Major Water Problems

Date: 2015-10-07; view: 443.

Even though North America has a lot of water (only the Great Lakes, contain 18% of the Earth's fresh water), some areas in this region often ran short of water. The drier areas of the Western United States often have a lack of water; areas of the Canadian prairie are also very dry. Because there is so much water, it is quite cheap, this causes people to use water more often. Because people are using water more often, the large resource is being threatened, leading to public concerns.

About 1/5 of all Americans receive water from an area that does not meet the requirements of water quality. Pollutants commonly found in water are: bacteria, copper, lead and other toxic chemical substances.

There are three chief sources of water pollution. These sources are (1) industrial wastes. (2) sewage, and (3) agricultural chemicals and wastes.

Industrial wastes. United States industries discharge pollutants that include many toxic chemicals. Industries discharge much chemical waste directly into natural bodies of water. In addition, the burning of coal, oil, and other fuels by power plants, factories, and motor vehicles releases sulfur and nitrogen oxides into the air. These pollutants cause acid rain, which enters streams and lakes. High levels of mercury have been found in fish far from industrial areas.

Some industries pollute water in yet another way. They use large quantities of water to cool certain equipment. Heat from the equipment makes the water hot. The industries then discharge the hot water into rivers and lakes, heating those bodies of water. Such heating that harms plants or animals is known as thermal pollution.

Sewage. Most of the sewage in the United States goes through treatment plants that remove solids and such dissolved substances as the nutrients, nitrogen and phosphorus. About 25 percent of the households of the United States use septic tank systems, which pass the sewage through tanks and filter it through leaching fields into the land. Some sewage in the United States still goes untreated directly into waterways or the ocean. However, government regulations control the amount and the quality of the discharge.

Agricultural chemicals and wastes. Water from rain or melted snow flows from farmland into streams, carrying chemical fertilizers and pesticides that farmers have used on the land. Animal wastes also can cause water pollution, particularly from feed lots with many animals. Cattle, hogs, sheep, and poultry raised on feed lots do not distribute their wastes over widespread pastureland. Instead, much of their wastes runs off into nearby streams. Water used for irrigation also may be polluted by salt, agricultural pesticides, and toxic chemicals on the soil surface before it flows back into the ground.

Effects

Human illness. Water polluted with human and animal wastes can spread typhoid fever, cholera, dysentery, and other diseases. About 80 percent of the U.S. community water supplies are disinfected with chlorine to kill disease-causing germs. However, disinfections does not remove harmful chemical compounds, such as polychlorinated biphenyls (PCB's) and chloroform, or harmful metals, such as arsenic, lead, and mercury. The careless release of such toxic wastes, primarily into waste dumps, threatens ground water supplies. PCB's, chloroform, and pesticides have been found in some municipal drinking water. Scientists are concerned that drinking even small quantities of these substances over many years may have harmful effects.

Reduced recreational use. Pollution prevents people from enjoying some bodies of water for recreation. For example, odors and floating debris make boating and swimming unpleasant, and the risk of disease makes polluted water unsafe. Oil spilled from ships or offshore wells may float to shore. It can kill water birds, shellfish, and other wildlife. Water pollution also affects commercial and sport fishing. Fish can be killed by oil or by a lack of oxygen in the water, or they may die because of a reduction in the quantity and quality of their food supply. Industrial wastes, particularly PCB's, also harm fish.

Disruption of natural processes. Various natural processes that occur in water turn wastes into useful or harmless substances. These processes use oxygen that is dissolved in the water. Water pollution upsets these processes, mainly by robbing the water of oxygen.

In 1974, the U.S. Congress passed the Safe Drinking Water Act to protect the nation's public water supply against pollution. This act authorized the Environment Protection Agency (EPA) to establish uniform quality standards for more than 200,000 public systems throughout the United States. The standards were designed to reduce the amount of harmful bacteria, chemicals, and metals in drinking water. The EPA and the state governments began to enforce the standards in 1977. The Safe Drinking Water Act was amended in 1986 and 1996 to further improve the quality of drinking water. Among the many changes were provisions to improve methods to detect and kill certain disease-causing microorganisms.

Important progress has been made in other areas of pollution management. Industrial waste, sewage, fertilizers, and other contaminants have polluted the Great Lakes since the mid-1800's. By the early 1970's, Lake Erie, Lake Ontario, and shallow regions of Lake Huron and Lake Michigan were so polluted that the waters had turned green and smelled foul, and huge fish kills were common. In 1972, Canada and the United States signed the Great Lakes Water Quality Agreement. Since then, local governments around the lakes have improved sewage treatment plants, controlled the runoff of chemical fertilizers from farms, and worked to reduce the use of phosphate detergents. They have also forced industries to reduce the pollutants they dump into the lakes. Today, the Great Lakes are much cleaner.

Major Land Problems. Waste Disposal

In the USA, the population of people who are agriculturalists has decreased in the progression of history. To this day half the land in the United States is still used for agriculture.

North America has many land problems. They range from poor land usage and poor farming practices, erosion, soil contamination to other forms of land degeneration.

The brand new farming practices have greatly attacked the land. Chemicals such as DDE has not just ruined the land, but the human bodies as well, which has caused a big amount of people getting sick. Chemical reduction programs are encouraging farmers and other land users to decrease their use of chemicals that might harm the land.

Land disposal involves hauling garbage to an area owned by a community or a private firm. Such areas range from unsanitary open dumps to properly operated sanitary landfills.

Open dumps are a poor method of waste disposal because they cause environmental problems. In the United States, it is illegal to create a new open dump. Existing dumps are required to convert to sanitary landfills or to close.

Few people want to live or work near a garbage disposal site. As it grows increasingly difficult to find locations for new landfills and incinerators, and as people have become more aware of environmental concerns, recycling and waste reduction have gained importance. In the mid-1990's, Americans buried about 57 percent of their municipal solid waste in landfills, recycled about 27 percent of it, and burned 16 percent in incinerators.