Science Unit 7
When the Deepwater Horizon oil well exploded in 2010 and leaked oil into the Gulf of Mexico, the result was not only environmental, but financial:
- $2.5 billion hit to Louisiana's fishing industries - $3 billion hit to Florida's tourism industry - $20 billion fine paid by BP The oil company's fine helped pay for damages to local fishing and tourism industries. The fine also helped to cover the costs of rehabilitating the ecosystem.
Which of the following happened partly in response the fire on the Cuyahoga River? Select the two correct answers.
- Congress passed the Clean Water Act into law. - The National Environmental Policy Act was passed, which led to the formation of the EPA.
Water treatment plants use
several filtration methods that involve physical, chemical, and biological processes. The objective of water treatment is to make the water environmentally safe and produce solid waste that can be reused or disposed of in landfills.
The rise of modern aquaponics came as a solution to
the problem of large amounts of waste from fish farms. An aquatic environment with fish provides the moisture and nutrients plants require and eliminates soil-borne pests. The plants regulate the algae blooms and provide cover for fish. Despite all these benefits, some drawbacks need to be considered as well.
What is the definition of water treatment ?
the process of removing physical, biological, and chemical contaminants from wastewater and household water
Processes used in water treatment and sanitation of water vary depending on
the source and kinds of water. Municipal water is treated differently from industrial water as contaminants vary.
Supporters of the CWA argue that all water is connected in the water cycle. Therefore, wastes that are discharged into ditches or ponds will run into larger bodies of water over time. Supporters also point to the economic benefits of having cleaner water:
- Municipalities save money on cleaning water for drinking when the water is less polluted. - Tourism earnings increase when the water is clean enough to swim or fish in. - Waterfront property usually has a higher value when the water is cleaner.
Which of the following are symptoms of lead poisoning in children? Select the three correct answers.
- learning difficulties - abdominal pain and vomiting - developmental delays.
Once the appropriate data has been collected, hydrologists interpret and analyze the data. Communities, governments, and water industry experts use the data and the analysis to prepare for future events and to make decisions regarding water resource management. For example, the data and analysis can be used to do the following:
- predict floods and droughts - determine the effects of leaking underground oil storage - plan water projects, such as construction of dams and levees
Which of the following should a student study in order to become a hydrologist?
- statistics - biology - mathematics
According to the U.S. Environmental Protection Agency (EPA), in the United States alone, household leaks waste nearly
1 trillion gallons of water per year. That's equal to the total amount of water used by over 11 million homes!
The water that leaves a home after being used must be treated before returning to the water cycle. Because of this, many Americans are choosing to rethink the way they use and conserve water in their homes. Water-saving strategies fall into four general categories:
1. limiting consumption 2. reusing and recycling 3. eliminating losses 4. preventing pollution
According to a U.S. Geological Survey (USGS) report from 2010, American households use about
27.4 billion gallons of water per day. This equates to about 90 gallons per person per day. Most of this water is not consumed, but merely flows through the home. This includes toilet flushing, dishwashing, bathing, and many other household uses.
Why is chlorine added?
Chlorine is added to disinfect, to kill pathogenic bacteria, and to reduce odor.
Water ecosystems are a vital part of the environment
Ecosystems regulate climate processes; break down wastes and recycle nutrients, filter and purify water; buffer against flooding; maintain soil fertility; purify air; and provide natural resources and, of course, food. Biodiversity is a fundamental part of ecosystem health. Reduction in biodiversity can lead to the collapse of these ecosystems on which people depend. Understanding and tracking water quality is an essential part of managing water ecosystems' resources and maintaining biodiversity.
Decide with methods are effective or ineffective in removing chemical contaminants such as lead.
Effective: - distillation - reverse osmosis Ineffective: - micro-filtration - ultraviolet radiation
What are some advanced wastewater treatment techniques and why are they needed?
Examples of advanced wastewater treatment techniques are filtration, carbon adsorption, distillation, and reverse osmosis. These techniques are being used to remove pollutants such as heavy metals, chemical compounds, and toxic substances.
Which of the following supports the idea that aquaponics systems help reduce water pollution?
Fish waste reduces the need to use chemical fertilizers.
What caused the water to change and suddenly become unsafe?
