Air Pollutant Watch List
Proposed Change
Removal of Texas City, Benzene
Texas Commission on
Environmental Quality
Air Permits Division
March 11, 2013
Summary
The Texas Commission on Environmental Quality (TCEQ) established the Air Pollutant
Watch List (APWL) to address areas of the state where air toxics were monitored at
levels of potential concern, and the TCEQ uses the APWL to reduce air toxic levels by
properly focusing limited state resources on areas with the greatest need. The TCEQ
added a portion of Texas City to the APWL to address persistent, elevated ambient
concentrations of air toxics, including the air toxic benzene. Since Texas City’s inclusion
on the APWL, the TCEQ has increased monitoring, investigations, enforcement, and air
permitting efforts for the companies located in the APWL area. The primary benzene
contributors in the Texas City APWL area have implemented significant equipment
improvements. Companies have implemented voluntary measures to reduce benzene
and have also agreed to make improvements through the TCEQ and U.S. Environmental
Protection Agency (EPA) enforcement process. Certain companies continue to use
monitoring data to identify elevated concentrations and mitigate emissions.
The TCEQ’s Toxicology Division establishes air monitoring comparison values (AMCVs)
to evaluate ambient air toxic data. No adverse health effects would be expected if
annual average benzene concentrations remain below 1.4 parts per billion by volume
(ppbv). Stationary monitoring data show that annual average benzene concentrations
have remained below 1.4 ppbv at each monitoring location in Texas City for two
consecutive years. For example, the 2010 and 2011 annual average benzene
concentrations were 0.5 ppbv at TCEQ’s Texas City Ball Park Monitor; 0.4 ppbv and 0.3
ppbv (respectively) at BP’s 31st Street Monitor; 0.6 ppbv and 0.5 ppbv at BP’s Logan
Street Monitor; and 0.9 ppbv and 0.8 ppbv at Marathon’s 11th Street Monitor. The TCEQ
determined that monitored concentrations can reasonably be expected to be maintained
below levels of potential concern and is proposing to remove benzene in Texas City from
the APWL. Texas City would remain on the APWL for the air toxic propionaldehyde.
2
Area and Pollutant of Concern
The TCEQ established the APWL to address areas of the state where air toxics were
monitored at levels of potential concern. Figure 1, Texas City APWL Area 1202,
illustrates the portion of Texas City that the TCEQ has included on the APWL. The
TCEQ added this area to the APWL to address persistent, elevated ambient
concentrations of air toxics, including the air toxic benzene.
Figure 1: Texas City APWL Area 1202
Benzene, a widely used industrial chemical, is a clear liquid that readily evaporates into
the air. Benzene occurs naturally in crude oil, and therefore refined products like
gasoline contain benzene. Benzene is also used to make glues, lubricants, and certain
prescription medications. Several agencies, including the TCEQ, the EPA, the National
Toxicology Program, and the International Agency for Research on Cancer, have
3
designated benzene as a human carcinogen. The TCEQ has developed a Development
Support Document, which provides additional detailed information on the potential
toxicological effects of benzene.
The bold yellow line in Figure 1 shows the boundary of the Texas City APWL area, and
the thinner green lines represent streets. Some of the industrial equipment owned and
operated by the companies in the Texas City APWL area, like larger storage tanks, can
be seen in Figure 1.
Designated Land Use and Proximity to Residential Areas
and High-Traffic Roadways
The Texas City APWL area boundary encompasses the area south of Texas Avenue/State
Highway (SH) 348/Farm-to-Market Road (FM) 1765, east of Highway 146, and west of
Galveston Bay. The majority of this land area is industrial; however, there are some
residences located within the APWL boundary designation for the area. Some of these
homes are also located in close proximity to industrial equipment. Most of the
population density in the area is located north of SH 348 (approximately a quarter-mile
north of the industrial complexes) and west of Hwy 146 (where, in some places, homes
are within one-tenth of a mile of industrial equipment).
The streets that make up the APWL boundary are high-traffic roadways. Highway 197 is
also a high traffic roadway, running between some of the industrial complexes in the
APWL area. In addition, the area around Swan Lake is located within the APWL
boundary and is designated as a waterfront conservation and recreational area.
4
Companies Located in the Texas City APWL Area
Table 1, Companies in the Texas City APWL Area, lists the 19 industrial complexes
located within the APWL boundary.
