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PUBLIC HEALTH ASSESSMENT

TRANS CIRCUITS, INCORPORATED
LAKE PARK, PALM BEACH COUNTY, FLORIDA


1.0 SUMMARY

A large building and asphalt parking lot cover most of the one-acre Trans Circuits site at 210 Newman Road, Lake Park, in Palm Beach County, Florida. Two companies manufactured electronics there from 1976 to 1985. The plant operators discharged the waste stream to an on-site evaporation pond. When the waste stream volume exceeded the pond's capacity, the Trans Circuits manager had holes punched in the pond liner, releasing solvents and metals to the soil and groundwater. In the shallowest groundwater, the contaminants moved to the east and northeast. In deeper groundwater (75' plus, below the land surface), the released chemicals were pulled southeast, toward Riviera Beach municipal supply wells. The City of Riviera Beach Utilities has equipped these wells with air strippers that remove volatile organic chemicals from water. Although air strippers do not remove metals, the metals that have moved off the site have not impacted any private or municipal drinking water wells.

The Florida Department of Health (DOH) is not aware of any residents who are currently exposed to site-related contaminants. Estimated past exposure levels are not likely to have caused illness. Some exposures in the 1970s may have occurred that we cannot quantify due to lack of information. Currently, people should not drink untreated groundwater from on or near the site and workers should avoid breathing dust or accidentally getting soil in their mouths from soil under (2 to 5 feet below the surface) the former percolation pond. In February 2000, DOH staff investigated the neighborhoods and businesses near the site to find and sample any private wells currently in use. We identified and sampled seven private wells from the Riviera Beach neighborhood south of the site. Analytical results showed that none of these wells contained site-related contaminants or any other chemicals at levels of concern. Only one of the seven private drinking water wells is near the area of groundwater contamination.

In the early 1980s, groundwater contamination caused the City of Riviera Beach Utilities to stop using a public supply well southeast of the site. By 1985, the city detected trichloroethene and other chlorinated solvents in the center of the city wellfield along Old Dixie Highway. In 1988, the city began operating air strippers to remove these volatile groundwater contaminants.

Community members have asked if chemicals that were in city tap water in the past could have harmed them. Only one "Finished Water" (tap water) sample suggests water quality problems. The City of Riviera Beach took this water sample in July 1982. It showed vinyl chloride at a level slightly above the drinking water standard. Water samples with no detectable vinyl chloride levels were taken 11 months earlier in August 1981, and 7 months later in January 1983. Based on the time frame of these results, city water users may have used tap water with very low levels of vinyl chloride for at most 18 months, although the actual length of time may be less. We estimate less than 18 months because the city mixes water from half its wells daily, and uses the other half the next day to prevent saltwater intrusion. Also, we do not know the precise date groundwater contamination reached the city supply wells. Nevertheless, we do not expect any illness from vinyl chloride in tap water in the early 1980s due to its low level and due to the relatively short time it was present (the drinking water standards are set for lifetime exposures).

Citizens contacted the city utilities about municipal water odors in the early 1970s. However, we cannot evaluate the likelihood of illness, if any, for exposure during that time because no groundwater analytical data from before 1981 exists.

DOH recommends limiting access to the on-site building to prevent anyone from being cut by the broken glass there. Existing soil analyses are acceptable for current site use. However, any future construction or excavation workers on the site could better limit their ingestion of lead from dust if they had better information on the levels of lead in subsoil below the former percolation pond. They could use protective equipment or suppress dust, if needed.

The Department of Health and the Department of Environmental Protection will work together to inform and educate nearby residents about the public health issues at this site.


2.0 PURPOSE AND HEALTH ISSUES

The Florida Department of Health (DOH), Bureau of Environmental Epidemiology prepared this report. The United States Environmental Protection Agency (EPA) asked the DOH in late 1999 if chemicals from the Trans Circuits, Inc. hazardous waste site suggest a public health threat. EPA's request was based on possible site-related chemicals in off-site groundwater. This is the first public health assessment of this site by either the DOH or the federal Agency for Toxic Substances and Disease Registry (ATSDR).

In this report, we evaluate people's past, current, and future potential for exposures to chemicals at and near the Trans Circuits site. We then discuss the likelihood of these exposures to cause illnesses. We also identify the need for additional actions to protect public health.

DOH conducted this public health assessment under a cooperative agreement with and funding from the ATSDR. The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA, or Superfund) authorizes ATSDR to conduct public health assessments at hazardous waste sites. ATSDR, headquartered in Atlanta, Georgia, is a federal agency within the U.S. Department of Health and Human Services. The EPA proposed Trans Circuits to the National Priorities List on October 22, 1999.


3.0 BACKGROUND

3.1 Site History

Etched Products, Inc. owned the 210 Newman Road, Lake Park property from April 1976 until 1978, when Trans Circuits, Inc. purchased it. Trans Circuits made electronic parts and subassemblies for electronic circuit boards at this location from 1978 to 1985, and still owns the property.

Trans Circuits used metals, liquid acids and bases, and solvents in their metal cleaning, etching and electroplating processes. Industrial waste reclamation efforts at the site were inadequate. Plant operators disposed of liquid wastes on the site, possibly to the land surface and then to an evaporation pond which they later modified to be a percolation pond. Tri-City Industrial Park did not connect their businesses to the sanitary sewer system in the 1970s and 1980s when the plant was operating. A contamination assessment report and two groundwater investigations confirm industrial chemical releases to groundwater through the waste disposal pond (Goldberg, Zoino and Associates (GZA), 1987; Florida Department of Environmental Regulation (FDER), 1985, 1992). Contamination levels and groundwater flow direction maps show that the shallowest groundwater moves to the northeast where it recharges deeper areas of the surficial aquifer. In the deeper portion (75 feet below the land surface), the pumping of large-volume, off-site public supply wells moved and continues to move the chemicals released to the groundwater.

