PETITIONED HEALTH CONSULTATION
CENCO PROPERTY (a/k/a CENCO TANK FARM)
HUNTINGTON BEACH, ORANGE COUNTY, CALIFORNIA
The Agency for Toxic Substances and Disease Registry (ATSDR) was petitioned by a citizen to consult on health issues relative to lead at the Cenco Refining Company (CENCO) in Huntington Beach, California. The primary concern expressed by the petitioner was the presence of lead-based paint on the former oil storage tanks and the potential for this lead to cause health problems for people living in the area, especially children. The California Department of Health Services (CDHS), under a cooperative agreement with ATSDR, is providing a health consultation on the petitioned CENCO property in Huntington Beach, California.
The 22-acre CENCO property, formerly known as the Huntington Beach Marine Terminal, is located at 21471 Newland Street at the corner of Newland and Hamilton Streets in Huntington Beach, California (Attachment: Figure 1). The CENCO property is located in a mixed industrial and residential area approximately 1,200 feet northeast of the Pacific Coast Highway. The Marine Terminal was constructed in the 1950s and formerly received and distributed crude oil from a sea berth offshore of Huntington Beach. CENCO acquired the Marine Terminal in 1998 from Golden West Refining of Santa Fe Springs, California. The terminal has been inactive since 1995. The terminal consisted of six above-ground storage tanks (ASTs) used to store oil. Five of these ASTs had a capacity greater than 50,000 barrels (1). The facility also had one AST to store slops (crude oil or unrefined oil) and one AST for diesel fuel. Other structures on the site included a pumping facility, a high-pour crude facility containing crude oil heaters and pumps, waste and fire water handling facilities and petroleum distribution pipelines.
Two underground storage tanks (USTs) were removed from the site in January 2000. One of the USTs reportedly contained diesel, the other contained waste oil. The two USTs were removed under the direction of the Orange County Health Care Agency. A release from one of the USTs was observed during the removal (1).
On August 24, 2001, CDHS and ATSDR personnel toured the CENCO property to observe demolition activities and the location of nearby residences and businesses. CDHS and ATSDR were accompanied during the site visit by the petitioner for the consult, a representative from the Santa Ana Regional Water Quality Control Board and by several CENCO representatives. All demolition activities were stopped during the tour. Operations on the site generally involved shearing the metal tanks using a specialized backhoe, vacuuming up paint chips, moving scrap metal to stockpiles and loading scrap metal into trucks for appropriate off site disposal. Vacuuming activities were reportedly completed using High Efficiency Particulate Air (HEPA) filter vacuums. However, CDHS did not see or inspect the vacuums during the site visit. The majority of the CENCO property is surrounded by 7-foot-high wire fencing. CENCO personnel placed plastic tarps over the portion of the fence closest to the abutting neighborhood across Lomond Drive to minimize the amount of dust and dirt blowing off the site during demolition. The CENCO property was generally flat with some earthen berms for containment around the ASTs. The site is located approximately 1,500 feet northeast of the beach. One residential neighborhood abuts the property to the north (across Lomond Drive). An Orange County Flood Control Channel runs along the western edge of the property. Another residential neighborhood is located approximately 600 feet south of the site. The majority of the site had limited vegetative cover during the site visit.
CENCO personnel described the demolition process during the tour of the property. Demolition consisted of shearing the tanks instead of torching to avoid production of harmful lead vapors. Approximately 80% of the cutting was reportedly done from the inside of the tanks to minimize dispersion of the lead-paint chips and lead dust. At the time of the interview it was estimated that the total time to complete the excavation work would be approximately six weeks.
Ambient air lead monitoring was conducted on the site during work activities to assess the potential occupational risks during demolition and to assure proper safety precautions were undertaken. During the site visit CDHS observed four pumps in operation with an associated generator used to run the pumps for the 8-hour sample. The ambient air monitors were hung 5 to 8 feet off the ground and were placed along the fence on the northern border of the site, across the street from residences on Lomond Drive.
