1. GET THE SALTWATER
The plant takes in 40-million gallons of water from TECO’s power plant at Big Bend. Asian green mussels have been found in that seawater and have caused big problems.
PROPOSED FIXES: Modify the water intake pump. Add chemical feed systems to control biological growth in the seawater supply lines.
2. CLEAN THE SALTWATER
Algae and small organic material must be removed before it reaches the reverse osmosis membranes. The water is chemically treated to cause particles to cluster together and to control biological growth. Then it is sent through 16 sand filters.
PROPOSED FIXES: Add a new microfiltration system. One team proposes cartridge filters coated with powder-sized sand; the other would use hollow fibers that resemble strands of spaghetti. Replace the clarifying chemicals. Modify existing chemical feed systems.
3. REMOVE THE SALT
Saltwater is forced through 10,000 reverse osmosis membrane filters to remove the salt. Each filter costs $500 and tiny hairs and other organic materials from those Asian green mussels clog the membranes faster than expected. When much larger quantities of cleaning solution were needed, the plant was forced to store 2-million gallons in tankers parked around the site.  PROPOSED FIXES: Install a new clean-in-place system for chemically cleaning the membranes. Modify parts of the high pressure pump. One team also would install a 500,000-gallon tank to store used cleaning solutions.
4. DELIVER THE DRINKING WATER
The treated water is sent to Tampa Bay Water’s facility near Brandon. The brine that is left is added to 1-billion gallons of saltwater from the power plant that flows into Tampa Bay. PROPOSED FIXES: Modify or replace the existing lime and carbon dioxide feed systems. Repair seals and make changes to improve water transfer to the treatment plant. |
The treated salt-free water is sent to Tampa Bay Water’s regional treatment facility near Brandon. The water is blended with surface and groundwater.