1 HOW HEALTHY ARE OUR W AT E R WAY S ? Water quality monitoring W. hether using simple, inexpensive Water Pollution Any physical, chemical, or field test kits, or more expensive biological change in Water quality that has a probes and meters, your students harmful effect on living organisms or makes Water can gather data about Water quality that will unsuitable for desired uses. Pollutants may be help them learn a tremendous amount about biodegradable, non-biodegradable, or slowly the rivers, streams, bays, and other Water degradable. Sewage, industrial chemicals, heavy bodies that they see everyday. Students can metals from industrial processes, and household use monitoring equipment and apply scientific cleaners are examples of materials commonly process skills as they gather data about many discharged into streams and rivers.
2 Additional parameters of Water quality . By assessing the Water pollutants include chemicals, pesticides, Water quality in a local Water body, students fertilizers, motor oil, litter, and other components will better understand how human activities of polluted runoff. Water can also be polluted by pollutants that come from the air a process are affecting this resource, and how we can called atmospheric deposition. protect Water quality in the future. Freshwater and saltwater ecosystems are complex and interactive physical, chemical, to dissolve a wide variety of compounds. and biological systems. Human activities cause Water 's superiority as a solvent plays a key changes in these attributes, and thus affect role in carrying dissolved nutrients into the living resources over time.
3 In this chapter, cells of living organisms, and removing cellular we will discuss some of the physical, chemical, waste. But it also means that Water is easily and biological parameters of Water that can polluted by Water -soluble materials. be monitored by students in middle and high school. We will also introduce some of the excellent programs, such as GLOBE, which offer teachers extensive support, and students the opportunity to participate in national and international environmental science investigations. P URE Water IN N ATURE ? Finding pure Water that is, Water with no impurities is very unlikely in nature. One of liquid Water 's unique properties is its ability WAT E R Q U A L I T Y M O N I T O R I N G 5 / 7. HOW HEALTHY ARE OUR W AT E R WAY S ?
4 H UMAN A CTIVITIES AND Water by preventing sediment from reaching streams. P OLLUTION Wetlands also promote the decomposition of some toxic substances and waste. HEALTHY Human activities can modify Water quality in riparian (streamside) areas also help naturally two ways. First, Water quality is changed when purify Water . As long as streams and rivers we add pollutants, including: are not overloaded with wastes, they can use sediment from erosion; their natural recovery processes of dilution and bacterial decay. But slowly degradable and nutrients from fertilizer and animal waste;. nondegradable pollutants, like mercury, PCBs, heat from paved surfaces and industrial and some pesticides, cannot be eliminated by processes; these natural processes.
5 Mercury cannot ever be degraded, even over thousands of years. fecal bacteria from sewage, farm Virginia's Department of Health advises people animals, pets;. to restrict or avoid eating fish from some rivers industrial chemicals; in Virginia due to mercury and PCB pollution. heavy metals (includes lead, mercury, and For a current list of these advisories, see cadmium from industrial sources, mining, and smelting); household cleaners;. FACTORS R ELATED TO Water P OLLUTION. oil and gasoline;. There are many factors related to Water litter and debris; pollution, including the number of people living in a watershed, how the land is used chemicals from the air; and (agriculture, forested, urbanized, etc.), and pesticides. the everyday behavior of the population.
6 Many things we do every day can have an impact The second way we impact Water quality is on Water quality . Human activities, such as by changing ecological processes that naturally urbanization, dam construction, forestry purify Water . HEALTHY aquatic ecosystems practices, agricultural development, and road- (wetlands, streams, bays, and oceans) all have building, have a profound effect on the quality natural processes that purify Water of wastes. of our Water . When we fertilize our lawns, For example, microorganisms decompose use pesticides, drive our cars, or use toxic organic wastes into nutrients that can be chemicals we have the potential to add absorbed by plants. Wetlands act as natural pollution to surface Water and groundwater.
7 Filtering systems as they trap sediment, there- Whether we make our living from mining, WAT E R Q U A L I T Y M O N I T O R I N G 5 / 8. HOW HEALTHY ARE OUR W AT E R WAY S ? forestry, farming, or construction, we have pollutants. In fact, according to the Alliance the capacity to add nutrients, sediments, for the Chesapeake Bay, it is estimated that toxics, minerals, or acids to lakes and streams. roughly a quarter of the nitrogen entering the Every land-use decision we make can either Chesapeake Bay is from air sources. While improve Water quality , or diminish it. there are some natural sources of emissions, most of these air-borne pollutants come Other pollutants enter Water from from fossil fuel burning, industrial processes, atmospheric deposition when pollutants cars and other forms of transportation, and in the air fall on the land or Water .
8 Nitrogen fertilizer. is one of the most common air deposition Water P OLLUTANTS , T HEIR I MPACTS , AND A PPROPRIATE T EST M ETHODS. Common Water pollutants can be placed in a few categories or classes. This table shows some of these pollutants, and tests that middle or high school students can conduct. More details about several key pollutants follow the chart. Chemical and Physical Water Pollutants Category Examples Impacts on Water quality Test Methods for Middle or High School Thermal pollution Paved surfaces and roofs Warm Water holds less dissolved Thermometers become hot, and transfer oxygen (DO) than cold Water , so Computer or calculator heat to rainwater. Water also heated Water lowers the DO in probes absorbs heat when it is used Water bodies.
9 Macroinvertebrate to cool industrial and power Can kill organisms that require high populations as indicators plants. levels of DO. Test kits and probes are Can disrupt spawning. available that determine Causes increased respiration rates the concentrations of and oxygen consumption in aquatic dissolved oxygen. organisms, and makes them more vulnerable to disease, parasites, and toxic chemicals. Sediment or Main source: soil eroded from Sediment can clog gills; settle out, Transparency tube suspended matter the land. Insoluble particles destroying feeding and spawning Turbidity test kits of soil and other solids that grounds of aquatic animals; cloud Macroinvertebrate become suspended in Water . Water and reduce photosynthesis; populations as indicators carry pesticides, bacteria, and other harmful substances; and disrupt aquatic food webs.
10 WAT E R Q U A L I T Y M O N I T O R I N G 5 / 9. HOW HEALTHY ARE OUR W AT E R WAY S ? Chemical and Physical Water Pollutants Continued . Category Examples Impacts on Water quality Test Methods for Middle or High School Plant nutrients Human sources: 1. Excessive growth of algae Chemical analysis test kits can ( Water -soluble nitrates sewage treatment plants, fer- ( algae blooms or red tide ) determine the presence and and phosphates) tilizer runoff, vehicle exhaust, and other aquatic plants. Bacteria concentrations of nitrate and atmospheric deposition, feed- decompose the algae when it phosphorus. lot/farm manure, and eroded dies, and can deplete Water of Test kits and probes are soil. dissolved oxygen. Low DO can available that determine the kill or stress aquatic animals.