can cause paint to peel and corrode steel buildings, bridges and stone sculptures. Acid rain develops when sulfur dioxide and nitrogen oxide emissions react with atmospheric water molecules and produce acid. Although the effects of pollution on structures were noted in the 1600s, the relationship between atmospheric pollution and the acid rain it produces was first brought to attention in 1852 in Manchester, England. Governments have been working since the 1970s to reduce these emissions and their efforts have had very positive results.

Interesting Acid Rain Facts:

1. Acid rain can also be produced from volcanic eruptions, burning coal and even rotting plant life.
2. Acid rain cannot rot your skin. It usually doesn't taste or smell any different than normal rain.
3. The sulfur dioxide and nitrogen oxide that creates acid rain can cause diseases such as cancer, asthma and even heart disease. It's a concern in the air, but not in the rain itself.
4. The acid in acid rain can damage a car's paint job, but it won't melt the car.
5. Acid rain can actually kill a forest. The acid rain can kill the leaves on the trees by cutting off their light and nutrient supply. It also changes the acidity in the soil, making it impossible for trees and other plant life to grow. It also poisons the soil and plant life.
6. When acid rain lands in the water such as streams, lakes and rivers, it changes the pH and makes the water toxic to the fish and other life in the water.
7. Entire lakes have been declared dead because of acid rain.
8. Acid rain has a pH of 4.3 while pure water is perfectly balanced at 7.
9. Acid rain has the same approximate pH as vinegar and orange juice.
10. Rain is not the only type of precipitation that can be called acid rain. Snow, fog, and even dust can contain the same damaging toxins as acid rain.
11. Acid rain can be neutralized the same way as acid can be. In some environments acid rain is more problematic. For instance, Eastern Canada lacks a natural alkalinity. Lime is able to neutralize acid, but there is no lime in the ground in some areas and because of this the acid rain is able to do more damage.
12. Sulphur dioxide, which is a major contributor to acid rain, is produced by burning fossil fuels and it is a by-product of many industrial processes.
13. A large amount of the acid rain that reaches Canada is the result of emissions in the United States.
14. Nitrogen oxide, a major contributor to acid rain, is produced by the exhaust from vehicles, from furnaces and other equipment. A large amount of Canada's nitrogen oxide emissions originate in the United States.
15. Despite major efforts to decrease acid rain, it is still killing lakes and aquatic life. 95,000 lakes in North America have been damaged by acid rain.

Reduce Pollution

What are S02, NOx, and CO2? How do they contribute to pollution?

    CO2: Carbon Dioxide is the principle "greenhouse gas" implicated in global warming. CO2 is released into the atmosphere as a result of burning fossil fuels such as coal, oil and natural gas. Coal is particularly dirty, producing about twice as much CO2 for the same amount of power as natural gas. CO2 is also generated in smaller amounts by forest clearing and cement production.

    NOx: Nitrogen oxides cause smog, irritate the lungs and lower resistance to respiratory infections such as influenza. Smog is formed when nitrogen oxides, which are emitted by burning fossil fuels at electric power plants and in automobiles, mix with other chemicals in the air, sunlight, and heat. The two largest sources of smog-forming pollution are motor vehicles (30%) and power plants (26%).

    The effects of short-term exposure to nitrogen oxides are still unclear, but continued or frequent exposure to concentrations higher than normal may cause increased incidence of acute respiratory disease in children. Nitrogen oxides are an important precursor to both ozone and acidic acid rain and can affect both land and water ecosystems.

    SO2: Sulfur dioxide comes from the combustion of fuel containing sulfur, mostly coal and oil. It is also produced during metal smelting and other industrial processes. The major health concerns associated with exposure to high concentrations of SO2 include effects on breathing, respiratory illness, alterations in the lungs' defenses, and aggravation of existing cardiovascular disease. While everybody is adversely impacted by SO2 to some degree, people that are particularly at risk include asthmatics and individuals with cardiovascular disease or chronic lung disease, as well as children and the elderly.

What is Global warming and why are greenhouse gas emissions raising the earth's temperature?

    Increases in concentrations of carbon dioxide and other pollutants contribute to global warming, which is predicted to raise average temperatures, alter precipitation patterns, and raise sea levels. These changes may negatively impact our quality of life, including increases in infectious diseases, respiratory illness, and weather-related deaths. Global warming may also decrease crop yields, water quality, and regional forest health and productivity. Atmospheric concentrations of CO2 have been increasing at a rate of about 0.5% per year and are now about 30% above pre-industrial levels.