Table 1: Companies in the Texas City APWL Area
Company Name
Regulated Entity (RN) Number
BP Products North America (BP)
RN102535077
Marathon Petroleum – Texas City Refinery
(Marathon)
RN100210608
Valero Refining Texas City Refinery (Valero)
RN100238385
Praxair Texas City (Praxair)
RN100220599
Praxair Texas City Hydrogen Complex (Praxair
HC)
RN104095435
Union Carbide Texas City (Union Carbide)
RN100219351
BP Texas City Chemical Plant B (BP Chem)
RN102536307
Eastman Chemical Texas City (Eastman)
RN100212620
INEOS Texas City Chemical Plant (INEOS)
RN104579487
Oiltanking Texas City Terminal (Oiltanking)
RN100217231
NuStar Texas City Terminal (NuStar)
RN100218767
Texas City Cogeneration (TX City Cogen)
RN100224245
South Houston Green Power (SH Green Power)
RN103934493
Enterprise Crude Pipeline, Seaway Texas City
Station (Enterprise)
RN102560182
Shell BP Texas City Compression Dehydration
Facility (Shell)
RN105644223
Marathon Pipe Line Texas City Pump Station
(Marathon Pipe Line)
RN104574918
Gulf Coast Waste Disposal Authority (GCWDA)
RN100212463
Bollinger Texas City (Bollinger)
RN100218627
Oxbow Marine Terminal Texas City (Oxbow)
RN102707049
As Table 1 illustrates, Texas City APWL area 1202 is highly industrialized. The APWL
area contains three petroleum refineries (BP, Marathon, and Valero), six chemical
plants (two Praxair sites, Union Carbide, BP Chem, Eastman, and INEOS), three
petroleum and chemical terminals (Oiltanking, NuStar, and Enterprise), two power
generation plants (TX City Cogen and SH Green Power), two oil and gas support
facilities (Shell and Marathon Pipe Line), a wastewater treatment facility (GCWDA), a
barge manufacturing and repair facility (Bollinger), and a petroleum coke and coal
5
material handling facility (Oxbow). Figure 2, Texas City APWL Companies, shows the
relative locations of the industrial complexes within the APWL boundary.
Figure 2: Texas City APWL Companies
Emissions Inventory
Owners or operators of certain stationary sources are required by Title 30 Texas
Administrative Code §101.10, Emissions Inventory Requirements, to submit an annual
emissions inventory to the TCEQ. A company is required to report all of its actual air
emissions each year, including all authorized and unauthorized emissions.
Unauthorized emissions may include those emissions released as a result of emissions
events or unauthorized maintenance, startup, and shutdown (MSS) activities.
Companies located in APWL areas are subject to this requirement. Of the 19 companies
located in the APWL area, 12 of them have reported benzene emissions in their
emissions inventories, as the following table illustrates.
6
Table 2: Tons of Benzene Emissions Reported by Companies in the APWL Area*
Company
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
BP
85.31
32.22
33.69
54.88
47.79
64.05
61.83
75.4
66.33
29.96
45.63
Marathon
12.84
17.06
16.32
16.28
15.61
14.52
14.31
15.2
14.58
10.88
8.55
Valero
9.84
8.56
8.37
40.41
5.92
3.35
4.25
4.59
7.85
4.44
5.04
Eastman
32.78
9.33
11.53
12.72
17.87
15.47
16.05
17.32
5.93
0
0
Union Carbide
17.15
10.64
17.3
26.17
1.23
0.95
0.05
0.05
0.02
0.03
0.02
Oiltanking
0.31
0.19
0.33
0.19
0.04
1.61
6.2
8.17
7.1
5.67
2.15
BP Chem
3.61
3.53
3.76
3.77
12.27
1.06
0.23
0.62
0.17
5.56
3.2
GCWDA
0.41
0.77
0.1
0.21
0.21
0
0
0
0
0
0
INEOS
0
0
0
0
0
6.33
4.85
15.34
3.51
1.84
1.87
NuStar
0
0.02
0.09
0.11
0.59
0.53
1.97
1.98
3.57
2.48
0
Enterprise
0.29
0.42
7.02
9.17
8.1
9.74
8.28
2.26
0.35
0.32
0.18
TX City Cogen
0
0
0
0
0
0
0
0
0.11
0.11
0.1
Total
162.54
82.74
98.51
163.91
109.63
117.61
118.02
140.93
109.52
61.29
66.74
*Includes emissions resulting from emissions events and unplanned MSS activities.
Monitoring of Benzene in Texas City
The TCEQ has historically conducted mobile monitoring projects and has also used
stationary monitoring data to evaluate ambient benzene concentrations in Texas City.
The TCEQ began evaluating ambient benzene monitoring data from the stationary
Texas City Nessler Pool Monitor in 1995. Since 2001, the TCEQ has conducted mobile
monitoring projects in Texas City and has measured elevated benzene levels.
