1

Site Visit Report

North Anna Power Station

1022 Haley Drive

Mineral, VA 23117

April 28, 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 (CWIS) technologies in use at typical 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. The North Anna Power Station (North Anna) was selected 

for a site visit due to its proximity to EPA Headquarters and its use of a 

freshwater reservoir.

2.0 Facility Description

North Anna occupies about a 1080 acre site in Louisa County, Virginia on the 

southern shore of Lake Anna. The facility is owned and operated by Dominion 

Virginia Power (Dominion). The North Anna facility is very similar in design to 

Dominion’s Surry site. The site is surrounded by Lake Anna, a 9600 acre lake 

created by impounding the North Anna River, and the Waste Heat Treatment 

Facility (WHTF), a 3400 acre series of three lagoons designed for the removal of 

waste heat, both owned by Dominion. Dominion owns up to 5 feet water 

elevation above the lake and WHTF and issues access rights to local home 

owners. The facility began operations in 19781and employs approximately 900 

people.

The facility’s NPDES permit (VA0052451) is due to expire October 24, 2012. In 

March 2003, the NRC extended licenses for both units 1 and 2 for an additional 

20 years (April 2038 for unit 1 and August 2040 for unit 2).

3.0 Electricity Generation and Transmission

North Anna was originally designed to have four nuclear reactors, but only two 

reactors2 were built that currently operate with a total of 1941 MW3(gross 

 

1

For Unit 1; Unit 2 began operations in 1980. Both are Westinghouse pressurized water reactors (PWRs).

2

See Section 8.0 for information on a proposed Unit 3.
2

summer capacity). Both generating units are baseload units (with a capacity

utilization rate [CUR] of over 90%) and provide power to over 450,000 homes in 

the Richmond and northern Virginia areas. In 2007, North Anna produced 

approximately 15 billion megawatt hours with a capacity factor of 87 percent.

Unit 1 was last shut down March 2009 for the refueling outage. North Anna 

rotates refueling outages between the two units every 18 months.

The transmission system is owned by Dominion but is operated by a different 

business unit.

 

4.0 Cooling Water System and Intake Structure

North Anna withdraws once-through cooling water from a CWIS on the shore of 

Lake Anna. The CWIS consists of a trash rack and eight intake bays (four for 

each unit). Each bay has a coarse mesh (1/8 x 1/2 inch) traveling screen4and one 

circulating pump.5 The screens are rotated based on a head differential across the 

screen and cleaned with a high pressure spray wash. There is no fish/debris 

return, as all materials are collected and transported to a landfill. The design 

through-screen velocity is 2.7 feet per second (fps).6 Modification of the existing 

intake to reduce the screen velocity down to 0.5 fps would require more than 

doubling the size of the existing intake bays, even assuming dual-flow (Passavant) 

type screens were retrofitted. Facility representatives indicated a low pressure 

spray and fish return could potentially be retrofit for impingement mortality

reductions if necessary.

The design intake flow (DIF) for North Anna is 2539 mgd. The average actual 

flows (AIF) for the facility are: winter flow is 1325 MGD with 3 pumps in 

operation (throttled) per unit; spring/fall flow is 1872 MGD with 3 pumps in 

operation per unit; summer flow is 2376 MGD with 4 pumps in operation per 

unit. The ΔT across the condensers is approximately 14°F.

Lake Anna was constructed for the specific purpose of providing cooling water 

for the North Anna facility. Dominion purchased over 18,000 acres and, in 1972, 

constructed an earthen dam on the North Anna River.7 Two distinct waterbodies

were created: Lake Anna, (9600 acres) and the WHTF (3400 acres) for the 

removal of waste heat.8 North Anna is the only facility permitted by the state of 

Virginia to withdrawal water from Lake Anna. 

 

3

In recent years, the facility has upgraded its turbines, moisture separators, and other equipment to provide 

an increase in capacity of over 100 MW.

4 The screens were installed in 2005.

5 Each pump has a capacity of 317 million gallons per day (mgd) (or 220,376 gpm).

6 The through-device velocity at the trash rack is 1.2 fps.

7 The dam is maintained and permitted by Dominion. Dominion recently installed a small hydroelectric 

generator at the discharge of the dam; the power is sold to the grid.

