1 Site Visit Report Valero

—Delaware City Refinery 2000 Wrangle Hill Road Delaware City , DE 09706 July 15 , 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 ge nerators 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 tec hnologies. EPA is also visiting facilities to better understand cooling water use and specific issues or technologies that can affect 316(b) compliance. Valero’s Delaware City Refinery was selected for a site visit because it utilizes cooling water in it s petroleum refining processes and in electricit y generation

. 1 , 2 2 .0 Facility Description Valero’s Delaware Cit y Refinery is located on approximately 5,000 acres 3 along the Delaware River south of Wilmington, DE. The refinery was built in 1956 and emplo ys approximately

760 Valero personnel. 4 The facilit y has two NPDES permits, one for the refinery and the other for a cogeneration power plant 5 (NPDES p ermit number s DE0000256 and DE0050601 , respectivel y)

. The permits have expired (August 31, 2002 and June 30, 2007, respectivel y) and are in the process of being renewed. 6

1 EPA provided a draft of this report to Valero but did not receive any comments from the facility. 2 According to online news reports, Valero announced in late 2009 that it would close the Delaw are City Refinery, eventually selling it to PBF Energy, who plans to reopen the refinery in 2011. 3 Approximately 500 acres are dedicated to the refinery and powe r plant and 800 acres for the petroleum storage tanks. Another 1800 acres are leased as farmland and 1700 acres have been designated as conservation easements. 4 There are often large numbers of contractors on

- site; the number varies according to construct ion projects and other operations. Valero purchased the facility from Premcor in 2005. Premcor purchased the facility from Motiva in 2004. 5 The refinery complex includes a 280 mega watt cogeneration facility. See Section 6.0. 6 Valero is also w orking th e Delaw are Department of Natural Resources and Environmental Control (DNREC) to merge the tw o permits.2

3 .0 Manufacturing Information The facility

processes heavy , high

- sulfur crude oil to produce conventional and reformulated gasoline, low

- sulfur and ultra low

- sulfur diesel, and home heating oil as well as liquid natural gas and propane. Crude is received b y ship at the facility ’s dock and offloaded to storage tanks. Production is approximately 180,000 barrels per day

(production was 160,000 barrels per day

the day prior to the site visit). Facility representatives noted that production is at or near historic levels, but that profits are currentl y much lower than before. Cooling w ater us ag e at the facilit y include s trim cooling via heat exchangers, overhead condensers on distil lation columns, and the firewater s ys tem. Water used for non - contact once - through cooling undergoes little pretreatment and is ty picall y dosed with small amounts of sodium hy pochlorite prior to being discharged back to the Delaware River

. Process water and contact cooling water is comprised of a combination of source waters ( nine onsite groundwater wells , municipal water s ys tems, and freshwater streams) and undergoes water treatment prior to use. 7 4 .0 Cooling Water System and Intake Structure The Valero Delaware City Refinery operates one CWI S that withdraws from the Delaware River. The CWI S is located at the end of an intake canal and is approximately

1⁄2 mile downstream of the main discharge outfall for the refinery and cogeneration plant. Th e CWI S is comprised of a concrete structure with a trash rack 8 with nine circulating water pumps and one one

- half capacit y pump. The design intake flow (DIF) is 465 million gallons per day (mgd) 9 but the facility is limited by

its water use permit with th e Delaware River Basin Commission (DRBC) 10 to a maximum withdrawal rate of 452 mgd. The actual intake flow (AIF) varies throughout the y ear; in the summer, the facilit y generall y operates all nine pumps. The facilit y does not know the through screen velocit y. Each pump has a dedicated 10

- foot travelling screen which is r otated and rinsed for 20 minutes three times per day

. The screens are of different mesh sizes and are being replaced at the rate of one per ye ar. The combined fish and debris return (an open concrete trough) is routed back to the canal outside of the initial trash rack. Downstream of the screens, there are three bay s and two six foot headers.