How does SO2 create acid rain?

    Scientists have confirmed that sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain. Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. Sunlight increases the rate of most of these reactions. The result is a mild solution of sulfuric acid and nitric acid.

How much CO2 is removed by planting trees in the Michoacan forest of Mexico?

    Every tree planted in the monarch forest will remove an additional .29 tons of atmospheric CO2 over the next 42 years. This is calculated by dividing the net carbon increase of a 42 year-old mature forest (157 tons/hectare) by the average number of trees (2000) which equals .0785 tons C per seedling. Because it takes several tons of CO2 to make a ton of carbon, we converted C to CO2 by multiplying the carbon by 3.667: (3.667 x .0785 = .29 tons CO2).

Air Quality Issues of Electricity Production

What is acid rain?

The term "acid rain" is used to describe rain, mist or snow that is unusually acidic. A pH value is the measure of acidic or alkaline material. The lower the pH, the higher the acid reading. Rain and snow are naturally slightly acidic due to naturally occurring chemical reactions in the atmosphere. Compared to normal rainwater with a pH readings of 5.6, the Eastern U.S. suffers from some of the most severe acid rain, with levels typically reading at 4.4, though some locations in the west also face severe impacts.

The burning of fossil fuels generates air pollution that scientists have determined is the major cause of acid rain. Power plants, along with factories and vehicles that also burn fossil fuels, all emit sulfur dioxide (SO2) and oxides of nitrogen (NOx). When combined with moisture in the atmosphere, these pollutants are returned to the earth as acids. This process is known as "deposition" and occurs when it rains or snows, but it can also occur when dust settles out of the atmosphere during dry periods.

Acid precursors can be carried in the atmosphere for several days and travel several hundred miles downwind of the power plant stack before being deposited on the earth's surface. Because of prevailing winds, the northeastern United States and Canada receive significant quantities of acid precursors from coal-fired power plants in states stretching from Missouri to the west and Pennsylvania to the east.

What are the consequences of acid rain?

Acid rain is linked to a range of negative impacts on the natural world as well as human environments:

Aquatic impacts Scientists

believe that acid rain is responsible for the dramatic disappearance of brook trout and other fish species from pristine lakes and streams. These treasured water bodies receive acid directly from the atmosphere and from runoff from the surrounding watershed. Of the lakes and streams studied in a National Surface Water Survey conducted by the US Environmental Protection Agency, acid rain was determined to cause acidity in 75 percent of the acidic lakes and 50 percent of the acidic streams analyzed. Some lakes are particularly susceptible to acid rain since the underlying soil has limited ability to neutralize, or "buffer," the acids. Lakes suffering from chronic acidity can be found in several regions of the United States and Canada, including the Adirondacks, the mid-Appalachian highlands, the upper Midwest and the high elevation West.

Aquatic species vary in their tolerance to elevated levels of acidity. The acid interferes with reproduction much sooner in some especially sensitive species than with others. Generally speaking, acid rain fosters a shift in fish population from acid-sensitive to acid-tolerant fish and other aquatic plant and animal species.

Forest impacts

Acid rain may render intense impacts on the health of forest ecosystems. According to the National Assessment Precipitation Assessment Program's 1998 Biennial Report to Congress, the current mortality and decline of high elevation red spruce populations in the Northeast, and decline in growth rates for Appalachian red spruce, "are the only cases of significant forest damage for which there is strong scientific evidence that acid deposition is a primary cause." Nonetheless, several recent studies conducted by the United States Geological Survey and others point to acid rain as contributing to long-range damage to forests by depleting calcium, a nutrient vital to plant growth.

Materials

Acid rain affects many types of materials, from objects of particular historical artistic or cultural value -- buildings and monuments -- to more ordinary objects such as cars and trucks. Acid rain, especially in the "dry" form, corrodes metal, and accelerates the deterioration of stone and paint.

Visibility

Sulfur dioxide emissions reduce visibility when they form sulfate particles in the atmosphere. Visibility reductions are most pronounced in the eastern part of the United States, particularly in and around national parks. How does electricity production contribute to acid rain? Electricity generation accounts for the lion's share of air pollutants that spawn acid rain. Every year, the nation's fossil fuel power plants spew roughly 70 percent of SO2 emissions and 30 percent of NOx emissions that are critical ingredients in making acid rain.

