Aquifer –an underground layer of rock, sand, or gravel that contains water in sufficient quantities to supply a well.

Aquitard – an underground, saturated zone, sand, or gravel that will not provide significant quantities of water to a well for spring.

Artesian well – a well that penetrates a confined aquifer. The water level in these wells rises above the upper surface of the aquifer in due to the pressure in the confined aquifer. If the water pressure is great enough, the well will overflow.

Condensation-the process whereby water is changed from gas to liquid.

Cone of depression – the cone shaped area around a well where the ground water level is lowered by pumping. The shape of the cone is influenced by the underground porosity and water yield of the well.

Confined aquifer – aquifers that are wedged between layers of relatively impermeable material and are consequently under pressure. Also known as artesian aquifer.

Contaminants – any physical, chemical, biological, or radiological substance or material in the water.

Discharge area – the area or zone where groundwater emerges from the aquifer. The outflow may be into a stream, Lake, spring, wetland, etc.

Evaporation – the process whereby water is changed from the liquid to a gas.

Groundwater – water beneath the surface of the earth which saturates the pores and fractures of sand, gravel, and rock formations.

Hardness- a characteristic of water caused by the presence of various salts, calcium, magnesium and iron. Water is soft if the content of these materials as low, hard if the content is high.

Hydraulic cycle-the continuous circulation of water between the earth and the atmosphere, involving condensation, precipitation, runoff, percolation, evaporation and transpiration.

Non-point source of pollution-contaminants found in water from a source that cannot be specifically defined. For example contamination resulting from municipal runoff or agricultural infiltration.

Perched water – unconfined groundwater held a ball Bill water table by a layer of impermeable rock or sentiment.

Percolate—the downward flow of water through the pores or spaces of unsaturated rock or soil.

Permeability – the capacity of rock or soil to transmit water.

PH – a numerical measure of acidity and alkalinity. This scale is from 1 to 14; neutral is pH 7, values below 7 are increasingly acidic, and above 7 are increasingly alkaline.

Plume – a flowing body of contaminated groundwater that extends from the source of contamination to another point in the direction of the groundwater flow.

Point source of pollution – contaminants found in water that can be readily identified from a specific source such as a leaking underground storage tank.

Pollution – any substance, natural or synthetic, that degrades water quality to such a degree that water is not suitable for a particular use.

Porosity – the degree to which the total body in of soil or rock is permeated with spaces or cavities through which water or air can move.

Potable water – water which is free from impurities that can cause disease or harmful physiological effects, such that the water is safe for human consumption.

ppb.(parts per billion) —a ratio used to describe the proportion of one substance to another. In terms of time, 1 ppm is equal to one second in 32 years.

Recharge areas – areas of land that allow groundwater to be replenished through infiltration or seepage from precipitation or surface runoff.

Salinity – the concentration of dissolved salts and water. The most desirable drinking water contains 500 ppm or less of dissolved minerals.

Saturated zone – the portion of subsurface soil and rock where every available space is filled with water. Aquifers are located in this zone.

Surface water – bodies of water, snow, or ice on the surface of the air (such as lakes, streams, ponds, wetlands, etc.)

Transpiration – the process by which plants give off water vapors into the atmosphere.

Turbidity – a measure of water cloudiness caused by the amount of suspended matter in the water.

Unconfined aquifer – an aquifer with the water table and is its upper boundary. Because the aquifer is not under pressure the water level in a well as the same as the water table outside the well. An unconfined aquifer is near to the earth’s surface causing it to be easily recharged as well as contaminated.

Unsaturated zone – an area, usually between the land surface and the water table, where the openings or pores in the soil contained both air and water.

Watershed – all land and water within a drainage area, defined by topographic high points.

Water table – the top of the unconfined aquifer were water pressure is equal to atmospheric pressure. The water table depth fluctuates with climate conditions on the land surface above and the usually gently curved and follows a subdued version of the land surface topography.

Well – an opening in this surface of the earth for the purpose of removing freshwater