Across
- 3. Physical chemical and biological changes that take place aftr a body of water receives input of plant nutrients from erosion and runoff.
- 7. Water that sinks into the soil and is stored in underground reservoirs.
- 8. Land area that deliveers water, sediment, adn dissolved substances via small streams to a major stream/river.
- 10. Mechanical sewage treatment in which large solids are filtered out as sludge.
- 11. Broad areas including many sources from which pollutants enter bodies of water and/or air.
- 12. Upper surface of the zone of saturation.
- 13. Water flowing off the land into bodies of surface water.
- 14. Underground tank for treating wastewater from rural or suburban homes.
- 15. Eutrophication caused by human activities.
- 17. Lake with a low supply of nutrients.
- 18. Area where all available ores in soil and rock in the earth's crust are filled by water.
Down
- 1. Single identifiable source that discharges pollutants into the environment.
- 2. Runoff of water that generally can be counted on as a stable source of water from year to year.
- 4. Condition in which an area does not get enough precipitation and/or very high temperatures.
- 5. Precipitation that does not infiltrate the ground or evaporate.
- 6. Waste treatment system in which aerobic bacteria decompose as much as 90% of degradable, oxygen-demanding organic wastes.
- 8. Any physical or chemical change in surface water or groundwater that can harm organisms or make water unfit for use.
- 9. screens and suspended solids settle out as sludge.
- 16. Underground areas that are porous, water-saturated layers of sand, gravel, or bedrock that yield significant amounts of water.