HEALTH RISK ASSESSMENT REPORT IDEAS AND QUESTIONS



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Santa Barbara County APCD

Health Risk Assessment Report

Facility: Venoco Carpinteria Gas Plant and Oil Pipeline

1.0 Summary

In October 2006, the APCD conducted an air toxics Health Risk Assessment (HRA) for the Venoco Carpinteria Gas Plant and Oil Pipeline, using the Hotspots Analysis and Reporting Program (HARP) software, Version 1.1 (Build 23.02.10). Cancer risk and chronic and acute non-cancer Hazard Index (HI) risk values were calculated and compared to significance thresholds for cancer and chronic and acute non-cancer risk adopted by the APCD’s Board of Directors. The calculated risk values and applicable thresholds are as follows (with significant risks shown in bold):

Venoco Carpinteria Max Risks Significance Threshold

Cancer risk: 30.1 /million >10/million

Chronic non-cancer risk: 0.75 > 1

Acute non-cancer risk: 2.23 > 1

Based on these results, the operations at the Venoco Carpinteria Gas Plant and Oil Pipeline present a significant risk to the surrounding community. For that reason, a revised Risk Reduction Audit and Plan is required. In addition, public notification is required.

2.0 Background

2.1 Facility Operations

The Venoco Carpinteria facility is an oil and gas processing plant. Venoco acquired the facility from Chevron in February 1999. The oil and gas are produced solely from Venoco’s Federal OCS Platforms Gail and Grace. After passing through the liquid slug catcher and scrubbers, the gas is compressed to about 500 psig through multiple compression steps. In between these steps, the compressed gas is cooled and scrubbed. The intermediate pressure gas is passed through the sweetening dehydration and low temperature separation (LTS) systems. At the LTS system, the natural gas liquids (NGL) separate out. The clean, sweet and dry gas is then compressed to about 1,000 psig and sent to the metering and sales system. The NGL collected at various points of the gas plant are held in a low-pressure NGL tank for pump level control and then blended into pipeline oil. Most of the natural gas produced at the plant is sold to the local utility company. However, a fraction of the produced gas is used by the internal combustion engines and by other combustion units at the plant. This fraction is processed through a main gas fuel filter prior to use.

The oil is entirely processed offshore on the platforms. The treated oil is metered as it comes to shore and is piped to the onsite storage tank. The oil is piped to Venoco’s Rincon oil storage tank in Ventura County for eventual shipping to refineries in the Los Angeles basin.

2.2 Venoco Carpinteria in the AB 2588 Air Toxics “Hot Spots” Program

The Air Toxics "Hot Spots" Information and Assessment Act requires businesses and industries throughout the state to: 1) quantify and report their emissions of listed air toxics; 2) assess the possible health risks from their emissions; 3) notify members of the public who are exposed to significant risks attributable to their emissions; and, 4) take steps to reduce this risk.

The HRA described in this report was conducted as part of the AB 2588 Air Toxics “Hot Spots” Program. Based on its permitted potential to emit, the Carpinteria Gas Plant and Oil Pipeline have been part of “Hot Spots” since the program began, and Chevron submitted the Gas Plant’s first Air Toxics Emission Inventory in November 1989. The “Hot Spots” Program initially required biennial updates. In the 1990’s the legislation changed to require quadrennial updates to Air Toxics Emission Inventory Plans and Reports. The HRA discussed in this report was conducted as part of the quadrennial reporting cycle, for inventory year 1999, under the “Hot Spots” Program.

2.3 Health Risk

As used in this report, the term “health risk” addresses the likelihood that exposure to a given toxic air contaminant under a given set of conditions will result in an adverse health effect. Health risk is affected

by several factors, such as: the amount, toxicity, and concentration of the contaminant; the meteorological conditions; the distance from emission sources to people; the distance between emission sources; the age, health, and lifestyle of the people living or working at a location; and, the duration of exposure to the toxic air contaminant.

Health effects are divided into cancer and non-cancer risks. “Cancer risk” refers to the increased chance of contracting cancer as a result of an exposure, and is expressed as a probability: chances-in-a-million. The values expressed for cancer risk do not predict actual cases of cancer that will result from exposure to toxic air contaminants. Rather, they state a possible risk of contracting cancer over and above the background level.