Of course, not all power plants generate the same level of air pollutants contributing to acid rain. Emissions rates vary widely depending upon factors as the precise fossil fuel type used, the nature of the combustion process, pre- and post-combustion air emission controls, as well as vintage of the power plant. Older coal plants exempt from modern clean air standards under "grandfathering" provisions of the Clean Air Act (especially those designed to burn high sulfur content coal) are at one extreme and are the most significant source of acid rain pollutants. These power plants are highly concentrated in the Ohio Valley and Midwest. Given the prevailing winds, these older, largely uncontrolled pollution sources exacerbate the acid rain experienced in the Northeast.

On the other end of the spectrum are new natural gas-fired generation fitted with best available control technology. They release a fraction of the SO2 produced by coal-fired power plants. However, the performance of natural gas plants is decidedly more mixed in the area of NOx emissions, the other major precursor of acid rain. Although possible to mitigate NOx emissions using advanced technologies, many gas-fired power plants now in service use older, more polluting technologies.

How can consumer electricity choice address acid rain?

Competition in the electricity industry offers consumers for the first time the opportunity to directly influence the environmental footprint of electric power production. In several states, suppliers are assembling electricity resource portfolios that are significantly cleaner than the status quo. By selecting one of these resource portfolios, which boost the amount of renewable energy sources in the fuel mix, consumers can help ensure that the emissions of pollutants that cause acid rain are reduced. Consumers can send a powerful signal to electricity suppliers that they demand their supply not include power from older coal power plants exempt from the nation's federal air quality standards. These dirty power plants have increased their power production recently in response to wholesale competition. Between 1995 and 1995  a single Midwestern utility increased coal-fired generation by 10 percent, which increased its share of NOx emissions by over 50,000 tons. That increase in NOx emissions from a single utility surpasses the total NOx emissions from all fossil power plants operating in Massachusetts and New Hampshire combined.

Acid Rain Effect On Lakes and Aquatic Ecosystems

One of the direct effects of acid rain is on lakes and its aquatic ecosystems. There are several routes through which acidic chemicals can enter the lakes. Some chemical substances exist as dry particles in the air while others enter the lakes as wet particles such as rain, snow, sleet, hail, dew or fog. In addition, lakes can almost be thought of as the "sinks" of the earth, where rain that falls on land is drained through the sewage systems eventually make their way into the lakes. Acid rain that falls onto the earth washes off the nutrients out of the soil and carries toxic metals that have been released from the soil into the lakes. Another harmful way in which acids can enter the lakes is spring acid shock. When snow melts in spring rapidly due to a sudden temperature change, the acids and chemicals in the snow are released into the soils. The melted snow then runs off to streams and rivers, and gradually make their way into the lakes. The introduction of these acids and chemicals into the lakes causes a sudden drastic change in the pH of the lakes - hence the term "spring acid shock". The aquatic ecosystem has no time to adjust to the sudden change. In addition, springtime is an especially vulnerable time for many aquatic species since this is the time for reproduction for amphibians, fish and insects. Many of these species lay their eggs in the water to hatch. The sudden pH change is dangerous because the acids can cause serious deformities in their young or even annihilate the whole species since the young of many of such species spend a significant part of their life cycle in the water.

Subsequently, sulphuric acid in water can affect the fish in the lakes in two ways: directly and indirectly. Sulphuric acid (H₂SO₄) directly interferes with the fish's ability to take in oxygen, salt and nutrients needed to stay alive. For freshwater fish, maintaining osmoregulation is key in their survival. Osmoregulation is the process of maintaining the delicate balance of salts and minerals in their tissues. Acid molecules in the water cause mucus to form in their gills and this prevents the fish to absorb oxygen as well. If the buildup of mucus increases, the fish would suffocate. In addition, a low pH will throw off the balance of salts in the fish tissue. Salts levels such as the calcium (Ca⁺²) levels of some fish cannot be maintained due to pH change. This results in poor reproduction - their eggs produced would be damaged; they are either too brittle or too weak. Decreased Ca⁺² levels also result in weak spines and deformities. 

