POTENTIAL FOR BENEFICIAL USE OF COAL-BED METHANE PRODUCED WATER IN WESTERN ALABAMA TO AUGMENT WATER SUPPLIES DURING INTENSE DROUGHT

Recent extreme and exceptional dry weather periods in the southeast have lead to increasing concern over water availability during times of intense drought, resulting in a two decade legal battle between Alabama, Florida, and Georgia over surface water consumption. In order to sustain potable water resources and mitigate the effects of drought, additional emphasis could be placed on the use of reclaimed waters for non-potable uses. Currently, around 80 million barrels (3.2 billion gallons) of coal-bed methane produced water are generated annually from the Black Warrior Basin in western Alabama. This study investigates the potential for beneficial use of Black Warrior Basin produced water as a means to augment water supplies for local agricultural and industrial use. Chemical characterization was performed using available literature and analysis of produced water samples. Chemical constituent concentrations were compared with published beneficial use criteria (crop irrigation and cooling water) to determine the percentage of samples that may be suitable for use. Common constituents that limit reuse were also identified for future evaluation of treatment technologies. Of 126 produced water samples identified from literature and 7 analyzed in the laboratory, 46.6% met irrigation criteria for salt tolerant crops such as cotton. 45.1% of the samples did not meet the criteria due to excessive conductivity. 77.2% of the samples met the criteria for use as cooling water; however, 15.7% of the samples did not meet the criteria due to excessive iron. Other constituents in excess of beneficial use criteria for either irrigation or cooling water in some samples were sulfate, cadmium, and manganese. Based on the samples characterized, some Black Warrior Basin coal-bed methane produced water has the potential to be used in place of potable water for irrigation of cotton and as cooling water thus preserving or enhancing potable water resources.