For non-cancer health effects, risk is characterized by a “Hazard Index” (HI), which is obtained by dividing the predicted concentration of a toxic air contaminant by a Reference Exposure Level (REL) for that pollutant that has been determined by health professionals, the Office of Environmental Health Hazard Assessment (OEHHA) and the California Air Resources Board (ARB). RELs are used as indicators of the potential adverse effects of chemicals. A REL is the concentration at or below which no adverse health effects are anticipated for specific exposure duration. Thus, the HI is a measure of the exposure relative to a level of safety and is appropriately protective of public health.

2.4 Health Risk Assessment for Reporting Year 1996

The previous HRA results for Chevron’s facility based on inventory year 1996 are shown below.

Chevron Carpinteria Max Risks Significance Threshold

Cancer risk: 14 /million >10/million

Chronic non-cancer risk: 8.0 > 1

Acute non-cancer risk: 0.92 > 1

The cancer risk identified in the HRA for inventory year 1996 was driven by polycyclic aromatic hydrocarbons (PAH) from marine vessels. Acrolein from natural gas combustion was the largest source of chronic non-cancer risk. The original Risk Reduction Audit and Plan (RRAP) was approved October 6, 2000. As part of the original risk reduction plan for the chronic non-cancer risk, Venoco source tested the natural gas-fired internal combustion engines to better quantify acrolein emissions. The marine vessels contributing to the cancer risk are no longer associated with the stationary source. For that reason, PAHs no longer contribute substantially to the cancer risk. The original RRAP is discussed in more detail in Section 11.0 of this report.

2.5 Health Risk Assessment for Reporting Year 1999

The HRA for inventory year 1999 was conducted as part of the quadrennial reporting cycle under the AB 2588 Air Toxics “Hot Spots” Program. Venoco submitted an Air Toxics Emission Inventory Plan (ATEIP) that discussed the methodologies used for quantifying emissions. Upon APCD approval of the ATEIP, Venoco calculated the emissions and submitted that information in an Air Toxics Emissions Inventory Report (ATEIR). The ATEIR was reviewed by the APCD and amended to include results from sampling emissions from fugitive components and testing of engines. The APCD conducted a preliminary HRA based on the modeling parameters and emissions submitted in the ATEIP/R and subsequent test reports. The preliminary HRA results showed that the Gas Plant and Oil Pipeline continued to create a significant cancer risk, but no longer created a significant chronic non-cancer risk. The acute non-cancer risk was not significant based on the preliminary HRA. Venoco submitted a revised RRAP based on the results of the preliminary HRA. The RRAP elements and the preliminary HRA results are discussed in Section 11.0.

In February of 2006, the APCD received information that the stack heights presented in Venoco’s 1999 ATEIP and ATEIR for the natural gas-fired internal combustion engines were incorrect. This prompted the APCD to reexamine the modeling parameters, including stack heights. The audit of the modeling parameters is discussed in detail in Section 4.0. After completion of the modeling parameter audit and revisions, the APCD conducted a HRA in October 2006. The results of the HRA are summarized in Section 1.0.

2.6 Results of 1999 Health Risk Assessment

Benzene from fugitive hydrocarbon emissions is the primary contributor (risk driver) to this facility’s significant cancer risk status. Fugitive emissions are emissions which result from minute leaks in piping connections, valves, flanges and other piping components. Acrolein emitted from natural gas-fired internal combustion engines is the risk driver pollutant for the acute non-cancer risk. Further discussion of risk driver devices and pollutants is found in Section 10.0.

Based on the results of the HRA for reporting year 1999, the Carpinteria Gas Plant and Oil Pipeline remain a significant risk to the surrounding community. Venoco is required to develop and implement a RRAP to reduce the risk below the APCD’s Board-approved significant risk thresholds. In addition, public notification is required. There are no residences within the significant risk footprints. However, the owners of the businesses within the significant risk footprints will be notified by mail of the modeled risk that is projected on their property. In addition, the information will be posted on the APCD website at: .

3.0 Facility Information

EQUIPMENT OWNER/OPERATOR: Venoco, Inc.