8

In addition to providing for the removal of heat, Lake Anna has also been extensively developed as a 

recreational waterbody. Waterfront homes and a state park occupy much of the 200 miles of shoreline, 
3

The WHTF is separated from Lake Anna by a series of dikes, inundating former 

creek watersheds upstream. It was expressly designed as a heat treatment 

technology and was designed prior to the passage of the Clean Water Act (CWA) 

in 1972. The Virginia Department of Environmental Quality (DEQ) has 

consistently supported this design and its classification as a treatment system 

rather than waters of the US; the state Attorney General also recently issued a 

formal legal opinion that detailed the state’s legal position in support of this 

classification. 

Cooling water is withdrawn via the CWIS from Lake Anna. After passing 

through the facility, heated effluent is discharged to a 1/4 mile long discharge 

canal, which discharges into the first of a series of three treatment lagoons that 

comprise the WHTF. Lagoon 1 (the smallest of the three) is separated from Lake 

Anna by Dike 1 and is connected to Lagoon 2 by a 1/2 mile long canal on its 

southern shore. Lagoon 2 is bounded by Dike 2 and connected to Lagoon 3 via 

another 1/2 mile long canal, also on its southern shore. Effluent in Lagoon 3 

passes through a subsurface discharge weir9in Dike 3 into Lake Anna, near the 

dam. Facility representatives stated that modeling results suggest that residence 

time in the WHTF is approximately one week.

Water levels in the WHTF are typically 1-1.5 feet higher than the level in Lake 

Anna, creating an induced current in the WHTF. The design discharge velocity at 

the weir is approximately 6 fps. Given the volume of effluent discharged from 

the WHTF and the volume of water discharged at the dam (usually 40 cfs10), 

facility representatives stated that there is some circulation of effluent in a 

northerly direction (i.e., towards the CWIS).

5.0 Impingement and Entrainment Information

Lake Anna has numerous fingers from incoming streams and an average depth of 

25 feet.11 Facility representatives stated that the North Anna River previously had 

very low flows and supported minimal biological activity. When the lake was 

formed, the species composition changed from riverine species (e.g., yellow 

perch) to a distribution more typical of lakes (e.g., bluegill), but for over the past 

10-15 years, the species composition has remained relatively constant. The 

 

including along the WHTF. However, there is no public access or commercial enterprise in the WHTF—

access is strictly limited to those residents along the shores. Dominion owns the entire shoreline (from an 

elevation of 250 to 255 feet above sea level) and the lake bottom and regulates any uses, construction, and 

other activities in both the lake and WHTF.

9 The weir is a controlled discharge structure that passes beneath the roadway spanning Dike 3. A curtain 

wall extends downward to approximately 13 feet below normal lake level, where a series of 6 discharge 

bays are located. Each bay is approximately 20 feet wide and 15 feet deep (extending to the lake bottom). 

Each bay can be fitted with up to three stop logs to block discharge flows; Dominion currently operates the 

weir with 10 of the 18 stop logs in place, forming an open discharge area in the center of the weir.

10 Reduced to as low as 20 cfs during drought conditions.

11 The deepest portion of the lake is near the dam, with 80 foot depths.
4

Virginia Department of Game and Inland Fisheries (DGIF) stocks Lake Anna 

with a variety of fish; Lake Anna is widely recognized as a prime recreational 

fishery.

12

Dominion has conducted biological monitoring at multiple locations since before 

the facility was constructed. They have conducted electrofishing at nine locations 

and gill net sampling at six locations spread out in Lake Anna and the WHTF in 

March, June, August, and November. As required by North Anna’s permit, 

Dominion reports the monitoring results to the state. Dominion has collected over 

1700 electrofishing samples totaling 194,000 fish representing 39 species and 

1100 gill net samples totaling 35,000 fish representing 37 species. Facility 

representatives added that the monitoring indicates a stable, sustainable fish 

population in both the lake and the WHTF and that the biological composition in 

Lake Anna and the WHTF are virtually identical in both density of organisms and 

distribution of species.13 Dominion also conducts thermal and biological 

monitoring at several sites uplake and downlake of the facility and noted that the 

North Anna River (downstream from the facility) has been similarly studied since 

the 1960s. 

From 1979-1983 Dominion conducted an impingement and entrainment study. 