Because of its location, contamination from Trans Circuits affects the Town of Lake Park and City of Riviera Beach groundwater. This contamination affects no known drinking water wells in the Town of Lake Park. Before 1992, Seacoast Utilities operated the Old Dixie Wellfield with nine public supply wells between ½ mile and 1 mile northwest of Trans Circuits. Seacoast supplied this water to Lake Park. Seacoast closed the Old Dixie Wellfield in 1992 because of contamination from a nearby dry-cleaning operation.

In 1981, groundwater contaminants from Trans Circuits reached a City of Riviera Beach public water supply well. The EPA found chlorinated solvents and their breakdown products in well # PW-17, 2,300' southeast of the site (Appendix B, Figure 1). This discovery led to additional testing of Riviera Beach city water, and the City of Riviera Beach utilities took PW-17 out of service in 1982.

The City of Riviera Beach blends water from its 27 municipal supply wells to assure adequate water supply and prevent salt water intrusion. They use half of the wells on one day and half the next. Available analytical data show this "Finished Water" (processed water ready for the tap) has generally met drinking water standards. However in 1982, a "Finished Water" sample contained vinyl chloride at a level slightly above the drinking water standard.

Shutting down contaminated city supply wells did not prevent public supply well uptake of contaminated groundwater. Early wellfield investigations showed that as the city utilities removed wells from service, contaminated groundwater was drawn toward the next nearest high-volume pumping city supply wells. In 1988, the City of Riviera Beach Utilities began using air strippers (Appendix B, photo 8) to remove volatile chemicals from the extracted groundwater.

When investigations linked contaminated groundwater in well # PW-17 to the Trans Circuits site (Figures 2 and 3, FDER, 1985), Trans Circuits signed a consent agreement with FDER to clean up the contaminated groundwater. In 1987, their contractor, GZA, installed a four-inch recovery well and air stripper in the northeastern portion of the site to pump and treat contaminated groundwater (Appendix B, photo 9). This air stripper reportedly treated 18 million gallons of groundwater in the next 18 months. However, the Florida Department of Environmental Protection (FDEP) turned down a resolution of the consent agreement in 1990 because fluoride and VOCs were found in groundwater east of the site.

The EPA oversees current efforts to find out what contamination remains on and near the site. The EPA's contractor, Black and Veatch, released the Data Evaluation and Summary Report for the Trans Circuits Site on November 16, 1999. They submitted a Draft Remedial Investigation Report and Risk Assessment Report in January 2000, and a Final of the same document in May 2000, based on this recently-collected data. In June 2000 they submitted a Remedial Alternative Screening Technical Memorandum for Groundwater and in November a Final Feasibility Report. Appendix A summarizes relevant incidents and investigations of groundwater contamination. The Draft Record of Decision that explains the options for the site cleanup was released in December 2000, but as of March 2001, it has not been signed.

3.2 Site Description

Trans Circuits operated in a large building which covers more than three-quarters of the one-acre site (Appendix B, Figure 1). This building is mostly one-story, but the eastern half has a second floor. This building shares a wall with Action Bolt (Appendix B, Photo 4; Action Bolt's building is taller and is in the background). The former percolation pond is northeast of the building. Its dimensions were 45' by 40' by 4' deep. Photo 3, Appendix B, shows how vegetation has obscured the former pond area. Also obscured by this vegetation are a set of inactive railroad tracks and parts of an air stripper. Three drainage grates lie south of the building in an asphalt and grass area where the septic drain field was.

3.2.1 Demographics -The area within one mile of the site encompasses parts of the U.S. Census Bureau's tracts #11, #12, #13, #14 and #15 in Palm Beach County. We estimate13,500 people lived within a mile of the site in 1990. About 31 percent were under the age of 18. Of the total population, 75% were black, 22% were white, 2% were Hispanic, and 1% were American Indians, Asians and other racial/ethnic groups (U.S. Census Bureau, 1990).

3.2.2 Land Use - The site is in Tri City Industrial Park north of Silver Beach Road. Silver Beach Road is the southern boundary for the Town of Lake Park. Silver Beach Road is just north of the boundary for the City of Riviera Beach. Lake Park and Riviera Beach are in Palm Beach County, on the southeast coast of Florida, approximately five miles north of West Palm Beach. The northern part of Riviera Beach is mostly residential with single family homes, a few churches and small businesses are in the commercial district along Old Dixie Highway. The Industrial Park makes up the southernmost part of Lake Park. Businesses in the Industrial park surrounding the site include an auto salvage operation, "Thousands of Parts", "Baron Sign", "Action Bolt", "Tri City Wood Works", specialty auto repair shops, and a fireplace supply business. North and west of this industrial park is a natural area held by the MacArthur Foundation. North of the MacArthur property are additional businesses: the former Kelsey (plant) Nursery and Rinker Concrete. Businesses also line the east side of the railroad tracks that parallel Old Dixie Highway. East of these businesses and the railroad is a residential area including single-family homes and apartment complexes.

3.2.3 Natural Resource Use - The area immediately surrounding the site (the Town of Lake Park) is supplied municipal water by Seacoast Utilities. Riviera Beach Utilities supplies the area south of Silver Beach Road. The Trans Circuits site is eight-tenths of one mile north-northwest of the Riviera Beach Utilities water treatment plant. However, the nearest Riviera Beach public supply well, PW-17, is less-than ½ mile to the southeast. As discussed above, it appears that the shallowest groundwater at the site follows the natural flow directions, to the east and northeast. Recharge processes incorporate this water into lower levels of the aquifer. Once the water reaches 75' below the land surface, it is drawn into a capture zone created by the Riviera Beach wellfield, which moves it to the southeast. Air strippers at the water treatment plant currently treat water from this zone. Air strippers remove the chemicals from the water and release them to the air. Daryl Graziani of the Palm Beach County Health Department analyzed air near the air strippers on August 8, 2000. He found all chemical releases to be below state standards. Therefore, by rule, these air strippers are exempt from any state permitting requirements. Riviera Beach Utilities serves approximately 29,500 people from 27 supply wells (Black and Veatch, 1992).