SOURCE IDENTIFICATION NUMBER: 0027

EQUIPMENT LOCATION: 5675 Carpinteria Ave., Carpinteria

FACILITY UTM COORDINATES: Venoco provided the UTM coordinates of the facility’s property boundaries, buildings and structures, and emission release points. The APCD verified the UTM coordinates with a handheld Global Positioning System (GPS) unit.

UTM Zone 11

Easting: 269600 m

Northing: 3807850 m

Datum: NAD 27

EQUIPMENT DESCRIPTION: The HRA included emissions from 34 stacks or emission release points. This includes emissions from internal combustion engines, a heater, a glycol regenerator, tanks, sumps, pigging equipment, solvent usage and fugitive components.

4.0 Stacks and Modeling Parameters

The stack locations and modeling parameters used in the HRA are found in Table 4.1. Additional information on the modeling parameters and devices is found in the ATEIP and ATEIR.

4.1 Internal Combustion Engines’ Stack Height Discrepancy

When it came to the APCD’s attention in February 2006 that the stack heights reported in the ATEIP/R for the natural gas-fired internal combustion engines did not accurately represent the actual heights of the stacks, the stack heights from the 1996 ATEIP/R submittal were reviewed. The Ingersoll Rand (IR) engines’ stack heights were reported significantly shorter in the 1996 ATEIP/R than in the 1999 ATEIP/R. Also of interest is that a sensitivity analysis was requested by Chevron in 1999 to determine the reduction of risk from an increase in stack height. The APCD performed the analysis. However, the project file indicates that neither Chevron nor Venoco requested to increase the heights of the physical stacks, nor did the APCD ever approve such a change. Notwithstanding, Venoco submitted the inaccurate heights in the ATEIR on March 1, 2004, and these inaccurate data were included in the initial model. The results of such data would be to lower (reduce) the computed risk from such equipment.

The APCD measured the stack heights in February 2006 and revised the HRA accordingly. Table 4.2 summarizes the discrepancies in the stack heights.

Table 4.2 – Comparison of Stacks Heights

|Engine Name |Measured by APCD |Submitted by Venoco in |Submitted by Chevron in 1996 |Sensitivity Analysis |

| |(ft) |1999 ATEIP/R |ATEIP/R |(ft) |

| | |(ft) |(ft) | |

|Ingersoll Rand #1 |15.68 |29.2 |10 |25 |

|Ingersoll Rand #3 |15.68 |29.2 |10 |25 |

|Ingersoll Rand #4 |15.68 |29.2 |15 |30 |

|Ingersoll Rand #5 |15.68 |29.2 |20 |35 |

|Ingersoll Rand #6 |15.68 |29.2 |15 |30 |

|SACS Cooper |30.27 |32.8 |25 |40 |

Table 4.1 – UTM Coordinates and Modeling Parameters for Emission Release Points

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4.2 Modeling Parameter Audit

The large discrepancy in stack heights prompted a thorough audit of the modeling input parameters. APCD personnel measured the stack diameters and stack heights of all combustion equipment. In addition, the circumference and height of each tank were measured.

The APCD confirmed or revised the UTM coordinates of the internal combustion engines, heater, glycol regenerator, sumps, tanks, pigging equipment and solvent usage. A handheld GPS was used to obtain the UTM coordinates of the above-mentioned equipment. These UTM coordinates were then plotted and compared to the UTM coordinates presented by Venoco in the ATEIP/R. The GPS-obtained coordinates were used in the risk assessment where discrepancies arose.

As part of the parameter audit, the APCD also compared the combustion exhaust temperatures presented in Venoco’s 1999 ATEIP/R to the temperatures submitted in Chevron’s 1996 ATEIP/R. Because significantly lower temperatures were reported by Venoco for the same equipment, the APCD required Venoco to hire a source test contractor to measure the exhaust temperatures of all combustion equipment. This temperature testing effort was completed on July 26, 2006. The APCD witnessed this testing and used the temperatures obtained by the source test contractor as inputs in performing the HRA that is reported herein.