CENCO personnel indicated that ambient air levels of lead were so low that unless workers were directly handling lead or lead dust (e.g, vacuuming paint chips), they would not need respirator protection. During work situations where exposure to lead was elevated, such as working in the tanks or vacuuming paint chips, CENCO workers reportedly used respirators and additional personal protective equipment to reduce or eliminate lead-exposure risks.
According to CENCO personnel, other health and safety procedures included dust minimization and asbestos identification and removal. To accomplish dust minimization, water trucks were on site all day during the demolition. The reported operation was to spray down the area early in the day before work began to avoid puddling in work areas. According to CENCO personnel, asbestos abatement was performed at the site early in the project with mainly floor tile being removed from one small onsite building. CENCO representatives also indicated that any pipes uncovered during the excavation were to be inspected for asbestos.
The primary concern of the petitioner for this site is the lead-based paint on the former oil storage tanks and any lead that may have found its way into soils on the site. The petitioner expressed concern that as sand from the beach and surrounding area blew through the site it was abrading the paint. The petitioner was concerned that some of the paint was falling off in chips and that this lead would get into the air and could reach the residences nearby and cause health problems, especially for children who live in the area. Because the winds in the area can be strong and persistent, lead on the site could blow off site to nearby locations.
No environmental data has been collected off site to evaluate the potential impacts on the nearby residential neighborhoods. Therefore, CDHS used the California Department of Toxic Substances Control (DTSC) risk calculation model called Leadspread to estimate lead exposure levels on the site using data collected on the CENCO property and ambient air levels in Orange County. This approach provides a multi-media estimate of lead concentration in blood for exposures on the CENCO property. This approach provides a conservative estimate of the lead dose expected in the residential areas because off site lead concentrations would be expected to be below those on the site, unless additional sources of lead contamination were introduced off the site.
Summary of Paint Chip Sampling
During demolition activities at the site, CENCO collected two paint chip samples from the site and had them analyzed for lead. The paint chip from oil tank # 1 contained 49,000 parts per million (ppm) of lead, or 4.9% lead. The paint chip from oil tank #2 contained 69,000 ppm, or 6.9% lead. Although this is a small sample of the paint used on tanks on the CENCO property, it is generally on the lower end of the range for lead content in lead paints. Lead was used in paints until it was restricted for use in residential paint in 1978. Currently, residential paint must contain less than 600 ppm lead.
The concentration of lead in paint before 1978 can vary greatly. Homes built prior to 1950 may contain paint with lead concentrations as high as 500,000 milligrams per kilogram (mg/kg) or ppm (50% lead) (2). However, lead concentration in lead-based paint is generally lower than 50%. Although lead-based paints have been banned for use in residential settings since 1978, they are still allowed for certain industrial, military and marine purposes, and lead paint remains on interior and exterior surfaces of an estimated 8.6 million older housing units in California (2).
Summary of Air Monitoring Collected During Demolition
Ambient air lead monitoring was conducted on the site by CENCO during work activities to assess the potential occupational risks during demolition and to ensure proper safety precautions were taken. Ambient air sampling consisted of a pump that forces a measured volume of air over a filter for an 8-hour period. The filter is then taken to a laboratory using standard chain-of-custody methods and analyzed for the lead content. The result is then averaged over the 8-hour period to give an approximate hourly lead ambient air concentration. During the site visit CDHS observed four pumps in operation with an associated generator used to run the pumps for the 8-hour sample. The ambient air monitors were hung 5 to 8 feet off the ground and were placed along the fence on the northern border of the site, across the street from residences on Lomond Drive.
Upon review of ambient air data collected by CENCO, CDHS concluded that the concentrations of lead in the air were below occupational health and safety standards that would require respiratory protection.
