Geo lecture #17

Consumptive Usage

Refers to water use that diminishes the supply of water available for subsequent usage, such as drinking and irrigation.

Nonconsumptive Usage

Water use that does not diminish the supply of water available for subsequent usage, such as transportation of goods, recreation, and hydroelectric power.

Peak Water

The concept that underscores growing constraints on the availability, quality, and use of freshwater resources.

Daily Drinking Water Requirement

The average freshwater intake needed per person, which is between 2-4 liters.

Freshwater Usage Increase Rate

Freshwater use has been increasing about 1% per year since the 1980s.

Drinking Water Quality

Water quality is considered drinkable if it has less than 500 ppm of dissolved solids.

Acid Rain

Precipitation that contains sulfuric and nitric acids due to pollutants like SO2 and NO2.

US Clean Air Act

Legislation that resulted in significant reductions of SO2 and NO2 emissions, enacted in 1970.

Desalination

The process of removing salt from seawater by methods such as distillation or reverse osmosis.

Maximum Contaminant Level (MCL)

The legal limits set by the EPA on over 90 contaminants in drinking water.

Point Source Pollution

Pollution that can be traced to a single source, such as a pipe emptying into a river.

Nonpoint Source Pollution

Pollution that comes from many diffuse sources, such as fertilizer runoff from farmland.

California's Groundwater Basins

Comprises 515 groundwater basins that contribute about 38% of the state's total water supply.

Carlsbad Desalination Plant

The largest desalination plant in the western hemisphere, located in California.

USGS 2008 Study Findings

Found 130 man-made chemicals in natural waters in the US, many of which are unregulated in drinking water.