5.0 Emissions

The emission estimate techniques were presented in the ATEIP for inventory year 1999. Emissions were quantified in the 1999 ATEIR. Since the submittal of the ATEIP and ATEIR, additional testing and sampling was done to more accurately quantify emissions. These included the following:

1. Source tested Ingersoll Rand engines IR#1, IR#4 and IR#6 for benzene, acrolein, formaldehyde and acetaldehyde in August 2004 and October 2004. The source test results from IR#1 were used for IR#3, as the engines are similar. The source test results from IR#6 were used for IR#5, as the engines are similar. Prior to its implementation, the APCD reviewed and approved the source test plan. The APCD reviewed the source test report and modified the results to reflect the method’s (ARB Method 430) calculations. The APCD approved the modified report and used the modified results in the HRA reported herein.

2. Sampled and analyzed the oil and gas streams for benzene, toluene, xylene, ethylbenzene and hydrogen sulfide as fugitive hydrocarbon emissions in August 2004. This included sectioning off the gas plant and oil pipeline and determining representative sampling locations for each area. The APCD reviewed and approved the sampling plan, report and designation of sample locations. The results of the sampling report were used for fugitive emissions from components and pigging equipment.

In addition to the above-mentioned test results, the APCD modified the PAH emissions from the natural gas-fired internal combustion engines (IR#1, IR#3, IR#4, IR#5, IR#6, SACS Cooper). Venoco initially proposed using Ventura County APCD’s AB 2588 Combustion Emission Factors to quantify PAH emissions. The APCD suggested using the results of the source tests on IR#3, IR#4 and the SACS Cooper engines that were conducted by Chevron in 1995. Venoco agreed and the emission factors were modified to reflect the results of the source tests performed at the Chevron facility on December 12 & 13, 1995.

The toxic emissions from the Venoco Carpinteria Stationary Source for reporting year 1999 are presented in Table 5.1. These emissions include the above-listed modifications to the ATEIP/R.

Table 5.1 – Facility Emissions Summary for 1999 [1]

|Pollutant Name |Emissions (lb/year) |

|1,3-Butadiene |0.0828 |

|Acetaldehyde |140.9 |

|Acrolein |45.8 |

|Arsenic |0.0006 |

|Benzene |829.0 |

|Cadmium |0.0006 |

|Chlorobenzene |0.0001 |

|Chromium, hexavalent |0.0000 |

|Copper |0.0016 |

|Ethylbenzene |72.2 |

|Formaldehyde |3633.2 |

|Hexane |4314.7 |

|Hydrochloric acid |0.0710 |

|Hydrogen sulfide |0.0082 |

|Lead |0.0032 |

|Manganese |0.0012 |

|Mercury |0.0008 |

|Naphthalene |0.1840 |

|n-Butyl alcohol |0.1080 |

|Nickel |0.0015 |

|PAHs (not including Naphthalene) |0.0196 |

|Propylene |2483.9 |

|Selenium |0.0008 |

|Toluene |368.0 |

|Xylenes (mixed) |78.1 |

|Zinc |0.0085 |

| | |

6.0 Building Information

UTM Coordinates for buildings and structures (e.g., tanks) were submitted by Venoco in the 1999 ATEIP/R. The APCD verified all building and structure UTM coordinates with a GPS unit. Building downwash applies for these structures and all were included in the HRA.

7.0 Met Data & DEM Files

Meteorological data used in the dispersion analysis was acquired in a coastal area (UCSB West Campus) representative of the area surrounding the Venoco Carpinteria facility. The data file is found under LFC89.ASC located in the VenocoCarp1999_RevisedModelingParameters.zip file referenced in the Attachment section of this report. The Digital Elevation Model (DEM) file used was carpinteria.dem. This file is also found in the VenocoCarp1999_RevisedModelingParameters.zip file.

8.0 Model Information

The dispersion modeling and risk assessment were conducted using the California Air Resources Board Hotspots Analysis and Reporting Program, Version 1.1 (Build 23.02.10). A grid range of 500 m × 500 m with a grid increment spacing of 25 m was established. The Control options that were used for the dispersion model are found in Table 8.1.

The cancer analysis method chosen in HARP was the Derived (Adjusted) Method for a 70 year lifetime exposure duration (adult resident). The chronic non-cancer analysis method chosen in HARP was the Derived (OEHHA) Method for a resident. Multipathway cancer and chronic analyses were performed with the following exposure pathways: inhalation, soil, dermal and mother’s milk. A deposition rate of 0.02 m/s was used. Grid and receptor data may be found in VENOCOCARP3099_REVISEDMP.SRC and VENOCOCARP3099_REVISEDMP.ISC files located in VenocoCarp1999_RevisedModelingParameters.zip.

