PUBLIC HEALTH ASSESSMENT
Air Addendum
AMOCO-SUGAR CREEK
(a/k/a AMOCO-SUGAR CREEK)
SUGAR CREEK, JACKSON COUNTY, MISSOURI
The Agency for Toxic Substances and Disease Registry (ATSDR) released this Amoco Oil Company public health assessment air addendum for public review and comment from March 29, 2000, through June 30, 2000. Each comment received was logged and became part of the administrative record. This section contains both the comments received during the public comment period and ATSDR's responses to those comments. The comments have been numbered for convenience in referring to them. Following each comment is ATSDR's response to the comment.
Comment 1: The stated purpose of the May 1999 public health assessment is contrary to the public petition made to the ATSDR. The ATSDR has chosen to limit its study to determine "if current chronic indoor air exposures are of potential health concern for local residents." The petition made to the ATSDR did not limit the study to "current" health effects.
Response 1: In this public health assessment air addendum, ATSDR focused on known, site-specific, indoor air exposures for which environmental data were available. No indoor air data for the Norledge area are available prior to June 1998. Our evaluation, therefore, was necessarily limited by the available environmental data to current, chronic health effects of indoor air exposures.
Of note, the May 1999 public health assessment is a separate document from this public health assessment air addendum. The May 1999 public health assessment was a public comment document released in final form on November 29, 2000. In the November 2000 public health assessment, ATSDR noted that residents are concerned about past air exposures from when the facility was operating. The agency also stated that groundwater data from the 1960s and 1970s, if available, could be used to model past indoor air concentrations. Since the release of the November 2000 public health assessment, however, EPA has been unable to locate any groundwater data collected at the site in the 1960s and 1970s (or earlier) that would be of use to ATSDR for modeling purposes (EPA 2002). If modeling had been feasible, the information it provided could have assisted in addressing community concern about past indoor air exposures.
Comment 2: By choosing to examine only "current" health effects, the ATSDR ignored past health effects caused by Amoco on the residents of Sugar Creek and Independence in the Amoco refinery area, thereby avoiding a potentially contentious dispute with BP Amoco and the expense of a comprehensive study.
Response 2: As indicated in Response 1, ATSDR did not necessarily choose to limit our evaluation – it was limited by a lack of air data from when the facility was operating. The agency did, however, consider other options to address the residents' health concerns about past exposures. One of these options – modeling past indoor air concentrations – was not feasible. A second option targeted specifically at residents' concerns about multiple sclerosis (MS), was feasible. In fact, through the Jackson County Health Department ATSDR is funding a prevalence study to determine if higher rates of MS exist in Sugar Creek. Thirdly, to address concerns about cancer rates, ATSDR played an active role in reviewing the Missouri Department of Health's (MDOH's) cancer cluster investigations. Therefore, although ATSDR's public health assessments and health consultations focused on current and future exposure pathways, the agency supported other options to address past exposure concerns.
Comment 3: ATSDR's lack of a strong position on the subject of past exposures leaves the residents confused and uninformed about the impact of Amoco's past operations on their health. The ATSDR serves Amoco's purposes by avoiding the subject of past exposures, including cancer clusters which the Missouri Department of Health has indicated probably existed in the 1960's through 1970's.
Response 3: Please see Responses 1 and 2. ATSDR's evaluations are limited by the type of environmental and health outcome data available.
MDOH investigated brain cancer, leukemia, and lymphoma. Their Level 2 inquiry showed mixed evidence for an incident brain cancer cluster and no evidence of a cluster of incident cases of leukemia or lymphoma (MDOH 2000). MDOH's Level 3 inquiry showed mixed evidence of a time and space clustering of brain cancer cases (MDOH 2000). The Level 4 inquiry determined it would not be feasible to undertake an etiologic study of environmental petrochemical exposure and primary brain cancer in Sugar Creek (MDOH 2001). However, MDOH will continue cancer surveillance in this area (MDOH 2001).
The results of an independent brain cancer cluster investigation found no statistically significant increase in the number of brain cancer cases in the community, although there are several limitations in this investigation (Neuberger et al 2003).
ATSDR is funding a MS prevalence study in the Sugar Creek area. Anecdotal information suggested a 2- to 4-fold elevation in MS prevalence above the expected national figures. The Jackson County Health Department entered into a cooperative agreement with ATSDR to address this issue. The research activity included the development of methods for case ascertainment and confirmation and the estimation of MS prevalence for Sugar Creek (ATSDR 2003). A final report for this project is expected soon (ATSDR 2003).
Comment 4: The ATSDR has based its public health assessment, which provoked the air sampling, on incomplete data supplied by BP Amoco to the EPA and MDNR.
Response 4: ATSDR based its evaluations on air data that were available to the agency for review. The data reviewed are considered adequate for the purposes of our evaluation.
Comment 5: Figure 3, "Norledge Area Air Sampling Locations - 1999", is not accurate with respect to the location of several of the tested homes. Locations 1, 4, 5, 6 & 7 are not indicated correctly on Figure 3.
Response 5: Figure 3 provides the general locations of the homes where air sampling was conducted in 1999. ATSDR contacted the EPA to pinpoint further these locations. Modifications were incorporated into Figure 3.
Comment 6: The reference to CERCLIS No. should be changed throughout the text and figures to RCRIS No.
Response 6: ATSDR has deleted the designation "CERCLIS No." on all text and figures and replaced it with the designation "EPA Facility ID."
Comment 7: Section 2 indicates there are 100 residences in the Norledge area. This is incorrect as there are approximately 130 homes in the Norledge area.
Response 7: ATSDR modified the number of homes in Section 2.
Comment 8: In Section 2, paragraph 3, to clarify the type of samples collected, it is suggested that the text "(24 hour sample intervals)" be changed to "(24 hour composite samples)". It is also suggested that the second sentence in this paragraph be replaced with the following: Each home was sampled every other day for a period of one week. In July, three of these homes were re-sampled for an additional week.
Response 8: The suggested changes were made (see Section 2).
Comment 9: Section 3.1 is ambiguous in that it states only crude oil was spilt or leaked throughout the site. Free product like leaded gasoline and naphtha have been found in off-site monitoring wells. The fuel additive MTBE has been found in soil and groundwater off of Amoco's Refinery property.