The most abundant species collected were gizzard shad, yellow perch, and black 

crappie. The majority of impingement (approximately 75%) occurred in the 

winter and biologists determined that the impingement represented less than 1% 

of the standing stock of fish in Lake Anna.

From July, 2005- July, 2006 Dominion collected impingement data in preparation 

for compliance with the now-suspended 2004 Phase II rule. During the sampling 

periods, North Anna conducted impingement sampling two times a month for a 

year for a total of 24 sampling events. During each 24-hour sampling event, the 

facility ran the screens continuously and collected impingement samples from 

each screen wash for 10 minutes each hour. The facility did not conduct 

entrainment sampling.

14

The 2005-2006 data collection showed 1386 individuals from 18 species, with 

bluegill as the predominant species.15 Facility representatives noted they

 

12 It is not clear how the stocking affects overall fish populations or mitigates any potential changes to 

biology of the lake as a result of the plant intake structures.

13 There is also some evidence of movement of organisms between Lake Anna and the WHTF; a tagged 

walleye was released at the northern end of the lake and was caught by a fisherman at the discharge canal 

less than a year later.

14 The facility is located on a lake and would therefore not have been subject to entrainment requirements.

15 Threadfin shad and gizzard shad were the second and third most abundant; threadfin shad are stocked as 

a prey species for walleye and largemouth bass. 
5

collected more fish at night and that many were young of the year. The estimated 

annual impingement rate was calculated as approximately 153,880 fish.16

6.0 Cooling Tower Feasibility

North Anna has not considered retrofitting cooling towers for the two existing 

units. Facility representatives stated the heat exchangers on the existing units 

would need to be replaced to accommodate the higher back pressures of a cooling 

tower. Much of the available area near the power block (originally left for units 3 

and 4) may eventually be occupied by the proposed new Unit 3.17 The new Unit 3 

as proposed would be approximately 1600 MW (roughly equal to the production 

of units 1 and 2 combined) and would employ a hybrid of dry-cooling and closedcycle wet cooling. The dry-cooling unit would be used during the highest heat 

loads to reduce cooling water temperatures prior to the wet cooling tower, 

reducing evaporative losses and reducing make-up water requirements from Lake 

Anna. Facility representatives indicated Unit 3, if constructed, could begin 

operation by 2018.

Facility representatives also stated that enclosing the WHTF (by sealing the 

discharge at Dike 3) and adding a circulating pump to return water to the CWIS 

would be prohibitively expensive, given the long piping distance.18

7.0 Debris Handling

North Anna does not have significant problems with debris loading. Facility 

representatives did note that there are occasional problems with hydrilla or other 

debris (especially after storms), but these events do not significantly affect 

operations. 

8.0 Repowering/Future Uses

As stated above, the original design plan for North Anna included four generating 

units. Dominion has received an Early Site Permit for the proposed Unit 3, which 

would come online in approximately 2018. The new unit as proposed would have 

a generating capacity of 1600 MW and would be located adjacent to Units 1 and 

2. Unit 3 would employ a closed-cycle cooling system;19 it would not contribute 

any additional heat to the WHTF or Lake Anna.

 

16 This estimate was based on withdrawal rates at 100% of the DIF for the entire year, which is very rarely 

the case. Additionally, the impingement data did not exclude moribund fish (such as gizzard shad), which 

likely led to a larger estimate for annual impingement.

17 The early site permit (ESP) application for unit 3 was approved by the NRC in 2007. Application for a 

combined construction and operating license was submitted for a GE–Hitachi Economic Simplified Boiling 

Water Reactor (ESBWR).

18 A straight line pipe would be approximately 8 miles long, but would require installing pipe across all 

three cooling lagoons; a land-based route would be far longer.

19 Unit 3’s cooling system would be a hybrid system; a low profile natural draft cooling tower (with fan 

assistance and some dry cooling design features to minimize the visible plume) would be the primary 
6

There are currently no plans to construct Unit 4, but facility representatives 

indicated that the site plans for Unit 3 would allow for addition of a fourth unit.

9.0 Cooling Ponds

As discussed in Section 4.0, the WHTF has been identified by the permitting 

authority as a treatment system for waste heat. Lake Anna is classified as a water 

of the U.S. and is subject to water quality standards.

10.0 Ownership

North Anna is owned by Virginia Electric and Power Company d/b/a Dominion 

Virginia Power, a subsidiary of Dominion Resources, Inc., an investor-owned 

company.