The Galveston City-County Health Department previously operated the stationary
Nessler Pool Monitor, which was located at 17th and 5th Avenue North. The monitoring
site operated from January 1, 1979, to July 30, 2007. On October 20, 1997, the TCEQ
activated the Texas City Ball Park Monitor (AQS Number 481670005), a stationary
monitor located at 2516 ½ Texas Avenue. The TCEQ continues to collect ambient
benzene data from this site. The Texas City Ball Park Monitor is a 24-hour canister
sampler, as was the Nessler Pool Monitor. These canisters collect a 24-hour sample
every sixth day.
In addition to the active TCEQ stationary monitoring site, individual Texas City
companies sponsor four monitoring sites. Two companies installed the monitors
7
pursuant to individual enforcement agreements with the TCEQ and/or the EPA and U.S.
Department of Justice (DOJ). The TCEQ refers to these monitoring locations as
“industry-sponsored” monitoring sites. These four monitoring sites contain automated
gas chromatograph monitors (auto GCs), which provide the ambient concentration of
benzene and other chemicals on an hourly basis. Table 3, Industry-Sponsored
Stationary Monitors, lists the four industry-sponsored monitoring sites.
Table 3: Industry-Sponsored Stationary Monitors
Monitoring Site Name
AQS Number
Location
Owner
Texas City BP Logan Street
Monitor
481670621
303 Logan Street
BP
Texas City BP On-Site Monitor
481670616
BP property near
Highway 197
BP
Texas City BP 31st Street Monitor
481670615
BP property between
Texas Avenue and 5th
Avenue
BP
Texas City 11th Street Monitor
481670683
502 10th Street South
Marathon
The Texas City/La Marque Community Air Monitoring Network also operates four
stationary monitors in the Texas City area. This network is supported by a financial
agreement between participating companies and an independent operator/contractor
who conducts and validates the monitoring data from the Texas City/La Marque
Community Air Monitoring Network. This data is then presented to the TCEQ on a
periodic basis. Unlike the Texas City Ball Park Monitor and the industry-sponsored
monitors, the TCEQ does not prescribe data quality standards for the community air
monitoring network.
The four Texas City/La Marque Community Air Monitoring Network monitoring sites
are: (1) Avenue A; (2) 2nd Avenue; (3) 34th Street; and (4) the North Site. The 34th
Street site contains an auto GC, the Avenue A and North Site1 Monitors contain 24-hour
canister samplers, and the 2nd Avenue site contains an auto GC and a 24-hour canister
sampler. Use of the 34th Street Monitor was critical in the TCEQ’s evaluation,
remediation, and delisting of APWL 1203, which was a separate benzene APWL area
near the Black Marlin Pipeline Company Texas City (Williams Field Services Group
LLC; RN100906155), in 2004. Figure 3, Texas City Stationary Monitoring Sites,
illustrates the locations of the monitors discussed in this section in relation to the Texas
City APWL 1202 area (bottom right corner) and the historical APWL 1203 area above
left (surrounding the 34th Street Monitor).
All canister samplers discussed in this document collect a 24-hour sample every six days, with the
exception of the North Site and 2nd Avenue canister samplers, in which a 24-hour sample is collected
every 12 days.
1
8
Figure 3: Texas City Stationary Monitoring Sites
Evaluating Air Monitoring Data
The TCEQ evaluates concentrations of air toxics, like benzene, through the use of its
AMCVs. AMCVs are screening values that are chemical-specific air concentrations
established by the TCEQ’s Toxicology Division, and are designed to protect human
health and welfare. The Toxicology Division establishes both short-term AMCVs and
long-term AMCVs. Short-term AMCVs are based on data concerning acute health
effects, the potential for odors, and effects on vegetation. Long-term AMCVs are based
on data concerning chronic health and vegetation effects. Short- and long-term, healthbased AMCVs are set below levels at which health effects would occur. Short-term
AMCVs are based on a one-hour exposure scenario, whereas long-term AMCVs are
based on lifetime exposures, approximately 70 years. The Toxicology Division uses its
scientifically-rigorous effects screening level guidelines to establish these AMCVs, in
9
which proposed AMCVs are scrutinized through a scientific peer review and public
comment process. More details on AMCVs can be found on the TCEQ’s Web site.
The short-term, health-based AMCV for benzene is 180 ppbv. The long-term, healthbased AMCV for benzene is 1.4 ppbv as a lifetime average exposure concentration,
although it is compared to the calendar year annual average to determine if
concentrations should be reduced. Canister samplers (like the Nessler Pool and Texas
City Ball Park Monitors discussed previously) collect data every six days for a 24-hour
period. Canister data are then averaged and compared to long-term AMCVs. Auto GCs
(like the industry-sponsored monitors) collect data every hour. Auto GC data are,
therefore, appropriate for comparison to short-term AMVCs. Auto GC data are also
averaged annually for comparison to long-term AMCVs. Mobile monitoring samples
provide data over a short duration (samples are usually instantaneous or are taken over
a period of time up to three hours) and must be compared to short-term AMCVs.