Table 8.1 – Control Options for Dispersion Model

|Control Option |Assumption |

|Use Regulatory Default? |Yes |

|Rural or Urban |Urban |

|Gradual Plume Rise? |No |

|Stack Tip Downwash? |Yes |

|Buoyancy Induced Dispersion? |Yes |

|Calms Processing? |Yes |

|Missing Data Processing? |No |

|Include Building Downwash? |Yes |

|Lowbound Option? |No |

|Terrain Model |Both |

9.0 Results

Risk assessment results at the point of maximum impact (PMI) receptor locations for cancer and for chronic and acute non-cancer health effects are shown in Table 9.1. The italicized values indicate the maximum offsite risk for each risk category. Bolded numbers represent a significant offsite risk.

Table 9.1 – Risk at Point of Maximum Impact Receptors

|Receptor |Location |Cancer Risk |Chronic HI |Acute HI |Acute HI |UTME |UTMN |

| | |(in a million) | |(Screening) |(Refined) |(m) |(m) |

|887 |PMI |30.14 |0.09 |1.41 |1.06 |269725 |3807825 |

|765 |PMI |27.85 |0.75 |2.37 |1.27 |269750 |3807900 |

|723 |PMI |20.93 |0.75 |3.74 |2.23 |269725 |3807925 |

Risk contours representing these risk isopleths were plotted on aerial photographs of the facility and adjacent land and are attached to this report. All resultant HRA risk data by receptor are found in the VenocoCarp1999_RevisedModelingParameters.zip file referenced in the Attachment section of this report.

The screening acute risk is a timesaving approximation that is conservative in nature. It is calculated by assuming that the contribution of risk from each source is at its maximum at the same instant in time. The maximum hourly risk from each source is summed to give the screening value, as if they had all occurred at the same time. In reality, the time that the risk from each source is at a maximum will differ depending on location and meteorology. The screening acute risk values greater than one were further refined (using the Refined Max Hourly Acute HHI feature in HARP). In the refined analysis, ten receptors exceeded the significance threshold as shown below.

Table 9.2 – Receptors with Significant Acute Non-Cancer Risk

|Receptor No. |Max Acute HI |Screening Risk |UTME |UTMN |

|723 |2.230 |3.739 |269725 |3807925 |

|681 |1.986 |2.369 |269700 |3807950 |

|682 |1.352 |1.849 |269725 |3807950 |

|806 |1.297 |2.525 |269750 |3807875 |

|765 |1.273 |2.792 |269750 |3807900 |

|847 |1.079 |1.794 |269750 |3807850 |

|680 |1.072 |1.712 |269675 |3807950 |

|887 |1.061 |1.407 |269725 |3807825 |

|724 |1.050 |2.172 |269750 |3807925 |

|640 |1.028 |1.336 |269700 |3807975 |

10.0 Risk Driver Devices and Pollutants

10.1 Cancer Risk

The primary cancer risk driver pollutant is benzene for the 1999 risk assessment. The largest contribution to benzene is fugitive emissions from components, specifically in the gas plant. Table 10.1 shows that if benzene emissions were removed, the facility would no longer create a significant cancer risk.

The secondary cancer risk driver pollutant is formaldehyde. Formaldehyde emissions alone do not create a significant risk to the surrounding community. However, formaldehyde does have a large contribution to cancer risk at some offsite receptors, as much as 7.3 in a million (at receptor 723). The risk driving devices emitting formaldehyde are natural gas-fired internal combustion engines. Specifically, IR#1, IR#3 and the SACS Cooper engine contributed the largest amount of cancer risk from formaldehyde. Table 10.2 shows the risk contribution from benzene and formaldehyde for significant risk receptors with a risk contribution from formaldehyde greater than one in a million.

10.2 Non-Cancer Risk

Acrolein is the risk driver pollutant for acute non-cancer risk, contributing more than 82 percent of the risk to all receptors with a hazard index greater than one. The primary risk driving devices are natural gas-fired internal combustion engines. Specifically, IR#1 and IR#3 contribute the largest amount of risk. Table 9.2 presents the risk from each receptor with a refined acute risk greater than one.