In 1992, FDER site-investigators measured a northeasterly groundwater flow direction in the quadrant northwest of the site. This suggests the influence of pumping at that time by the Seacoast Utility municipal wells, Kelsey Nursery, or Rinker Concrete supply wells (FDER, 1992). We could not find any private wells in this area that use this groundwater for drinking. Seacoast Utilities has stopped using the Old Dixie wellfield wells (shown as SU-#s on Figure 2, Appendix B) due to their contamination by a nearby dry-cleaner. Bill Vaught, Rinker Operations Manager, confirmed that Rinker uses on-site wells for toilet facilities and concrete preparation; they use bottled water for drinking (personal communication, 12/1/99). Bruce Gregg of Seacoast Utilities said that Kelsey Nursery is out of business and their property is being considered for development as an office park (personal communication, 1/12/2000).

A recent investigation by DOH staff (February 2000) found seven homes south of the site using well water for drinking and other household uses. The primary use for other private wells in the area is irrigation. Irrigation wells are abundant because groundwater is only about eight feet below the surface.

We did not see surface water bodies or drainage ditches at the site, or in the area immediately surrounding the site. A lack of surface drainage features is consistent with past site descriptions (USGS 1983 and Sullivan, 1997). Three onsite catch-basins (open grates) are in the parking lot on the south side of the site. Runoff from the site is directed to these basins where the water percolates directly into the ground.

3.3 Site Visit

On December 1, 1999, Connie Garrett, with the Bureau of Environmental Epidemiology, FDOH, visited the site and the surrounding area. Lee Martin and Geetha Selvendran both with the Southeast District of the FDEP, accompanied her. They also met with employees of Seacoast and Riviera Beach Utilities and CSR Rinker Materials to find out if private drinking water wells are near the site.

We include photos of the site as it appeared in July (Photo 4) and December 1999 (remaining photos) in Appendix B. The building has no doors. Portions of the roof-overhang are decaying and pigeons are living inside. The manager of an auto repair service north of the site said that transients use the Trans Circuits building. He mentioned that someone has removed all the copper wiring and the air-conditioning system from the building.

We drove through the neighborhoods south of the site (Appendix B, Photo 2). The homes were primarily middle and lower-middle income. Photo 8 shows the air strippers at the City of Riviera Water Plant.


4.0 DISCUSSION

In this section we review the available site information (groundwater and soil data). We look for information on the chemicals Trans Circuits may have released to soil or water. Then we try to determine the levels of these chemicals that are still on the site. Next, we make judgments about how people may contact chemicals from past releases. Then we try to predict if the released chemicals could affect people's health if they were to contact these chemicals.

The public health assessment process has inherent uncertainties because (NJDEP 1990):

  • Science is never 100% certain,
  • The risk assessment process is inexact,
  • Information on the site and on actions (and interactions) of chemicals is never complete,
  • Opinions on the implications of known information differ.

We address these uncertainties in public health assessments by using health-protective assumptions when estimating or interpreting health risks. We also use wide safety margins when setting health-related threshold values. The assumptions, interpretations, and recommendations we make throughout this public health assessment err in the direction of protecting public health.

4.1 Environmental Contamination

In this section we review the environmental data collected at and near the site since the early 1980s, we evaluate sampling adequacy, and we select contaminants of concern. In this section we list the maximum concentration and detection frequency for the contaminants of concern in the various media (for water and soil only; no air data were available). We select contaminants of concern by considering the following factors:

  1. Contaminant concentrations on and off the site. We only eliminate contaminants from further consideration if both the background and on-site concentrations are below standard comparison values, although background concentrations are useful in determining if contaminants are site-related. This is necessary to assess the public health risk of all contaminants detected, whether site-related or not.


  2. Field data quality, laboratory data quality, and sample design.


  3. Community health concerns.


  4. Comparison of maximum concentrations with published ATSDR standard comparison values, for media providing complete and potential exposure pathways. The ATSDR's published standard comparison values are media-specific concentrations used to select contaminants for further evaluation. They are not used to predict health effects or to set cleanup levels. Contaminants with media concentrations above an ATSDR standard comparison value do not necessarily represent a health threat, but are selected for further evaluation. Contaminants below an ATSDR standard comparison value are unlikely to be associated with illness and are not evaluated further, unless the community has a specific concern about the contaminant.


  5. Comparison of maximum concentrations with toxicological information published in ATSDR toxicological profile documents, for complete and potential exposure pathways. These profiles are chemical-specific and summarize toxicological information found in scientific literature.

We used the following ATSDR standard comparison values (ATSDR 1992), in order of priority, to select contaminants of concern:

  1. EMEGs (Environmental Media Evaluation Guides) - The ATSDR derives EMEGs from their Minimal Risk Levels (MRLs) using standard exposure assumptions, such as ingestion of two liters of water per day and body weight of 70 kg for adults. MRLs are estimates of daily human exposure to a chemical likely to be without an appreciable risk of noncancerous illnesses, generally for a year or longer.


  2. CREGs (Cancer Risk Evaluation Guides) - The ATSDR calculates CREGs from the EPA's cancer slope factors. The CREG is the contaminant concentration estimated to result in no more than one excess cancer per one million persons exposed over a lifetime.


  3. RMEGs (Reference Dose Media Evaluation Guides) - The ATSDR derives RMEGs from the EPA's Reference Dose (RfD) using standard exposure assumptions. RfDs are estimates of daily human exposure to a chemical likely to be without an appreciable risk of noncancerous illness, generally for a year or longer.


  4. LTHAs (Lifetime Health Advisories for Drinking Water) - LTHAs are the EPA's estimates of the concentrations of drinking-water contaminants not expected to cause illnesses for lifetime exposure. LTHAs provide a safety margin to protect sensitive members of the population.

Florida has enforceable, health-based, drinking water standards for fluoride and lead. We used these standards because ATSDR does not have screening levels for these two metals. We also compared the Florida vinyl chloride drinking water standard (Appendix B tables) with vinyl chloride levels in public drinking water supplies. We compared soil lead levels with FDEP's (Residential) Soil Target Cleanup Level for lead because ATSDR doesn't have a soil screening level for lead.