Response 9: ATSDR updated Section 3.1 to state that leaded gasoline and naphtha were used on site. Amoco has been required to include the fuel additive methyl-tert-butyl ether (MTBE) in their sampling analyses even though Amoco maintains that MTBE was not used on site (EPA 2001b).
Comment 10: The report should clarify the location of Amoco's active pipelines. The active pipelines are located on the eastern portion of the site, well away from the study area. In addition, the active pipelines enter the site from off-site on the eastern and northern borders of the site.
Response 10: ATSDR modified Section 3.4.
Comment 11: Despite Amoco's stated policy of replacing underground pipelines in the 1970's, Amoco didn't institute that policy until the mid 1970's and never finished raising pipelines aboveground prior to closing the Refinery in March 1982.
Response 11: Starting in the 1970s Amoco began to replace underground pipelines with above-ground pipelines to reduce the potential for undetected releases (TriTechnics Corporation 1995). The decommissioned underground lines were flushed with water in 1986-1987. A leaking pipe in a tank dike indicated, however, that some product remained in the lines after the flushing occurred. EPA requested that Amoco prepare a plan for investigating underground pipelines. As part of future investigations, Amoco will address underground piping and other subsurface structures (EPA 2001b). ATSDR modified the text in Section 3.4.
Comment 12: Since 1989, Amoco has successfully limited the reporting to the government agencies of Norledge area groundwater analysis to benzene, toluene, ethyl benzene and xylenes (BTEX). It has only been since 1999 that any environmental agency has required Amoco to test for a broader suite of constituents. When the government agencies did require Amoco to test for a broader suite of constituents, more were found. The testing is occurring too late to help the ATSDR to determine the health impact on Norledge area residents.
Response 12: Although it might have varied due to sampling location, Amoco analyzed on-site samples for BTEX, polycyclic aromatic hydrocarbons (PAHs) and metals in soils, sludges and groundwater in the 1980s and 1990s (EPA 2002). Sampling in the 1980s and early 1990s, however, did not include sampling in the off-site Norledge area.
ATSDR did evaluate the site from the standpoint of its health impact on Norledge area residents. Specifically, we focused our evaluation on current and potential future exposures of Norledge area residents using available off-site data. The results of our evaluations are contained in a series of public health assessments and health consultations (see Section 10).
Comment 13: After nearly 12 years, the Amoco Refinery site still does not have an environmental agency approved RCRA RFI report.
Response 13: Although responding to comments concerning the RFI are out of the purview of ATSDR's mission and of this public health assessment, ATSDR did contact EPA for clarification on this issue. EPA and MDNR are under joint signature to approve RFI documents (EPA 2001a). Since the 1995 RFI report was submitted, the EPA and MDNR have taken a different approach to completing the RFI process. Due to public concern, the agencies have focused most of the investigation in the off-site plume area and Amoco submitted an RFI report focused solely in this off-site area. This was done to expedite investigations and to implement cleanup activities in the off-site area. Subsequent investigations will be conducted in a phased manner for the remainder of the site (EPA 2001a). This information has been added to Section 3.4.
Comment 14: As of April 1998, the EPA and MDNR had over 120 comments and criticisms of Amoco's RFI, most of which have not been resolved. Since 1998 Amoco has implemented "remedial" measures with the dual purpose of enhancing its litigation position in lawsuits filed to force Amoco to clean up its off-site pollution and of avoiding environmental agency penalties.
Response 14: Comments concerning the RFI for the Amoco site and the lawsuits filed against Amoco are outside the purview of ATSDR's mission (see Response 13).
Comment 15: The EPA and MDNR are aware that several of the laboratories used by Amoco for analysis of water and soil samples during the RFI investigation have been discredited and are under investigation for improper laboratory procedures. Amoco is aware of this faulty laboratory analysis and in 1998 informed the MDNR. The ATSDR's reliance on Amoco's faulty RFI investigation is a disservice to the people relying on the mission of the ATSDR to provide answers to their questions and concerns about how their health has impacted by Amoco's operations.
Response 15: EPA reported that Intertek laboratory (also known as Inchscape and ITS) was indicted for falsifying data and quality assurance procedures. Intertek laboratory provided laboratory services for hundreds of sites in Region 7 and many hundreds more nationally (EPA 2001a). In the case of Amoco, Intertek laboratory data was used in the 1995 RFI report and in quarterly reports for 1995 and 1996. Data from a second laboratory was also called into question because of the lack of quality assurance documentation. EPA reported that there is no indication that the data were not acceptable, but the laboratory in question had been under investigation for questionable laboratory practices during the time period in which the data were produced. Given this information it was decided that these data should be considered questionable. That said, however, EPA reported that this was a small amount of data that have not been used to make site decisions (EPA 2001a).
This public health assessment did not rely on any data from the 1995 RFI, as the focus was on air sampling reports from 1999. Of note, the November 2000 public health assessment did include a review of water and soil data. These data were compiled from a variety of sources and did not solely depend on the RFI data. As such, our conclusions in the November 2000 public health assessment remain unchanged.
Comment 16: Section 3.4 is incorrect when it states that Amoco installed the interceptor trench to control migration of hydrocarbons dissolved in groundwater. Amoco installed the trenches to collect and recover petroleum containing groundwater for reuse and re-refining to be added to its product stream.
Response 16: According to the EPA, the interceptor trench served two purposes: 1) to recover free product, and 2) to control migration (EPA 2001a).
Comment 17: The first section of interceptor trench was installed in 1967, the second extension was installed in 1976, the third in 1983, the fourth in 1988 and the fifth & sixth sections in 1990. A gap was found between the 1967 and 1976 extensions and was finally closed in 1983. It wasn't until 1990 that the entire Burton Street area south of Norledge Avenue was "protected" by the interceptor trench.
Response 17: Comment noted.
Comment 18: As of June 2000 the Norledge area bordered by Evans, Willow, Ash and Scarritt still does not have any interceptor trench or barrier wall to prevent hydrocarbon contaminated groundwater from migrating from the Refinery through the neighborhood.
Response 18: ATSDR is aware no interceptor trench or barrier wall has been constructed in this area. Due to the possibility of volatization of chemicals from groundwater, indoor air sampling was conducted in homes in this specified area. These are the data evaluated in this public health assessment.
In addition to the interceptor trench, current interim measures in the Norledge area include enhanced fluid recovery (EFR) and total fluids extraction (TFE) (BP 2002). See Section 3.4 for further information.