Formaldehyde and acrolein are the primary risk driver pollutants for the chronic non-cancer risk. However, the analysis indicates that no significant chronic non-cancer risk is projected beyond the property boundary of the plant. The primary risk driving devices are natural gas-fired internal combustion engines. Specifically, IR#1, IR#3 and the SACS Cooper engine contribute the largest amount of risk. When the SACS Cooper is removed from the analysis, the maximum chronic hazard index at any offsite receptor is decreased from 0.75 to 0.54 (see Rep_Chr_Res_DerOEH_AllRec_AllSrc_AllCh_ByRec_NoSACSCoop.txt). When all three engines are removed from the analysis, the risk is less than 0.02 at all offsite receptors (see Rep_Chr_Res_DerOEH_AllRec_AllSrc_AllCh_ByRec_NoIR1_NoIR3_NoSACSCoop.txt).

Table 10.1 – Benzene Contribution to Receptors with Significant Cancer Risk

|Receptor No. |UTME |UTMN |Total |Risk from Benzene |% Risk from Benzene |

| | | |Receptor Risk | | |

|887 |269725 |3807825 |30.15 |29.23 |97 |

|765 |269750 |3807900 |27.85 |20.31 |73 |

|806 |269750 |3807875 |22.28 |18.47 |83 |

|1010 |269725 |3807750 |21.15 |20.68 |98 |

|723 |269725 |3807925 |20.93 |13.32 |64 |

|1051 |269725 |3807725 |20.51 |20.04 |98 |

|724 |269750 |3807925 |18.28 |12.37 |68 |

|929 |269750 |3807800 |17.57 |16.98 |97 |

|1130 |269650 |3807675 |17.05 |16.23 |95 |

|888 |269750 |3807825 |17.00 |16.17 |95 |

|766 |269775 |3807900 |16.99 |12.18 |72 |

|847 |269750 |3807850 |16.62 |15.06 |91 |

|970 |269750 |3807775 |15.21 |14.73 |97 |

|807 |269775 |3807875 |14.89 |11.92 |80 |

|1129 |269625 |3807675 |13.66 |12.68 |93 |

|725 |269775 |3807925 |13.28 |8.95 |67 |

|969 |269725 |3807775 |12.69 |12.15 |96 |

|1011 |269750 |3807750 |12.68 |12.26 |97 |

|1171 |269650 |3807650 |11.96 |11.29 |94 |

|848 |269775 |3807850 |11.93 |10.41 |87 |

|767 |269800 |3807900 |11.47 |8.13 |71 |

|680 |269675 |3807950 |11.44 |4.79 |42 |

|681 |269700 |3807950 |11.39 |7.67 |67 |

|889 |269775 |3807825 |11.19 |10.33 |92 |

|1128 |269600 |3807675 |11.09 |10 |90 |

|1170 |269625 |3807650 |11.02 |10.23 |93 |

|930 |269775 |3807800 |10.84 |10.27 |95 |

|1172 |269675 |3807650 |10.80 |10.25 |95 |

|808 |269800 |3807875 |10.55 |8.19 |78 |

|679 |269650 |3807950 |10.55 |7.43 |70 |

|682 |269725 |3807950 |10.39 |7.11 |68 |

|1092 |269725 |3807700 |10.26 |9.84 |96 |

|1052 |269750 |3807725 |10.05 |9.66 |96 |

|1086 |269575 |3807700 |10.03 |8.76 |87 |

Table 10.2 – Contribution of Risk Driver Pollutants for Significant Risk

Receptors with a Contribution from Formaldehyde (HCHO) > 1.0 in a Million

|Receptor No. |Total |Risk from Benzene |% Risk from Benzene |Risk from HCHO |% Risk from HCHO |% Risk from Benzene |