Using the components and criteria listed above, we selected six chemicals as contaminants of concern. They are 1,2-dichloroethene, fluoride, lead, nickel, tetrachloroethene, and trichloroethene. We only use the ATSDR and other standard comparison values to select contaminants of concern for further consideration. Identification of a contaminant of concern in this section does not necessarily mean that exposure will cause illness. Identification serves to narrow the focus of the public health assessment to those contaminants most important to public health. When we selected a contaminant of concern in one medium, we also reported that contaminant in all other media. We evaluate the contaminants of concern in subsequent sections and estimate whether exposure is likely to cause illness.

In this public health assessment, we first discuss the contamination that exists on the site and then the contamination that occurs off the site.

4.1.1 On-Site Contamination - For this public health assessment, we define "on-site" as the area within the Trans Circuits property boundaries as shown in Figure 1, Appendix B.

4.1.1.1 On-site Groundwater - Between February 1985 and June 1999, FDEP and various contractors for Trans Circuits and the EPA collected 136 on-site groundwater samples from nine on-site monitoring wells (FDER 1987, 1992, Goldberg, Zoino and Associates (GZA), Inc., 1990, Black and Veatch Special Projects Corp., 1999). Various laboratories analyzed these samples for solvents, pesticides, and metals. These labs didn't analyze all samples for all chemicals.

We consider groundwater samples from all depths together and summarize the results in Table 1, Appendix B. For this public health assessment, the combined groundwater studies have adequately tested on-site groundwater.

4.1.1.2 On-Site Surface Soil (0 to 3") - GZA staff collected five soil samples as part of a Site Screening Investigation in December 1989. Their field screening for purgeable halocarbons all showed concentrations less than 1 milligram per kilogram (mg/kg), the detection level for the field-sampling equipment (GZA, 1990). Black and Veatch took ten surface soil samples (nine on-site and one background) in July 1997 for the Expanded Site Investigation (Black and Veatch Special Projects Corp., 1999). We summarize the results for on-site surface soil analyses in Table 2, Appendix B. For this public health assessment, Black and Veatch have adequately tested on-site soil.

4.1.1.3 On-Site Air - We are unaware of any on-site air monitoring data or any site conditions that would warrant air monitoring (no dusty conditions or odors were apparent at the time of the site visit).

4.1.2 Off-Site Contamination- For this public health assessment we define "off-site" as the area outside the Trans Circuits property boundaries as shown in Figure 1, Appendix B.

4.1.2.1 Off-site Groundwater - Between February 1985 and June 1999, FDEP and various contractors for Trans Circuits and the EPA collected 245 off-site groundwater samples from 43 off-site monitoring wells (FDER 1987, 1992, GZA, Inc., 1990, Black and Veatch Special Projects Corp., 1999). Various laboratories analyzed these samples for solvents, pesticides, and metals. These labs didn't analyze all samples for all chemicals.

We summarize the results from the off-site groundwater analyses in Table 3, Appendix C. The off-site boundary of the groundwater contamination has been fairly well determined. Contamination moves from shallow water 400' feet north of the site to deep levels (75' or more) 1/4 mile northeast of the site. Here, the pumping of City of Riviera Beach public supply wells pulls deeper groundwater to the southeast (FDER 1985, 1992). The City of Riviera Beach treats water from these public supply wells to remove chlorinated solvents. For this public health assessment, the combined groundwater studies have adequately tested off-site groundwater.

Most of the area surrounding the site is supplied municipal water. However, DOH recently found seven homes that are using well water for drinking and other household uses (February 2000 investigation). Analyses of samples from these wells did not show the presence of site-related contaminants.

4.1.2.3 Off-Site Air- Air strippers remove volatile chemicals from the groundwater and release them to the air. Daryl Graziani of the Palm Beach County Health Department analyzed air near the air strippers on August 8, 2000. He found all chemical releases to be below state standards. Therefore, by rule, these air strippers are exempt from any state permitting requirements. Riviera Beach Utilities serves approximately 29,500 people from 27 supply wells (Black and Veatch, 1992). We are unaware of any additional off-site air monitoring data or any site-related conditions that indicate a need for off site air-monitoring.

4.1.2.4 City of Riviera Beach - Municipal Water Supply - We summarize analytical results of 30 "Finished Water" samples taken from 1981 to 1986 and current results for 1999 in Table 4, Appendix C. "Finished Water" is a blend of water from a dozen or more municipal supply wells. Analyses for "Finished Water" are also available from 1986 to 1999, but we did not include these because no solvents were detected (Ismael Gonzolez, 1999). No analyses of "Finished Water" are available before 1981.

4.1.3 Quality Assurance and Quality Control- In preparing this public health assessment, we relied on the existing environmental data. We assume these data are valid since governmental consultants or consultants overseen by governmental agencies collected and analyzed the environmental samples. We assumed consultants who collected and analyzed these samples followed adequate quality assurance and quality control measures concerning chain-of-custody, laboratory procedures, and data reporting.

Expanded Site Investigation and Remedial Investigation/Feasibility Study authors (Black and Veatch Special Projects Corp., 1999) accepted all their 1997 data. They rejected some 1998 groundwater data which they listed with the data qualifiers "R":

"R = Data is considered to be rejected and shall not be used. This flag denotes the failure of quality control criteria such that it cannot be determined if the analyte is present or absent from the sample. Resampling and analysis are necessary to confirm or deny the presence of the analyte."

The completeness and reliability of the referenced information determine the validity of the analyses and conclusions drawn for this public health assessment. In each of the preceding on-site and off-site contamination subsections, we evaluated the adequacy of the data to estimate exposures. We assumed that estimated data and presumptive data were valid. This second assumption errs on the side of public health by assuming that a contaminant exists when it may not exist.

