How is Brine Stored?
Brine is a solution of water and some amount of salt(s) in varying concentrations. The salts found in brines are necessary for life and humans have found myriad uses for brines for industries ranging from textile manufacturing to natural gas storage. Fortunately, it is one of the most abundant natural resources on the planet. However, brine is also deadly or damaging to life in high enough concentrations, and corrosive to many metals and products used by humans. Brines of all sorts need to be stored, whether in preparation for use and re-use, or after they have reached the end of their use, in the process of reduction or disposal.
Tank Storage
In some cases where relatively small amounts of brine need to be stored for fairly short periods of time, storage tanks built of rigid fiberglass and coated with chemically resistant plastics may be a sensible solution. Many companies sell products of this type and can offer selection and installation options. Still, in cases where you’ll be storing large volumes of water, especially if you’re dealing with highly concentrated brine, tanks are rarely the most efficient solution. Tanks, by definition, offer strictly limited storage volume. If your storage needs vary, or are likely to increase over time, the need to establish new storage banks, the necessary secondary spill protection, plus tank replacement cost every few years can make this an impractical solution.
Brine Ponds
Brine ponds are one of the simplest and most economical ways to handle brine storage. If the goal is to maintain the brine until it’s ready to be used again, deep ponds with a small surface area and covers are excellent solutions. The small surface area minimizes evaporation while total volume increases with depth, meaning you can store a large volume with a small footprint. A cover can help inhibit evaporation for these ponds, but even more importantly, it can prevent the incursion of rain or other types of precipitation. This avoids problems with dilution that could affect the usefulness of the stored brine. Covers also inhibit access by wildlife.
Brine ponds should always be lined with a corrosion-resistant impermeable liner. Even naturally occurring ponds are subject to water seepage into the surrounding soil, and since brine contains salts, damage to the local ecosystem can be substantial. Soil, freshwater aquifers, nearby surface waters, and the entire local ecosystem can be contaminated, especially when exposed to concentrated brine waste containing additional pollutants.
Since the threat to the surrounding environment is so severe, many brine ponds are required to establish secondary containment protocols along with leak detection systems. These all can be conveniently constructed with the use of a high-quality RPE (reinforced polyethylene) liner which offers extremely high chemical resistance, superior strength and durability, and ease of installation.
Brine Storage Guidelines:
Improper storage of brine has been implicated in contamination of drinking water and groundwater in the State of Michigan. The state has defined brine as any solution or mixture containing as little as 1% of the following compounds:
- Sodium chloride (rock salt)
- Potassium chloride
- Calcium chloride
- Magnesium chloride
Storage of brines in preparation for future use (highway de-icing or dust suppression) have strict guidelines in Michigan’s guidelines, including:
- Aboveground storage tanks require secondary containment such as double-walled tanks and spill containment dikes lined with an impervious material. Notably, even concrete or asphalt dikes must be free of cracks and covered with a waterproof coating.
- Secondary containment areas must be able to contain at least 10% of the total volume stored within that containment area, or 100% of the largest individual container’s volume.
- When storage tanks are used, squirt protection must be accounted for. Generally, that means the containment area should stretch at least as far as the height of the tallest container from its base. Pond storage doesn’t have this requirement, since there’s no risk of squirting.
- Brine designated for disposal can be collected in a lined lagoon until it is hauled to an appropriate facility. The lagoon must be lined with an impervious material capable of withstanding changing weather conditions without significant deterioration and/or loss of integrity.
Keep in mind that these guidelines apply only for the State of Michigan at the current time (Dec 2021). Other states’ requirements may be more or less defined and may permit more (or less) flexibility in design and materials. Regardless, the use of a durable, lightweight, reinforced, and flexible geomembrane like BTL’s Reinforced Polyethylene liners provides superior protection against leaks, deterioration related to chemical exposure, environmental factors, and exposure to UV rays when compared to alternatives. Look at your locations’ requirements and contact our experts to discuss your needs. We’ll be happy to help you evaluate the options and prepare an estimate for your best possible solution.