Comment 19: Prior to 1998, Amoco only monitored the quality of the Norledge area groundwater. It didn't remove free product or any contaminated groundwater.
Response 19: Starting in the 1960s, Amoco began to install an interceptor drain system and trenches to collect and recover petroleum in the groundwater (free product) for reuse and to prevent migration of hydrocarbons dissolved in the groundwater. The trench system affects the area south of Norledge Avenue. The interceptor trench was installed in several phases. See Section 3.4 which describes current interim measures occurring in the Norledge area.
Comment 20: Amoco collected hydrocarbon-contaminated groundwater at the Norledge Trench, but only after the benzene containing groundwater had passed and volatized under the majority of the residences in the Norledge area. Amoco has admitted its releases have been occurring since 1950. Many generations of Norledge area residents have been affected by Amoco's pollution.
Response 20: ATSDR agrees historical groundwater releases have been documented in the Norledge area. ATSDR's May 1999 public health assessment evaluated groundwater data, and recommended additional indoor air sampling in the Norledge area to determine if BTEX was volatizing from the groundwater into the air in Norledge area homes at levels of health concern. This public health assessment air addendum focuses on current indoor air exposures. Using the data reviewed by ATSDR, any benzene currently volatizing under Norledge area homes is not at levels of health concern.
Comment 21: We are glad that ATSDR raised the issue of the Norledge Trench. This system is nothing more than a French drain that leaks. We believe that the chemicals here are volatilizing, thus contributing to the ambient air contamination in the area. Until there is 24 hour, 7 days a week, 365 days a year ambient air monitoring, this will not be resolved. Testing ambient air occasionally will not give us a true picture of what is in the air.
Response 21: Outdoor (that is, ambient) air samples were collected and ATSDR evaluated these data in this public health assessment and in other ATSDR documents regarding the Norledge area. At the chemical levels detected, no adverse health effects would be expected for chronic exposure to outdoor air. Therefore, ATSDR does not recommend continuous monitoring of outdoor air.
Comment 22: We wonder why Section 3.4 discusses planned sampling activities on the part of EPA and Amoco.
Response 22: ATSDR believes it is important to provide the community with information about activities occurring in the Norledge area. The current interim measures will reduce the levels of contamination in groundwater and soil vapor.
Comment 23: You failed to include in your References section the three Amoco citations. These references should be added. It has come to our attention that these citations were Amoco Fact Sheets (a/k/a Amoco propaganda). If you are so willing to publish in your report, these Amoco Fact Sheets, you should also include information provided via the Citizens Investigation done by CLEANUP, who have provided substantial evidence relevant to your health assessment.
Response 23: The noted references were Amoco fact sheets. These fact sheets were not used for our public health evaluation – they were used as references to provide information about remediation and sampling activities Amoco planned. Section 3.4 has been updated to include current information, which is referenced accordingly.
During the public comment period for the May 1999 public health assessment a variety of entities including CLEANUP provided numerous additional environmental data sets to ATSDR. These data were reviewed in the final release of that document in November 2000.
Comment 24: The report should clarify that Amoco has completed the collection of additional soil vapor and air samples. The results will be included in the RFI Report to be submitted to MDNR and EPA.
Response 24: ATSDR received requests from Amoco, MDNR, and EPA to review additional air, soil, sediment, and surface water samples collected after this report was released. The results of our evaluations are contained in a series of health consultations (see Section 10). Overall, the data indicate no adverse health effects would be expected. At this time, ATSDR has not received any additional soil vapor sampling data.
Comment 25: Amoco is collecting 70 soil vapors from homes in the Norledge area. I'd request that the ATSDR receive, review and offer for public comment the results of Amoco's soil vapor investigation.
Response 25: Because soil gas measurements can only be evaluated to determine the extent to which contaminated groundwater might affect the air pathway, ATSDR prefers to review sampling data collected directly from the air pathway. ATSDR did, however, previously review RFI data on 35 soil gas samples collected primarily from the Norledge area in the November 2000 public health assessment. Because benzene, toluene, ethyl benzene and xylenes (BTEX) were detected in soil gas, ATSDR had recommended additional indoor air sampling. This public health assessment provides a review of the additional indoor air sampling results.
At this time, ATSDR has no plans to review additional soil vapor sampling data. Given current remedial measures in the Norledge area, including EFR and TFE, soil gas levels should be decreasing. Therefore, any potential contribution from the soil vapor media to indoor air levels should decrease as well.
Comment 26: In Section 3.5, the discussion concerning future responses to indoor air complaints should be revised to reflect the following: The preferred first responder to future indoor air complaints are the local police and fire departments. To assist them in their first responder role, the EPA has provided the Sugar Creek Fire Department a combustible gas indicator (CGI) and Photo Ionization Detector (PID). The equipment would be used to collect initial field screening information which EPA and MDNR would use to determine if additional response or sampling is necessary.
Response 26: Section 3.5 has been modified accordingly. Furthermore, EPA recently transferred ownership of the CGI to the fire department and it is expected that PID ownership will also be transferred to the fire department in the near future (EPA 2002).
Comment 27: Section 3.5 is incorrect when it states that the MDNR and EPA have established procedures that "will enable those initially responding to odor complaints to take Summa canister air samples; that is, chemical specific samples, in Norledge area homes." As of April, 2000, the EPA and MDNR's preferred primary responder to the odor complaints was the City of Sugar Creek Fire Department. The EPA and MDNR loaned to the City of Sugar Creek Fire Department a MSA Model 260 combustible gas indicator and a Hnu Model PL 101 photo ionization detector. This loan is for only 18 months. Firefighter training on this equipment occurred on March 23, 2000. No Summa canisters or training have been provided to the City of Sugar Creek Fire Department. Please revise the Air Addendum to correctly reflect these facts.
Response 27: This public health assessment addendum was updated accordingly (see Response 26 and Section 3.5).
Comment 28: Please note that the horizontal well system that is described has not been implemented according to Amoco's media announced time frame. The two horizontal wells installed in October were a "pilot test" and the EPA and MDNR's review of the results of the pilot test has not been completed. Amoco has installed none of the other horizontal wells it promised in the summer of 1999.
Response 28: ATSDR is aware that the pilot test has taken longer than anticipated. This public health assessment was updated accordingly. See Section 3.4 for current information on the TFE horizontal well system.