4.2 Physical Hazards

During our December 1, 1999 site visit, we saw a lot of broken fluorescent light bulbs in the Trans Circuits building. Appendix B, Photos 5, 6, and 9 show the accessible nature of the building: someone has removed most of the doors. If children were to enter this building, the broken glass could cut them.

4.3 Pathways Analyses

Chemical contaminants in the environment can harm people's health, but only if they have contact with those contaminants. Knowing or estimating the frequency of contact people could have with hazardous substances is essential to assessing the public health importance of these contaminants.

To decide if people can contact contaminants at or from a site, we look at the human exposure pathways. An exposure pathway has five parts. These parts are:

  1. a source of contaminants,
  2. an environmental medium like groundwater or soil that can hold or move the contamination,
  3. a point where people come in contact with a contaminated medium, like a drinking water well or a garden,
  4. an exposure route like drinking contaminated water from a well or eating contaminated soil on homegrown vegetables, and
  5. a population who may come in contact the contaminants.

We eliminate an exposure pathway if at least one of the five parts discussed above is missing and will never be present. Exposure pathways that we do not eliminate are either completed or potential. For completed pathways, all five pathway parts exist and exposure to a contaminant has occurred, is occurring, or will occur. For potential pathways, at least one of the five parts is missing, but could exist. Also for potential pathways, exposure to a contaminant could have occurred, could be occurring, or could occur in the future.

In the past, workers at Trans Circuits may have been exposed to metals dust, caustic acids or chlorinated solvents by inhalation, incidental ingestion, and/or skin absorption. The EPA Initial Site Investigation (EPA, 1984) reports workers diluted hydrochloric acid outside the building, but we have no measurements of the levels of worker exposure to hydrochloric acid or other site-related chemicals. This public health assessment does not estimate either exposure or the possibility of illness for these workers. Worker health and safety are the responsibility of the federal Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH).

4.3.1 Completed Exposure Pathway- We considered the City of Riviera Beach municipal water supply a completed pathway for up to 18 months from August 1981 to January 1983. These are the dates for water samples in which no vinyl chloride was detected, the intervening July 1982 sample detected vinyl chloride just above the drinking water standard; however, we don't know when vinyl chloride first impacted the municipal wells or if daily levels varied due to the city utility's mixing practices (data shown in Table 4, Appendix C).

4.3.1.1 Municipal Water Supply - From sometime after 1960 until 1985, solvent wastes from Trans Circuits and a nearby site, Solitron Devices, introduced chlorinated solvents into the City of Riviera Beach groundwater supply. Near these sites, shallow groundwater contamination initially followed natural groundwater flow patterns; it flowed to the east and northeast. When the depth of the contaminated groundwater reached 75 feet or so below the land surface, the pumping of the nearest municipal wells influenced its flow direction. Well # PW-17 is the closest to Trans Circuits. It pulled contaminated groundwater to the southeast. Well #s PW-9 and PW-10 pulled contaminated groundwater to the north from Solitron. When the City of Riviera Beach took PW-9 and PW-10 offline, well # PW-11 pulled this contaminated groundwater to the northeast. When the City of Riviera Beach took PW-11 offline well #s PW-4, PW-5 and PW-6 pulled it farther to the northeast, to the public wells along Old Dixie Highway.

No analytical data are available for "Finished Water" (blended water supplied to customers from the City of Riviera Beach utilities plant) before 1981. Solvent levels are very low in most of the available data (Appendix C, Table 4). Only one "Finished Water" sample suggests water quality problems. The City of Riviera Beach took this water sample in July 1982. It showed vinyl chloride at a level slightly above the drinking water standard. The city utilities did not take any additional finished water samples until January the following year. City water users may have used tap water with low levels of vinyl chloride for up to 18 months. We do not know when solvents first reached the public wells. Because tests showing no vinyl chloride are only known from 11 months before this sample and 7 months after it, we have an 18 month time frame in which vinyl chloride impacted the wells and then was apparently diluted. However, the actual length of time could have been less, due to the mixing of water from city wells, and variations in groundwater contamination levels. Because drinking water standards are set for lifelong exposures, we do not expect any illness from vinyl chloride in tap water due to the short time it was present and due to the low level found. The other solvents and solvent breakdown products in this tap water are lower than health-based standards for lifelong ingestion.

Citizens notified city utilities staff of municipal water odors in the early 1970s. However, we cannot evaluate the likelihood of illness, if any, for exposure during this time because no analytical data from before 1981 exist.

The City of Riviera Beach first responded to solvent contamination in groundwater by closing (or not using) the affected wells. When groundwater investigations showed solvent contamination was spreading, the city began treating the water after they pumped it from the ground. The treatment system was completed and in use by 1988.

The Town of Lake Park is supplied municipal water by Seacoast Utilities. Seacoast Utilities had a wellfield (Old Dixie Wellfield) between one-half and one mile northwest of Trans Circuits. The Town of Lake Park abandoned this wellfield in 1992 due to solvent contamination from an industrial park found north of Trans Circuits (Rim Bishop, Seacoast Utilities, personal communication, 1999). In addition, available groundwater data do not link movement of site-related chemicals to Seacoast Utilities wells.

4.3.2 Potential Exposure Pathways - DOH considered the following human exposure pathways to be potential, based on the existence, depth and location of private wells (Table 6, Appendix C):

4.3.2.1 Private Well Water - Ingestion and inhalation of groundwater contaminants from tap water are potential exposure pathways for people using wells without treatment devices (Table 6, Appendix C). While possible, such pathways are unlikely to be completed, for two reasons. First, northeast of the site (the nearest down-gradient direction for groundwater) only a few private wells are still in use. Since the mid-1960s, most of the surrounding area has had municipal water service provided by the Seacoast Utilities for the Town of Lake Park and the City of Riviera Beach Utilities. Private wells, both for home use and irrigation, may be too shallow to reach the contaminated groundwater (FDER, 1985). Because the site-related chemicals are heavier than water, they sink once they reach the water table. Within 600 feet of the site, the contaminated groundwater is 75' below the land surface (Figure 3). Further from the site, most of the contaminated groundwater is even deeper, between 150 and 250 feet below the surface.

