Glossary M-R

M N O P Q R

mineral water—water that contains minerals.

municipal water—municipal water may come from either groundwater or surface water sources. Once water has entered a municipal water system, from any source, it is considered municipal water.

natural recharge—the replenishment of a groundwater source from natural water supplies such as precipitation and stream flows.

natural resources—sources of supply for earth materials.

Nevada Department of Environmental Protection (NDEP)—the state agency responsible for overseeing air and water quality regulations and the primary agency for enforcing compliance with the federal Clean Water Act and Clean Air Act.

nitrates—compounds containing nitrogen as nitrates; found in animal wastes, fertilizers and septic tanks or untreated wastewater.

non-point source pollution—pollution that cannot be traced to a specific location. Non-point source pollution occurs when rainwater, snowmelt or irrigation washes off plowed fields, city streets or urban backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants, such as nutrients and pesticides.

overdraft—that quantity of water pumped in excess of the available supply; the act of overdrawing a water supply or aquifer in amounts greater than replenishment. Also, the sustained extraction of groundwater from an aquifer at a rate greater than the recharge rate of the aquifer, resulting in a drop in the level of the water table.

ozonation—a water treatment process that destroys bacteria and other micro-organisms. It's one of the most advanced water treatment processes in the industry.

M N O P Q R

particles—small bits of matter.

pathogen—disease-causing agents; usually bacteria or viruses.

percolate—to drain or seep through a porous and permeable substance; to filter, such as liquid passing through a porous body (water through soil to an aquifer).

permeability—the ability of a material to allow the passage of a liquid, such as water, through rocks. Permeable materials, such as gravel and sand, allow water to move quickly through them, whereas impermeable material, such as clay, doesn't allow water to flow freely.

perspire—to sweat; to lose water through skin.

pH—a measure of the concentration of hydrogen ions in solution. The pH scale ranges from 0-14, where 7.0 is neutral; values less than 7.0 are acidic; and values greater that 7.0 are alkaline or basic. Every unit decrease in pH means a 10 fold increase in concentration. Thus, a pH of 3.0 is 10 times as acidic as a pH of 4.0 and 100 times more acidic than a pH of 5.0.

phosphates—important ion and plant nutrient; found in many fertilizers.

point source pollution—pollution that can be traced to a single source such as a pipe or an outlet (example: wastewater treatment plant, industrial sites, etc.).

polar molecule— a covalent molecule having a partial positive (+) and a partial negative (-) end.

pollutant—any substance suspended or dissolved in water that builds up in sufficient quantity to impair water quality.

polluted water—water that contains one or more impurities that make the water unsuitable for a desired use.

pond—a still body of water smaller than a lake.

porosity—a description of the total volume of rock or soil not occupied by soil matter.

potable water—water suitable for drinking.

precipitation—any form of water, such as rain, snow, sleet, or hail, that falls to the earth's surface

primary treatment—the first stage of wastewater treatment that removes settled or floating solids only; generally removes about 40 percent of the suspended solids.

pumping station—a facility that pumps water to a higher elevation.

purveyor or provider—with reference to public water supply systems, a municipality or other organization that sells and delivers water to customers. There are seven purveyor members in the Southern Nevada Water Authority: The cities of Boulder City, Henderson, Las Vegas and North Las Vegas; Big Bend Water District; Clark County Sanitation District and the Las Vegas Valley Water District.

receiving reservoir—a water holding structure at the terminal end of a delivery system constructed and equipped to provide storage and release of water.

recharge—to replenish a water body or an aquifer with water; the replacement of any water that may have flowed out or been pumped out of an aquifer.

recharge area—an area where infiltration moves downward into an aquifer.

reclamation—bringing land that has been disturbed by some process back to its original condition.

regulating tank—a tank constructed for the purpose of regulating system hydraulics within an acceptable range over a particular reach of the transmission facilities. A regulating tank absorbs pressure fluctuations and temporary mismatches between downstream demands and upstream water supplies to maintain a balanced operation.

rehydrate—to replace lost water.

reservoir—a place where water is collected and stored for use.

return flow credit—credits Nevada receives for treating wastewater and returning it to the Colorado River System.

riparian—areas adjacent to rivers and streams with plants adapted to moist growing conditions found along waterways and shorelines. These areas are frequently important to wildlife habitat because of their greater density and succulence.

river—a large body of flowing water that receives water from other streams and/or rivers.

River Mountains Tunnels—two 3.9 mile tunnels that convey water from Lake Mead through the River Mountains to the Las Vegas Valley. One tunnel is 10 feet in diameter, constructed in 1971. The other tunnel is 12 feet in diameter and was constructed in 1997.

ROFC Station—Rate-of-Flow Control Station. A facility constructed to control the rate at which water is delivered to a turnout.

runoff—water that flows across surfaces rather than soaking into the ground; eventually enters a body of water; may carry a variety of pollutants.

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