Reasons for Texas City’s Inclusion on the APWL
The TCEQ added Texas City (APWL 1202) to the APWL in 2001 to address elevated
concentrations of the air toxic propionaldehyde—an odorous compound used in the
manufacture of plastics, in the synthesis of rubber chemicals, and as a disinfectant and
preservative. The TCEQ then added benzene to the Texas City APWL area in 2003
because, for multiple years, the annual average benzene concentration at the Texas City
Ball Park Monitor had exceeded the long-term, health-based AMCV of 1.0 ppbv.2 In
addition, the TCEQ measured five exceedances of the 180 ppbv short-term, health-based
AMCV during a 2001 mobile monitoring project in Texas City.
Benzene Data Collected After Area’s Inclusion on
the APWL
After Texas City was added to the APWL, annual average benzene concentrations have
exceeded the long-term AMCV of 1.0 ppbv at additional locations other than the Texas
City Ball Park Monitor. These exceedances have been monitored at the 34th Street, 31st
Street, and 11th Street Monitors. In 2007, the TCEQ conducted a thorough scientific
evaluation of the toxicity of benzene and derived a new long-term, health-based AMCV
of 1.4 ppbv using the most up-to-date and scientifically defensible methods. After the
TCEQ established the current long-term AMCV of 1.4 ppbv in 2007, annual average
benzene concentrations continued to exceed levels of concern at the 11th Street Monitor.
In addition, although the data are not representative of public exposure and therefore
not used to determine the potential for health effects in the general public, annual
average benzene concentrations have exceeded the 1.4 ppbv long-term AMCV at the BP
On-Site and Marathon On-Site Monitors.3
The annual average benzene concentration at the Texas City Ball Park Monitor was 1.2 ppbv in 1998, 1.1
ppbv in 1999, 1.5 ppbv in 2000, 1.3 ppbv in 2002, and 1.2 ppbv in 2003.
3 Ambient concentrations are evaluated in conjunction with wind directional data in order to help identify
sources of air toxics that potentially contribute to elevated concentrations. BP operates an on-site
monitor, and Marathon previously operated an on-site monitor. These on-site monitors provide data
that, from the predominant wind direction, is upwind of the companies’ benzene sources (and nearby
houses). Having an upwind and a downwind monitor is extremely useful in better understanding an
2
10
In addition to data collected from stationary monitors in the surrounding area, a mobile
monitoring project in 2008 measured three exceedances of the short-term, health-based
AMCV.
Health Effects Reviews of Ambient Monitoring Data
and Previous Source Determinations
The TCEQ has conducted annual health effects evaluations regarding the benzene
monitoring data in Texas City for many years. In its health effects review
memorandums, the TCEQ’s Toxicology Division has encouraged emission reductions in
Texas City because annual average benzene concentrations have exceeded long-term,
health-based AMCVs at the Texas City Ball Park, 31st Street, and 11th Street Monitors.
The memorandums also describe the Toxicology Division’s source evaluations using the
Texas City Ball Park, 31st Street, and 11th Street monitoring data as well as data from BP
and Marathon’s on-site monitors. The Toxicology Division determined that auto GC
data at the 31st Street Monitor indicated that higher benzene concentrations were
associated with winds blowing from the direction of BP. Similarly, the Toxicology
Division determined that higher benzene concentrations at the 11th Street Monitor were
most frequently associated with winds blowing from the direction of Marathon.
TCEQ Actions to Reduce Benzene Emissions
The purpose of the APWL is to reduce ambient air toxic concentrations below levels of
potential concern. The TCEQ uses the APWL to properly focus limited state resources
on areas with the greatest need. The TCEQ also uses the APWL to heighten awareness
of elevated concentrations and to engage the companies in APWL areas to encourage
efforts to reduce emissions.
In Texas City, the TCEQ increased its monitoring efforts with the deployment of its
mobile monitoring team. Additionally, as discussed previously in this document, two of
the larger benzene contributors in the area operate stationary monitors.
The TCEQ also focused its compliance and enforcement resources to ensure that
companies located in the APWL area are operating in compliance. Initially, the TCEQ
used monitoring data in conjunction with emissions events and compliance reports as
well as information found during routine records reviews and inspections to identify
potential violations and non-compliant emissions. In addition to the routinely
scheduled, comprehensive compliance investigations for all major sources in the region,
investigators have conducted surveillance (during business hours and also after hours)
individual company’s contribution of an air toxic to the ambient air, and is also helpful in better
pinpointing sources of emissions. It is important to note that BP’s on-site monitor and, formerly,
Marathon’s on-site monitor do not provide data that is representative of potential exposure to the
community due to their locations. These monitors were located on industrial property, away from
residences and other sensitive receptors. Where the data from the on-site monitors is used to better
pinpoint benzene sources, the Texas City Ball Park, Logan Street, 31 st Street, and 11th Street Monitors are
downwind monitors that are located closer to residences and provide data that is, hence, more
representative of community exposure. As discussed later in this document, data from the Texas City Ball
Park, Logan Street, 31st Street, and 11th Street Monitors demonstrate that the annual average benzene
concentrations have been maintained below the AMCV, a level of potential health concern.