Shallow private wells in Lake Park would only be at risk of intercepting contamination if they were in areas with contaminated water. As a part of this health assessment, DOH staff asked Seacoast Utilities about the location of private wells in southern Lake Park. There were only three in this area and all were located about ½ mile east of the groundwater contamination. In the City of Riviera Beach, DOH staff located and sampled seven private wells between the Trans Circuits and Solitron Devices sites. Analyses of these samples showed that groundwater from these citizen's wells did not contain site-related chemicals or other contaminants at levels of concern.

4.3.2.2 On-Site Surface Soil and Contaminated Dust - The soil pathway is currently of minimal concern based upon the inactive status of on-site manufacturing. Polynuclear aromatic hydrocarbons (PAHs) were found in the background surface soil (background means normal conditions that are not related to the site) and in all the on-site surface soil samples but one. PAHs are the remnants of incompletely burned organic material and so can be naturally occurring as well as man-made. They are also present in asphalt roadways and parking lots, roofing tar and other building materials. We attributed these soil PAH levels to the site's urban setting rather than the use of site-related chemicals. Although we have not included PAHs in the table of on-site soil contaminants, we did a dose calculation for the highest PAH level found on the site. This dose was not associated with adverse health effects except a low increase in the probability of cancer (to one in one hundred thousand). PAHs are associated with stomach and skin cancer. However, this is probably a high estimate. Our dose calculation assumes that an adult will eat 100 milligrams (the weight of 1 postage stamp) of soil per day and a child will eat 200 milligrams per day (the weight of 2 postage stamps), every day. It is unlikely that adults or children would eat this much site soil due to present site use, and distance from residential areas. Soil ingestion levels assumed for these doses are also probably unlikely with future industrial use of the site.

Photo 3, Appendix B shows the approximate location of the railroad spur that had the highest level of lead in surface soil (beneath the trees, to the right, in the foreground). Black and Veatch list this sample in the data evaluation report as a background sample (BVSPC, 1999). Between these trees and the building is the area which used to be a percolation pond. Elevated lead was found in pond subsurface (2.5' to 5' deep) soil. Incidental contact with (and ingestion of) surface soil is unlikely because most of the remaining site surface is beneath the building, is paved with asphalt, or is overgrown by vegetation.

In the future, workers could incidentally ingest lead if they excavate deep soil from the former pond area (Table 6, Appendix C). The nearby auto shops, Action Bolt, sign-painting and boat-painting companies were working with their doors open the day we visited the site. Therefore, approximately 50 workers at nearby business could inhale uncontrolled dust from such excavations. Current soil characterization is adequate for the present site conditions. In the future, if workers disturb soil beneath the percolation pond for construction purposes, the EPA might better characterize soil contamination to assure workers follow adequate dust control measures.

Likewise, if this area became residential, excavation could expose construction workers to deeper soils (2.5 to 5' deep) if they poured a concrete foundation. For such a change in land use, the building and asphalt parking lot would have to be removed. At this time, conversion of the site to residential land is not likely because the area is zoned for commercial/industrial use and the building has been purchased for redevelopment.

4.3.3 Eliminated Exposure Pathways -

4.3.2.1 Surface Water and Sediments - We do not address surface water and sediment contamination because surface water does not migrate off the site. No storm drainage systems or ditches are now found in the area immediately surrounding the site. Currently and in the past, runoff from the site area, including runoff into the three onsite drainage catch basins, percolates directly into the ground (USGS, 1983; Sullivan, 1997).

4.3.2.1 Air - Air strippers at the Riviera Beach water treatment plant currently treat groundwater that contains low levels of site-related chemicals. These air strippers remove chemicals from the water and release them to the air. Daryl Graziani of the Palm Beach County Health Department analyzed air near the air strippers on August 8, 2000. He did calculations based on these measurements to estimate what 24-hour and annual chemicals levels were likely to be. He found all these estimated chemical releases to be below annual and 24-hour state standards. Therefore, by rule, these air strippers are exempt from any state permitting requirements. State air emissions standards are based on health considerations.

4.4 Public Health Implications

In the following sections, we discuss exposure levels and possible health effects that might occur in people exposed to the contaminants of concern at the site.

4.4.1 Toxicological Evaluation - In this subsection, we discuss exposure levels and possible health effects that might occur in people exposed to the contaminants of concern at the site. Also in this subsection, we discuss general ideas such as the risk of illness, dose response and thresholds, and uncertainty in public health assessments.

To evaluate exposure, we estimated the daily dose of each contaminant of concern found at the site. Kamrin (1988) explains a dose in this manner:

"...all chemicals, no matter what their characteristics, are toxic in large enough quantities. Thus the amount of a chemical a person is exposed to is crucial in deciding the extent of toxicity that will occur. In attempting to place an exact number on the amount of a particular compound that is harmful, scientists recognize they must consider the size of an organism. It is unlikely, for example, that the same amount of a particular chemical that will cause toxic effects in a 1-pound rat will also cause toxicity in a 1-ton elephant."

Thus instead of using the amount that is administered or to which an organism is exposed, it is more realistic to use the amount per weight of the organism. Thus 1 ounce administered to a 1-pound rat is equivalent to 2000 ounces to a 2000-pound (1-ton) elephant. In each case, the amount per weight is the same: 1 ounce for each pound of animal.

This amount per weight is the dose. We use dose in toxicology to compare the toxicity of different chemicals in different animals."

In expressing the daily dose, we used the units of milligrams of contaminant per kilogram of body weight per day (mg/kg/day). A milligram is one-thousandth of a gram (a gram weighs about what a raisin or paperclip weighs), a kilogram is about 2 pounds.

To calculate the daily dose of each contaminant, we used standard assumptions about body weight, ingestion and inhalation rates, exposure time length, and other factors needed for dose calculation (ATSDR 1992, EPA 1997). In calculating the dose, we assume people are exposed to the maximum concentration measured for each contaminant in each medium. In Tables 7, 8, and 9, Appendix B, we summarize the maximum estimated exposure doses for all six contaminants of concern.

