Tetra Tech, Inc.

10306 Eaton Place, Suite 340 Fairfax, VA 22030 phone 703 - 385 - 6000 fax 703 - 385 - 6007 TO : Paul Shriner and Jan Matuszko, EPA FROM : Kelly

Meadows DATE: January

7, 2010 SUBJECT: Cooling Towers in Brackish Waters EPA request ed that Tetra Tech design characteristics of cooling towers that used brackish water as a source for makeup flows . Th is memo summarizes Tetra Tech’s efforts to contact Da ta Sources Tetra Tech identified facilities using salt or brackish water as the makeup source two documents: 1) Maulbetsch, J. and M. DiFilippo. “Performance, Cost and Environmental Performance of Salt Water Cooling Towers.” Prepared for the California Commission. June 2007. 2) DiFilippo, M., J. Maulbetsch and K. Zammit. Status, I mpacts and Operations of High
- Salinity

Wet Cooling Towers. PowerPoint presentation. Facility Calls Tetra Tech attempted to contact all manufacturing facilities that have installed salt water towers since the Clean Water Act was passed in 1972, as well as an y electric generating facilities that have installed salt water towe ye ars. A representative from Dow Chemical in California stated that the facility d operate a salt water cooling tower. 

### MEMORANDUM

10306 Eaton Place, Suite 340

Paul Shriner and Jan Matuszko, EPA Kelly Meadows January 7, 2010 Cooling Towers in Brackish Waters Tetra Tech contact individual facilities regarding the prevalence and design characteristics of cooling towers that used brackish water as a source for makeup

summarizes Tetra Tech’s efforts to contact those facilities
facilities using salt or brackish water as the makeup source Maulbetsch, J. and M. DiFilippo. “Performance, Cost and Environmental Performance of Salt Water Cooling Towers.” Prepared for the California Commission. June 2007. Table 4
- 1. DiFilippo, M., J. Maulbetsch and K. Zammit. Status, I mpacts and Operations of Salinity Wet Cooling Towers. PowerPoint presentation.
Tetra Tech attempted to contact all manufacturing facilities listed in the above documents that have installed salt water towers since the Clean Water Act was passed in 1972, as well as an y electric generating facilities that have installed salt water towe rs in the past 5 A representative from Dow Chemical in California stated that the facility d oes operate a salt water cooling tower. After further discussion, it appears that the facility

1 the prevalence and design characteristics of cooling towers that used brackish water as a source for makeup facilities
. facilities using salt or brackish water as the makeup source from Maulbetsch, J. and M. DiFilippo. “Performance, Cost and Environmental Performance of Salt Water Cooling Towers.” Prepared for the California Energy DiFilippo, M., J. Maulbetsch and K. Zammit. Status, I mpacts and Operations of

listed in the above documents that have installed salt water towers since the Clean Water Act was passed in 1972, as rs in the past 5

oes not After further discussion, it appears that the facility2

may have used a salt water tower at one time (the docume ntation stated it was built in 1976) but the facilit y currently uses fresh water and has for quite some time. A representative from Lansing Smith (a power plant in Ly nn Haven, Florida) stated that the facility has been in operation with once
- through units since the 1960s, but added a natural gas combined cycle unit in 2001. The new generating unit uses mechanical draft cooling towers, with the makeup water being withdrawn from the discharge of the once
through units. The cy cle of concentration for the to wer is approximately 2.0 and the representative stated that they have had no significant problems with operating the towers and that chemical costs have been approximately as expected. The facility performs its own maintenance on the towers. T he tower al so utilizes a drift eliminator, as the facility has drift limits in its air quality permit. A representative from Watson (a power plant in Gulfport, Mississippi) stated that their facility has several t ypes of cooling towers. The facility ’s Unit 5 was bu ilt with a round cooling tower approximately 30 y ears ago ; it was recentl y demolished and replace d with a new linear bank of towers . The new towers are mechanical draft with a cy cle of concentration between 3 and 7 1 and were designed with plume and drift abatement. 2 The tower draws its makeup flows from the discharge canal of the other (once
- through) units. Construction of the new tower took approximately 12 months, with 6 months being required for the basins and another 6 months for the fiberglass struc ture and other above
ground elements. The tower was tied into the existing cooling sy stem during a planned 30 day outage, but the facility

representative noted that the outage would have been shorter if it had been solely for cooling tower tie
- in. The ne w tower cost approximately $42 million 3 and appears to be meeting its goals for parasitic power needs, chemical usage, and maintenance. Watson also has a helper cooling tower in its discharge canal; the tower straddles the canal, draws water up into the t ower, cools it, and then allows the water to fall back into the canal. There are no chemicals in use at the helper towers. Calls to the following facilities were not returned: Delano Biomass (CA), Intalco Aluminum (WA) , St. Johns River Power Park (FL) , C ry stal River (FL)
. Calls to the following facilities were not completed, as contact information could not be located: Pfizer (NC)
.

1 Due to the tidal activity near the facility, as well as precipit ation, salinity can vary widely; the frequency of blowdown depends on the buildup within the circulating water and varies accordingly. 2 The facility representative noted that there is a nearby highway. 3 The facility representative noted that this cost does not include any retrofit costs, as much of this infrastructure was already in place from the previous set of cooling towers.