Brackish Water or Well Water is water that is more salty than potable fresh drinking water, in other words is has a higher salinity concentration levels, but not as much as sea water. The word originally deviate from the Dutch root of “Brak” meaning "salty".
Brackish water condition commonly occurs when fresh water meets sea water. In fact, the most extensive brackish water habitats worldwide are where a river meets the sea.
The term “brack” or Brackish was first used to describe bodies of waters that had been mixed with seawater in the 1500s, Brackish Water was not as salty as seawater, yet very distasteful, and was described as harmful water due to its characteristics and to unique microorganisms that caused human illness .
Brackish water usually contains from 0.5 to 30 grams of salt per liter (500 to 30,000 ppm or mg/L), however, the brackish water salinity concentrations may vary considerably over space and time.
In general Brackish Water is a term for water that contains a significant concentration of dissolved salts (Na Cl). The concentration is usually expressed in parts per million (PPM) or milligram per liter (mg/L) of salt. Brackish Water that is saline contains significant amounts (referred to as "concentrations") of dissolved salts
The salinity concentration is the amount of salt in the water by weight, as expressed in "parts per million" (PPM). For example if water has a concentration of 5,000 ppm of dissolved salts, then one percent (5,000 divided by 1,000,000) of the weight of the water comes from dissolved salts.
The salinity concentration level used by US Geological Survey classifies brackish water in three categories.
- 1- Slightly saline water contains around 1,000 to 3,000 ppm.
- 2- Moderately saline water contains roughly 3,000 to 10,000 ppm.
- 3- Highly saline water has around 10,000 to 35,000 ppm of salt.
Brackish Water can be found in wells, boreholes, mangrove swamps, inland lakes and seas. The Caspian Sea which is very famous for the great sturgeons fish (source of the best caviar in the world) is the largest brackish lake in the world with a salinity level of 1.2%, (12,000 PPM) about one third that of normal seawater. The Baltic Sea is another example of brackish water, the Baltic Sea has the least Saline concentrations in the world with a salt concentration of 0.5% (5000 PPM) compared to the Red Sea and the Persian Gulf both with a salt concentration of about 4.5% (45,000 PPM)
What is Brackish Water?
Brackish water is water that has more salinity than fresh water but less than seawater. It typically measures between 0.5 and 30 parts per thousand (ppt) dissolved salts — compared to the ocean's average salinity of around 35 ppt. Brackish water is commonly found in surface waters near river mouths, estuaries, and coastal areas where freshwater and saltwater mix. Inland brackish sources include certain lakes, aquifers, and water wells with elevated total dissolved solids (TDS).
Natural ecosystems such as mangrove forests thrive in brackish environments and are closely associated with estuarine and coastal brackish water zones. For water treatment purposes, brackish water (typically 1,000–10,000 mg/L TDS) requires desalination or reverse osmosis treatment to produce potable drinking water or process-grade water suitable for industrial, agricultural, or municipal use.
Brackish water is found in coastal lagoons, estuaries, and inland aquifers across many coastal areas of the world. It is defined by salinity between 0.5 and 30 parts per thousand — above freshwater but significantly below the average salinity of seawater. Brackish surface waters and groundwater sources support unique ecosystems — including mangrove forests — and serve as critical water supply sources for communities and industries in arid and semi-arid regions.