Comment 29: The ATSDR's reliance on "default" conditions from the general population is flawed. The ATSDR has made no effort to determine (1) what the past Amoco site specific conditions were during and immediately after Amoco's closure of the Refinery's operations and (2) to what degree those Amoco site specific conditions were higher or lower than the general population "default" conditions. ATSDR's reliance on the environmental data is building a house on the sand.
Response 29: As ATSDR uses the term, "default conditions of exposure" refers to the assumption that the average 70-kilogram (kg) adult consumes 2 liters of water and 100 milligrams (mg) of soil, and breathes about 20 liters of air, every day. For a 10-kg child, the corresponding defaults are 1 liter of water, 200 mg soil, and less than 10 liters of air, every day. These defaults are intentionally conservative overestimates. For example, few children actually consume more than 50 mg soil per day. ATSDR conservatism is enhanced when the defaults are used in site-specific exposure scenarios where it is typically assumed that all of the soil, water, or air that enters a person's body is contaminated with the highest detected site-specific concentration of the chemical of concern. In reality, the person's daily intake of any environmental medium comes from various sources that contain variable levels of contamination. Thus, dose estimates based on default conditions of exposure will generally exceed by a significant margin any dose estimates based on site-specific conditions of exposure. ATSDR's goal is to base public health decisions on dose estimates that are highly unlikely to underestimate the actual exposure of anyone associated with the site.
Comment 30: The report states in Section 4.1 that no other sources in the homes exist. Amoco representatives present during the testing observed the following potential sources of indoor air contaminants (especially benzene): cigarette smoking, natural gas usage, and paint/thinner storage. The report should be revised to include these as other potential sources in the homes. Also, the last sentence should refer to Tables 2 and 3.
Response 30: EPA staff conducting the sampling reported to ATSDR that each basement was inspected prior to sampling. None of the sources mentioned in this comment were reported. The tables are referenced in the second paragraph of Section 4.1.
Comment 31: The seven homes chosen for sampling by the EPA were based on the location of an underground plume identified exclusively by Amoco. The boundaries of this plume have never been defined; therefore, the number of persons who may be affected is unknown. We have documented visible signs of pollution north, south, east and west of these seven homes. We estimate that there are approximately 1000 households (if not more) in the affected area. Which means only 1 home in every 142 homes (less than 1% of the 1000 households) was sampled. This is outrageous and completely insufficient to determine any public health threat. At a minimum, quarterly sampling in 25% of area homes, for seven days (24 hour intervals) should have been part of the ATSDR's recommendation to regulators for the health assessment. Because chemical levels in indoor air are affected by weather, humidity, season, etc., quarterly sampling should be a given.
Response 31: The homes chosen were located above the known groundwater plume and are considered representative of indoor air in the Norledge area which encompasses approximately 130 homes. Changing seasons could affect the amount of groundwater contaminants volatilizing into the air in nearby residences. Considering this public health assessment and other ATSDR documents regarding the Norledge area, ATSDR evaluated indoor air data from both warm and cold months. The range of concentrations within the homes appears consistent.
Comment 32: In Section 4.1, you note that EPA took nine outdoor samples from five of the homes sampled. These were considered background samples. This is absurd. Background samples must be taken in an area that is not contaminated by toxic chemicals. With the background samples being already contaminated due to their location, the other test data is highly questionable, thus causing the indoor air samples to look less health threatening. In lay terms, if the background air already shows chemical levels, instead of subtracting that level, it should be added to indoor level to show what is in the air.
Response 32: ATSDR stated that these samples were considered background by EPA, not by ATSDR. To avoid confusion, the statement was removed from the public health assessment. Of note, ATSDR evaluates exposure to the maximum value detected, regardless of whether it is considered background by another agency. ATSDR's goal is to base public health decisions on dose estimates that are highly unlikely to underestimate the actual exposure of anyone associated with the site (see Response 29).
Comment 33: In Section 4.1, it would help to identify those chemicals that exceeded the health-based comparison values for both indoor and outdoor samples. This would help to show the limited impact of contaminant migration from the soil to indoor air.
Response 33: ATSDR modified this section to specify which chemicals exceeded comparison values in indoor samples and which chemicals exceeded comparison values in outdoor samples.
Comment 34: The report needs to state more clearly that although many chemicals were detected in the homes, most of these are not constituents of the groundwater contamination. The report could potentially mislead the reader into believing that all chemicals detected in the homes are potentially from former refinery operations. Many of the detected compounds in indoor air (e.g., chloroform, methylene chloride, tetrachloroethylene, trichloroethylene, carbon tetrachloride, 1,2-dichloroethane) have not been detected in the groundwater below the neighborhood. Most of these compounds are unlikely to be associated with petroleum hydrocarbons found in refinery processes, and are probably related to other indoor air sources.
Response 34: ATSDR's public health conclusions are determined by the magnitude and by the duration of exposures to specific chemicals, rather than by the source of those exposures. Nevertheless, the chemicals mentioned in this comment were not detected in groundwater, thus appropriate qualifying statements were added to this public health assessment (see Section 5, paragraph 2).
Comment 35: Section 4.2 indicates that representatives of the EPA, Amoco and ATSDR are attempting to determine if anything on-site could have triggered these releases. Due to a resident's investigation, an EPA representative visited on-site refinery tank berms, upgradient of a home, and found pipes containing hydrocarbons and stained soil. Amoco stated to the EPA and MDNR that these pipes were flushed and cleaned in the late 1980s and yet, in November 1999, hydrocarbon product is still present in the leaking underground pipelines.
Response 35: Access to this area is restricted. The EPA and MDNR visited this area and found exposed pipes which had obviously leaked. Amoco responded by excavating the pipes to determine where they go, flushing out the pipes, and capping them. The contaminated soil has also been removed. See Response 11 and Section 3.4 for additional information.
Comment 36: Section 5 is flawed in its entirety because it is based on limited air testing in current conditions. Section 5 fails to provide any satisfaction to residents concerned about the long term and chronic impact of Amoco's operations on their health.
Response 36: Section 5 and Appendix E address the issue of whether current exposure levels will impact the residents' health today and in the future. Using the data reviewed in this document, the November 2000 public health assessment, and several air health consultations, ATSDR concluded that current chemical levels are not likely to cause adverse health effects.
