1 Site Visit Report Wateree Station 142 Wateree Station Road Eastover , SC 29 044 February 10 , 2009 1.0 Background and Objectives The Environmental Protection Agency (EPA) is in the process of developing 316(b) cooling water intake structure requirements that reflect the best technology available (BTA) for minimizing adverse environmental impact for all existing power plants and manufacturing facilities. As part of this process, EPA staff is visiting electric generators and manufacturers to better understand the cooling water intake structure (CWI S) technologies in use at ty pical facilities, including the site

- specific characteristics of each facility and how these affect the selection and performance of CWIS technologies. EPA is also visiting facilities to better understand cooling water use and specific issues or technologies that can affect 316(b) compliance. Wateree Station ( Wateree ) was selected for a site visit due to its use of a retrofitted recirculating cooling water system

. 2.0 Facility Description W ateree Station is owned and operated b y South Carolina Electric and Gas (SCE&G) and is located in rural Eastover, South Carolina along the Wateree River . The facility

is located on approximately 2300 acres. Wateree Station employ s 105 people and began op eration in 1970. Cooling and process water withdrawals from and wastewater discharges to the Wateree River are regulated under NPDES permit number SC000 2038 which expire d on May

31, 2005

. SCE&G submitted its NPDES permit application in a timely manner and is awaiting renewal of its permit by the state. 3.0 Electricity Generation and Transmission Wateree Station has two generating unit s . Both Units 1 and 2 have generating capacities of 370 MW at full load. Units 1 and 2 began operation in 1970 and 1971, respectivel y. The fuel source for both units is eastern bituminous coal. The overall capacity

utilization rate ( CUR ) at Wateree Station is approximately 85 %. That is, the plant is alway s operating , but cycles its load to respond to peaks. The facilit y has two routine two week maintenance outages that occur during the spring and fall. The facility also has an 8

- 10 week turbine unit outage approximately

every 5 y ears for unit overhaul.2 Like the generating portion of Wateree Station, the transmission sy stem is owned by SCE&G , but is operated by a different business unit. 4.0 Cooling Water System and Intake Structure Both generating units at Wateree Station operate with closed cy cle recirculating sy stems (CCRS). Each unit has a dedicated CCRS. Each g enerating unit originally had individual CWIS s that provided once - through cooling water. The intake structures are located in an approximately 500 foot long intake canal connected via culverts to the Wateree River. E ach intake structure had two intake pumps and four standard traveling screens. The through

screen velocit y is unknown, but based on responses to EPA’s industry questionnaire was estimated to be 2.3 fps. The design intake flow (DIF) of cooling water withdrawal was approximately 490 mgd ( 170,0 00 gpm ) per unit. At that time, the permit allowed for up to two

- thirds of the river flow to be pulled into the plant as cooling water. Wateree’s discharge point to the Wateree River is on the opposite side of the facility as the intake screens and empti es directly into the river. 5.0 Impingement and Entrainment Information Wateree Station has not conducted an y source water monitoring , impingement or entrainment studies. 6.0 Cooling Tower Feasibility To address 316(a) concerns, the facility was originally co nstructed with two “helper towers” located near its discharge point. T he facilit y passed 100% of its discharge flow through the helper towers and was able to alter the towers’ operation depending on their needs ; different combinations of cells and fans co uld be operated independently depending on the temperature needs. However, the Wateree River experienced an extreme drought for several years. Due to the drought and the temperature of the river water, Wateree was unable to meet its cooling water requi rements or its required discharge temperatures. As a result, Wateree Station converted to closed

- cy cle cooling in 2006 by constructing new cooling towers

. 1 The facility tied in Unit 2 first and Unit 1 six months later. Each retrofitted fiberglass mech anical draft CCRS consists of ten cells with standard GEA fill in a back

- to
- back configuration (five cells each side).

1 The helper tow ers are located on a different part of the site than the ne wer tow ers. One helper tow er collapsed some time ago and it not usable. The second has been decommissioned and the facility is in the process of determining what to do with the equipment.3 Each tower has two fixed speed circulating water pumps each rated at 123.8 mgd (86,000 gpm) and uses ten 200 horsepower fan s . The facil ity designed each unit’s tower basins to allow for expansion of 4 extra cells per unit. Wateree Station requires a total of 16 mgd ( 11,000 gpm ) of make

- up cooling water for the CCRS sy stems. 2 Wateree continues to obtain make

- up water from the intake canal, but replaced the circulating pumps with much smaller pumps to provide makeup water . The new s ys tem passes make

- up water through the existing coarse mesh traveling screens 3 and then through a series of 10 micron sand filters that backflush automatical ly at a minimum of every

120 hours or more frequentl y if solids accumulation becomes an issue

. 4 The facility installed the sand filters to address concerns with river pollutants associated with run

- off from local dairy

farms. A second filtration loop withdraws approximately 1 mgd (700 gpm) from within the cooling tower basin to further remove solids. The CCRS at Wateree is automatically controlled through a remote control center equipped with back