7 Boiler feed w ater is softened and demineralized, while contact cooling water is treated by reverse osmosis or ion exchange to remove Total Solids and T DS. 8 A second trash rack is installed across the width of the canal approximately 100 feet in front of the CWIS. 9 Each full capacity pump operates at 34,000 gallons per minute (49 mgd)

. 10 The DRBC is a collaborative stave

- level regulatory agency for dis chargers on the Delaware River. As part of its duties, it assesses a fee for water withdraw als.3 The refinery ’s fire suppression sy stem is c omprised of a single pump located at the CWI S and a holding tank at the refinery . The pump operates intermittently to maintain an adequate water level in the tank, but can also directl y suppl y water to the fire suppression sy stem if needed. This portion of the Delaware River is tidal and brackish in nature. The canal is dredged twice per ye ar (spring and fall). Since the Delaware River is tidal in this segment, the facility ’s intake can entrain warm water from the discharge outfall depending on tidal di rection. 11 The refinery

discharges through a 13 MGD water treatment plant and into two holding ponds (aka “guard basins”). These basins provide additional evaporative cooling and also serve as a safet y factor in case of catastrophic failures or leaks at the facility . The power plant effluent discharges just downstream of the basins; the combined effluent cascades down a series of steps (for aeration and cooling) before entering the river. 5 .0 Flow Diagram Based on information provided in the facility ’s detailed industry questionnaire and from the site visit, EPA has constructed a water flow diagram. Virtually all water withdrawn at the refinery and power plant is for non

- contact cooling water. A small amount of pipe washing occurs but generally uses tr eated freshwater from other sources. Some contact water is used in other processes and the coker unit uses some quench water, but much of the process water (and an y heat produced ) at the refinery

is recycled. Contact water is treated at the facilit y’s wa stewater treatment plant before discharge

. See Attachment C for the diagram. As noted above, the DRBC limits the amount of water Valero can withdraw. In an effort to reduce water withdrawals as it grew and added processes and to recover as much heat as possible, the facility began installing dry

and wet cooling sy stems in the 70s 12 and 90s, respectivel y. 6. 0 Electricity Generation and Transmission The refinery has a 280 MW cogeneratio n facility located onsite. The cogeneration facility

was originall y d esigned to use the refinery ’s petroleum coke production as the fuel source. In 1998, the power plant was repowered with a combined cycle turbine to increase the generating capacity and now uses gasified petroleum coke as its fuel. 13 The power plant suppli es electricit y and steam to the

11 In the summer, changes in the direction of the tide may require the facility to also operate the half

capacity pump to ensure sufficient heat rejection. 12 The fin fans (radiators) w ere installed as a response to rising energy costs at that time. Facility representatives noted that many refineries are shifting to air cooled processes when possible; how ever, due to the reliance on ambient air temperatures (i n the case of Valero, no more than a 20 degree differential may be available), air cooling may be limited to processes with small circulating flows. 13 The pow er plant can also burn #2 fuel oil.4 refinery and accounts for approximately 33% of the cooling water needs for the complex (refinery

and cogeneration plant). 7 .0 Impingement and Entrainment Information Impingement and entrainment studies were conducted in th e 1990s

– 2000 time period. 8 .0 Cooling Tower Feasibility Valero has several cooling towers, several of which are process

- dependant. 14 One was constructed for a process that is no longer in operation and is not currently being used. The cogeneration facility has a 3

- cell helper cooling tower which is used approximately

4 months per y ear to provide supplemental cooling in the warmer summe r months. All of the cooling towers are wooden and man y are only operated seasonall y. Ty

pically , the towers using the untreated saline river water have 1.5 cy cles of concentration

. 15 An onsite vendor maintains standard antifouling and antiscaling chemica l feeds for all the towers. The facility

has considered retrofitting additional closed

- cycle cooling at the site , but has concluded that closed

- cycle cooling is not the most appropriate solution

. 16 Facilit y representatives discussed the limitations of both dry and wet cooling and the difficulties with the use of existing cooling towers at both the refinery and cogeneration plant. Specifically , they noted that the brackish nature of the Delaware River may influence the metallurgy within the cooling s ys t em and limit the cy cles of concentration that can be achieved without pretreatment

. They added that the existing wastewater treatment capacity at the refinery

might not be able to treat the increased flows that would be generated b y closed

- cycle cooling s ys tems. 17 Inaddition, groundwater or municipal sources are unlikel y to be available for makeup water

. Facility representatives also noted that closed

- cycle cooling s ys tems are limited by the ambient air temperature and humidity , requiring that the coolin g towers be overdesigned to per form in worst case conditions. Facilit y personnel also mentioned potential drift or plume f rom the towers ; however, no mention was made of an y problems from current towers on

- site.

