Tetra Tech, Inc.

10306 Eaton Place, Suite 340 Fairfax, VA 22030 phone 703
- 385
- 6000 fax 703
- 385
- 6007
DATE: February

28, 2011
TO : Paul Shriner, EPA
FROM : Kelly

Meadows, Tetra Tech
SUBJECT: Space Constraints for Cooling Tower The size of the property play s an important role in determining whether a retrofit to cooling towers is feasible. EPA previously addressed the issue of land availability for cooling tower retrofits in its final effluent limitation guideline (EL facilities (39 FR 36186, October 8, 1974). In this EL G, determined that “28 acres per 1000 megawatts (MW) generating capacit y i s ample land on which an y existing plant can construct a mechanical draft c 36190.) The ELG also required a facility to consider relocating existing uses (such as parking areas), alternative cooling tower designs (e.g., natural draft towers, which require approximately

40% less land area), or the acquisi of whether sufficient space is available. earl y 1970’s, EPA collected new plant properties from site visits memo then explores the uncertainty over land availability retrofitting wet cooling towers on an existing facility

. This memo primarily

documents those sites EPA has v proposed section 316(b) rulemaking, and is not intended However , the data collected suggests (expressed in MW) to facility acreage

1 The ELG required that all existing facilities with a generating capacity of 500 megawatts or more w ould be required to retrofit to closed

- cy cle cooling. 2 Portions of the final ELG (including the requirements to retrofit to closed in 1976 in Appalachian Power Co. v. Train 1977 and modified in 1982) did not include requirements for reducing cooling flow. The Fourth Circuit rem anded the retrofit requirements on the g requirements; the Court did not specifically address the viability of the threshold for land availability. 3 See section 6 of the preamble. 

### MEMORANDUM

10306 Eaton Place, Suite 340

February 28, 2011 Paul Shriner, EPA Kelly Meadows, Tetra Tech Space Constraints for Cooling Tower Retrofits The size of the property play s an important role in determining whether a retrofit to cooling towers is feasible. EPA previously addressed the issue of land availability for cooling tower retrofits in its final effluent limitation guideline (EL G) for steam electric facilities (39 FR 36186, October 8, 1974). In this EL G, 1 the Agency stated that it had determined that “28 acres per 1000 megawatts (MW) generating capacit y i s ample land on which an y existing plant can construct a mechanical draft c ooling tower.” (See 39 FR 36190.) The ELG also required a facility to consider relocating existing uses (such as parking areas), alternative cooling tower designs (e.g., natural draft towers, which require approximately

40% less land area), or the acquisi tion of adjacent land in its consideration of whether sufficient space is available. 2 Since land uses have likel y changed since the new data on the acreage and production capacity site visits , reg ional offices, draft permits, and other sources. memo then explores the uncertainty over land availability 3 and other space constraints to retrofitting wet cooling towers on an existing facility

. This memo primarily

documents those sites EPA has v isited in support of the 2011 proposed section 316(b) rulemaking, and is not intended to provide a statistical anal ys is.

the data collected suggests that power plants where the ratio of facility

facility acreage is equal to or exceeds 160 should have ample space The ELG required that all existing facilities with a generating capacity of 500 megawatts or more w ould cy cle cooling. Portions of the final ELG (including the requirements to retrofit to closed

- cycle cooling) were re Appalachian Power Co. v. Train , 545 F.2d 1351 (4th Cir. 1976); the subsequent ELG (issued in 1977 and modified in 1982) did not include requirements for reducing cooling flow. The Fourth Circuit rem anded the retrofit requirements on the g rounds that EPA did not adequately consider the benefits of the requirements; the Court did not specifically address the viability of the threshold for land availability. The size of the property play s an important role in determining whether a retrofit to cooling towers is feasible. EPA previously addressed the issue of land availability for G) for steam electric the Agency

stated that it had determined that “28 acres per 1000 megawatts (MW) generating capacit y i s ample land ooling tower.” (See 39 FR 36190.) The ELG also required a facility to consider relocating existing uses (such as parking areas), alternative cooling tower designs (e.g., natural draft towers, which require tion of adjacent land in its consideration Since land uses have likel y changed since the acreage and production capacity of power

and other sources. This and other space constraints to
isited in support of the 2011

statistical anal ys is. facility size have ample space The ELG required that all existing facilities with a generating capacity of 500 megawatts or more w ould cycle cooling) were re ma nded (4th Cir. 1976); the subsequent ELG (issued in 1977 and modified in 1982) did not include requirements for reducing cooling flow. The Fourth Circuit rounds that EPA did not adequately consider the benefits of the requirements; the Court did not specifically address the viability of the threshold for land availability.to construct retrofit cooling towers. 4 EPA bases this ratio on the observation that

approximately 95 percent of the 4 7 sites with a ratio of 160 and above would have sufficient acreage to retrofit mechanical draft 5 cooling towers. For the 25 observed sites with a ratio less than 160 MW per 1000 acres, as many as 20 percent of the facilities would likely

be space constrained. This memo documents only the observations of each site visit team, and does not reflect a detailed engineering feasibility assessment for each site. For example, the configuration of the existing facility , topography , existing structures or uses, neighboring properties and uses, and other site

