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: John Sunda (SAIC)

DATE: June 15, 2009

SUBJECT: Review of Existing Cooling 

EPA requested a review of existing cooling tower installations to examine the degree of 

optimization (i.e., minimized makeup withdrawals) exhibited by these systems.

Estimates of theoretical make

power plants and different cycles of concentration (COC)

the cooling tower variable that has the greatest influence on make

requirements. A COC of 1.5 is a design maximum for saltwater. For freshwater s

a COC of 1.5 is considered the baseline below which 

be operating poorly with respect to flow reduction. 

considered as optimized. Estimated flow values for a COC of 2.0 

midpoint between the two. Attachment A

gpm/MW for each closed-cycle facility

DIF and AIF. These values are shown in comparison to the calculated make

for selected COC values of 1.5, 2.0, and 4.0. Note that other process flow such as 

requirements for flue gas desulphurization

values but this analysis does not attempt to

that show the make-up volumes graphically for different plant types and how the make

up volume varies with COC for an example tower.

Excluding the partially closed

Seven operate in an optimized manner, 

and six operate with a COC less than 

(greater than twice the COC = 1.5 

database.

 

1

Including facilities with cooling ponds.

MEMORANDUM

10306 Eaton Place, Suite 340

Paul Shriner and Jan Matuszko, EPA

John Sunda (SAIC) and Kelly Meadows

9

Review of Existing Cooling Tower Optimization

EPA requested a review of existing cooling tower installations to examine the degree of 

optimization (i.e., minimized makeup withdrawals) exhibited by these systems.

stimates of theoretical make-up volumes in gpm/MW expected for different types of 

power plants and different cycles of concentration (COC) were developed. The COC is 

the cooling tower variable that has the greatest influence on make-up volume 

requirements. A COC of 1.5 is a design maximum for saltwater. For freshwater s

the baseline below which the system should be considered 

poorly with respect to flow reduction. A COC of 4.0 or above should be 

stimated flow values for a COC of 2.0 are include

Attachment A contains an analysis that shows the calculated 

cycle facility1that completed a detailed questionnaire 

These values are shown in comparison to the calculated makefor selected COC values of 1.5, 2.0, and 4.0. Note that other process flow such as 

flue gas desulphurization could add up to 2.0 gpm/MW to the expected 

analysis does not attempt to adjust for that. Also included are two 

up volumes graphically for different plant types and how the make

up volume varies with COC for an example tower.

ly closed-cycle systems and cooling ponds, there are 20 intakes. 

operate in an optimized manner, seven operate in between a COC of 4.0 and 1.5, 

less than 1.5. Only 2 facilities could be considered outliers 

he COC = 1.5 flow) and one appears to be misclassified in the 

 

Including facilities with cooling ponds.

1

EPA requested a review of existing cooling tower installations to examine the degree of 

optimization (i.e., minimized makeup withdrawals) exhibited by these systems.

rent types of 

The COC is 

up volume 

requirements. A COC of 1.5 is a design maximum for saltwater. For freshwater systems, 

should be considered to 

A COC of 4.0 or above should be 

are included as a 

analysis that shows the calculated 

that completed a detailed questionnaire for both 

-up volumes 

for selected COC values of 1.5, 2.0, and 4.0. Note that other process flow such as 

could add up to 2.0 gpm/MW to the expected 

are two graphs 

up volumes graphically for different plant types and how the makeponds, there are 20 intakes. 

COC of 4.0 and 1.5, 

facilities could be considered outliers 

and one appears to be misclassified in the