To estimate exposure from incidental ingestion of contaminated soil, we made the following assumptions: 1) children between the ages of 1 and 6 ingest an average of 200 milligrams (mg) of soil per day, 2) adults ingest an average of 100 milligrams of soil per day, 3) children weigh an average of 15 kilograms (kg), 4) adults weigh an average of 70 kg, 5) children and adults ingest soil at the maximum concentration measured for each contaminant.

To estimate possible future exposure from drinking contaminated groundwater, we made the following assumptions: 1) children between the ages of 1 and 6 ingest an average of 1 liter of water per day, 2) adults ingest an average of 2 liters of water per day, 3) children weigh an average of 15 kilograms (kg), 4) adults weigh an average of 70 kg, 5) children and adults ingest contaminated groundwater at the maximum concentration measured for each contaminant.

To evaluate health effects, the ATSDR has developed Minimal Risk Levels (MRLs) for contaminants commonly found at hazardous waste sites. An MRL is an estimate of daily human exposure to a contaminant below which noncancer, adverse health effects are unlikely to occur. The ATSDR may develop MRLs for each route of exposure, such as ingestion and inhalation. The ATSDR also develops MRLs for the length of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (greater than 365 days). The ATSDR presents these MRLs in Toxicological Profiles. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status.

4.4.1.1 1,2-Dichloroethene and Tetrachloroethene- If, in the future, people drink or use contaminated groundwater, either on-site or off-site, they are unlikely to become ill from the 1,2-dichloroethene or tetrachloroethene in this water (ATSDR, 1996; ATSDR, 1997a). None of the calculated doses would be likely to cause illness.

4.4.1.2 Fluoride - Although long-term household use of groundwater from on or near the site could result in several illnesses due to elevated levels of fluoride, we are not aware of anyone who is or has been drinking this water. Figure 2, Appendix B shows the area with elevated fluoride concentrations. The body can use fluoride in place of calcium. When teeth are forming, low levels of fluoride incorporated into the teeth protect them from the bacteria which cause caries (cavities). However, higher fluoride levels in teeth can cause discolored patches and holes (dental fluorosis) which makes them more susceptible to decay. With long-term exposure, the levels of fluoride in the groundwater on and off the site could cause dental fluorosis (ATSDR, 1993). The highest on-site and off-site fluoride levels could also cause nausea, vomiting and gastric pain for single exposures in children, while long-term exposures in adults at these levels could cause skeletal fluorosis. Signs of skeletal fluorosis range from increased bone density to severe deformity, also called crippling skeletal fluorosis. Crippling fluorosis can cause the backbone to become rigid and can cause the back to be humped or arched. Long-term exposure to these levels could also cause joint stiffness because fluoride may cause muscle attachment sites to fuse with bones.

The doses calculated for children on and off the site are above or near those causing breakdowns of liver tissue in long-term studies in mice; and decreased endocrine activity in long-term studies in rats (the endocrine system is made up of internal glands that control hormone production; ATSDR, 1993). Only the on-site child dose is as high as the level linked with decreased antibodies in long-term rat studies (this indicates an impairment of the body's disease-fighting system because antibodies are components of the blood that fight specific disease-causing agents; ATSDR, 1993). Animals have different metabolic rates than humans and differ from humans in other aspects of physiology (physiology is the study of the workings of the body). Nonetheless, some health effects of chemicals are only known from animal studies, so we consider them when looking at toxicity levels and health effects.

The area of groundwater with elevated fluoride is much smaller than the area containing chlorinated solvents and their breakdown products. The flushing action of the air stripper may have aided the binding of fluoride with sediments (or alternatively moved soluble fluoride compounds off the site) because the levels measured in 1985 on the site are not confirmed by more recent sampling. Although current fluoride levels are higher off site than on site, people should not use groundwater with elevated fluoride on or near the site as a source of drinking water. Again, our investigations did not find anyone using water with fluoride above drinking water standards.

4.4.1.3 Lead - Long-term household use of groundwater on and very near the site in the past could have resulted in illnesses due to elevated levels of lead. However, the latest analytical testing of groundwater has not shown elevated lead levels. Nevertheless, all our calculations use the highest levels found, following our instructions from ATSDR. At levels detected in the past, lead interferes with bone growth and nerve function causing slowed mental and physical development in children (ATSDR, 1999b). These changes could decrease growth rates, inhibit performance on neurobehavioral tests and decrease stature (height). Like fluoride, the body can use lead in place of calcium. Lead is stored in the bones but studies have shown that a fraction of the lead in the body remains available in the soft tissue. Lead in the bloodstream interferes with the body's ability to make new red blood cells (ATSDR, 1999b). A condition characterized by too few red blood cells (anemia) means the body's uptake of energy from food and oxygen from air are less efficient. At the highest levels seen on and off the site in the past, lead could also have contributed to the breakdown of the heart muscle, which could result in abnormal electrocardiogram readings in children (an electrocardiogram measures the heart's action, a graph of currents from the machine that measures this action are called an electrocardiograph).

The processes leading to anemia are seen at all levels of lead exposure (there is no threshold for this effect), and occur in adults and children. Lead's role in kidney cancer has only been established at high levels of exposure in long-term studies of rats and mice with lead compounds (lead acetate and lead phosphate) that are readily available for use by living systems. A link with inorganic lead and cancer in humans has not been established.

The area of groundwater that had elevated lead in the past is much smaller than the area currently containing fluoride. Figure 2, Appendix B shows the area with elevated lead in the past corresponds with the black rectangle outlining the site. As with fluoride, the flushing action of the air stripper probably aided the binding of lead with sediments, reducing its presence in groundwater. The detection of lead in subsurface soil samples supports this possibility. Because it was not detected in the June 1999 round of groundwater samples on and near the site, and because we could not find anyone using untreated groundwater in the area, it is unlikely people could come in contact with groundwater with elevated lead from drinking water, now or in the past.