Of note, ATSDR reviewed several options to address concerns about the effect of past exposures on residents' health. Please refer to the agency's responses to Comments 1, 2 and 3 for further information.
Comment 37: ATSDR notes the very phenomenon that has plagued the residents: Odors here today, gone the next.
Response 37: ATSDR sympathizes with the residents who have been plagued by odors. Any environmental data provided to ATSDR for review from odor response reports will be evaluated and provided to the community.
Comment 38: In Section 5, paragraph 4, you note that you are merely "estimating" levels of benzene (using median value). Unacceptable. If there was a consistent, chemical-specific air monitoring plan in place, you would not have to do this. What of the people breathing in high levels every other day or week?
Response 38: ATSDR provided a detailed evaluation of site-specific benzene exposures in Appendix E. The paragraph in Section 5 of the main text is a summary of the two pages of detailed benzene text found in Appendix E. Exposures to the maximum air levels of benzene, along with other chemicals, were evaluated assuming people in the Norledge area were chronically breathing the maximum level. No adverse health effects would be expected at these levels.
Comment 39: In Section 5, paragraph 5, the first sentence should be revised to read as follows "The CREGs for chloroform, methylene chloride, tetrachloroethylene, and trichloroethylene are not derived from human exposure data, but rather are all based primarily on mouse liver tumors and male kidney tumors produced by species specific mechanisms that are evidently dependent on unusually high doses."
Response 39: ATSDR modified the sentence.
Comment 40: We are still dissatisfied with the limited list of contaminants in question, since each time a new set of tests are conducted, it changes the entire overview such as modeling for example. You note in Section 5 that "the October 1999 chemical-specific air data are included in this evaluation because ATSDR considers the data representative of chronic exposure levels (that is, the reported odors had dissipated before chemical-specific testing was conducted)" and that "The primary focus is on those contaminants that were present at levels in excess of one or more health-based comparison levels." This makes no sense. How can this be representative AT ALL? You should be recommending more indoor and ambient air sampling that IS chemical specific to be sure! The minimum of test homes should never be less than 25% of the affected area.
Response 40: The homes chosen were located above the known groundwater plume and are considered representative of indoor air in the Norledge area, which encompasses approximately 130 homes. Considering this public health assessment and other ATSDR documents regarding the Norledge area, ATSDR evaluated numerous sets of chemical-specific air data. The range of concentrations within the homes appears consistent. No adverse health effects would be expected at the detected levels of chemicals.
Comment 41: What about the chemicals that do not cause an odor therefore are not as noticeable to be concerned about? For example: A person has a headache, but there are no noticeable odors, yet when the air is tested contaminants are discovered. The people have not made note of what they cannot smell, perhaps putting themselves in jeopardy.
Response 41: Headaches are non-specific symptoms of numerous health conditions, most of which are not related with exposure to airborne contaminants. And there is no correlation between a chemical's odor threshold and its threshold of toxicity. Some compounds have odor thresholds generally lower than their toxicity thresholds – such substances are said to have "warning odors" – while others do not. The odor threshold of benzene, for example, is around 4.9 mg/m3 or about 1.5 ppm which is lower than levels known to cause adverse health effects in animals or humans and exceeds the highest level detected in Sugar Creek homes by an order of magnitude.
Comment 42: The literature on which you base your assessment is both misleading and often irrelevant to the Sugar Creek investigation. Worker exposures (typically, young, male, 40 hours per week, high level exposure, protective gear) differ substantially from chronic residential exposures (women, children, elderly of all ages which are likely to unknowingly receive both low and high level exposures from multiple exposure pathways) for many more hours a day.
Response 42: ATSDR takes great care not to mislead its readers. If some of the literature cited in ATSDR's assessment for Sugar Creek appears not to be directly relevant to the investigation, it could be because such material (like historical occupational data) is introduced to put site-specific exposures into a more meaningful perspective. Even though a 24-hour day is 3 times longer than a typical 8-hour work day, historical occupational exposures are often 10-1000 times higher than current exposures in the general population. This sizeable difference in daily exposures makes historical occupational exposures particularly useful for purposes of comparison. Assume, for example, that no adverse health effects had ever been seen in workers exposed for a working lifetime to average levels of a substance more than 10 times the maximum level of the same substance detected off-site in the general population. Under such assumptions there would be little reason to expect adverse health effects to occur in response to non-occupational exposures, even if they did occur for 24 hrs/day. As useful as they are, however, such comparisons are used for illustrative purposes and do not constitute the sole basis of ATSDR's conclusions. The latter are based on the best medical and toxicological data available and are designed to be conservatively protective of public health, including susceptible populations like the elderly and young children.
Comment 43: The research you have cited regarding animals is irrelevant to research done on human animals. You make this point yourself in Section 5 when you argue: "the CREGs for chloroform, methylene chloride, tetrachloroethylene, and trichloroethylene have limited relevance to humans because all are based primarily on mouse liver tumors and male rat kidney tumors produced by species-specific mechanisms that are evidently dependent on unusually high doses." However, you contradict yourself three paragraphs later when you argue: "In a recent inhalation study (ATSDR 1994), no increased carcinogenic effects were seen in rats chronically exposed for 2 years, therefore, indoor air exposures to the levels of 1,2 -dichloroethane detected in the Norledge area would not be expected to result in adverse health effects." You cannot extrapolate "data" from animals to human animals. This makes no sense! Animals and humans are radically different (for example, biologically, immunologically, histiologically, etc.) and animals are subjected to ridiculously high doses of toxic chemicals in high stress situations. Unacceptable.
Response 43: It is well known that the results of animal assays are not accurately predictive of human health effects. Animal data have numerous limitations in this regard and must therefore be interpreted very carefully by anyone using them to estimate the potential implications of chemical exposures in humans. For this reason, ATSDR emphasizes species differences and aspects of animal study protocols (for example, the use of unrealistically high doses) that differ markedly from human exposure conditions. While human data are obviously preferable to animal data, the former are often unavailable – there is no choice but to use animal data as an admittedly imperfect surrogate. But even when epidemiological information is available it is fraught with problems of its own. For example, in human studies the exposure is never as well defined, in terms of number, magnitude, and duration of exposures, as it is in animal studies. Therefore, whether human data are available, a critical evaluation of the animal data is an important part of ATSDR's overall assessment. The relevance of the animal data to the human condition is always carefully evaluated for each chemical and the appropriately conservative assumptions and safety factors are introduced to assure that any conclusions drawn will be protective of public health. All assumptions, safety factors, and other caveats are called to the readers' attention in the text of the health assessment.