11.0 316(a)

As discussed in Section 4.0 above, the WHTF was specifically designed and 

constructed to dissipate waste heat from North Anna. Facility representatives 

stated that the water temperature at the discharge is within a few degrees of the 

lake temperature.

North Anna has a heat rejection limit at the discharge canal from the facility that 

is based on BTUs per hour in its NPDES permit; temperature monitoring is 

conducted at the Dike 3 discharge.20 The facility was granted a 316(a) variance 

for thermal discharges at Dike 3.

12.0 Ash Handling

North Anna does not use coal as a fuel and therefore has no ash ponds.

 

13.0 Air Emissions Controls

North Anna does not use any air emissions controls.

14.0 Additional Information

The Blue Ridge Environmental Defense League (BREDL), a regional 

environmental group, appealed the NPDES permit renewal issued by the State 

Water Control Board to North Anna in 2007. A focal point of the suit concerned 

the point of application of the thermal discharge limits and the classification of 

 

cooling mechanism. When lake levels become low and water consumption is a concern, the unit would 

switch over to a series of dry cooling towers.

20 Dominion also collects temperature data from other locations (e.g., locations within the WHTF) but these 

are for informational purposes.
7

the WHTF as a waste treatment system. The state circuit court issued a final 

order in September 2009, finding that the Board’s classification of the WHTF as a 

waste treatment system was contrary to law. Dominion and the Board appealed 

the decision to the Virginia Court of Appeals in October 2009, and a decision is 

expected in 2010.

Facility representatives indicated that they had not reached a decision on how they

would have complied with the 2004 Phase II existing facility rule on cooling 

water intakes . They were evaluating technologies, restoration, and other 

alternatives when the rule was suspended. At that time, they were leaning 

towards the cost-benefit alternative and/or restoration.

Attachments

Attachment A List of Attendees

Attachment B Aerial Photos

Attachment C PowerPoint Presentation (April 28, 2009)

Attachment D North Anna Emergency Plan Map

Attachment E Impingement and Entrainment Studies for North Anna Power 

Station (1978-1983)
8

Attachment A--List of Attendees

Paul Shriner, EPA

Jan Matuszko, EPA

Shari Goodwin, Tetra Tech

Kelly Meadows, Tetra Tech

Bill Bolin, Dominion 

Randy Markey, Dominion 

Judson White, Dominion 
1

Site Visit Report

Sunoco—Philadelphia Refinery

3144 Passyunk Avenue

Philadelphia, PA 19145

July 14, 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 (CWIS) technologies in use at facilities, including the sitespecific 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. Sunoco’s Philadelphia Refinery was selected for a site visit 

because it utilizes cooling water in refining of petroleum products.

2.0 Facility Description

Sunoco’s Philadelphia Refinery is located on a 1000 acre site in southwestern 

Philadelphia along the Schuylkill River. The site originally began operations in 

the 1860s (processing whale oil), began processing crude oil in 1900, and 

eventually merged with an adjacent refinery; accordingly, Sunoco considers the 

site as two separate entities1from a water use perspective and has retained 

separate NPDES permits for each.2 The site employs approximately 1000 people.

3.0 Manufacturing Information

The Philadelphia Refinery processes petroleum into a variety of fuels, chemicals, 

and other products. Point Breeze produces gasoline, diesel, and a small amount of 

other products, while Girard Point produces a similar mix of products plus 

benzene.3 According to facility representatives, the facility is typical of a midsize 

refinery.

 

1

Point Breeze (formerly the Atlantic Refinery) is the original refinery and was purchased by Sunoco in 

1988; the adjacent Girard Point was acquired in 1994. Since the facilities previously operated 

independently, each site has much of the same equipment, increasing operational flexibility. The site is 

generally operated as a single refinery (it has one central management/operations center and single air 

emissions and solid waste permits) but is treated as separate sites for water-related functions. The sites 

share some water and steam, but are largely independent for water usage.

2

Point Breeze’s permit number is PA0012629 and Girard Point’s is PA0011533. Girard Point’s permit is 

due to expire on February 28, 2011 and Point Breeze’s is due to expire on January 31, 2011.

3

Intermediate products can be shared between Point Breeze and Girard Point, as well as the Marcus Hook 

refinery.
2

Typically, the refinery operates 24 hours a day.