14 The facility began to install cooling towers in the 1990s in order to maintain a relatively constant rate of water withdrawal and heat rejection while increasing production. Increased production requires additional cooling capacity and the facility was already withdrawing nearly the full volume allowed under its D RBC permit. The facility also discharges at or near its thermal limit in summer months; the installation of cooling towers helped to mitigate any additional heat load. 15 Facility representatives noted other facilities withdrawing freshwater achieve up to 8 cycles of concentration. 16 A 25 to 30 cell cooling tower was estimated to be required to convert the facility to closed

- cy cle cooling. 17 Facility representatives were concerned about the ability to the existing treatment plant to handle the additional volume from cooling tower blowdown, which may require treatment for solids or other pollutants. The treatment plant has a capacity of appro ximately 13 mgd and currently treats about 10 mgd.5 Lastl y, facility representatives noted that the refinery had made significant capital investments in improving the metal tubing throughout the facility 18 in an effort to improve process efficiency and reduce the concentration of metals in the effluent; if closed

- cy cle cooling were installed, the cost
- effectiveness of these upgrades may be lost or significantly

reduced. 9 .0 Future Activities As part of its discussions with DNREC concerning the renewal of the facility ’s two NPDES permits , Valero may be required to reduce water usage at the facili ty
. 19 F acility

personnel are also continuing to investigate reusing treated effluent and redistributing the heat load throughout the facility as way s to reduce cooling water requirements. 20 10 .0 Cooling Ponds There are no recirculating cooling ponds on

- s ite. 1 1 .0 316(a) The NPDES permit contains temperature discharge limits including a daily maximum withdrawal volume. During portions of the summer, the facility has problems meeting the thermal limits, occasionally resulting in a reduction of production capacity

. 1 2 .0 Ash Handling There is no ash produced onsite

. 1 3 .0 Air Emissions Controls The facility

is currently

constructing a scrubber s ystem on the cracking unit and is retrofitting the boilers at the power plant to low NOx burners. EPA did not collect an y further data on air emissions.

18 The facility has installed several million feet of titanium tubing. 19 Valero has studied a wide variety of intake technologies for reducing impingement and entrainment at the facility. However, DNREC an d Valero have largely concluded that intake technologies are not sufficiently protective of the aquatic ecosystem (especially with regards to entrainment) and may adversely affect the refining process. (See Section 14.0.) As a result, the refinery may be required to reduce its 12 month rolling average water intake by 33% over each of the next three permit terms. Facility representatives indicated they prefer a percent reduction requirement in the permits as opposed to specific technologies (e.g., cooling towers) being required. 20 Such options might include re

- routing some portion of the effluent back to the CWIS or optimizing the usage of existing cooling tow ers (including winter operations).6

13.0 Issues with Debris The Delaware River carries a high debris load, especiall y after large storms. Other than the dredging of the cooling water canal due to silt and sediment buildup, the facili ty

did not identify

an y problems with handling the debris loading. Periodic cleaning of the area directly in front of the CWI S (and behind the canal bar rack) also occurs to remove material. 15.0 Additional Information The facility

considered several intake technology options. A 2007 fine mesh wedgewire screen feasibility study concluded that a large number of screens would be required and that locating the screens in an area of sufficient depth would be difficult. Obt aining permits and ongoing maintenance (such as dredging) would also be difficult and expensive. Other technologies were examined, but were largely not considered due to poor performance in entrainment reduction. The facility ’s NPDES permit does not cont ain an y requirements for 316(b). As noted in Section 4.0, however, the facility does have a maximum permitted flow of 452 mgd. During portions of the summer, the facility occasionall y has to curtail production as it approaches the withdrawal limit. The facility

had a 3

- month shutdown earlier this year; this was the first time the entire plant had been closed in its history (nearl y 60 years). A small rail line within the propert y is owned b y Valero, but a second rail line (separating the refinery

from th e power plant) is not. Attachments Attachment A List of Attendees Attachment B Aerial Photo Attachment C Flow Balance Diagram7

Attachment A
-- List of Attendees Paul Shriner, USEPA Jan Matuszko, USEPA Steve Geil, Tetra Tech Kelly Meadows, Tetra Tech Mike Gudgeon, Valero Eric Jacobs, Valero Joe Greenfield, Valero John Gillespie, Valero Brian Muldowney , Valero Mike Seaner, Valero Bob Wojewodski, Valero

Attachment B
-- Aerial Photo Please see DCN 10

- 655 3 A accompan yi ng this document.8

Attachment C
-- Flow Balance Diagram

Intake Cooling Water (Delaware River) Once Through Cooling Water Trim Cooling

- Heat Exchangers Distallation Towers

- Condensers

Cogeneration Facility Cooling Towers and Makeup Water