For example, crayfish need Ca⁺² to maintain a healthy exoskeleton; low Ca⁺² levels would mean a weak exoskeleton. Another type of salt N⁺ also influences the well-being of the fish. As nitrogen-containing fertilizers are washed off into the lakes, the nitrogen stimulates the growth of algae, which logically would mean an increase in oxygen production, thus benefitting the fish. However, because of increased deaths in the fish population due to acid rain, the decomposition process uses up a lot of the oxygen, which leaves less for the surviving fish to take in.

Indirectly, sulphuric acid releases heavy metals present in soils to be dissociated and released. For example, aluminium (Al⁺²) is harmless as part of a compound, but because acid rain causes Al⁺² to be released into the soils and gradually into the lakes, it becomes lethal to the health of the fish in the lakes. Al⁺² burns the gills of the fish and accumulates in their organs, causing much damage. So, although many fish may be able to tolerate a pH of approximately 5.9, this acid level is high enough to release Al⁺² from the soils to kill the fish. This effect is further augmented by spring acid shock. The effect of acid rain can be dynamically illustrated in a study done on Lake 223 which started in 1976. Scientists monitored the pH and aquatic ecosystem of Lake 223. They observed that as the pH of the lake decrease over the years, a number of crustaceans died out because of problems in reproduction due to the acidity of the lake caused by acid precipitation. At a pH of 5.6, algae growth in the lake was hindered and some types of small died out. Eventually, it was followed by larger fish dying out with the same problem in reproduciton; there were more adult fish in the lake than there were young fish. Finally, in 1983, the lake reached a pH of 5 and the surviving fish in the lake were thin and deformed and unable to reproduce. This case study obviously illustrates the significant effect of acid rain on lakes and its aquatic ecosystem.

The following is a chart which summarizes the effect of the pH level of the lake on its lifeforms.

pH LEVEL	EFFECTS
<6 font="">	*Basic forms of food die off. Eg. Mayflies and stoneflies are important food sources for fish. They can't survive at this pH level.
<5 .5="" font="">	*Fish cannot reproduce. *Young have difficulty staying alive. *More deformed adult fish due to lack of nutrients. *Fish die of suffocation.
<5 .0="" font="">	*Fish population die off.
<4 .0="" font="">	*Very different lifeforms, if any, from before.

The "safe" level of mercury in food has been set at about 0.05 parts per million. Indians and Eskimos in parts of Canada and the United States eat fish and seal meat with mercury levels as high as 15.7 and even 32.7 parts per million.

Fish, being one of the primary members of the food chain, is food for many other lifefoms, including hunans. Because toxic materials such as mercury are deposited in the fish due to acid rain, it is dangerous for humans to consume the fish. Like the domino effect, fewer fish can be sold as food, fishermen lose their hobby and people selling fishing supplies are affected. Amphibians are also affected; like the fish, they cannot reproduce in an acidic environment. The amphibian embyos have membranes that are too tough because of the acids, such that they are unable to break through at the proper time. So, they continue to grow, only to have deformed spines. They are then killed by a fungus that has been allowed to grow on their membranes. Hence, in essence, the effects of acid rain on lakes and its aquatic ecosystem are numerous and overwhelmingly magnified as we move down the food web.

In just ten years, from 1961 to 1971, Lumsden Lake in the beautiful Killarney region of Ontario, Canada, went to a pH reading of 6.8 to 4.4. That's an increase in acidity of more than 200 times. Most lakes with dropping pH values are at higher elevations. These lakes are usually small and located in watersheds where the rock and soil have a low neutralizing capacity.

Acid Rain

1. Washes minerals as calcium out of the soil and with the lack of these minerals, the trees and other plants are hurt. Impacts crop growth and soil structure. For optimum growth, many plants have a specific pH level and acid rain varies that number affecting the growth. Can also change the ionic balance in clayey soils, affecting structure.

2. At higher altitudes, trees are weakened by the acid in clouds and the mountaintops turn barren. A forest damaged by acid rain contains fewer niches for wildlife.

3. Acid is added to rivers and lakes, which in turn affects plants and fish in the water. Acidic water reduces the pH of water and impacts the health and breeding success of fish and aquatic invertebrates. Increases the metal amount in the water. 

4. Stone and metal is eaten away by acid so it is weathered more quickly than naturally.

5. Sulfur dioxide and nitrogen oxides (pollutants causing acid rain) are inhaled and causes an increase in heart, lung conditions, and premature death.

How is Acid Rain produced?