Flint switched from the Detroit Water and Sewage Agency to taking water from the Flint River. Officials decided to not sufficiently treat the water and it began to cause corrosion in the pipes.
Drag each phrase to indicate whether it supports an argument for or against the installation of an aquaponics farm.
For Aquaponics: - The practice produces almost no waste - Aquaponics uses less water from the local water supply Against Aquaponics: - Money is needed for equipment and maintenance - Aquaponics is profitable when used on a large scale
What is the importance of a grit chamber?
In a grit chamber, cinders, sand, and small stones settle to the bottom. A grit chamber is particularly important in communities with combined sewer systems where sand or gravel may wash into sewers along with stormwater.
The Cuyahoga River fire was one of the catalysts for the clean water acts enacted in the 1970s. Were the regulations able to save this waterway?
In the 1960s, it was a fire hazard with little or no wildlife. Today, the river has been repopulated with fish that require clean water to live, such as the steelhead trout and northern pike. While fishing is now permitted in much of the Cuyahoga River, advisories are still in place regarding fish caught from the river and its tributaries. Officials warn against eating more than one meal a week of fish caught from the river because of high levels of harmful chemicals.
Which is true about distillation?
It may leave some chemicals such as herbicides and pesticides in the water.
How does lead get into water?
Lead gets into water by leaching (or seeping) out of old plumbing pipes made of lead. The more corrosive the water, the more lead leaches out.
What are some problems associated with lead poisoning in children?
Lead poisoning can lead to a number of problems including developmental delays, learning disabilities, irritability, decrease in appetite, fatigue, abdominal pain, and vomiting.
What was in Flint's water that caused 12 people to die?
Legionella pneumophila
How did city and state officials respond to reports of high lead levels?
Officials initially denied that there were high lead levels and did not warn residents about the risks.
The United States produces roughly 34 billion gallons of sewage every day. Where does all of that wastewater go?
Prior to the Clean Water Act (CWA) , wastewater could be legally dumped into surface waters with little or no treatment. Industrial wastewater was also dumped directly into the nearest body of water. These practices led to situations like the Cuyahoga River fire.
Which of the following allows the EPA to regulate water onboard aircraft to ensure that the public is not exposed to high levels of bacteria?
Safe Drinking Water Act
What is sludge?
Sludge is the mass of solids produced in the primary stage.
What is the Environmental Protection Agency's (EPA) limit on lead in water? What levels of lead were detected in households in Flint?
The EPA has set a limit for lead at 15 parts per billion for drinking water. In Flint, lead was found at levels around 104 parts per billion, nearly seven times higher (one household had levels up to 13,200 parts per billion) .
How is activated sludge better than trickling filters?
The activated sludge process speeds up the work of the bacteria by mixing new sewage with air and sludge filled with bacteria. After the sewage leaves the settling tank in the primary stage, it is pumped into an aeration tank, where it is mixed with air and sludge loaded with bacteria and allowed to remain for several hours. During this time, the bacteria break down the organic matter into harmless by-products. This sludge can also be reused again and again.
What are the two basic stages in treatment of waste?
The two stages are primary and secondary. In the primary stage, solids are allowed to settle and then removed from wastewater. The secondary stage uses biological processes to further purify wastewater.
What role do bacteria play in an aquaponics system?
They transform fish waste into plant food.
What is the definition of Environmental Protection Agency ?
a federal agency of the United States government that sets and enforces guidelines that protect the environment
What is the definition of biodiesel ?
a fuel similar to fossil diesel fuel that is derived from organic sources such as plant or animal oils
What is the definition of hydrologist ?
a scientist who studies how water interacts with Earth's systems and helps manage water resources
What is the definition of Safe Drinking Water Act ?
act passed in 1974 that ensures drinking water is safe by requiring drinking water be monitored for microorganisms, disinfectants, disinfectant by-products, inorganic and organic chemicals, and radionuclides
Which of the following would a groundwater hydrologist study?
an aquifer
Scientists working in the field of hydrology collect and
analyze data. They also monitor, manage, and protect water resources on Earth.
Aquaponics combines
aquaculture (the growing of fish in a closed environment) and hydroponics (the growing of plants in a soil-less environment) in one practice. This method relies on reusing fish effluent, or waste, to supply nutrients and grow plants. In an aquaponics system, bacteria and other microbes in the water break down the fish waste into a nutrient solution for the growing vegetables. The plants absorb the nutrients from the water, cleaning the water before being recirculated back into the fish tanks.