| |Receptor Risk | | | | |and HCHO |

|723 |20.93 |13.32 |64 |7.29 |35 |98 |

|765 |27.85 |20.31 |73 |7.21 |26 |99 |

|680 |11.44 |7.79 |68 |3.53 |31 |99 |

|724 |18.28 |12.37 |68 |5.67 |31 |99 |

|766 |16.99 |12.18 |72 |4.61 |27 |99 |

|725 |13.28 |8.95 |67 |4.16 |31 |99 |

|806 |22.28 |18.47 |83 |3.66 |16 |99 |

|681 |11.38 |7.67 |67 |3.60 |32 |99 |

|767 |11.47 |8.13 |71 |3.22 |28 |99 |

|682 |10.39 |7.11 |68 |3.18 |31 |99 |

|679 |10.55 |7.43 |70 |3.01 |29 |99 |

|807 |14.89 |11.92 |80 |2.85 |19 |99 |

|808 |10.55 |8.19 |78 |2.27 |21 |99 |

|847 |16.62 |15.06 |91 |1.50 |9 |100 |

|848 |11.93 |10.41 |87 |1.45 |12 |99 |

|1086 |10.03 |8.76 |87 |1.19 |12 |99 |

|1128 |11.09 |10.00 |90 |1.02 |9 |99 |

11.0 Risk Reduction

In 1999, the APCD notified Chevron that a RRAP was required. Venoco acquired the facility in 1999 and submitted a RRAP in July 1999. The APCD approve the RRAP in October of 2000 with the following measures: 1) Elimination of marine vessels; 2) re-evaluation of acrolein emissions; 3) investigation and installation of post-combustion control equipment; and, 4) if needed, investigation of other emerging emission reduction options.

Risk reduction measure number one was completed as there are no longer marine vessels that are associated with the Venoco Carpinteria stationary source. It is the APCD’s understanding that Venoco continues to use marine vessels at the Carpinteria pier. The relationship of these vessels to the Venoco Carpinteria source needs additional consideration to ensure emissions from these vessels are not legitimately included in the operation’s emissions profile.

Risk reduction measure number two was completed in 2004 through the source testing of three internal combustion engines for acrolein, as well as for benzene, formaldehyde and acetaldehyde.

The RRAP has not fully been implemented because it was believed that the risk identified in the 1996 HRA was reduced. However, the facility is still a significant risk source due to a newly identified cancer risk from fugitive components emitting benzene. This new risk was identified by the 1999 HRA which used emissions from Venoco’s plant-wide fugitive sampling program.

A new RRAP was submitted in 2004 and revised in 2005 to address the newly identified risk from the 2004 testing and the preliminary HRA. This RRAP was based on a preliminary risk assessment that included erroneous model input information provided by Venoco. With the correction of these inputs, the facility’s significant cancer risk has increased from the preliminary results and the acute non-cancer risk is now significant. For completeness, the preliminary HRA results are presented below. These preliminary results have been superseded by the results shown in Section 1.0 of this report.

Preliminary Max Risks Significance Threshold

Cancer risk: 24.7 /million >10/million

Chronic non-cancer risk: 0.593 > 1

Acute non-cancer risk: 0.874 > 1

The RRAP based on the preliminary HRA was approved on June 13, 2005 with the following measures: 1) Implement an Enhanced Inspection and Maintenance Program to further reduce fugitive emissions; 2) replacement of 1,981 valves with non-leaking bellows valves within two years of RRAP approval to further reduce fugitive emissions; 3) removal of the SACS Cooper engine from service; and, 4) removal of a large storage tank from service. Measures 3 and 4 have been implemented and Venoco’s operating permit has been modified to reflect that the engine and storage tank are out of service. The replacement of the valves will also require a permit modification and, pursuant to the approved RRAP, must be accomplished by June 13, 2007.

The RRAP approved on June 13, 2005 must be revised to address the risk due to the corrected stack heights and modeling parameters. In addition, the RRAP may be revised to modify risk reduction measures 1 and 2. Venoco notified the APCD that they are pursuing a different approved emission calculation methodology to quantify the facility’s fugitive hydrocarbon emissions. As part of this effort, Venoco hired a contractor to make a detailed count of gas-service and oil-service components within the facility and revised their Inspection and Maintenance (I&M) plan. Venoco submitted the draft revised I&M plan for APCD review on August 3, 2006. The APCD submitted comments to Venoco on the I&M plan on September 8, 2006. Venoco is in the process of addressing the APCD’s comments. The APCD must concur with Venoco’s implementation of the emission calculation methodology before it is considered final and representative of the facility’s fugitive hydrocarbon emissions. If the APCD does not concur in the recalculation of the facility’s emissions, or if the risk remains significant after the approved approach is implemented, Venoco is still required to implement risk reduction measure 2 according to the June 2007 timeline.

