Presentation on theme: "Chapter 20 Water Pollution Dontae Landley Laura Alzate Period 3."— Presentation transcript:
Chapter 20 Water Pollution Dontae Landley Laura Alzate Period 3
20-3 What Are the Major Pollution Problems Affecting Groundwater and Other Drinking Water Sources ? Common pollutants such as fertilizers, pesticides gasoline and organic solvents can seep into ground water causing hella pollution. When ground water becomes contaminated it cannot cleanse itself. Ground water has lower concentration of dissolved oxygen and smaller population of decomposing bacteria. And that is why it is difficult to cleanse the water. It can take decades to thousands of years for contaminated groundwater to cleanse itself.
Ground water pollution is a very serious threat to the environment. Ground water is curtail because it provides 70% of le countries drinking water. By 2006, the EPA (environmental protection agency) had completed the cleanup of about 350,000 of the more than 460,000 underground tanks in the United States that were leaking gasoline into groundwater. The clean up cost ranges from 10 thousand to 250 thousand.
Case Study A natural threat from arsenic in groundwater Pg.544 Protecting water sheds instead of building water purification plants Pg.546
20-4 What Are The Major Pollution Problems Affecting Oceans? 40 % Of the worlds population live on or near a coast. Coastal populations are expected to double by 2050. 80% of marine pollution originates on land. 80-90% of the pollution dumped into the water is not treated, and it could rise by 2050.
In deeper waters the ocean can dilute, disperse and degrade large amounts of raw sewage. Dumping harmful waster into the ocean further degrades the vital part of earths life support. Cruise ship cause equal amounts of pollution as a small city. They also create a lot of plastic garbage, this garbage usually gets dumped around important ecosystems. According to one study one fourth of people using coastal beaches in the US develop ear infections, eye irritation, and respiratory disease due to the pollution in the water. Harmful algal blooms are called red, brown, or green toxic ties. They release water born and air born toxins that damage fisheries and poison seafood.
Dead zones 200 oxygen-depleted zones 43 zones are known as “dead zones” Dead zones have low oxygen levels, they contain few oxygen-consuming fish and bottom-dwelling organisms, but they abound with decomposing bacteria.
Crude petroleum comes out the ground. Refine petroleum is processed products. In 1989 Exxon Valdez tanker went off course and released 40.8 million litters of oil into Alaska's prince William. Damaged 34 thousand fisheries in Alaska and the total cost was 4 billion. Studies showed that the largest source of ocean oil pollution is urban and industrial run off from land. Half of the oil reaching the oceans is dumped, spilled or leaked by city sewers, industries and people.
The key to protecting the ocean is to reduce the flow of pollution for land and air and from streams emptying into these waters.
20-5 How Can We Best Deal with Water Pollution? Solutions to better water quality: 1. Drainage Area Management Plans 2. Agriculture plots 3.1987 Water Quality Act 1987 Water Quality Act-Main goals to make U.S. waters safe for fishing and swimming. Restore and maintain the chemical, physical, and biological integrity of nations waters. Discharge trading policies under this program a permit holder can pollute at high levels than it is allowed if it buys credits from permit holders who are polluting below levels. Case study pg 552
Primary sewage treatment of physical process that uses screens and grit tanks to remove large floating objects and allows solids to settle out Secondary sewage treatment biological process which bacteria removes 90% of dissolved biodegradable waste. These two together move 95-97% of organic waste. 70% of toxic. 70% of phosphorus and 50% of nitrogen. Tertiary sewage series of specialized chemicals and physical process to remove specific pollutants.