Brownsville, Texas and the Rio Grande Valley will soon have access to another water source. The Southmost Regional Water Authority’s desalination plant will convert 9.5 million gallons of salty groundwater into drinking every day. Originally projected to cost USD 36 million, the price tag has since dropped close to USD 30 million. Equipment for the groundwater wells and the reverse osmosis plant incurred the highest costs. PUB will provide the electricity needed to operate the plant. The SRWA board has awarded NRS a $1 million contract to oversee the project, and contracted other firms for the project’s construction. There are three steps to process water through the desalination plant, First, it is drawn from a well field west of Rancho Viejo, where pipes probe 300 feet below the surface to extract the water from 20 wells. A 30â? diameter pipeline will transport 9.5 million gallons of water daily to the plant six miles way. At the plant, the water is treated to adjust the acidity level and extract solids. Then, the reverse osmosis takes place, a high-pressure filter allows water molecules to pass through a semi-permeable membrane, but holds back larger particles. The water then goes to the transfer pump station and is sent through a de-gasifier to rid the water of carbon dioxide. The purified water is sent to the 55â concrete holding tank, which stores up to 7.5 million gallons. The reverse osmosis process removes nearly all impurities, including necessary minerals that prevent pipe corrosion or lead contamination. The water is mixed with a small amount of untreated water to add back the necessary minerals, and it is chlorinated as well. The wastewater produced by this process contains a high concentration of salt. It is funnelled into a drainage ditch that empties into the Brownsville Ship Channel.