Of the 33 samples collected by CENCO between August 13, 2001 and August 29, 2001 via National Institute for Occupational Safety and Health (NIOSH) Method 7082 (3), there were three samples that had lead above detection limits, two of which were from personal lead samplers worn by workers directly handling lead paint or lead dust. The detection limit of this methodology was 0.002 mg, which translates into a time-weighted volumetric range of approximately 1 microgram per cubic meter (µg/m3) to 4 µg/m3, depending on the volume of air pumped through the sampler filter. The three detections were: 3.57 µg/m3, 14.12 µg/m3 and 3.2 µg/m3. Personal lead samplers would be from workers who are working directly in the lead-paint areas and would be expected to present the greatest lead-exposure levels. The California ambient air standard for lead is a running average of 1.5 µg/m3 over a 30-day period (4). The majority of on site ambient air samples collected at the site during demolition were below the 1.5 µg/m3 standard.
NIOSH recommends workers not be exposed to lead levels of more than 100 µg/m3 for up to 10 hours. The ambient air concentrations at the CENCO site were significantly below this standard. The maximum concentration of lead detected in ambient air at the site was 3.2 µg/m3. The maximum concentration of lead detected on the personal air monitoring devices was 14.12 µg/m3.
Summary of Soil Investigations Conducted at the CENCO Property
CDHS reviewed the Supplemental Site Assessment Report and Soil Removal Work Plan (5) for the Former Huntington Beach Marine Terminal property, prepared by TRC Environmental Solutions, Inc. (TRC), for CENCO. This report summarized activities at the site and provided data on 105 surface (0.5 feet below grade) soil samples collected on the site in February 2002. After the demolition and tank removal activities, TRC collected samples that transected the areas where the ASTs were formerly located at 25-, 50- and 100-foot intervals (Attachment: Figure 1). TRC collected transects running to the north, south, east and west of the former AST locations. The larger tanks (17006, 17007 and 17014) had additional sampling transects to the northeast, northwest, southeast, and southwest. Four additional samples were collected along the western portion of the property.
Soil samples were analyzed for total lead via USEPA Method 6010B and for soluble lead using a Waste Extraction Test (WET) and USEPA Method 6010B (5). Total lead concentrations for the 105 surface soils samples ranged from 6.9 ppm to 2,200 ppm, with the mean concentration being 120 ppm. Natural levels of lead in surface soils are usually below 50 ppm (6) and the USEPA reports that typical background soil lead concentration is about 15 ppm (2). Total lead concentrations for soil samples collected at 0.5 feet below ground surface adjacent to the former AST locations ranged from 2.5 ppm to 150 ppm. The maximum lead concentration detected in soils from the February 2002 sampling was 2,200 ppm, immediately to the west of AST 55002. In general, total and soluble lead concentrations are greatest close to the former AST locations. Concentrations generally decrease as one travels away from the former AST locations.
CDHS reviewed the data in order to identify sample locations that may be helpful in determining if the lead contamination might spread into the neighborhood across Lomond Drive. CDHS identified six samples that were collected on the CENCO property closest to residences across Lomond Drive to the north of the CENCO Marine Terminal. These samples (R4, 3NC, 3NED, 7NWD, 7NC & 7NED) were collected to the north of where AST 17006 & AST 17007 were formerly located. These six surface soil samples had an average total lead concentration of 50.7 ppm. The California EPA Preliminary Remedial Goal for lead in soil is 400 mg/kg (400 ppm) in residential settings and 750 mg/kg (750 ppm) for industrial settings (7).
CDHS determined that soil lead data collected near the two large ASTs closest to the residences across Lomond Drive to the north of the CENCO Marine Terminal (AST 17006 & 17007) had an average total lead concentration of 93.6 ppm.
Health effects of lead exposure include effects on the nervous system, blood, kidneys and the reproductive system. Lead is toxic to the nervous system, particularly in young children and the developing fetus. Scientific studies have indicated that, at low to moderate blood lead levels, neurologic and developmental effects of lead include: decreased intelligence; short-term memory loss; reading and spelling underachievement; impairment of visual motor functioning; poor perception integration; disruptive classroom behavior; and impaired reaction time (2).