Comment 44: As we have stated in previous comments regarding other ATSDR and MDOH health reports, we are concerned that there is no consideration of the interactive and/or cumulative effects of toxic chemicals. Note: we do not buy the argument you give in Section 5: "the combined effect of all these contaminants is not likely to be of public health concern based on studies which suggest that a mixture produces no adverse health effects in dosed animals."
Response 44: Additional supporting toxicological information is provided in Appendix E (see Appendix E, Section 3).
Comment 45: Paragraph 9 of Section 5 illogically concludes that "(S)ince the individual contaminants detected in indoor air at this site have consistently been present below levels that might be expected to result in adverse health effects, ATSDR considers that the combined effect of all these contaminants is not likely to be of public health concern." The ATSDR does not have the breadth of data, the historical knowledge of the past residential exposures, or the complete knowledge of Amoco's past operations to conclude that the contaminants detected in the indoor air have consistently been below levels expected to cause adverse health effects. The ATSDR should remove this inaccurate statement from the Air Addendum.
Response 45: ATSDR has amended the statement to include the time-frame of evaluation. Specifically, the sentence now states "Because the individual contaminants detected currently in indoor air at this site have consistently been present below levels that might be expected to result in adverse health effects, ATSDR considers that current exposures to the combined effect of all these contaminants is not likely to be of public health concern."
Comment 46: Please advise why the EPA didn't respond to the October 14, 1999, odor complaint with the proper equipment to sample and quantify the constituents of the odor. If the EPA had responded with proper equipment, then the ATSDR could have given its opinion on the health implications of the odors.
Response 46: EPA reported that because the odor complaint dealt with an indoor air quality issue, the EPA response team was equipped with and used the appropriate monitoring equipment (PID and draeger tubes) to assess the scene (EPA 2002).
Comment 47: Approximately 8 pages were dedicated to the October 1999 odor event. We are outraged by your accusations that imply the event and the odors were rigged. First, for the record, this is what happened. One of the homeowners and an associate returned from a walk to find the home filled with petroleum-like odors. The other homeowner, who had been in the home for some time, was totally unaware that the odor was present. In fact he argued that he could not smell it. The homeowners associate was able, through some difficulty, to reach a member of the ATSDR and Bob Aston (EPA Region VII). At that point, we realized that there was no entity prepared to respond to an emergency such as this. Several hours passed before the EPA Emergency Response team arrived. These people were not dressed in any kind of safety gear. We can only assume that the odor report was not taken seriously. The fact that they did not show up with the proper equipment, further supports our suspicions. Once in the home, however, both members of the team confirmed that they too smelled petroleum-like odors. Testing commenced.
Response 47: ATSDR did not mean to imply the odor event was rigged. In fact ATSDR agrees with the community that accurately capturing the chemicals related to odor events is difficult due to the very nature of the odor events. All those involved with the odor event took it seriously. Although ATSDR was not present during the October 1999 odor event, Atlanta-based staff spoke to those individuals who were involved with the odor event in an attempt to piece together what occurred. ATSDR apologizes for any inconsistencies in our report of the event. ATSDR did, however, document each telephone call and cannot change what was reported to us at that time by the individuals in question.
The EPA response team was composed of personnel from the Superfund Emergency Response and Removal Branch. As stated previously, the EPA response team was equipped with and used the appropriate monitoring equipment. The complaint did not deal with a spill type of situation which would have involved potential dermal exposures and would have required additional health and safety considerations (EPA 2002).
Comment 48: Despite the resident evidently committing the apparently horrendous offense of leaving the "cleanout line" open, the ATSDR, in its own explanation of the purpose for the cleanout line, appears to overlook the fact that the air from the sewer which migrated via the cleanout line contained benzene, chloroform, methylene chloride, tetrachloroethylene and trichloroethylene in exceedance of health-based comparison values.
Response 48: In Section 5 and Appendix E, ATSDR assumed residents would be chronically exposed to the maximum levels detected of these chemicals (whether the maximum value was from the cleanout line, or the basement indoor air, or the outdoor air) for our evaluation. At the maximum levels detected, no adverse health effects would be expected based on chronic exposure.
Comment 49: With respect to the open cleanout line, it has a chained, bathtub-type plug, white in color, attached. The homeowner had been doing laundry that day of the odor event and as was customary, she removed the bathtub-type plug from the line so that the excess water could drain. Often, if the plug is not removed, the drain would overflow into the basement. Sometimes, the homeowner forgets to put the plug back in. You said that no cap or plug was in sight when EPA arrived. It was there, as it is attached by the chain to the pipe. There were different times where the homeowners were told to leave the plug in or take it out, so there is nothing sinister in that. The point is in this situation that, there were odors then and odors have been detected since then, so they do come and go which is a perfect reason why sampling of any homes should be done regularly rather than once in awhile.
Response 49: ATSDR sympathizes with the residents who have been plagued by odors. Any environmental data provided to ATSDR for review from odor response reports will be evaluated and provided to the community.
As stated in Response 47, ATSDR apologizes for any inconsistencies in our report of the event. ATSDR did, however, document each telephone call. One person reported to ATSDR that no cap or plug was in sight; however, because the plug is chained to a pipe, the agency has deleted reference to "no cap or plug was in sight' from Section 4.2.
Of concern, the "plug" should not be removed for any reason other than plumbing maintenance. Sewer gases will escape into the basement with the plug removed. To avoid this problem homeowners who regularly have drain overflows when doing laundry should contact a professional plumber to ensure the washing machine is properly connected.
Comment 50: Never at any time did we smell sewer gas during the odor event, and even Amoco tests show no H2S. A petroleum odor does not smell like sewer gas. If ATSDR had come out that night they would have smelled it and not accused us of rigging the test results. Your report is a public document, therefore, the public would conclude that the homeowners and their associate somehow faked the odors to cause the event. Clarification of what really happened should be made publicly.
Response 50: ATSDR does not believe the odors were faked. As stated previously, ATSDR apologizes for any inconsistencies in our report of the event. ATSDR did, however, document each telephone call and the agency cannot change what was reported to us at that time by the individuals in question.