- specific details may constrain the potential locations for siting cooling towers. The table below summarize s the data collected (see Attachment A)

. EPA obtained most of the acreage data from facility ’s stated propert y boundaries during site visits

. Other site data was provided from facility permit app lications, by

EPA regions and state permitting authorities, or other site reports. This acreage includes the power block itself, transmission y ards, parking areas, coal piles, and all other existing equipment or land uses. 6 Next, the land area was normali zed by dividing the acres by

the facility ’s generating capacity

. 7 In doing so, a ratio of acres per 1000 MW was generated for all sites, thereb y allowing for a comparison of faci lities of all sizes and ty pes. Facility Type Range

(acres/1000 MW) Average Ratio

(acres/1000 MW) Median Ratio

(acres/1000 MW) All Site Visit Facilities 7

– 6216 858 350 Sites With Retrofit Cooling Towers 160

- 6216 2235 1920 Sites With Non

Retrofit Cooling Towers 83

– 5657 2318 1266

EPA also collected data on the facility size of plants with existing closed

- cycle cooling sy stems (i.e. the cooling towers were not a retrofit) . EPA was able (through basic internet searches) to find information on facility acreage for an additional 2 5 fa cilities with either partial or full closed

- cycle sy stems. Facility Type Range

(acres/1000 MW) Average Ratio

(acres/1000 MW) Median Ratio

(acres/1000 MW)

4 The analysis of acreage per 1000 MW only addresses electric generating facilities, as manufacturers may not generate any electricity or are otherwise engaged in other activities that will affect the applicability of such a ratio. 5 O nly mechanic al draft towers w ere considered; natural draft tow ers would generally occupy a smaller footprint of acreage, and may pose additional flexibility if the site were required to retrofit to closed

- cy cle cooling. 6 EPA recognizes that some elements of the pow er plant ma y be owned by other parts of the facility’s parent firm (e.g., the transmission yard is sometimes owned by a sister company). EPA considers these areas to also be part of the facility’s property, as it is still under the parent firm’s control. 7 As stated in the 1974 ELG, [t]he size of the evaporative c ooling tow er is related to the generating capacity of the unit.” (39 FR 36189)Partial CCRS 202

– 16,667 3077 1304

Closed

- Cycle Cooling 117

– 5654 1285 850

Case Studies
Two facilities are worth discussing in greater detail as case studies for space constraints to cooling tower retrofits

. Brayton Point : Bray

ton Point Station in Massachusetts is currently constructing two natural draft cooling towers as part of a closed

- cy cle cooling sy stem retrofit. EPA Region I and Dominion Energy conducted thorough anal ys es on all aspects of the retrofit before Dominion Energy determin ed the final design. S pace constraints at the site w as not identified as a feasibility issue in retrofitting to cooling towers. In this analy sis , Bra yt on Point’s ratio was 160 acres/1000 MW. McDonough : McDonough Power Plant in Georgia converted an older coal

- fired plant to closed

- cycle cooling (with a wet cooling tower) in 2008 as part of a broader plan to repower the site to use multiple natural gas combined cy cle generating units. To install the towers, Georgia Power demolished the adjacent Atkinson Plant to create space to construct the cooling towers. Georgia Power also faced a number of challenges in retrofitting the towers, including relocating maintenance buildings, burying cooling water pipes, and adding pump stations. 8 According to data collected during the site visit , the ratio for McDonough (using the cur rent coal

- fired generating capacity and the original dimensions of the site) is 612 acres/1000 MW. However, given the construction of the two new combined cycle units on other parts of the propert y, the effective acreage of the McDonough site could be as little as 80 acres , making the facility ’ s ratio 163

. 9

8 See EPA’s site visit report for this facility ( DCN 10

- 6536 ) for a complete description. 9 Using aerial photos of the site, the footprint of the two new combined cycle units an d the existing coal pile occupy a significant portion of the site. By approximating the remaining area that would be dedicated to the existing generating unit (and eventually the final combined cycle unit), a polygon approximately 3500 feet by 1000 feet can be identified, resulting in an area of 80 acres.