Fixing a water leak can be
as simple as tightening a washer, or can be more complex, such as hiring a plumber to stop the leak. But how do you know if your household has a leak? A leaky faucet is easy to spot but other leaks can be trickier to detect.
What is the definition of surface water ?
bodies of water on the surface of Earth such as oceans, rivers, and lakes
Environmental regulations do have costs. The costs include
businesses having to find a way to safely dispose of wastes, instead of simply discharging them into the water or ground. Because the CWA made point-source pollution illegal, the EPA can fine businesses that break the law.
Another major benefit of the CWA is that
by the late 1990s, it provided more than $62 billion in grant money for municipalities to construct or expand their treatment works. In the late 1980s, the CWA was amended to include the State Revolving Fund, which has provided over $126 billion in loans to states. As the money is repaid, it returns to the fund where it can be loaned to fund additional projects.
In water ecosystems, the qualities of the water itself are
central to defining the health of the whole ecosystem. The water must provide the nutrients for aquatic life. Too high a level of nutrients leads to the overgrowth of algae, plankton, and other microorganisms, which can have a serious negative effect on other aquatic life. To determine the overall health of a water ecosystem, scientists look for water conditions that do not promote eutrophication or promote a toxic environment for aquatic life.
Which of the following is a type of water pollution caused by leaded gas, the production of some pesticides, and burning garbage?
dioxins
Which filtration method purifies water using the process of boiling and cooling?
distillation
What is the definition of eutrophication ?
excessive nutrients in a water body causing overgrowth of algae, plankton, and other microorganisms
The quality of drinking water is very important. Water must be purified to
get rid of contaminants that are harmful to the environment and people's health. Various water filtration methods are used by households, industrial facilities, and water treatment plants to filter, purify, and disinfect water before it is used again.
What is the definition of water pollution ?
harmful substances contaminating a stream, river, lake, ocean, aquifer, or other body of water, lowering water quality and making the water toxic
When people think about recycling, they usually think about sending paper, cardboard, or plastic to a recycling plant. Did you know that water can be reused and recycled, too? One way that households can recycle water is by
harvesting rainwater. The most common way that households do this is by purchasing and installing rain barrels. A rain barrel usually holds between 50 and 100 gallons and can be installed at a gutter downspout.
All organisms on Earth need water for survival. Water covers nearly 71 percent of Earth's surface. Water is a universal solvent, which means
it dissolves more substances than any other liquid. This characteristic of water makes it susceptible to pollution.
The last water conservation method is focused on
keeping the water that flows through your home free of pollutants. Every single product that you use in a sink, bathtub, shower, or toilet ends up in the water supply. Some of these products contain ingredients that are known to be dangerous to the water supply. Even though the wastewater that leaves your home is treated before going back into the water supply, some chemicals that enter the water supply cannot be removed.
What is the definition of Clean Water Act?
law that regulates discharges of pollutants into U.S. waters and regulates the quality standards for surface water
Collected rainwater can be used for any
nonpotable use. Water collected using a rain barrel is commonly used to water lawns and gardens, or to wash vehicles and pets. However, with the right system in place, rainwater can be used for just about any nonpotable use in the home.
Scientists must be able to critically evaluate information. You read about products that contain chemicals that are dangerous to the water supply. Many companies have begun labeling their products to make consumers think that they are more ecologically friendly than they actually are. Just because a product is labeled green , natural or biodegradable , doesn't necessarily mean it's
nontoxic. When purchasing products for the home, don't be fooled by marketing. Be a scientist; read the ingredient list and decide for yourself if the product is truly nontoxic.
What is the definition of nonpotable ?
not safe for drinking
Water pollution is a widespread problem that affects water resources, water quality, the environment, and the health of all living organisms. Groundwater and surface water can be
polluted from countless sources
What is the definition of point source pollution ?
pollution that comes from a known and specific location
What is the definition of point-source pollution ?
pollution that comes from an identifiable confined source such as a smokestack or wastewater treatment plant
What is the definition of nonpoint-source pollution ?
pollution that does not come from a single, identifiable point
What is the definition of nonpoint source pollution ?
pollution that does not have a specific point of origin
What is the definition of runoff ?
precipitation or irrigation water that reaches streams, rivers, lakes, or the ocean, often carrying pollutants
While it's true that most municipalities in the U.S. now treat their sewage wastewater , overflows do still happen resulting in
raw sewage being leaked or dumped into waterways. This is largely due to how sewers developed through history. Initially, before flush toilets and running water, sewers were only designed to handle stormwater to reduce flooding in streets. As plumbing was installed in housing, sewage drained into existing stormwater sewers.
