The term brine doesn’t just refer to the combination of water and salt. Many brines contain other compounds and chemicals that are highly corrosive or reactive. Fracking fluids, cleaning chemicals, and heavy metals can all be found in many brine waste mixtures. Brines come from many sources, including:
- Desalination Plants: Regardless of the method used, only 50 to 70 percent of brine can become clean drinking water. The resulting 30 to 50 percent of brine is highly concentrated, making brine pond evaporation a better choice for processing than ocean release.
- Manufacturing Processes: The textile and leather tanning industries both produce large amounts of highly concentrated brine. Brines from leather processing in particular often contain other corrosive and reactive ingredients like chromium salts, caustic soda, and hydrochloric acid.
- Salt Manufacturing: Most salt harvesting processes leave little brine behind, but any liquids left after evaporation are highly concentrated and need secure storage until the next batch of brine is added.
- Hydraulic Fracturing: Brine found in salt deposits deep underground mixes with the fracking fluids during hydraulic fracturing. Known as produced water, the amount that leaves the mine during pumping requires special handling. Brine ponds work well for storage as well so the brine can be reused as the base for new fracking fluids to minimize the use of fresh water.
- Natural Gas Storage and Mining: The brine created during salt cavern formation can be reused for retrieving the stored natural gas, but only if it’s stored properly in a brine pond in the meantime.
- Power Plant Cooling Towers: Power plants rely on highly purified water for cooling purposes, and a tiny amount of concentrated wastewater is left behind from each gallon of distilled water. With each cooling tower requiring millions of gallons of water, all that wastewater adds up. The water tends to be a brine due to a high salt concentration, requiring either processing or special storage.
- Food Processing: The production of pickles, olives, and other brined foods also leaves behind both plain salt and water mixes and highly acidic vinegar brines. Facilities producing thousands of gallons of waste brine a year can economically deal with this waste on-site with lined brine ponds.
- Chlor-Alkali Processing: Creating both caustic soda/lye and chlorine results in thousands of gallons of caustic brine leftover as a waste product. Careful processing of the brine is necessary and requires secure storage to prevent spills or accidental exposure before further filtration is applied.
These are all global industrial processes producing millions of gallons of brine per year, but there are many other less common sources that still require proper pond design. No matter how much brine needs storage or treatment, a lined pond is likely a good investment for at least one stage of the process.