Comment 51: To us it is ironic that so much time was devoted to the famous PLUG (mentioned eight times out of ten pages of an eighteen page report) when the kinds of chemicals discovered should have been much more important.
Response 51: ATSDR provides an evaluation of exposure to air chemicals in Section 5 and Appendix E.
Comment 52: The situation (odor event) was very confusing because there was an expression of the need to evacuate by authorities, then by the time it was safer, the homeowners returned. The odors are not new either. People in Sugar Creek think they have to live with the smell, never realizing it may be hurting their health. The lack of concern and attitude that people are liars when they call in air complaints have deterred others from reporting new ones. Very recently, the city told an individual that the odors were coming from New Mexico when the person called to make a complaint. Although the mayor has apologized (privately) for this incident, how many other times have people been treated like that?
Response 52: ATSDR sympathizes with the residents who have been plagued by odors. ATSDR encourages individuals continue to report odor events. However, as stated in Response 41, the presence of a detectable odor does not, by itself, constitute evidence that conditions are unsafe and warrant evacuation.
Comment 53: The drain at the homeowner's home comes from the Burton street sewer line which has been verified to be seriously contaminated. Two other homes had odors but aired their basement and ignored it. It is important that an investigation of the sewers be conducted, but we have heard nothing about that. The sewers are a likely source of pollution pathways as your report indicates. We believe the sewer system on the refinery is a major concern also, but EPA and MDNR seem disinterested in that source. We would like to remind you that an EPA contractor (Tetra Tech EM Inc. September 18, 1997), made strong recommendations to EPA about RBCs, exposure pathways via sewer systems, plume definitions, etc. and we would like those comments to be included with our comments for ATSDR's consideration, since we believe the same basis for comment applies now.
Response 53: As stated in this public health assessment, the sewer system was investigated as a potential source of the reported odors. The investigation failed conclusively to identify soil gas, contaminated groundwater, or the sewers as a probable source of the odors reported in this home on October 14, 1999.
Comment 54: With regard to Comment 1 of Section 6, please note that methane is a byproduct of natural attenuation of hydrocarbons. In fact, levels of methane and other VOCs were so high in the isolated plumes near the City of Sugar Creek Fire Station that Amoco proposed fueling a V-6 engine from the fumes on the plume.
Response 54: Amoco originally wanted to test the ability of vapors recovered from the EFR system to be used as a partial source of fuel for an internal combustion engine. Initial tests revealed that the recovered vapors would not sustain the fuel requirements of an internal combustion engine without substantial amounts of primary fuel (gasoline). This vapor treatment alternative was never implemented (EPA 2001b).
Comment 55: With regard to Comment 4, will the ATSDR revise its report when additional contaminants are found off-site, for example, like the MTBE which was recently found on and off-site by environmental agencies? This points out again the limited and flawed testing that Amoco has done over the last 12 years and the flawed reliance on the data by the ATSDR and environmental agencies.
Response 55: ATSDR will revise its report if additional data are found that indicate conclusions that are not consistent with what has been previously determined.
Comment 56: As early as 1986 and 1989, the City of Sugar Creek noted staining and deposits of hydrocarbons in the sewer lines. This information is in the possession of the City of Sugar Creek and has been offered to the US EPA.
Response 56: Comment noted.
Comment 57: Please advise when the ATSDR will evaluate the public health significance of the reported odors that residents e-mail to the government agencies on a daily basis.
Response 57: ATSDR is maintaining a file of the odors reported to our regional office; however, the agency suggests the residents contact the fire department to report the odors. If requested, ATSDR will evaluate environmental air sampling data that are collected in response to the odor complaints.
Comment 58: Please advise how the ATSDR can find chemicals, including benzene, during June 1999 sampling that exceed health-based comparison values and yet, still opine that the current, chronic exposures to indoor air pose No Apparent Public Health Hazard.
Response 58: As stated in this public health assessment, health-based comparison values are not thresholds of toxicity. Although concentrations at or below the relevant comparison values could reasonably be considered safe, it does not automatically follow that any environmental concentration exceeding a comparison value would be expected to produce adverse health effects. The fact that a contaminant exceeds a health-based comparison value does not necessarily imply the existence of a public health hazard. Comparison values are used only to identify those site-specific contaminants that warrant further investigation. The health implications – if any – of exposures can only be determined in the context of the best medical and toxicological information available (see Section 5, Appendix C, and Appendix D). After a review of the data, ATSDR determined that current, chronic exposures to indoor air in the Norledge area are not at levels of health concern.
Comment 59: By proclaiming there is No Apparent Public Health Hazard, the ATSDR appears to want to ignore that the health-based comparison values found in the year 2000 would not be reflective of the values that could have been found (if the EPA and MDNR had required Amoco to test for them) in the 1950s, 1960s, 1970s, 1980s or early to mid 1990s.
Response 59: This focus of this PHA was to determine whether current, chronic exposures to indoor air in the Norledge area are at levels of health concern. ATSDR determined that current, chronic exposures to the contaminant levels detected are not likely to be associated with adverse heath effects. ATSDR cannot evaluate the public health implications of chemicals that might have been present from 1950 to mid-1990 because environmental data are not available.
Comment 60: The ATSDR concludes that due to remedial activities in the Norledge area, contaminant concentrations will decrease as well. This opinion parallels Amoco's conclusion drawn in the early 1980's when faced with the magnitude and expense of cleaning up the off-site hydrocarbon contamination. Amoco's "do nothing, it'll go away" attitude has saved it millions of dollars in remediation costs.
Response 60: ATSDR is unable to comment on Amoco's conclusions; however, current and planned remedial activities in the Norledge area should result in decreasing contaminant concentrations. In October 2002, EPA reported that since the initiation of the EFR system, levels of contamination have decreased (EPA 2002). See Section 3.4 for additional information.
Comment 61: We disagree that "groundwater and subsurface soil remedial activities in the Norledge area should result in decreasing contaminant concentrations in the future" and believe that your responsibility to assess public health risk is NOW, not in some distant future.
Response 61: ATSDR did evaluate the current public health risk and determined that air chemicals are not at levels of health concern for chronic exposure. Concentrations of groundwater contaminants will decrease in the future because of remedial activities. EFR has been successful in assisting in the natural attenuation of VOC concentrations in groundwater; benzene concentrations have been decreasing (BP 2003). And, approximately 87,300 pounds of hydrocarbon were removed by TFE (BP 2003). ATSDR states that any future exposures possibly related to chemicals that could volatilize into homes in the Norledge area should decrease as the groundwater contamination decreases.