Acid rain is produced by a chemical reaction created when sulfur dioxide and nitrogen oxides are released into the air. When mixed with water, oxygen, and other chemicals from rising high into the atmosphere - Acid rain is formed. Sulfur dioxide and nitrogen oxides can be carried far by the wind and dissolved easily in water. As a result of being carried the compounds become rain, sleet, snow, and fog. The main reason these compounds are created is by humans. Electrical utility plants send out the majority of sulfur dioxide and much of the nitrogen oxides when fossil fuels (coal) are burned to produce electricity. Approximately 15 million tons of sulfur dioxide is pumped out each year, out of the 22 million tons in total generated annually by other human activities. Nitrogen oxides account for almost 30% of all acid deposition. Industrial processes, cars, trucks, and buses are also release a large number of nitrogen oxides and sulfur dioxide into the air. As nitric acid and sulfuric acid eventually fall back to Earth's surface as acid deposition  it falls as wet precipitation (rain, snow, or fog) or dry precipitation (gases or acidic salts).

When was Acid Rain first noticed?

Acid rain began entering the atmosphere during the Industrial Revolution and was first discovered by Robert Angus Smith (a Scottish chemist) in 1852. The relationship between acid rain and atmospheric pollution was discovered in that year in Manchester, England. Although discovered in the 1800s, acid deposition didn't gain public notice until the 1960s and it was coined "acid rain" in 1972. Harold Harvey was among the first that researched a "dead" lake. The public was noticing more and more in the 1970s when reports about problems in the Hubbard Brook Experimental Forest in New Hampshire was published in the New York Times. 

Where is Acid Rain most common?

Acid deposition is present in the northeastern United States, southeastern Canada, and much of Europe including areas of Sweden, Norway, and Germany, today. Portions of South Asia, South Africa, Sri Lanka, and southern India are in huge danger of becoming impacted by acid rain in the future. Acidification is occurring in the Adirondacks and Catskill Mountains in New York State, the Appalachians, the upper Midwest, eastern Canada, Scandinavia, parts of the United Kingdom, and mountainous areas in the western U.S.Today, acid deposition is present in the northeastern United States, southeastern Canada, and much of Europe including portions of Sweden, Norway, and Germany. In addition, parts of South Asia, South Africa, Sri Lanka, and Southern India are all in danger of being impacted by acid deposition in the future. The most acidic lake in the U.S. is Little Echo Pond in Franklin, New York, with a pH of 4.2. Over 90% of streams are acidic in the New Jersey Pine Barrens. 30% of streams and 70% of lakes are at risk in the mid-Appalachian region (severe enough to kill fish).

Does the world view Acid Rain as a major concern?

The world through EPA's eyes is a serious concern. EPA is doing everything they can to make sure everyone knows of the problems being dealt with because of acid rain. The problem with most of the world is that they're ignorant to the problem surrounding them. The world is not educated on the difficulties going on in the world around them, nor that we're trying to keep this problem from spreading to Australia. If more of the world knew about acid rain and how serious it actually is, many more would be doing their part in order to help out in solving this ever-spreading problem. Acid rain is dangerous, and needs to be viewed as a major concern, whether of not it actually is. 

What has the world done (if anything) to counteract the effects or production of Acid Rain?

1. Acid Rain Programs from congress:

Congress passed a law (the Clean Air Act Amendments of 1990) that stated that EPA should begin the Acid Rain Program. This program put limits on the amount of sulfur dioxide that power plants are allowed to release into the air and gave allowances to the power plants in order to cover their sulfur dioxide emissions. This also reduces the amount of nitrogen oxides allowed to be released from power plants. 

2. Reducing pollution:

Many different ways have been found by scientists in order to reduce the amount of sulfur dioxide being released from coal-burning power plants. One of the ways was to use coal that contains less sulfur. A second way was to "wash" the coal in order to remove amounts of the sulfur. Another  way was to install scrubbers which removes the sulfur dioxide from gases leaving the smokestack. And last, power plants are beginning to change the way they burn coal because nitrogen oxides are  created through the process of burning coal and other fossil fuels.

3. Using other sources of energy:

In order to reduce acid rain, renewable energy sources (solar and wind power), and items such as nuclear power, hydro-power  and geothermal energy can be used without burning fossil fuels. These renewable energy sources help to reduce acid rain by producing much less pollution. These sources can be used to power machinery and to produce electricity. Nuclear and hydro-power are used most widely in the U.S., as wind, solar, and geothermal energy have not been tested on a big enough scale to make them economically-feasible alternatives to fossil fuels. Natural gas, batteries, and fuel cells are also available to power automobiles as an alternative energy. 

