Is Groundwater Depletion Affecting Streams and Water Quality?

Groundwater refers to the water existing below the Earth’s surface. This could be just below in the soil, or miles deep in aquifers. Aquifers are large spaces between layers of underground rock that become filled with freshwater from the surface that seeps through the soil and porous rock layers. The water is usually filtered and purified as it seeps through the earth’s crust, becoming very pure. These vast stores of freshwater in underground aquifers are frequently tapped by wells, with water pumped out of them to be used for drinking water. Constant pumping of groundwater from these aquifers can lead to groundwater depletion. Depletion becomes serious when these large aquifers begin to run low, or run out of water.

Our groundwater aquifers and watersheds are essential components of our hydrosphere and the freshwater system humans rely on to sustain life. Groundwater is the supply of freshwater that is below ground, often near the surface but at times miles deep. Groundwater usually pools in large aquifers, which are openings in layers of permeable underground rock where freshwater pools in large amounts. Principal aquifers are those large enough to be used as sources of drinking and agricultural water, usually accessed with wells.

Groundwater depletion occurs when these aquifers cannot be replenished by their natural water sources as quickly as water is being removed from them by wells. One result can be significant decreases in groundwater levels, leading to the need for deeper wells to access the remaining water. Other effects of groundwater depletion are lower water levels in streams, rivers and lakes because more of the surface water is needed to seep into the ground to replenish groundwater supplies. Such seepage causes a decrease in surface water levels.

Another effect is that, as pollutants such as petroleum products, fertilizers, heavy metals, sewage, etc., contaminate surface waters, these pollutants are also seeping into depleted groundwater and polluting our aquifers. Groundwater pollution has now become a very serious problem in the areas where principal aquifers are being depleted and contaminated.

The State of California is experiencing the worst problems with groundwater depletion, due to a decades long severe drought, rapid population growth and massive agricultural water needs. Other Western states are experiencing these problems for very similar reasons. Agricultural water needs have grown exponentially over the past several decades. Almost every area of the United States where underground aquifers are being used to supply water needs and population growth is experiencing the effects of groundwater depletion and pollution.

The biggest problem that professional water quality testing can help with is determining groundwater quality. Well water should be tested regularly, especially in and around agricultural and industrial areas, to ensure that it is free of groundwater pollution from seepage into underlying aquifers. Today’s water testing methods, equipment and technology are capable of identifying a wide range of potential contaminants at extremely low concentrations. Since many chemicals and heavy metals are dangerous at extremely low levels, this is vitally important to human health. 

Environmental testing services are at the forefront of the efforts to maintain surface water and groundwater quality. The engineers and chemists of Torrent Laboratories are experts at testing our streams, rivers, lakes, reservoirs and groundwater aquifers for pollutants in order to identify water and groundwater pollution, and thereby keep us all safer and healthier. If you are on a well-fed water system it is important to get your water tested regularly, especially if you have noticed any changes in taste, color or odor. But because many of these contaminants are odorless and tasteless they must be tested for contaminants.