Across
- 2. Water that contains sewage and other wastes from homes, farms, and industries.
- 5. Relatively pure water containing few dissolved salts
- 8. Condition in which an area does not get enough water because of lower-than-normal precipitation or higher-than-normal temperatures that increase evaporation.
- 9. Underground tank for treating wastewater from a home, used in rural and suburban areas. Bacteria in the tank decompose organic wastes, and the sludge settles to the bottom of the tank. The effluent flows out of the tank into the ground through a field of drainpipes.
- 10. Any physical or chemical change in surface water or groundwater that can harm living organisms or make water unfit for certain uses.
- 11. A structure built across a river to control the river’s flow or to create a reservoir.
- 12. Step in most waste treatment systems in which aerobic bacteria decompose as much as 90% of degradable, oxygen-demanding organic wastes in wastewater.
- 14. Type of water already used from bathtubs, showers, sinks, dishwashers, and clothes washers that can be stored in a holding tank and reused to irrigate lawns and nonedible plants, flush toilets, and wash cars.
- 15. Flat valley floor next to a stream channel. For legal purposes, the term often applies to any low area that has the potential for flooding, including certain coastal areas.
- 16. Mechanical sewage treatment stage in which large solids are filtered out by screens and suspended solids settle out as sludge in a sedimentation tank.
- 17. Single identifiable source that discharges pollutants into the environment. Examples include the smokestack of a power plant or an industrial plant, drainpipe of a meatpacking plant, chimney of a house, or exhaust pipe of an automobile.
Down
- 1. Slow or rapid sinking of part of the earth’s crust that is not slope-related.
- 3. Artificial lake created when a stream is dammed.
- 4. Purification of salt water or brackish (slightly salty) water by removal of dissolved salts.
- 6. Upper surface of the zone of saturation, in which all available pores in the soil and rock in the earth’s crust are filled with water.
- 7. Type of water that is not directly consumed but is used to produce food and other products.
- 13. Broad and diffuse area, rather than a specific point, from which pollutants enter bodies of surface water or air. Examples include runoff of chemicals and sediments from cropland, livestock feedlots, logged forests, urban streets, parking lots, lawns, and golf courses.