The Clean Water Act was created in order to
regulate water pollution. It gave the Environmental Protection Agency (EPA) the authority to set standards for industrial wastewater. It made it illegal for anyone to discharge pollutants without a tightly controlled permit. The CWA also funded the construction of sewage treatment plants to help reduce municipal point-source pollution.
Hydrologists work toward understanding the
relationship between water and the environment within the hydrologic cycle . Hydrologists apply mathematical principles, scientific knowledge, and engineering practices to help solve society's problems related to the quantity, quality, and availability of water resources.
Up until the 1970s, in many places the combination of stormwater and household sewage was
simply dumped into a local body of water. Now, however, nearly all combined sewage wastewater is sent to the local publicly owned treatment works (POTW) where sewage sludge is separated out. (Sludge is an unpleasant combination of fecal matter, toilet paper, and various solids that have been flushed or washed into storm drains.) The wastewater is then cleaned before being reintroduced to local waterways. However, because populations have grown dramatically, the combined sewer systems must now handle far more wastewater than they were designed for. During heavy rains, this leads to overflows.
Prior to the CWA, only about one-third of U.S. waterways were safe for
swimming and fishing; now nearly two-thirds of waterways qualify. While wetlands are still being lost, the rate has dropped from 500,000 acres per year to 60,000 acres per year. Now, about 93% of water systems for U.S. communities meet all the health-based standards of the Safe Drinking Water Act (SDWA) . This is an increase of over 14% since 1993.
What is the definition of water-saving technologies ?
the application of scientific knowledge to save water
What is the definition of hydrologic cycle ( water cycle) ?
the continual movement of water throughout Earth's atmosphere, oceans, and land surface by evaporation, transpiration, condensation, and precipitation
It was called the river that oozes rather than flows. For over a century, the Cuyahoga River was used by the city of Cleveland as a dumping ground for chemical and sewage wastes. It was such a problem that the oil slicks on the river caught fire 13 times. However, when the river caught fire on June 22, 1969, the country finally took notice. This is because
the cultural revolution of the 1960s and 1970s included a new awareness and appreciation of the environment. The first photographs of Earth taken by astronauts inspired people to view the planet as a small, finite resource. Books like Silent Spring by Rachel Carson highlighted the damage caused by the irresponsible use of toxic chemicals. People began to wonder how things could be changed and if the damage to the environment could be undone.
What is the definition of aquaponics ?
the farming of plants and aquatic animals in a recirculating environment
Distillation, filtering, boiling, and adding chlorine are some of
the most common water purification methods. These small- to medium-scale methods can be used in households, labs, and other facilities.
Even when the combined sewers are working well, there is still the question of what can be done with
the sewage sludge. A few scientists have begun tackling this issue and have engineered a solution
What is the definition of hydrology ?
the study of the occurrence, movement, distribution, and quality of water throughout Earth
Many believe that aquaponics is a new trend, but the practice has been used since
the thirteenth century by both Aztec and Chinese civilizations. The Aztecs created movable islands called chinampas , where they grew crops such as maize, beans, squash, and chilies. Several ancient Chinese texts provide references of combining rice and fish farming. The practice is still very common in Taiwan, Japan, and India.
What is the definition of biodiversity ?
the variety of life within an ecosystem, including all plants and animals
What is the definition of groundwater ?
water stored in the cracks and spaces of underground rock
What is the definition of wastewater ?
water that has been used for household or industrial purposes
One of the weaknesses of the CWA and SDWA is that
while point-sources of pollution have become much more strictly regulated, not enough has been done to address nonpoint-source pollution such as city and farm runoff . Areas that are heavily populated, used for livestock, or where pesticides and fertilizers are applied all produce a great deal of runoff pollution that ends up in rivers, lakes, and oceans.