4

 Production may fluctuate 

depending upon product demand, which can be impacted by outside factors such 

as industry capacity. At the time of the visit, the site was producing at 

approximately 70-80% capacity. Production does not vary greatly on a seasonal 

basis, but the mix of products may change.5

Crude oil is supplied by the Fort Mifflin Terminal Complex on the Delaware 

River in Philadelphia to the Point Breeze Facility, and by Hog Island Wharf Dock

in Tinicum Township and Fort Mifflin Terminal Complex to the Girard Point 

facility where ships unload crude oil to storage tanks and pipelines. Point Breeze 

processes approximately 130,000 barrels per day (bpd), while Girard Point 

processes approximately 210,000 bpd.

4.0 Cooling Water System and Intake Structure

The site has 3 active CWISs, each with a shoreline intake.6 Point Breeze operates 

one CWIS near the boat dock; it feeds a fully recirculating cooling water system 

(CWS) with mechanical draft cooling towers.7 The other 2 CWISs (on the 

shoreline of the inside bend of the river) service Girard Point’s CWS; it uses both 

once-through cooling and recirculating cooling via mechanical draft cooling 

towers. The following table summarizes the information for these intakes; more 

information is below.

Point Breeze Girard Point Total

# CWIS 1 2 3

# traveling 

screens

0 3 3

Design Intake 

Flow (DIF)

20.7 MGD 31.7 & 15.8 MGD 68.2 MGD

Actual Intake 

Flow (AIF)

4.2 MGD 11.8 & 0.4 MGD 16.4 MGD

Through-screen 

velocity

1.5 fps 1.5 fps

 

4 The entire refinery is never taken offline at the same time. Individual process units may close for 

maintenance, with sufficient storage of intermediate products to enable continued production at the other 

process units. Alternatively, the process unit may share capacity or products with the adjacent equipment 

or the Marcus Hook refinery or may purchase the needed products commercially. Some unit closures may 

require that additional associated units also be closed.

5

For example, the facility may increase the production of heating oil in the winter.

6

Point Breeze’s North Yard CWIS is out of service. Girard Point also has one CWIS that has been out of 

service for decades.

7

Facility representatives noted that the cooling towers have been in place for some time; they were 

unaware of the rationale for constructing them instead of using once-through cooling.
3

Point Breeze’s CWIS had coarse mesh fixed screens located in the bulkhead near 

the dock (at a depth of approximately 15-20 feet) but they had been removed from 

service many years ago. 

The screens are periodically cleaned by divers, as debris and silt are much less 

problematic at this intake. The only cooling water uses are for makeup water for 

the cooling towers.

Girard Point’s CWISs are located on the shoreline of the inside bend of the river 

at a depth of approximately 14-16 feet. They are fitted with rotating coarse mesh 

(3/8”) traveling screens. One CWIS is used to provide non-contact, boiler, and 

process water to the plant and uses the intake structure for a former onsite water 

treatment plant and has two 6 foot wide coarse mesh traveling screens. These 

screens were rebuilt in 1990 and facility representatives stated that they have 

proven to be expensive to operate. These screens are rotated twice per shift and 

the combined fish/debris return trough discharges just outside the pumphouse into 

the river. A chain link fence submerged in the river acts as an additional layer of 

screening in front of the trash racks.

The other CWIS for Girard Point (located just to the north of the CWIS described 

above) is largely used for supplemental (service water) flows and has one 

functional 6 foot wide traveling screen. (A second screen is non-functional.) 

Two circulating pumps are installed, but typically only one is used. This screen is 

rotated once per shift. Dredging in front of both Girard Point intakes occurs on an 

occasional basis.

The Girard Point intakes previously supplied a much larger volume of oncethrough cooling water before some process lines were converted to recirculating 

systems in the 1980s. (See Section 5.0 below.)

In sum, the DIF for the entire refinery is 68.2 MGD and the total AIF for both 

sites is approximately 16.4 MGD, according to facility representatives. At the 

time of the site visit, approximately 12.9 mgd was being withdrawn, with 

approximately 3.6 mgd as makeup water for the various cooling towers; the 

remaining flows are largely dedicated to boiler feed water.8 Water usage varies 

seasonally, as the capacity of the cooling tower, evaporative potential, and drift 

change with the weather. In the summer, the facility typically withdraws 15.0

MGD to 20.0 mgd, with approximately <5% being used as once-through noncontact cooling water.