11
using the GasFind Infra-Red camera to detect equipment leaks in an effort to identify
possible non-compliant volatile organic compound emissions (which include benzene).
Investigators conducted on-site investigations regarding any issues identified during
surveillance activities and also conducted focused benzene investigations at APWL
companies to look for unreported and under-reported benzene emissions. Additionally,
TCEQ’s Region 12 Office undertook an initiative regarding the degassing or cleaning of
stationary, marine, and transport vessels in 2010 in response to citizen complaints.
The increased efforts by TCEQ’s Region 12 staff have resulted in the issuance of multiple
Notices of Violation (NOVs) to several of the companies in the Texas City APWL area.
The commission has thusly been able to enter into Agreed Orders with several of the
companies to resolve its concerns. Through the enforcement process, several companies
in Texas City have agreed to conduct significant activities to monitor and reduce
benzene emissions in Texas City. In addition, the EPA’s Petroleum Refinery Initiative
resulted in emission reductions from refineries across the country. All three of the
refineries located in Texas City entered into settlement negotiations with the EPA in
response to its Petroleum Refinery Initiative and agreed to implement improvements to
reduce benzene emissions. The summary below describes some of the positive changes
that were effectuated through the TCEQ Agreed Order and/or EPA Consent Decree
process.
BP has entered into multiple Agreed Orders with the TCEQ since the mid-90s regarding
alleged violations at its petroleum refinery located at 2401 5th Avenue South. Two of the
relevant Agreed Orders stipulating improvements are Agreed Order 2001-0329-AIR-E
and Agreed Order 2005-0224-AIR-E. BP also entered into a Consent Decree (Civil No.
2:96 CV 095 RL) with the EPA in 2001 relating to alleged violations at multiple
locations around the country, including the Texas City refinery. Some significant
improvements required by Agreed Order/Consent Decree include:

Requirement to cease discharging process wastewater into the oil-water separator
and storm water basin at Plant A along Highway 197;

Requirements for Benzene Waste National Emission Standards for Hazardous Air
Pollutants Program enhancements, including a waste stream audit and installation
of dual, sequential carbon canisters;

Requirements for Leak Detection and Repair enhancements and sustainable skip
period monitoring program;

Preparation of a comprehensive report identifying each benzene emission point and
fugitive source, its authorization and other requirements regulating benzene, and
benzene emissions data;

Development of a monitoring plan including the installation of two auto GC
monitors, one near the refinery’s northwest corner and one near the southeast
corner;

Commencement of the Benzene Tank Upgrade project to install controls on floating
roof tanks used for storing benzene or benzene containing materials; and

Minimization of emissions from flares and other combustion devices, including the
operation of flare gas recovery systems.
12
In response to BP’s March 2005 explosion, the Texas Attorney General’s Office issued a
Temporary Injunction (No. D-1-GV-09-00921), requiring BP to operate the Logan Street
Monitor. The Agreed Final Judgment, filed in Travis County District Court in December
2011, stipulated a large penalty and no additional technical requirements, although BP
continues to operate the Logan Street Monitor. Additionally, the EPA conducted a
series of inspections after the explosion to determine BP’s compliance with the terms of
the 2001 Consent Decree, and BP agreed to implement additional measures to address
benzene.
Marathon, who operates a petroleum refinery at 1320 Loop 197 South, through the
enforcement process, has also agreed to conduct ambient benzene monitoring. Agreed
Order 2001-0575-AIR-E required Marathon to submit a benzene monitoring plan to
measure concentrations of benzene within the surrounding communities, using an auto
GC monitor for a 12-month period. Marathon conducted this monitoring from October
2004 to October 2005. Marathon continued to collect monitoring data at the site from
January 2006 to January 2007 under a benzene emission investigation plan with the
TCEQ and the EPA. Marathon, through a Consent Decree with the EPA and the DOJ
(Civil Action No. 4:01-CV-40119-PVG, which also stipulated decreases in emissions from
leak detection and repair of fugitive components and the control of benzene emissions
from wastewater treatment and conveyance systems), again began monitoring benzene
in April 2007 and continued monitoring until December 2009. Agreed Order 20081709-AIR-E required the continuation of monitoring through December 2010, including
the implementation of an Environmental Monitoring Response System, which notifies
Marathon staff that an internal investigation is warranted when ambient concentrations
exceed a specified trigger level. More recently, Marathon has entered into an agreed
order settlement with the EPA (EPA Docket No. CAA-06-2011-3318), specifying that
Marathon continue monitoring from July 1, 2011 to July 1, 2014. Marathon, in response
to an EPA Consent Decree, optimized the operation of its flares.