4. Cleaner cars:

Being as cars and trucks are major sources of the pollutants that produce acid rain, something needed to be changed here. One car alone does not produce much pollution, but all the cars added together out on the road create tons. So, car manufacturers are required to reduce the amount of nitrogen oxides and other pollutants released from new cars. One new item of technology created is the catalytic converter which has been used for over 20 years to reduce nitrogen oxides released from cars. Cars are also beginning to use a cleaner fuel, such as natural gas. Cars labeled as low emissions vehicles are cars that produce less pollution and are better for the environment. There is a guide called EPA's Green Vehicle Guide used to determine which cars are low emissions vehicles. Tailpipe restrictions were tightened recently in order to help lower nitrogen oxides emissions. 

5. Restoring the environment:

Because of the deepening penetration into the fabric of the ecosystem caused by acid rain the chemistry of the soil, streams, and narrowing have been hugely changed. Since there have been so many changes it can sometimes take many years for these ecosystems to recover, even after the emissions have been reduced and the pH balance is restored to normal. It can take decades, or even centuries for acidified lakes, streams, forests, and soils to heal. But, in order to make this process faster limestone or lime can be added to acidic lakes to "cancel out" the acidity. The process (liming) has been majorly used in Norway and Sweden but not very often in the U.S. This process tends to be expensive and has to be a reoccurring thing in order to keep it to returning to the previous condition. It is only considered a short-term remedy in specific areas, rather than an effort to reduce/prevent pollution. The broader problems of changes in soil chemistry and forest health is not solved and it does nothing to help with visibility reductions, materials damage, and risk to human health. But liming can help to keep fish in a lake, allowing the population of fish around to survive in that area until the emissions are reduced in their area.

6. As individuals:

Acid deposition is caused by the cumulative actions of millions of individual people, therefore each individual can reduce their contribution to the problem. One can:

Turn off lights, computers, and other appliances when not being used.

Use energy-efficient appliances: lighting, air conditioners, heaters, refrigerators, washing machines, etc.

Only use electric appliances when needed.

Keep thermostat at 68 degrees in the winter and 72 degrees in the summer. When away from home lower the temperature in the winter and raise the temperature in the summer.

Insulate home

Carpool, use public transportation, walk, or bicycle.

Buy low emission vehicles and keep it maintained.

Be well informed.

Acid Rain and Ground Water pH

An important measure of water quality is its pH.   The letters (pH) describe the acidic or basic nature of a substance.  Scientifically a liquid’s pH is a measure of the concentration of hydrogen ions (H+ ) it contains.  The Danish biochemist S.P.L. Sorenson originally proposed the concept or the pH scale in 1909 as a method to describe the “acidity” of beer. 

The pH scale ranges from 0 to 14 with a value of 7 indicating a neutral pH (neither acidic nor basic].  Distilled water has a pH of 7.  Basic (or alkaline) solutions (i.e. bleach and ammonia) have values greater than 7.  Acidic solutions (i.e. battery acid, lemon juice, and vinegar) have values less than 7.  Each unit change in pH is equal to a 10-fold (10 times) change in the pH.  The table shows the approximate pH value for some common substances.

Rain and snow (the principal sources of ground water) have pH values near 5.6, if they are relatively free of pollution.  However, in many areas of the United States “acid rain” is now the norm because of pollution emissions from sources such as coal-fired power plants and car exhaust.  Acid rain can have pH values near 4.  There are concerns that acid rain is having effects on vegetation and aquatic fauna. Once on the ground, some of the acidic precipitation infiltrates downward to mix with ground water and can affect the ground water pH.  

The pH of ground water will vary depending on the composition of the rocks and sediments that surround the travel pathway of the recharge water infiltrating to the ground water.  Ground water chemistry will also vary depending on how long the existing ground water is in contact with a particular rock.  The chemical composition of the bedrock tends to stabilize (buffer) the pH of the ground water.  The longer the contact time, the larger the effect of the rock chemistry on the composition and pH of the ground water.  Ground water passing through carbonate-rich rocks (e.g., limestones and marbles) will usually have pH values greater than 7 as the acidic water is “neutralized.”  If the geology of the aquifer containing the ground water has few carbonate rocks (e.g., sandstones, metamorphic granitic schists and gneisses; volcanic rocks, etc.) the ground water will tend to remain acidic.

