Objectives: Students will be able to:
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list sources of contamination
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describe the federal laws that are designed to protect our water supplies
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discuss some of the health hazards
associated with contamination
You may wish to begin this section with a slide presentation available from the water authority. Contact Rosemary Marcionus 624-6671 Ext 263 Also there is a script of the slide show available at the Yale-New Haven Teachers Institute.
The number and types of contaminants in drinking water have been growing faster than the ability to detect and treat them as well as being able to set standards for. One hundred years ago the major contaminant of our water supply was a bacteria called Escherichia coli as well as some other common bacteria found in human feces. This problem was easily removed by the addition of chlorine, and therefore, the control of such diseases as typhoid and cholera.
Today we face contaminant from “point” sources such as industrial or municipal discharge pipes, or “nonpoint” sources, such as farmland, urban runoff, disposal and construction sites. Substances such as bacteria, nutrients, minerals, salts, trace metals and organic matter are normally found in water. At elevated levels some of these such as salt, selenium, fluoride, and radioactive elements become contaminants which at certain levels may be toxic.
Certain common industrial operations, such as mining, drilling, construction and forestry can contaminate water as part of their “normal” activities. There are other industries such as the chemical, medical, oil, which are more readily recognized as waste producing sources.
The disposal of industrial wastes has led to widespread contamination of many water sources due to the method of disposal. Landfilling, the most widely used method (although now illegal in Connecticut) has resulted in the ground water contamination from over one-third of the hazardous waste sites studied by the Environment Protection Agency (EPA) in 1982. Although safeguards are made to protect our water supplies, all landfills are subject to leaks.
As controls on liquid disposal in landfills have tightened, underground injection of wastes into deep wells has become more prevalent. Concern over contamination of aquifers has led to bans on the injection of hazardous waste in all of New England.
Many industries discharge their effluents into local sewage systems that then contaminate rivers and other water sources. Although there are laws that govern the discharge of industrial wastes very few industries are in compliance.
The disposal of radioactive wastes is a serious problem, not only to our water supplies but because of the potential threat of radioactive contamination. The volume of highlevel radioactive waste from nuclear power plants is supposed to quadruple in the next 15 years.
Pesticides and fertilizers from agricultural processes as well as lawn services have been detected from coast to coast. The true extent of pesticide contamination is only now being revealed. Certain conditions such as soil type, crops, irrigation practices, weather and other geological conditions as well as the properties of the pollutant influences the extent of contamination.
Eroding soil carries accumulated nutrients and pesticides into streams, rivers, and lakes causing contamination in sedimentation. Because there are few requirements to test for them, most of the chemicals go undetected by water treatment plants.
Municipal landfills which are designed to accept only solid wastes, not toxic, receive many toxic materials from household, municipal, commercial and even industrial wastes. These toxic materials eventually leach into our water supplies.
As mentioned previously, industrial wastes are often dumped into sewage systems. The sewage plants are not equipped to treat such wastes which then releases toxic materials into surface waters.
Urban runoff has contaminated many of out nation’s rivers and lakes. Urban runoff may contain heavy metals such as cadmium and lead, inorganic chemicals, petroleum products, de-icing salts, pathogens and animal wastes.
Further contamination of drinking water occurs in your own home. The improper disposal of such household products as cleaners for your oven, sink, rug, furniture, and bathroom. Automotive products such as oil, anitfreeze, and rust removers, paint removers and solvents, garden and lawn products, the list seems to be endless are all possible contaminants to our water supplies if they evaporate or do not biodegrade.
Governmental operations also generate toxic wastes, and the disposal of these wastes have been generally under- estimated because security regulations have made it difficult for states to make accurate on-site investigations. Metal-plating solvents, spent fuel, heavy metals and other toxic chemicals, such as nerve gas have been stored unsafely and dumped regularly at many federal sites.
Until 1974, there was no federal legislation protecting our water supplies. It had been assumed that chemicals like chlorine took care of any contaminants, but the contaminants that the country faces now are far more threatening than the bacteria and viruses that chlorine is designed to remove.
The Safe Drinking Water Act (SDWA) of 1974 is intended to protect drinking water through the setting, monitoring and enforcement of standards and to a certain extent, to prevent contamination of underground water supplies.
The federal water management has been hampered by the conflicting legal, regulatory, and administrative actions of numerous agencies. There is no single body to coordinate water management. There are agencies such as the US Geological Survey that collect data and make assessments of water supplies and their quality.
The regulation of water quality and quantity as well as the management of these supplies is divided among many different agencies. The Environmental Protection Agency (EPA) has the primary responsibility for regulating pollution control and water quality. The Federal Food and Drug Administration, however, regulates bottled water and the water used in the packaging and processing of food. Other agencies that play a dominant role in the management of water are: the Army Corps of Engineers, the Department of Interior’s Bureau of Reclamation, the Department of Agriculture’s Soil Conservation Service, and the Tennessee Valley Authority.
The Safe Drinking Water Act requires the EPA to set national primary drinking water standards known as Maximum Contaminant levels. These standards are based on the health risk assessments and the feasibility of attaining those standards. Revised standards which were to go into effect in 1977 are only now being put into effect as a result of the 1986 amendments to the SDWA.
There are many deficiencies in the law because certain items are not covered such as private wells, systems serving under 10,000 people, underground injection of certain brines from oil and gas mining, and there is also no support for research on alternative treatment technologies.
The Clean Water Act as amended is designed to restore and maintain the quality of surface waters. States have been required to develop water quality standards for rivers and streams. Contaminant levels in effluents discharged directly into these bodies are regulated by a permitting system, the National Pollutant Discharge Elimination System (NPDES), on a basis of the “best technology generally available” for municipalities and industries. For effluents discharged by industries into public sewer systems, pretreatment standards are required. However, thousands of companies have expired NPDES permits and there are thousands more who are illegally discharging into public sewer systems.
The Resource Conservation and Recovery Act (RCRA) regulates the storage, transportation, treatment and disposal of hazardous wastes to assure minimal effects on human health and the environment. A manifest system is responsible for tracking waste. Treatment, storage, and disposal facilities must have permits and must state the potential for public exposure to hazardous wastes. Certain restrictions on the disposal of liquid waste in landfills were also adopted.
The EPA has given enforcement powers to most of the states which have responsibility for conducting site inspections. However, there are numerous deficiencies in the enforcement of this law.
The Comprehensive Emergency Response, Compensation, and Liability Act (CERCLA or Superfund) authorizes government cleanup of chemical spills and inactive hazardous waste sites that may pose threats to human health or the environment. The current “cleanups” are temporary rather than permanent solutions, and the available sites for disposal of Superfund waste are lacking. For this reason the 1986 Superfund amendments require cleanups that necessitate permanent solutions and the compliance with other environmental laws.
Another federal law is the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) is intended to protect public health and the environment through the regulation of pesticide registration, re-registration, marketing and the use in the US. EPA recognizes that pesticide residues in groundwater present a potential risk to human health. When evaluating a pesticide’s risks, EPA takes into consideration both its inherent toxicity and the potential routes of human exposure to such compounds.