Valero entered into multiple Agreed Orders for its petroleum refinery located at 1301
Loop 197 South. Some of the Agreed Orders addressed violations relating to benzene
and/or volatile organic compounds. Valero agreed to implement corrective measures.
Valero also installed a flare gas recovery system in April 2009 (Agreed Order 20100390-AIR-E). Valero also committed to implement enhanced procedures to reduce or
eliminate fugitive benzene waste emissions through a consent decree with the EPA (Civil
Action No. SA05CA0569RF).
INEOS, who operates a chemical plant at 2800 Farm-to-Market Road 519, entered into
Agreed Order 2010-0261-AIR-E, relating to an unauthorized release of benzene from
the cooling tower in the ethylbenzene unit when multiple tubes in a heat exchanger
failed due to corrosion. The company implemented corrective measures including the
complete retubing of the heat exchanger with upgraded metallurgy, updating the lab
system to flag high sample results, and training personnel to avoid future violations.
In addition to increased monitoring, investigations, and enforcement, the TCEQ has
focused its air permitting efforts for companies located in APWL areas, including Texas
City. The TCEQ has scrutinized air permit applications for those companies in the Texas
City APWL area requesting an increase in benzene. In addition, the TCEQ is in the
process of evaluating emissions from routine MSS that have been historically
13
unauthorized for sites located throughout the state. A permit review of MSS activities
includes an evaluation of best available control technology and a health impacts review,
and MSS permitting often requires controls and/or operational changes for activities
that have been previously uncontrolled (and, in some cases, controls are required for
equipment whose emissions were previously vented to the atmosphere). The TCEQ has
specifically evaluated and permitted MSS activities from two of the three petroleum
refineries in Texas City—BP and Valero. BP is now required to control vapors from
depressurizing, draining, and degassing equipment; implement additional controls for
degassing floating roof and fixed roof tanks; and painting white the tanks that store
liquid temporarily during the duration of MSS for other equipment. Valero’s permit
now also specifies additional control requirements for tank purging; eliminates
convenience tank landings; requires controls for vacuum truck vapors; and requires
certain tanks to be painted white. The authorization of MSS activities for these two
refineries requires additional controls, helping to further ensure that activities at the
refineries are properly controlled and are protective of human health and welfare.
Additional Pollution Prevention Efforts
In addition to the improvements described in the previous section that were effectuated
through the enforcement process, some companies in the Texas City AWL area have
implemented additional, voluntary measures to reduce benzene emissions. Marathon
implemented operational changes to significantly reduce emissions associated with
losses from the tanks that have historically stored high benzene-content liquid near
sensitive receptors, including reducing throughput and the number of turnovers from
the tanks. Marathon also installed a new solvent sewer in its aromatic recovery unit,
installed a thermal oxidizer for its wastewater treatment plant, and has changed the
method of operation of its benzene extraction unit to reduce emissions. In addition,
Marathon has implemented internal notification procedures to better identify and
respond to elevated benzene concentrations observed at the 11th Street auto GC. As
discussed previously, Marathon is required to conduct monitoring. The company is also
required to take action when ambient hourly benzene concentrations are monitored at a
certain trigger level; however, Marathon has implemented much lower trigger levels to
investigate lower concentrations of benzene. Additionally, Marathon inspects sewers,
tanks, and fugitive components with an FLIR camera to check for vapor tightness.
BP has also implemented procedures to respond to elevated hourly concentrations at its
auto GCs and also uses an infrared camera to check for leaks. In addition, Eastman
permanently shut down its ethylbenzene and styrene units in 2008, reporting no
benzene emissions in its 2009 or 2010 emissions inventories.
Monitored Decline in Ambient Benzene
Concentrations
TCEQ’s Texas City Ball Park Monitor
The annual average benzene concentration at the Texas City Ball Park Monitor was at its
highest value in 2000, in which the annual average concentration was 1.5 ppbv. This is
the only year in which the annual average benzene concentration exceeded the current
14
long-term AMCV of 1.4 ppbv. In 2001, the monitor did not collect enough valid data to
be considered complete for the year (the TCEQ established a 75 percent completeness
objective for data analyzed at the TCEQ laboratory), but the average of the data collected
was 1.0 ppbv. In 2002, the annual average benzene concentration was 1.3 ppbv, and the
annual average concentrations have declined significantly since that time. The annual
average concentration was 1.2 ppbv in 2003, 1.0 ppbv in 2004, 1.1 ppbv in 2005, 0.8 ppbv
in 2006, 0.6 ppbv in 2007, 0.7 ppbv in 2008, 0.6 ppbv in 2009, 0.5 ppbv in 2010, and 0.5
ppbv in 2011. All of these concentrations are below the long-term AMCV of 1.4 ppbv and
show a downward trend. Furthermore, the TCEQ determined that the rolling 12-month
average as of March 28, 2012, was 0.5 ppbv at the Texas City Ball Park Monitor, also
indicating sustained improvement.