The effects on intelligence appear to occur above and possibly below the 10 micrograms per deciliter (µg/dL) "level of concern" identified by the Center for Disease Control (CDC) and the National Academy of Science (2). A threshold for neurodevelopmental effects from lead exposure has not been identified (2). In addition to being more susceptible to lead's toxicity, children are also at greater risk for lead exposure because they tend to engage in hand-to-mouth activity. The CDC, of the Department of Health and Human Services, has set a goal of reducing children's blood lead levels to below 10 µg/dL (8).
In addressing lead contamination health risks, CDHS used the DTSC risk calculation model called Leadspread (9). The DTSC developed this mathematical model for calculating blood lead concentrations as a function of cumulative exposure to lead-contaminated environmental media (air, soil, water and food). The model calculates the effects of multi-media lead exposures in blood lead levels under residential and industrial scenarios and utilizes site-specific measurements, if available. In the absence of site-specific lead-concentration data, default values may be used. The only site-specific data that is required for the Leadspread model is site soil lead concentrations.
If no ambient air data is available for the site, it is recommended that air data collected from the nearest California Air Resources Board (CARB) air-sampling station be used. If there is no site
data and no lead air data for the air basin that the site is located in, then the default of 0.028 µg/m3 is used. The default value represents the average lead concentration in air in California, based on data collected in 1997 (9).
CDHS ran the Leadspread model using the average total lead concentration (120 ppm) in surface soil samples collected on the site (Attachment: Table 1). CDHS also replaced the default ambient air lead value of 0.028 µg/m3 with the year 2000 lead average for the CARB monitoring station closest to the site (0.016 µg/m3). The North Long Beach air monitoring station is located approximately 20 miles north of the CENCO property. The annual average concentration of lead in the air at the North Long Beach CARB station from the year 2000 was 0.016 µg/m3.
CDHS considered using the occupational ambient air data collected by CENCO during tank demolition. However, this data is not appropriate for the Leadspread model because the data was collected and analyzed for the purposes of assessing occupational health risks using detection limits that are well above those needed for residential exposure risk estimate calculations. The detection limit for this data is much higher than needed for the Leadspread model. Therefore, CDHS used air monitoring data from the closest CARB air monitoring station.
Based on Leadspread model calculations using site-specific variables and appropriate default values, the blood lead estimates on the CENCO property would be expected to be less than 9.0 µg/L for children and adults, except for children who get onto the site and exhibit PICA (soil- eating) behavior. Furthermore, using the parameters discussed above, the Leadspread model estimates that the majority of people (95%) would be expected to have a blood lead level of 6.5 µg/dL or less. These estimates would be expected to be lower for areas off the CENCO property.
Short-Term Health Concern
In November 1970, California adopted an ambient air quality standard for lead based on a 30-day running average of 1.5 µg/m3 (2). Although 30-day residential sampling was not collected for this site, a review of the occupational ambient air data collected by CENCO suggests that this criteria would not likely be exceeded. Of the 33 ambient air samples collected during the tank demolition, lead was detected in only three air samples. Assessing the risk further, CDHS averaged these detections with one half the detection limit for all of the samples that were below detection limits for lead. Assuming that the lead concentration in the air was at half the concentration of the detection limit for those samples recorded as non-detect, the average ambient air lead concentration would be 1.0 µg/m3, which does not exceed the 1.5 µg/m3 30-day average standard. Thus, air emissions of lead during the demolition should not result in short-term health effects on the CENCO property. Therefore, offsite areas would also likely be below the 1.5 µg/m3 30-day average standard.
ATSDR recognizes that infants and children may be more sensitive than adults to environmental exposures. This sensitivity is a result of several factors: 1) Children may have greater exposures to environmental toxins than adults because pound for pound of body weight, children drink more water, eat more food, and breathe more air than adults; 2) Children play outdoors close to the ground which increases their exposure to toxins in dust, soil, surface water, and in the ambient air; 3) Children have a tendency to put their hands in their mouths while playing, thereby exposing them to potentially contaminated soil particles at higher rates than adults (also, some children ingest non-food items such as soil which is a behavior known as "pica"); 4) Children are shorter than adults, which means they can breathe dust, soil, and any vapors close to the ground; 5) Because children grow and develop rapidly, they can sustain permanent damage if toxic exposures occur during critical growth stages; and 6) Children and teenagers may disregard "No Trespassing" signs and wander onto restricted locations. Because children depend on adults for risk identification and management decisions, CDHS is committed to evaluating their special interests at hazardous waste sites as part of the ATSDR Child Health Initiative.