Typically, one operator is charged with multiple duties at a process unit, including 

operating the cooling tower or operating the traveling screens. The worker may

conduct visual inspections, basic chemical tests to ensure proper tower 

functioning, and manually triggering screenwash cycles.

 

8

Facility representatives stated that the facility produces less steam than in the past, as it is cheaper to buy 

electricity than to produce it onsite; as such the water withdrawals have decreased.
4

Aside from the two halves of the refinery, there are no other major users of 

cooling water nearby, thereby reducing the viability of sharing steam, reclaimed 

water, or other approaches to reduce intake withdrawals.

5.0 Flow Diagram

The facility withdraws surface water for once-through non-contact cooling, 

cooling tower makeup, boiler feed water, process water, and for fire suppression. 

A significant portion of the facility’s water withdrawals are dedicated to 

providing makeup water for cooling towers or for supplying treated water for 

boiler feed or other process uses. The remaining <5% is used for non-contact, 

once-through cooling.

Facility representatives noted that the refinery previously used much higher 

quantities of water--especially once-through cooling water. During the 1980’s, it 

significantly reduced once-through cooling. For example, it added new cooling 

towers to handle cooling loads. The facility continues to reduce water usage. 

Facility representatives noted that engineers were making a concerted effort to 

recover condensate and identify other opportunities for process optimization, as 

the water recovered is of very high quality, has already been treated, or retains 

some amount of heat that can be recovered. Stripping steam is typically recycled 

as process water, largely as wash water for desalters. The fluid cat cracking units 

also collect steam and reuse the water as sour water. Boiler water is treated and 

softened, and is then injected into the process unit as steam. However, the facility

noted that while it strives to reduce water usage, some activities lead to increased 

water usage. For example, the facility recently constructed a wet gas scrubber to 

control air emissions, which increased water usage at the site by approximately

10-15%.

6.0 Electricity Generation and Transmission

Point Breeze has a one 2.5 MW generating unit and Girard Point has three 

generators.9 The Point Breeze generating unit operates on gas produced by 

offgassing and produce power to be used onsite. The Girard Point generators 

operate on 680# steam. The units use river water for cooling.

7.0 Impingement and Entrainment Information

Facility representatives were unaware of any source water characterization, 

impingement, or entrainment studies conducted at the site.

Neither NPDES permit contains requirements for 316(b). The facility does, 

however, have a water use permit with the Delaware River Basin Commission 

(DRBC), which assesses a fee for water withdrawals.

 

9 The turbines typically generate approximately 4 MW each, but have a capacity of 30 MW.
5

8.0 Cooling Tower Feasibility

As noted in Section 3.0, the Sunoco Philadelphia site uses numerous mechanical 

cooling towers. The towers are built from either fiberglass or redwood, 

depending on the age of the tower. Facility representatives stated that there are no 

problems with drift, noise, or plume/visibility,

10 as the towers are located well 

inside the plant property. They did state that two towers have been replaced in 

recent years. One tower partially collapsed a few years ago and was rebuilt,11

while the other was replaced 2-3 years ago.12 The new tower has high efficiency

fill and facility representatives have not experienced any difficulty in operating 

the tower; it operates at approximately 4-5 cycles of concentration.13 An onsite 

vendor maintains the chemical additives (antifouling and antiscaling chemical 

feeds) and there has been no noticeable change in chemical usage over the 

previous cooling tower designs.

Four towers are process-specific and can be taken out of service for maintenance 

when the associated process unit is also out of service. Other towers serve more 

than one process unit and essentially never stop operating; individual cells are 

taken offline and serviced separately.

Point Breeze has 4 cooling towers that serve the entire cooling needs for the site. 

The towers are located at the crude unit,14 the hydrogen desulfurizing unit, the 

fluid/cracking unit, and at the hydrogen complex.

Girard Point has 4 cooling towers, including the largest tower at the refinery. 

This tower has 20 cells and is 55 feet tall. A second tower (serving the Girard 

Point crude unit) has 12 cells; facility representatives noted that this was amongst 

the least efficient towers on the site and may be upgraded or replaced in the 

future. A third tower was recently built at the fluid unit and crackers, a process 

line which is a large user of water at the refinery. The 14 cell tower is much 

 

10 The facility also noted that some of the towers are located approximately 2 miles from the Philadelphia 

Airport.