Industry-sponsored Monitors
The annual average benzene concentrations at the industry-sponsored monitors have
also declined significantly. The TCEQ specifically evaluated the potential for health
effects from BP’s 31st Street and Logan Street Monitors and Marathon’s 11th Street
Monitor. These monitors are auto GCs, which provide data that are appropriate for
comparison to the short-term AMCV and for averaging for comparison to the long-term
AMCV.
At BP’s 31st Street Monitor, the 2003 annual average benzene concentration was 1.6
ppbv, though it should be noted that this was an incomplete year of data (the TCEQ
established an 85 percent completeness objective for industry-sponsored monitors).
The annual average concentration was 1.7 ppbv in 2004 and increased to 2.7 ppbv in
2005. In 2006, the annual average concentration decreased to 1.7 ppbv, but still
exceeded 1.4 ppbv. In 2007, the annual average concentration decreased to 1.0 ppbv and
has remained at or below the long-term AMCV, with 0.8 ppbv in 2008, 1.4 ppbv in 2009,
0.4 ppbv in 2010, and 0.3 ppbv in 2011. The rolling 12-month average as of April 15,
2012, was 0.4 ppbv at the 31st Street Monitor, also indicating sustained improvement.
The annual average benzene concentration at Marathon’s 11th Street Monitor was below
the long-term AMCV in 2003 at 0.9 ppbv. In the years 2004 – 2007, the data for each
calendar year was incomplete (monitoring was conducted October 2004 to October
2005, January 2006 to January 2007, and April 2007 to November 2007). These data
did not meet the 85 percent completion requirement for calendar years 2004 – 2007,
yet for the data that were validated, the average concentrations were 1.9 ppbv, 2.1 ppbv,
2.1 ppbv, and 2.2 ppbv, respectively. On November 5, 2007, the monitor was moved one
block north to the corner of 11th Street South and 6th Avenue South. In the years 2008
and 2009, the annual average benzene concentrations exceeded the long-term AMCV
with 1.8 ppbv and 1.6 ppbv, respectively, and the validated data met the required data
completeness specifications. In 2010, for the first time in several years, the annual
average benzene concentration was below the long-term AMCV at 0.9 ppbv. In 2011, the
annual average concentration was also below the long-term AMCV at 0.8 ppbv. The
rolling 12-month average concentration was 0.9 ppbv as of February 29, 2012, indicating
sustained improvement.
BP’s Logan Street Monitor began providing data in April 2010. The average
concentration for the available 2010 data was 0.6 ppbv, but not enough data were
15
collected for the year to be considered complete. The 2011 average annual benzene
concentration was below the long-term AMCV at 0.5 ppbv. The rolling 12-month
average concentration was 0.6 ppbv as of April 15, 2012.
Even the BP On-Site Monitor shows an improvement in air quality with a 2011 annual
average benzene concentration of 0.8 ppbv. As discussed previously in this document,
BP’s on-site monitor was installed to provide upwind concentrations and better pinpoint
benzene sources, but does not provide data that is representative of community
exposure due to its specific on-site location. Yet, the data indicates that the annual
average of this site monitor was below 1.4 ppbv in 2011.
Community Monitors
Several of the companies in the area, including BP and Marathon, pay a third party
contractor to collect data at four monitoring locations within the Texas City community.
As discussed previously, this monitoring network consists of the 34th Street, 2nd Avenue,
Avenue A, and North Site Monitors and is known as the Texas City/La Marque
Community Air Monitoring Network. The third party contractor reports these data to
the TCEQ on a periodic basis, and a summary of these reported data is provided here.
Although the TCEQ did not evaluate the data specifically for the purposes of delisting
Texas City from the APWL, the TCEQ is providing the information in this proposal
because many individuals will likely be interested in the results from these monitors.
The first complete year of data collected at the 34th Street Monitor was 2004, in which
the annual average benzene concentration was 1.6 ppbv. The annual average benzene
concentration improved in 2005 and was reported as 0.8 ppbv, below the long-term
AMCV of 1.4 ppbv. The annual average concentrations were reported under the AMCV
in all subsequent years, with 0.4 ppbv in 2006, 0.3 ppbv in 2007, 0.2 ppbv in 2008, 0.2
ppbv in 2009, 0.2 ppbv in 2010, and 0.2 ppbv in 2011. The average benzene
concentrations at the Avenue A, 2nd Avenue, and North Site have been reported below
1.4 ppbv since 1994.
