There many options for managing brine waste that may include treatment and brine disposal. Brine treatment involves desalinating the brine for reuse and producing a concentrated brine (lower liquid waste volume), or residual solids with zero fluid discharge. Brine disposal includes discharging brine to sewers, surface water, injection wells, or sending it to environmental service providers
This piece discusses some of the ways to dispose of brine instead of treatment. Ideally, brine disposal is cost-effective to any company compared to treatment that requires many resources. For industry owners who need brine services, they can make use of third party companies for assistance.
Brine Disposal in the Ocean
Like discharging brine into surface water bodies, ocean discharge is another brine disposal method that tends to be very cost-effective. Due to the ocean’s naturally high salinity, there are lower environmental risks of brine discharge.
What makes this step challenging though still useful, is acquiring a permit before installing a brine discharge line. As part of the permit application, the regulatory body may ask for environmental studies that address the impact on the local marine ecology of the brine temperature, pH, salt density, and other property differences between the brine and seawater.
Deep Well Injection of Waste Brine
Waste brine can be disposed of by injecting it into deep wells. These injection wells are installed thousands of feet deep into the ground, away from the upper aquifers that feed drinking water sources. The availability of injection wells is geology-dependent, so they are not available in all regions. In the oil and gas industry, abandoned oil wells are often converted into disposal wells.
Deep well capacities have also reduced as regulations require lower injection pressures to minimize the risk of contaminating the upper water aquifers.
Brine Evaporation Ponds
Evaporation ponds are the artificial solution to inland surface water discharge of waste brine. Under the right climatic conditions, the water evaporates, allowing more brine to the ponds. One limitation of ponds is that they require large land areas to increase the surface area where the water can evaporate and represent a future environmental liability due to either animal entry or future decommissioning. For situations that may need to recover solids for disposal or reuse, multiple evaporation ponds may be necessary to rotate between brine evaporation and solids extraction. Evaporation also happens more quickly in warmer, arid climates.
Waste brine can be sent to an incinerator facility, where it is typically mixed with other solid wastes for processing. Incineration evaporates the water, while the brine’s salts become part of the residual ash that requires further management. Incineration is popular in countries with limited availability of land for landfills.
Brine Management from Environmental Service Providers
Some companies provide brine services to help industries manage brine wastes. These companies will typically take ownership of the brine and charge on a dollars-per-gallon basis. This is an option to consider if there are facilities nearby, although distance and transportation costs may reduce its cost-effectiveness. Once the service provider takes ownership, they will use their assets to either treat the brine or dispose of it.