Acidity in water is not in itself harmful to health. Many popular beverages have considerable acidity or alkalinity. The concern for acidity in drinking water is that even mildly acid water can dissolve lead or copper that may in plumbing pies and fixtures.  In theory, there should be no lead content in homes built since 1987.  However for millions of homes there is the potential for a problem.  For this reason, the United States Environmental Protection Agency has determined that drinking water should have a pH between 6.5 and 8.5 in order to limit the concentration of dissolved contaminants from acidic waters or the build up of scale deposits from alkaline water.  

It is a good idea to test the pH when a new well is drilled (check again after six months of use), when you move to a new home, or if your well has never been tested.  If the pH is not within the EPA recommended range then it may be necessary to increase the pH of the water with limestone or marble chips or to reduce the pH with caustic soda (sodium hydroxide) treatments.  These treatments are not expensive, not difficult to maintain, and can be easily installed by a professional.  Test your water to make sure you actually need the pH adjusted before you install any equipment.

Acid Rain Various Effects

Acid rain is rain that contains nitric and sulfuric acid. Snow and fog can also contain nitric and sulfuric acid, and the dangerous effects are the same whether the acid is falling to the earth by rain or snow, or dancing in the air via fog. Any precipitation or dust particle that contains abnormal levels of sulfur dioxide and nitrogen oxides is considered acid rain. Acid rain primarily affects the United States, Europe, and China.

Acid rain directly affects the chemical and pH balances in ground water. The excess aluminum created by acid rain makes aquatic environments such as the sea, lakes, and streams, toxic. The animals that can withstand the imbalance of the water's natural minerals might survive, but quickly lose their food source as the weaker creatures die off. Animals that cannot withstand the chemical imbalances die, fail to reproduce, become deformed due to bone decalcification, or fail to grow normally. Algae growth is increased by acid rain, and rock scaling microbial and invertebrate herbivores lose habitation and die.

Acid rain leaches calcium out of the soil when it is absorbed by the earth. This directly affects the mineral levels of the soil and the creatures, such as snails, that rely on that calcium for shell growth. Consequently, snails die off and birds, which eat them for calcium, lay eggs with shells that are weak and brittle and therefore fail to hatch. Decreased calcium also creates excess aluminum in the soil, preventing trees and other plant life from absorbing water. Weakened plant life cannot tolerate extreme temperatures or fight off insects and disease.

Those seeking an expensive paint job on their car might want to think twice in areas directly affected by acid rain. The excess sulfur dioxide and nitrogen oxides in acid rain damages automobile paint and corrodes surfaces. It is believed that the acid rain causes the damage as it dries on, and evaporates from, the surface. Auto and paint coating manufacturers are trying to develop protective coatings that prevent acid rain corrosion.

Acid rain directly impacts forest ecosystems and their inhabitants. The damage to the forest trees and plants is widespread. Acid rain damages leaves as it falls. Acid rain runoff from the trees and forest floors infiltrates the forest's water supplies; runoff that doesn't enter the water supply is absorbed by the soil. The consequence of this is just as it is for any soil or water source infected with acid rain: the plants and creatures die off, and the creatures that rely on those plants and smaller creatures lose their food source and die, as well.

Plants and animals aren't the only victims of acid rain. Acid rain is dangerous to humans. The same sulphate and nitrate particles that directly affect the soil and water pH balances can cause serious damage to the respiratory system if inhaled deeply. A damaged respiratory system means decreased oxygen in the blood supply, which eventually damages the heart. Studies show an increase of chronic conditions, such as asthma and bronchitis, in people who are regularly exposed to acid rain.

Preventing acid rain is the only way to stop its deadly impact on the environment. Acid rain is caused by pollution. It is released into the air naturally during a volcanic eruption, but the primary cause of excess nitric and sulfuric acid in the environment is manmade. Conserving energy is the number one way humans can prevent acid rain. Using less energy at home decreases the need for power plants. People also need to get out of their car. Using public transportation, biking or walking to destinations leaves fewer cars on the road, less emissions in the air, and a decreased dependency upon fossil fuels. Finally, manufacturing plants can reduce the emissions that cause acid rain by using scrubbers to clean and remove the dangerous chemicals from the pipes before they are released into the air.