Monitored Trends
Figure 4, Annual Average Benzene Concentrations, demonstrates the downward trends
in ambient benzene concentrations observed at all active Texas City monitors. These
downward trends represent a significant improvement in air quality. The monitoring
data show that ambient concentrations have remained below the long-term AMCV
(represented by the dashed line) at each monitoring location, including the active BP
on-site auto GC monitor, for two consecutive years (2010 – 2011). Additionally, as
discussed previously, available rolling 12-month average concentrations at BP’s 31st
Street Monitor, at Marathon’s 11th Street Monitor, and BP’s Logan Street Monitor
indicate sustained improvement.
16
Figure 4: Annual Average Benzene Concentrations
3.0
2.5
Ball Park
BP 31st Street
2.0
BP Logan Street
Marathon 11th Street
1.5
2nd Avenue
34th Street
1.0
Avenue A
North Site
0.5
0.0
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
TCEQ Determines that Monitored Concentrations
are Below a Level of Potential Concern
Conducting air monitoring enables the TCEQ to accurately characterize chemical
concentrations in the ambient air of communities in order to assess the potential for
adverse health effects in the general public. The TCEQ is able to evaluate an extensive
amount of monitoring data from several stationary monitors in the Texas City area—
several of which are auto GCs that measure ambient concentrations every hour. The
TCEQ has conducted multiple health effects evaluations of the ambient data collected at
the Texas City monitors. The data show that, consistently, annual average
concentrations show a significant improvement in air quality, decreasing to levels below
those of potential long-term health concern. All monitors demonstrate that the annual
average benzene concentrations have remained below the long-term, health-based
AMCV of 1.4 ppbv for two consecutive years, and rolling 12-month averages also remain
below the AMCV, indicating sustained improvements in air quality.
17
Figure 5: 2010 and 2011 Average Benzene Concentrations Below Level of Concern
at all Monitors
1.8
1.6
1.4
Ball Park
1.2
BP 31st Street
BP Logan Street
1.0
Marathon 11th Street
0.8
2nd Avenue
0.6
34th Street
Avenue A
0.4
North Site
0.2
0.0
2009
2010
2011
The TCEQ previously conducted source determinations to identify the primary benzene
contributors in the Texas City APWL area, and these companies have implemented
significant equipment improvements. Certain companies that were previously
identified as primary benzene contributors continue to use the industry-sponsored auto
GCs for rapid notification of elevated benzene concentrations, enabling them to make
repairs quickly and ensure that benzene emissions are mitigated. As such, the TCEQ is
confident that the annual average benzene concentrations will be maintained below the
AMCV. The TCEQ therefore determines that monitored concentrations can reasonably
be expected to be maintained below levels of potential concern, and the TCEQ is
proposing to remove benzene in Texas City from the APWL.
18
Public Comment Period
The TCEQ will accept comments on the proposed delisting of Texas City from the APWL
for the air toxic benzene. Interested persons may send comments to
APWL@tceq.texas.gov or may send comments to the APWL coordinator at the following
mailing address:
Ms. Tara Capobianco, P.E.
Air Pollutant Watch List Coordinator
Texas Commission on Environmental Quality
Air Permits Division
MC-163
P.O. Box 13087
Austin, Texas 78711-3087
The comment period began on March 11, 2013, and the TCEQ will accept comments
through April 26, 2013. Any questions regarding the proposed delisting or the APWL
process may be forwarded to Ms. Capobianco at (512) 239-1117.
Public Meeting
The TCEQ will conduct a public meeting to receive comments on the proposed delistings
of Texas City from the APWL for the air toxics benzene and hydrogen sulfide. The
public meeting will be held on Thursday, April 11, 2013, at 6:00 p.m. at the Nessler
Center Wings of Heritage Room, located at 2010 5th Avenue North, Texas City, Texas.
The TCEQ will give a short presentation of the delisting of both benzene and hydrogen
sulfide at 6:00 p.m. After a short question and answer session, the TCEQ will officially
open the public meeting. The public meeting will be structured for the receipt of oral or
written comments by interested persons.
Individuals may present statements when called upon in order of registration. Open
discussion within the audience will not occur during the public meeting; however, the
TCEQ staff will be available to discuss the proposed delistings and answer any
additional questions after the meeting.
Persons who have special communication or other accommodation needs who are
planning to attend the meeting should contact the Office of the Chief Clerk at (512) 2393300 or 1-800-RELAY-TX (TDD) at least one week prior to the meeting.
19