Comment 62: The lack of recommendations on the part of the ATSDR is not only irresponsible, it is unconscionable. You should have, at the very least, recommended more air monitoring. Ideally, this would be 24 hours a day, 7 days a week, 365 days a year, both ambient and indoor. It is not unheard of.
Response 62: The purpose of this public health assessment was to review air sampling data reports to determine whether current chronic air exposures were of potential health concern for local residents. ATSDR determined the chemicals detected in air were not at levels of health concern; therefore, additional sampling was not recommended at this time. The agency is available to review additional air sampling data collected from the Norledge area, upon request.
Comment 63: In Section 10, the last sentence of the text should be revised to reflect that residential surface samples have been collected by EPA, and ATSDR is preparing a health consultation on this data.
Response 63: Section 10, Public Health Action Plan, has been updated to include activities ATSDR accomplished since public comment release of this document.
Comment 64: In Appendix E, the ATSDR's reliance on the research of Dr. Otto Wong is ironic. Amoco hired Dr. Wong to testify on Amoco's behalf during the United States District Court Class Action. Dr. Wong's deposition was taken in that case in direct opposition to the interests of the residents of Sugar Creek and Independence, Missouri.
Response 64: Together with numerous other scientists Dr. Wong was cited in the agency's public health assessment because his work in the field was both highly relevant and scientifically valid.
Comment 65: We totally disagree with the almost exclusive focus on benzene. As we have noted before, the list of contaminants should be expanded. Independent testing has supported our opinion, as well as MDNR/EPA tests taken at areas we discovered and complained about. For example, MTBE has been found in both soil and groundwater in the residential areas, and Amoco denies ever having that chemical onsite.
Response 65: ATSDR agrees that a broad range of contaminants should be included in analyses of environmental media at the site. The focus of this public health assessment is to evaluate exposure to contaminants possibly volatilizing from groundwater into the air in Norledge area residences. Numerous potentially volatile contaminants were analyzed for in samples collected in homes in the Norledge area – none of those contaminants were detected at levels of health concern.
Comment 66: Again, we are requesting a public health meeting of a different format than you have provided in the past. We want a meeting, with the opportunity for the public to ask questions, NOT a few measly information tables. The public has a right to this type of forum.
Response 66: When ATSDR released the first public health assessment for public comment back in May 1999, the agency did hold a large public meeting. During this evening meeting, agency staff presented the findings of the document to the Sugar Creek community as well as answered many questions from the community. Earlier that same day, the agency held public availability sessions which allowed the agency to hear concerns and answer questions from Sugar Creek residents on an individual, one-on-one, basis.
Comment 67: LIMITATIONS? You do not discuss them in this report. Without knowing what the limitations are, we cannot comment, and they should be included to have a balanced study.
Response 67: As stated in Section 2, Purpose and Health Issues, this public health assessment is limited to an evaluation of indoor and outdoor air samples collected by the EPA in June, July and October 1999. The evaluation focused on a review of these sampling data reports to determine if current chronic air exposures were of potential health concern for local residents. Although other environmental media and exposure pathways are not addressed in this public health assessment, a summary of the results of ATSDR's other evaluations are contained in Section 10.
Comment 68: In November 26, 1997, Randall D. Maley, M.P.H., MDOH wrote Mr. Rob Morrison of the MDNR after they reviewed Amoco's Addendum to their Workplan. We want that document included with our comments since it makes suggestions that were likely ignored by MDNR.
Response 68: Responding to comments on another agency's workplan is out of the purview of this public health assessment. ATSDR suggests MDNR and MDOH be contacted directly to find out what comments were incorporated into the workplan.
Comment 69: According to Denise Joran-Izaguirre ATSDR Regional Representative, this report never passed her desk, otherwise she would have corrected all the errors. We cannot imagine a public health threat being handled so irresponsibly.
Response 69: ATSDR Regional Representative Denise Jordan-Izaguirre did review this health assessment before its release to the public. ATSDR based the report on data and information available to the agency at that time. One of the primary reasons for a public comment period is to ensure the agency's reports are accurate and address all pertinent issues. Appropriate changes are made to the public comment version before the document is released in final form.
References
[ATSDR] Agency for Toxic Substances and Disease Registry. 2003. March 3 fact sheet: multiple sclerosis and amyotrophic lateral sclerosis-related projects. Atlanta: US Department of Health and Human Services.
[BP] BP Products of North America, Inc. 2003. Annual interim measures performance monitoring summary, 2002, BP Products North America, Inc., (a former Amoco Oil Company) regarding the former refinery at Sugar Creek, MO. Golden, CO: The RETEC Group, Inc; project number AMO61-16275-780.
[EPA] Environmental Protection Agency. 2001a. March 12 electronic mail record with attachment (ATSDRQand A.wpd) sent by Robert Aston, EPA, to Denise Jordan-Izaguirre, ATSDR, containing EPA's responses to a list of questions ATSDR submitted about activities in the Norledge area of Sugar Creek. Kansas City, Kansas.
[EPA] Environmental Protection Agency. 2001b. March 12 electronic mail record with attachment (ATSDRQandA2.wpd) sent by Robert Aston, EPA, to Denise Jordan-Izaguirre, ATSDR, containing EPA's responses to a second list of questions ATSDR submitted about activities in the Norledge area of Sugar Creek. Kansas City, Kansas.
[EPA] Environmental Protection Agency. 2002. October 10 electronic mail record with attachment (atsdrquestions.wpd) sent by Robert Aston, EPA, to Denise Jordan-Izaguirre, ATSDR, regarding another list of questions ATSDR submitted about activities in the Norledge area of Sugar Creek. Kansas City, Kansas.
[MDOH] Missouri Department of Health. 2000. Sugar Creek cancer inquiry report, level three investigation. Jefferson City, Missouri.
[MDOH] Missouri Department of Health. 2001. Assessment of the feasibility of an etiologic study of the association of brain cancer and environmental petrochemical exposure. Jefferson City, Missouri.
Neuberger JS, Ward-Smith P, Morantz RA, Tian C, Schmelzle KH, Mayo MS et al. 2003. Brain cancer in a residential area bordering on an oil refinery. Neuroepidemiol 22:46-56.
