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, Tetra Tech

DATE: September 10, 2008

SUBJECT: Phase II Facilities 

Tetra Tech was tasked with determining the number of facilities who are subject to 

thermal discharge limits in their NPDES permits. While summary

is not readily available, a query of EPA’s Permit Com

some insight to the issue.

PCS was queried for all of the Phase II facilities (by NPDES permit number) and cooling 

water and temperature-related fields were examined. Data was further screened by 

eliminating records that appear to refer to permit conditions that are no longer contained 

in the facility’s current permit (e.g., optional monitoring and deleted monitoring 

conditions fields). The tables

facilities (of 544 or 14%) appear to have thermal discharge limits of some type.

Note that this analysis has significant limitations and likely represents an approximate 

number of facilities; most likely it represents the minimum number of facilities with 

thermal discharge conditions. These limitations include: 

 Several states do not submit information to PCS

 Some states may not input data to all fields

 PCS may not adequately display narrative limits (thermal limits often narrative, 

such as a limit not to exceed 1

MEMORANDUM

10306 Eaton Place, Suite 340

Paul Shriner and Jan Matuszko, EPA

Kelly Meadows, Tetra Tech

September 10, 2008

Phase II Facilities with Thermal Discharge Limits

Tetra Tech was tasked with determining the number of facilities who are subject to 

thermal discharge limits in their NPDES permits. While summary-level data of this type 

is not readily available, a query of EPA’s Permit Compliance System (PCS) provides 

PCS was queried for all of the Phase II facilities (by NPDES permit number) and cooling 

related fields were examined. Data was further screened by 

ear to refer to permit conditions that are no longer contained 

in the facility’s current permit (e.g., optional monitoring and deleted monitoring 

s below shows the results of the analysis: approximately 78 

appear to have thermal discharge limits of some type.

Note that this analysis has significant limitations and likely represents an approximate 

number of facilities; most likely it represents the minimum number of facilities with 

onditions. These limitations include: 

Several states do not submit information to PCS

Some states may not input data to all fields

PCS may not adequately display narrative limits (thermal limits often narrative, 

such as a limit not to exceed 1°C within a radius of 1000 meters of the discharge)

Tetra Tech was tasked with determining the number of facilities who are subject to 

level data of this type 

pliance System (PCS) provides 

PCS was queried for all of the Phase II facilities (by NPDES permit number) and cooling 

related fields were examined. Data was further screened by 

ear to refer to permit conditions that are no longer contained 

in the facility’s current permit (e.g., optional monitoring and deleted monitoring 

shows the results of the analysis: approximately 78 

appear to have thermal discharge limits of some type.

Note that this analysis has significant limitations and likely represents an approximate 

number of facilities; most likely it represents the minimum number of facilities with 

PCS may not adequately display narrative limits (thermal limits often narrative, 

a radius of 1000 meters of the discharge)
- 2 -

In short, a detailed review of each individual permit and fact sheet would be required to 

most accurately assess the presence and scope of thermal discharge permit conditions at 

these facilities.

Thermal Limits by Type

Number of facilities Percent of total

Water Temperature 32 41.03%

Temperature Difference 

between Sample and 

Upstream 4 5.13%

BTUs/Heat Rejected 21 26.92%

Combination of the Above 21 26.92%

Total 78

Thermal Limits by Monitoring Frequency

Number of facilities Percent of total

Continuous 17 21.79%

Monthly 3 3.85%

Daily/Weekly 37 47.44%

Hourly 0 0.00%

Combination 7 8.97%

Not Specified 14 17.95%

Total 78

Thermal Limits by EPA Region

Number of facilities Percent of total

Region 1 5 6.41%

Region 2 9 11.54%

Region 3 10 12.82%

Region 4 17 21.79%

Region 5 32 41.03%

Region 6 1 1.28%

Region 7 3 3.85%

Region 8 1 1.28%

Region 9 0 0.00%

Region 10 0 0.00%

Total 78