Desalination
From Water Wiki
North Carolina has several water plants that produce fresh water by removing salt, a process called desalination.
The viability of desalination for further water supply in North Carolina and elsewhere in the southeast is a hotly debated question. The technology certainly exists, but the costs (both capital and operating costs, including energy costs) are significantly higher than traditional surface or groundwater removal and treatment. Tampa Bay's large desalination plant is a case in point. "Bid at $79 million in 1999, the 25 million-gallon-a-day plant ended up costing $158 million after all the necessary upgrades. Tampa Bay Water customers pay $3.38 per 1,000 gallons of desalinated water, compared with about $1 per 1,000 gallons of groundwater. To remove salt, water must be piped at high pressures through membranes with holes 1/1,000 the width of a human hair. Creating that pressure requires a vast amount of energy, which is expensive. Tampa Bay Water spends $10 million a year to power the desalination plant, compared with $3.7 million to power various groundwater facilities -- even though five times more groundwater is produced."[2]
Also of concern is the high-salt concentrated effluent.
Despite these concerns, desalination is on the rise in a few countries around the world, particularly in the Middle East, and new technology, such as this pump that lowers energy costs, may improve its cost-effectiveness in the middle Atlantic states.
Notes
- ↑ Wade Rawlins, Coastal Towns Desalt Water, News and Observer, March 3, 2008 http://www.newsobserver.com/weather/drought/story/977780.html
- ↑ Zac Anderson, "More parched communities ponder desalination solution," HeraldTribune.com (Tampa Bay Herald Tribune online), June 15, 2008
