Brackish water or briny water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water.
Technically, brackish water contains between 0.5 and 30 grams of salt per a litre, more often expressed as 0.5 to 30 parts per thousand ‰, which is a specific gravity of between 1.005 and 1.010. Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition. It is characteristic of many brackish surface waters that their salinity can vary considerably over space and/or time.
Brackish water occurs in places in which sea water and fresh water get mixed, such as in estuaries, mangrove swamps and intertidal zones. Brackish water may also occur in brackish fossil aquifers.
Like sea water, human beings cannot drink brackish water unless it undergoes a desalinization process. When brackish water invades farmland, it is referred to as salinization. Brackish water kills most crops. Brackish water is not optimal for freshwater or marine life, so what can live in it is limited. Animal and plant species that can survive in brackish water include flounder, chameleon shrimp, three-spined stickleback, salicorn and sea aster.
The Brackish Water is that it is more salty than potable fresh drinking water, in other words it has a higher level of salinity concentration, but less than sea water. The word Brackish is originally derived from the Dutch root of “Brak” its meaning is "salty".
The Brackish water condition commonly occurs when fresh water meets or got mixed with sea water. So, the most extensive presence of brackish water habitats worldwide are where river meets the sea.
Generaly, Brackish Water is a term used for water that contains a significant amount of dissolved salts. The unit used for the measurement of concentration is parts per million (PPM) or milligram per liter (mg/L) of salt. The salinity concentration is the amount of salt in water by weight, measured in "parts per million" (PPM).
The salinity concentration level used by US Geological Survey classifies brackish water in 3 categories.
- Slightly saline water contains about 1,000 to 3,000 ppm.
- Medium saline water contains roughly 3,000 to 10,000 ppm.
- Highly saline water has around 10,000 to 35,000 ppm of salt.
The Brackish Water may be found in wells, inland lakes, boreholes, and in seas.
Brackish Water Treatment:
The Brackish Water can be treated with a Reverse Osmosis (RO) Water Purification System, while, desalinating of brackish water occurs at lower pressure as compared to seawater desalination, and it is more economical process, less energy consumption and more cost effective.