- up battery s ys tems. The facility

adds corrosion inhibito rs, dispersant, and biocide (in the form of 12 .5 % sodium hy pochlorite) to the water in the cooling towers. Through an automated s ys tem, Wateree regularl y monitors the turbidity

and pH levels in the recirculated water . The towers run at 2.7 cy cles in the summer and 4.3 cycles in the winter. Blowdown flows are approximately 1.7 mgd (1200 gpm) per tower in the summer (at full load) and 720,000 gpd (500 gpm) in the other seasons. Facilit y representatives noted the biggest challenges in retrofitting its sit e to CCRS were underground springs in the area where the tower s were constructed

. The facility

noted no other issues associated with the retrofit including permitting (they were required to obtain a wetlands permit), noise, air concerns, etc. The towers are also fitted with drift eliminators, but not plume or noise abatement. The entire construction project took two y ears, while the actual tie

- in required about an 8 week outage. Facilit y representatives indicated that the operation of CCRS was fairly sm ooth and that the CCRS ha s been reliable. Finally , facilit y representatives stated that the facility did not experience a reduction in power output upon CCRS retrofit. Rather, they experienced an increase in annual power output because they were no longe r limited by their previous summer to winter differential associated with 316(a) limits. Facility representatives also stated that the condensers are much cleaner than before, as mud and debris from river water is no longer present in the cooling water fl ow;

2 The CWIS has tw o 11,000 gpm makeup pumps but only needs to operate one; the other is a backup. 3 Facility representatives noted that they intend to remove the traveling screens in the near future, leaving onl y the trash rack at the CWIS. 4 Wateree noted that the sand filters have yet to reach the required cleaning level so that, in effect, the sand filters are backwashed every 120 hours irrespective of the need for cleaning.4 this has reduced maintenance and improved the efficiency of the condenser. Additionally , because Wateree installed new transformers as part of its CCRS retrofit, it also obtained additional electrical capacity within the plant. Wateree indicated that the total capital cost for the two closed cy cle recirculating sy stems was $65 million and estimates total chemical costs to be $200,000

– 250,000 per ye ar. Facility representatives indicated that the O&M costs associated with the CCRS were less than thos e associated with the helper towers. 7.0 Debris Handling Wateree does not have significant problems with debris loading. 8.0 Repowering/Future Uses SCE&G has not allocated any funds in its current capital budget for re

- powering or additional units. However, as explained above, the facility designed the towers to allow for possible expansion. 9.0 Cooling Ponds There are no cooling ponds onsite. 10.0 Ownership Wateree is owned b y S CE&G, an investor

- owned company

. 11.0 316(a) Following conversion to closed

- cy cle coo ling, Wateree meets all 316(a) requirements. 12.0 Ash Handling Units 1 and 2 have wet bottom ash handling. Bottom ash is sluiced and sent to a series of clay

lined ash ponds. The first pond (approximately 80 acres) receives the ash and provides some settlin g. The first pond discharges to the second pond (also approximately

80 acres) which provides additional settling. The discharge from the second p ond is treated with sulfuric acid and/or caustic to maintain an effluent pH of 7. Fly ash is shipped off

- s ite for sale, frequently

to cement companies. Prior to being shipped off

- site for sale, high carbon content fly ash is sent to a “carbon burnout” unit on - site. Carbon burnout is a process in which high carbon content ash is sent through a furnace allowin g for heat recovery and a higher grade of resulting ash for re

- sell.5

13.0 Air Emissions Controls Units 1 and 2 are equipped with baghouses for particulate control and SCRs ( which are operated ye ar round) for NO x control. They are planning on installing FGD s ys tems in the spring of 2010 as well. As part of that installation, Wateree Station is currently construct ing an on - site landfill to handle the associated FGD solid wastes. The landfill is designed to meet all applicable state (SCDHEC) solid waste r equirements including a comp osite liner (clay liner and geos ynthetic/clay liner) , leachate collection sy stem, and monitoring wells. Lea chate from the landfill will flow into a holding pond and then be transferred to the first ash pond discussed in Section 12.0

. As indicated in Section 2.0, at the time of the site visit, the facility ’s NPDES permit ha d expired. The main issue that delay ed the permit reissuance is local protests of the proposed landfill. Wateree indicated the permit was issued and SCE& G filed a subsequent permit modification application

. Attachments Attachm ent A List of A ttendees Attachment B Aerial Photo s Attachment C Cooling Tower Design Specifications Attachment D Site Visit Photos6

Attachment A -- List of Attendees Paul S hriner, EPA Jan Matuszko, EPA Kelly Meadows, Tetra Tech Steve Summer, SCANA Services, Corporate Environmental Services Milton Quattlebaum, SCANA Services, Corporate Environmental Services Mark Ferguson , SCANA Services, Corporate Environmental Services Apri l Kelly , SCE&G, Wateree Environmental and Safety Supervisor Robbie Padget, SCE&G Oscie Brown , SCE&G

## Copyrighted page(s) have been removed from this document. Please contact the EPA Docket Center, Public Reading Room to view this document. Address: 1301 Constitution Ave, NW Room 3334 Washington, DC 20004 Telephone: 202-566-1744 Fax: 202-566- 9744 Email: docket-customerservice@epa.gov8

Attachment C

— Cooling Tower Design Specifications Please see the attached materials. Attachment D

— Site Visit Photos Pl ease see the attached materials

.