Processing residual wastes from a proposed brackish-groundwater desalination plant in New Mexico, USA, could provide a revenue of around US$ 4.6 million/year, according to a preliminary engineer report just completed.
Reviewing the report’s findings on 21 January 2010, the commissioners of Sandoval County gave approval for design work to start on the plant, which would be sited west of Rio Rancho in the Rio Puerco basin.
The City of Rio Rancho has an immediate need for 5.0 MGD (19,000 m³/d) of additional supply. The proposed project would supply this need in its first phase, offering Rio Rancho an alternative water source. As future demand grows it is proposed that the utility would expand in 5 MGD increments.
The New Mexico Bureau of Business and Economic Research (BBER) is projecting a population growth in the area which will provide an ultimate demand of 36 MGD (136,000 m³/d) as early as 2050.
The Rio Puerco confined aquifer is located at a depth of 3,500 ft (1,065 m). At an initial plant capacity of 5 MGD, the aquifer will provide a 100-year supply under the lower storage estimate and assuming 100% operating capacity throughout the period.
Alternative 2 was the selected alternative and forms the basis of the recommended treatment process.
Residual waste processing into a marketable product or disposal represent a significant cost to constructing and operating this brackish water treatment plant. The three primary marketable residuals are magnesium carbonate, sodium chloride and lime.
Altogether, these products represent revenues of US$ 4.6 million/year. The report says this is a significant revenue stream and long-term contracts for the sale of these products should be secured before final project financing is closed. A preliminary market survey was performed and resulted in letters of interest for all marketable products.
Sandoval County has been approached by Native Energy Development, LLC, a Navajo tribal enterprise to co-locate a gas-fired power plant with the proposed desalination plant. The county would purchase power directly from the power plant and benefit from free heat. The water plant would provide water for cooling and injection.
The total capital cost of the project is estimated to be US$ 108,468,375. The average annual operation cost would be US$ 15,252,000.
A longer article about this project will appear in Desalination & Water Reuse‘s February/March 2010 issue.