CDHS has attempted to identify places (e.g., parks, schools, recreational facilities, etc.) in the vicinity of the site where children live, play, and/or go to school. The closest location where children would likely spend time is in the residential neighborhood across Lomond Drive to the north of the site. Multi-media model estimates of lead concentration in blood for exposures on the CENCO property were below the CDC's blood lead level goal of 10 µg/dL (8). This approach provides a conservative estimate of the lead dose expected in the residential areas because off site lead concentrations would be expected to be below those on the site.
Based on the information reviewed, CDHS and ATSDR conclude that the lead associated with the former tanks at CENCO Former Marine Terminal in Huntington Beach is not expected to produce health effects and does not pose an apparent past, present or future health hazard to people either on or off the CENCO property. This determination does not address other hazards or risks that may or may not be related to the CENCO facility and their potential risks to public health or the environment.
- Versar, Inc. Work Plan for Phase II Site Assessment for the Golden West Marine Terminal Huntington Beach, California. Prepared for CENCO Oil Refinery. March 29, 2001.
- CARB and the Office of Environmental Health Hazard Assessment. Final Statement of Reasons for Rulemaking: Staff Report/Executive Summary. Proposed Identification of Inorganic Lead as a Toxic Air Contaminant. April 24, 1997.
- National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods (NMAM), Fourth Edition. Method 7082.
- Ambient Air Quality Standards-California Air Resources Board website. California Air Resources Board. Site accessed on February 7, 2002. URL: http://www.arb.ca.gov/aqs/aaqs2.pdf.
- TRC. Supplemental Site Assessment Report and Soil Removal Work Plan for the Former Huntington Beach Marine Terminal, Huntington Beach, California. Prepared for CENCO Refining Company. March 28, 2002.
- Reagan, PL and Silbergeld, EK (1989). Establishing a Health-Based Standard for Lead in Residential Soils. In: Hemphill and Cothern, eds. Trace Substances in Environmental Health, Supplement to Volume 12, (1990) of Environmental Geochemistry and Health.
- Preliminary Remediation Goals (PRGs) Tables website. California Environmental Protection Agency. Site accessed on February 10, 2002. URL: http://www.epa.gov/region09/waste/sfund/prg/files/02table.pdf.
- CDC. U.S. Public Health Service, Preventing Lead Poisoning in Children. 1991.
- DTSC Webpage for the Leadspread Exposure Estimate Tool. Leadspread Version 7 last updated in 1999. Site accessed on February 4, 2002. URL: http://www.dtsc.ca.gov/ScienceTechnology/ledspred.html.
Environmental and Health Effects Assessors
Impact Assessment, Inc., Consultant to
California Department of Health Services,
Environmental Health Investigations Branch
Marilyn C. Underwood, Ph.D.
California Department of Health Services,
Environmental Health Investigations Branch
ATSDR Regional Representatives
William Nelson, M.S.
Regional Representatives, Region IX
Agency for Toxic Substances and Disease Registry
ATSDR Technical Project Officer
Tammie McRae, M.S.
Environmental Health Scientist
Agency for Toxic Substances and Disease Registry
This Petitioned Health Consultation for the CENCO site was prepared by the California Department of Health Services (CDHS) under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures exiting at the time this health consultation was initiated.
Tammie A. McRae, M.S.
Technical Project Officer, SPS, SSAB, DHAC
The Division of Health Assessment and Consultation (DHAC), ATSDR has reviewed this Health Consultation and concurs with its findings.
Section Chief, SPS, SSAB, DHAC, ATSDR