12.0 Health Risk Assessment for Reporting Year 2003

The APCD is currently reviewing Venoco’s ATEIP for reporting year 2003. Upon APCD approval of the ATEIP, Venoco will prepare and submit the ATEIR. The APCD will conduct the HRA for inventory year 2003 based on the emissions reported in the ATEIR. If the HRA shows that Venoco Carpinteria continues to pose a significant risk to the community, the public will again be notified and the RRAP will be modified, as necessary.

13.0 Conclusion

Per APCD guidelines, if a facility’s toxic emissions result in a cancer risk equal to or greater than 10 in a million, it is considered a significant risk facility. For non-cancer risk, if a facility’s toxic emissions result in a Hazard Index equal to or greater than 1.0, it is considered a significant risk facility. The risk assessment results show that the Venoco Carpinteria Gas Plant and Oil Pipeline present a significant risk to the surrounding community. Therefore, based on the results of this HRA, a RRAP is required and the public will be notified of the significant risk.

14.0 References

• Risk notification levels were adopted by Santa Barbara Air Pollution Control Board of Directors on June 1993. The risk notification levels were set at 10 per million for cancer risk and a Hazard Index of 1.0 for non-cancer risk.

• Risk reduction thresholds were adopted by Santa Barbara Air Pollution Control Board of Directors on September 17, 1998. These risk reduction thresholds were set at the same level as public notification thresholds, i.e., 10 per million for cancer risk and a Hazard Index of 1.0 for non-cancer risk.

• Compliance Source Test Report for Chevron U.S.A. Production Company Carpinteria Gas Plant IC Engines 3 & 4 and Cooper Bessemer Compressor Permit Number 7482-1 & 9122-1 Determination of Concentrations and Emissions of Polycyclic Aromatic Hydrocarbons (PAH)

• Venoco Carpinteria’s Fugitive Sampling Plan and Report (Submitted June 3, 2004; Revised August 11, 2004 and October 12, 2004)

• Toxic Emission Testing Carpinteria Gas Plant Ingersoll Rand Engines (August 11 & 12, 2004)

• Toxic Emission Testing Carpinteria Gas Plant Ingersoll Rand Engine #IR-4 (November 2, 2004)

• Air Toxics Emission Inventory Plan for Reporting Year 1999 (August 1, 2000)

• Air Toxic Emission Inventory Report for Reporting Year 1999 (Submitted July 11, 2001; Revised March 1, 2004 and June 14, 2004)

• Exhaust Temperature Testing Nine (9) Units Carpinteria Gas Plant (July 26,2006)

15.0 Attachments

• Significant Cancer Risk Footprint – 10 in a million

• Significant Acute Risk Footprint – Hazard Index of 1.0

• Onsite Chronic Non-cancer Risk Footprint – Hazard Index of 1.0

• Source parameter data and HRA input and output files may be found in the following location:

\\\toxics\Sources\Venoco_Carp\AB2588\1999 HRA Report\VenocoCarp1999_RevisedModelingParameters.zip

\\\toxics\Sources\Venoco_Carp\AB2588\1999 HRA Report\Venoco Carp 1999 HRA Report.doc

Venoco Carpinteria

Gas Plant and Oil Pipeline

[pic]

Significant Cancer Risk Footprint in Red – 10 in a million

Maximum Offsite Cancer Risk = 30.14 in a million

(Property Boundary in Blue)

Venoco Carpinteria

Gas Plant and Oil Pipeline

[pic]

Significant Acute Risk Footprint in Red – Acute Hazard Index of 1.0

Maximum Offsite Acute non-cancer Risk = 2.23

(Property Boundary in Blue)

Venoco Carpinteria

Gas Plant and Oil Pipeline

[pic]

Chronic Risk Footprint in Red – Chronic Hazard Index of 1.0

Maximum Offsite Chronic non-cancer Risk = 0.75

(Property Boundary in Blue)

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[1] The facility emissions summary does not include criteria pollutants or pollutants that do not have OEHHA/ARB approved risk assessment health values (i.e., pollutants that have no contribution to risk).

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