11 The rebuilt tower was constructed while the facility continued to operate. Facility representatives stated 

that the facility operated with a temporary cooling water tower and at a lower production capacity, but did 

not experience any plant-wide shutdowns as a result of the rebuilding process. The affected process unit 

was only taken fully offline during the tie-in; the facility could not recall the length of the outage for the 

tie-in.

12 The replacement tower was constructed to replace one of the oldest and least efficient cooling towers on 

the property. Facility representatives noted that they were able to adjust production rates and share (or 

purchase) intermediate products to minimize any construction-related downtime. The majority of 

construction took place during a major maintenance outage of 6-9 months (unrelated to the conversion to 

closed-cycle cooling). Major outages typically occur every 4-5 years and last approximately 6 weeks, 

although a recent outage lasted 3 months due to low demand. Facility representatives stated if the extended 

outage had not occurred, much of the construction of the replacement tower would have been done while 

the unit was operating; they stated that the standard 6 weeks might not have provided enough time to 

complete tie-in and startup activities.

13 Other towers at the refinery typically operate at 4-8 cycles, 3.2 cycles, and 3.8 cycles.

14 Facility representatives noted that this tower loses approximately 864,000 gpd to evaporation and 

504,000 gpd for blowdown, and can reject approximately 330 million BTUs of heat.
6

shorter than the other towers due to the use of high efficiency fill material. It cost 

approximately $10 million to construct.15 The fourth tower is a small 4 cell tower 

at the Au-433 alkylation unit.

In considering a retrofit to cooling towers for the remaining once-through flows at 

Girard Point, facility representatives noted that these are relatively small flows 

(0.4 mgd, as noted above), even compared to other process flows within the 

refinery. The process units also typically result in a relatively low delta T (10-15 

°F). From a spatial perspective, the two process units are far from each other, 

making a single cooling tower problematic; the facility would likely evaluate 

other options, such as reconfiguring the equipment in the process units. Facility

representatives also noted that, for Girard Point, the realized benefit derived from 

conversion to closed-cycle cooling is not justified by the cost. They added that 

much of the flow is used to cool an air compressor; construction of a cooling 

tower would be far more expensive than the compressor itself.

9.0 Future Activities

Facility representatives were not aware of any plans for major renovations, plant 

expansion, or production changes. Presently, the facility’s only investments are 

for required upgrades or general maintenance.

10.0 Cooling Ponds

There are no cooling ponds onsite.

11.0 316(a)

The NPDES permit contains temperature discharge limits (110°F) including 

requirements for a mixing zone. The facility has never had any problems meeting 

its thermal limits.

12.0 Ash Handling

There is no ash produced onsite.

13.0 Air Emissions Controls

Aside from the increased water usage from the wet gas scrubber (see Section 2.0), 

EPA did not collect any data on air emissions.

 

15 Note that this tower was able to use the existing piping and concrete basin, thereby significantly reducing 

the overall capital costs. Temporary cooling towers were brought in at the end of the production period to 

allow construction workers to prepare for demolition of the old tower.
7

14.0 Issues with Debris

The Schuylkill River carries a high debris load, especially after large storms, and 

has a high tidal variation (4-5 feet). However, the facility did not discuss any

problems with handling the debris loading, even though many of its screens are 

older (i.e., less efficient at screening and removing material). Facility

representatives did state that the screens are normally rotated once or twice per 

shift, but that the frequency of wash cycles may increase during high debris 

loading periods.

Attachments

Attachment A List of Attendees

Attachment B Aerial Photos
8

Attachment A--List of Attendees

Paul Shriner, USEPA

Jan Matuszko, USEPA

Steve Geil, Tetra Tech

Kelly Meadows, Tetra Tech

Jim Disario, Sunoco

Chuck Barksdale, Sunoco

Bob Gallagher, Sunoco
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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.gov
11

Attachment C--PowerPoint Presentation (April 28, 2009)

Please see the attached materials.

Attachment D--North Anna Emergency Plan Map

Please see the attached materials. [oversize—in hard copy only]

Attachment E--Impingement and Entrainment Studies for North Anna Power 

Station (1978-1983) 

Please see the attached materials.