1 Water Quality indicators and How Human Activities Affect Water Quality Name: Online Assignment: Period: Date: Purpose: to learn how to evaluate water quality and how pollution can make water unavailable or unsuitable for life. Read the following to answer question 1. A watershed is an area of land from which all the water drains to the same location, such as a stream, pond, lake, river, wetland or estuary. A watershed can be quite large, such as the Colorado River drainage basin, or very small, such as a small horse pasture that drains to a farm pond. Watersheds are nested, with many small watersheds comprising larger watersheds. Watersheds are comprised of upland areas, riparian areas (the strips of water-loving vegetation near streams, lakes and other water bodies), and the streams, lakes, and wetlands that collect and transport the water (and anything carried by the water). 1. What is a watershed? Now watch the teacher demo of a watershed and answer the following questions: 2. Where is the water flowing from, and where is it going? 3. Does all the water flow in the same direction? 4. How do materials in a watershed get carried to streams, lakes, and oceans? Read the following to answer questions 5, 6, and 7. The natural conditions of a watershed, such as its elevation, annual precipitation, temperature, native geology and plant communities, will determine the quality of the water leaving that watershed. Point sources of pollution are discharges from industries or waste water treatment plants and may be significant in some areas. In many watersheds, however, streams and lakes are more affected by nonpoint source pollution, which is collected primarily from rain and snowmelt runoff over land surfaces. The amount and types of pollutants are determined by the land uses and activities in a watershed. Different types of land uses and activities, such as roads and urban development, mining, timber harvesting, recreation, and agricultural activities, may result in quite different mixes and amounts of pollutants. Nonpoint source pollution is associated with rainfall and snowmelt runoff moving over and through the ground, carrying natural and human made pollutants into water sources. Examples of nonpoint source pollutants are fertilizers, pesticides, sediment, gas, and oil. Pollutants such as nutrients, pesticides, oil and gas products, salts, sediment and bacteria can drastically alter the state of the stream or lake s ecosystem. If we can determine the type of pollutant and its source, we can take preventative measures to reduce any further contamination. 5. What is point source pollution? 6. What is nonpoint source pollution? 7. Look at the different location sketches of the 6 card locations and write down what is going on and fill in the table. The cards are printed below the following table.
2 Site Gold Creek What is the land being used for? What type of things might be getting into the water? What does that mean for the quality of water (good or bad)? Straight Shot Stream Red Ribbon River Capital Creek Off Road Dream Stream Mayfly River
3 For the FOLLOWING water quality indicators (DO NOT highlight/color the pictures above): a. Highlight/color the definition of each indicator in. b. Highlight/color in how the indicator can harm the environment. c. Highlight/color in how it is good for the environment (not all indicators will have both good and bad effects). Turbidity: Turbidity tells us how much suspended material (such as sediment or microorganisms) is in the water. Suspended sediment eventually settles out in a stream and fills in the spaces between the rocks and gravel on a stream bottom. This can suffocate the tiny aquatic animals living between the rocks or the fish eggs laid on stream bottoms. Turbidity can also prevent sunlight from reaching aquatic plants and may also affect the ability of fish and aquatic invertebrates to see and capture their prey. Turbidity increases naturally when flows increase, but also increases from uncontrolled runoff from agricultural fields, roads and trails or construction sites. Nitrate (NO 3): This is the most common form of inorganic nitrogen in unpolluted waters. It is an essential nutrient for plant and animal growth. However, increased amounts of nitrate can lead to excessive plant growth which can decrease the aesthetic value of water bodies (by making it murky,
4 smelly or creating a slimy bottom). The decomposition of this extra plant material also uses up oxygen in streams and lakes, resulting in fish kills. Sources of nitrate include fertilizers, animal waste and failing septic systems. ph: This is a measurement of how acidic or basic something is. ph is measured on a scale from 0 to 14, with 7 being neutral (neither acidic nor basic). The lower numbers on the scale are more acidic, while the higher numbers are more basic. The ph scale is logarithmic, which means each unit change (e.g., from 7 to 8) in ph represents a 10-fold change in the acidity. The ph of water determines the solubility (amount that can be dissolved in the water) and biological availability (amount that can be utilized by aquatic life) of chemical constituents such as nutrients (phosphorus, nitrogen, and carbon) and heavy metals (lead, copper, cadmium, etc.). For example, in addition to affecting how much and what form of phosphorus is most abundant in the water, ph also determines whether aquatic life can use it. In the case of heavy metals, the degree to which they are soluble determines their toxicity. Metals tend to be more toxic at lower ph because they are more soluble. For instance, water coming out of an abandoned coal mine can have a ph of 2, which is very acidic and would definitely affect any fish crazy enough to try to live in it! Not only does the ph of a stream affect organisms living in the water, a changing ph in a stream can be an indicator of increasing pollution or some other environmental factor. Dissolved Oxygen: This is not the bubbles in water, nor the oxygen part of the H 20 water molecule. It is a separate oxygen molecule that is dissolved into water. It gets into the water either by oxygen from the atmosphere mixing into a river where there is turbulence, or by aquatic plants realeasing oxygen during photosynthesis. Fish and aquatic macroinvertebrates require a certain level of dissolved oxygen in order to breathe. Temperature: The temperature of water is the amount of heat energy it contains. Temperature can be measured in Fahrenheit or Celsius. Since state requirements are usually in Celsius, that is the preferred scale for testing water samples. Temperature has a huge influence on biological activity and growth. Temperature determines the kinds of organisms that can live in rivers and lakes. Temperature also influences the water s chemistry. Temperature determines how fast chemical reaction can happen. For example higher temperatures mean that more minerals can be dissolved. Temperature can also affect how much dissolved oxygen is in the water. High temperature waters tend to release more gas and thus dissolved oxygen goes down, which influences the survival of many aquatic life. Now read how different human activities can change the water quality and then write down what location could be causing this effect. More than one location could be used for each of the water quality changes. Human activities and how they change the water quality Turbidity: humans can change the amount of turbidity by the activities they do such as agriculture (farming) or creating roads and construction areas. Nature can also change the turbidity through erosion of different materials. 8. Nitrate (NO 3): Humans can change nitrate levels by the use of fertilizers (for farming, lawns and gardens) which get washed into rivers and streams. Animal waste from livestock and pets also alters nitrate levels. 9.
5 ph: Humans can change the ph by mining. ph also changes as water comes into contact with different minerals in rocks and in forest areas. 10. Dissolved Oxygen: Any change in temperature, turbulence, or salinity will change the amount of dissolved oxygen in the water. Such changes may come from factories, nuclear power plants, or even the runoff off from roads that were treated with salt to prevent ice from forming. 11. Temperature: Humans can change the temperature of water by destroying vegetation, releasing discharge from industrial and urban areas, and changing the climate. Water temperature also changes with elevation change, contact with vegetation, and where the water is coming from, such as mountain snow melt. 12.