Various forms of CBM water treatment methods before discharge.

All CBM produced water that is sent through a treatment facility is then discharged into a drainage. Thus CBM water treatment is generally used when the well field is in close proximity to a large river or stream. While water treatment is sometimes used farther from a drainage, it then requires large scale pumping and piping infrastructure to move the water to the treatment facility and then to the discharge point. There are numerous types of treatment methods that are marketed as a viable treatment method for CBM water prior to discharge that may include:

1. CBM-WTS by DEI is marketed as a CBM water treatement technology which is designed to treat specific feed specifications of numerous incoming chemical compositions, chemical removal of sodium ions, throughput ranging from 50 gallons per minute to over 1,000 gallons per minute, thus producing a secondary waist of salt concentrate which must be stored and disposed of. http://waterquality.Montana.edu/docs/methane/cbm-wts.shtml or http://drakeengineeringinc.net/index_files/page0004.htm.
2. Submerged combustion by SUBCOM is marketed as a water treatment technology for the CBM industry that can be utilized to heat liquids in order to treat waist water. This system is touted for the mining industry, pulp & paper industry for waste water treatment, ethanol and glycol reduction and many more industrial applications. http://www.subcom.ca/
3. Catalyx Fluid Solutions (CFS) also known as DynIXTM Technology is marketed as a water treatment technology for the CBM industry. http://www.catalyxfs.com/  and http://www.rgglife.com/
4. EMIT Water Discharge Technology is said to utilize a continuous countercurrent ion exchange (CCIX) method for removing sodium and other cations from CBM produced water. According to EMIT, this CCIX system is based on the Higgins Loop technology, which is a patented process exclusively licensed from Severn Trent Services. The Higgins Loop technology was invented in 1951 and has been adapted to treat produced water from coal bed methane extraction. The produced water containing high Na levels enters into the adsorption zone within the Higgins Loop where it contacts a strong acid cation resin which loads Na+ ions in exchange for hydrogen (H-) ions. The "loop" extracts 95% of the cations. Concurrent with adsorption and in the lower section of the Higgins Loop, Na-loaded resin is regenerated with hydrochloric acid and a small, concentrated spent brine stream is produced. Regenerated resin is rinsed with water prior to re-entering the adsorption zone to remove acid from its pores. As resin in the adsorption zone becomes loaded with Na, the flows to the Higgins Loop are momentarily interrupted to allow "pulsing" the resin bed through the loop in the opposite direction of the liquid flow. Liquid flows restart after the resin pulsing is complete. http://www.emitwater.com/
5. There are operator owned reverse osmosis plants (RO), with very large waist storage pits. Reverse osmosis is expensive, and evaporation and salt precipitation treatment is neither economical nor feasible with large quantities of saline CBM water. These facilities require large impoundment facilities and often are unable to handle the large quantuties of water needed for large CBM well fields.
6. There are operator owned chemical treatment plants. While it is possible to alter the chemistry of sodic water by adding calcium and magnesium. This does not eliminate or reduce sodium, but changes the ratio of sodium to other salts, thus decreasing the sodium adsorption ratio (SAR). The net result is more saline water with the sodium salt still dissolved in the water. This approach is not likely to work with CBM product water because the added calcium will combine with carbonate from the CBM water and precipitate out as calcium carbonate (lime). To make this process work, CBM product water must be de-gassed of carbonate by addition of acid, or additional calcium must be made available in the soil by acidification from sulfur additions.

The resulting issue from all of these treatment methods and systems is that that the CBM water is eventually discharged into some drainage or holding impoundment. This unfortunately depletes the local aquifers by removing the water from the landowners property. In most regions, discharge into rivers and streams is limited by regulation and under permit for seasonal discharge, where limits are maintained during the season and prohibited during the off season, i.e. during periods of water use for irrigation from these drainages. Further permitting may take as long as two years or may not be available. Treatment systems often have price tags in the millions of dollars and if the treatment facility become operational and then fails to properly treat the water the entire well whole field must be shut down.

The water treatment and discharge methods mentioned above are perhaps the most costly of all CBM water disposal methods. While historically many companies have paid an exceptionally high costs for these treatement systems there has been a general movement away from many of these CBM water treatment systems as they have had high failure rates or they do not prove out to handle the quantity of water necessary at a viable cost point. It has become more dificult for CBM Operators to get regulatory permits for discharge, landowners do not want these large facilities built on their property nor do they want the water removed from their property. Thus CBM water treatment is considered an expensive and environmentaly unfriendly way to handle CBM produced water.