4.4.1.4 Nickel - Nickel has only been found at levels above state drinking water standards in one on-site and two off-site monitoring wells. DOH has been unable to find anyone on or near the site who is currently drinking water contaminated with nickel, or who may have drunk water with nickel in the past. The highest level of nickel in groundwater was found in a deep monitoring well southeast of the site. Using the highest level, our dose calculation was less than the "No Observable Effects Level" for people ingesting (eating or drinking) nickel (ATSDR, 1997). Therefore, DOH would not expect illness from the nickel found in drinking water on or near the site.

4.4.1.5 Trichloroethene - Long-term ingestion and household use of groundwater from on and near the site with the highest levels detected in monitoring wells could result in developmental problems for children whose mothers were exposed to trichlorethene before or during pregnancy. Animal studies provide qualitative support for human epidemiological studies (studies that take statistical increases in health effects and look at possible environmental causes) that have found higher incidences of children born with heart defects to mothers exposed to trichloroethene, dichloroethene, and chromium in drinking water during pregnancy. Doses (1.8 mg/kg/day) and rates of heart abnormalities (about 5% more than normal) were similar for the human epidemiological study and an extensive rat study. The rat study is limited however because only two widely-spaced exposure concentrations were used and the dose did not seem to affect the percentage of offspring affected (that is, they saw no dose-response - ATSDR, 1997b). Because of this possible health effect, women of childbearing age should not use groundwater with elevated trichloroethene on and near the site as a source of drinking water. Again, we were unable to find anyone currently, or in the past who drank water containing site-related trichloroethene.

4.4.2 Risk of Illness, Dose Response/Threshold and Uncertainty-In Appendix D we discuss limitations on estimating the risk of illness, the theory of dose response and the concept of thresholds. Also in Appendix D we discuss the sources of uncertainty inherent in public health assessments.

4.5 Children and Other Unusually Susceptible Populations

Children
Exposure to contamination from the site is unlikely to have caused birth defects, but we evaluate such possibilities for each chemical found on the site above ATSDR's screening values. Before birth, children are forming the body organs that need to last a lifetime. Exposure of the mother can lead to exposure of the fetus since some contaminants cross the placental barrier (ATSDR 1997a). This is the time when contaminant exposure could lead to serious injury or illness. Injury during certain periods of growth and development may lead to malformation of organs (teratogenesis), disruption of function, or premature death.

After birth, the developing body systems of children can sustain permanent damage if toxic exposures occur during critical growth stages. Children may be at greater risk than adults from exposure to hazardous substances emitted from waste sites. They are more likely exposed because they play outdoors and because they may bring food into contaminated areas. They are shorter than adults, which means they breathe dust, soil, and heavy vapors close to the ground. Pound for pound of body weight, children drink more water, eat more food, and breathe more air than adults. In addition, children may accidentally wander or deliberately trespass onto restricted locations. The obvious implication for environmental health is that children can have much greater "doses" than adults to contaminants that are present in soil, water, and air (ATSDR 1998). For all of these reason, we give special consideration to children's health in this assessment. Again, at this time, DOH has no information that an exposure pathway is complete for any lead, fluoride, or trichloroethene exposures.

We calculated dose estimates specifically for children for 1,2-dichloroethene, fluoride, lead, trichloroethene, and tetrachloroethene, based on the highest levels found and then assumed that exposures to these levels would occur daily. Lead, fluoride, nickel, and trichloroethene are the chemicals that we estimate are present on and near the site at levels of concern for daily exposure. That is, if children or females of childbearing age were to drink these chemicals on a long-term, daily basis in contaminated groundwater, children could become ill. None of the doses calculated for children for the other chemicals listed above indicated risk of illness for children or developing fetuses.

Lead
Effects of exposure to lead at doses calculated for on and off-site groundwater include anemia (insufficient red blood cells), impairment of nerve development (results in slower learning and lowering of other neurobehavioral measures), slowed bone growth and problems absorbing vitamin D. Absorption of lead appears to be higher in children who have low dietary iron or calcium intakes.


Fluoride
Low doses of fluoride have been shown to protect teeth from bacteria which cause decay; however, too much fluoride can have the opposite effect. When their teeth are forming, children are especially sensitive to the effects of elevated fluoride ingestion which causes dental fluorosis, a brown mottling and pitting of the teeth which can leave teeth more susceptible to decay. Doses that could cause fluorosis were calculated for groundwater levels on and near the site.


Nickel
No effects specific to people were observed for reproduction or fetal development. Inferences from animal studies suggest occupational exposure could result in reproductive effects (such levels would be much higher than those seen on groundwater near the site). Effects at low levels are not known or expected. Nickel has been reported to interact with DNA, resulting in cross-links and strand breaks.


Trichloroethene
A 5% increase in offspring born with heart defects has been linked in animal studies to mothers' exposures to levels of trichloroethene approximating those found in off-site groundwater. While it is not known whether trichloroethene or its metabolites caused these heart defects, the results provide qualitative support for human epidemiological studies (studies that take statistical increases in health effects and look at possible environmental causes) that have found higher incidences of children born with heart defects to mothers exposed during pregnancy to drinking water with a combination of chemicals: trichloroethene, dichloroethene and chromium (ATSDR, 1997b).

Other Unusually Susceptible Populations
A susceptible population has different or enhanced responses to a toxic chemical than will most persons exposed to the same levels of that chemical in the environment. Reasons may include genetic makeup, age, health, nutritional status, and exposure to other toxic substances (like cigarette smoke or alcohol). These factors may limit that persons' ability to detoxify or excrete harmful chemicals or may increase the effects of damage to organs or systems in the body. This is not an exhaustive list and reflects only current available data, further research may target more subsets of the population. The special traits of children that make them more sensitive are discussed in the previous section, while we discuss other susceptible populations for specific chemicals below.

Fluoride
The toxic effects of fluoride may be enhanced in the elderly, and in people with malnutrition, cardiovascular disease or kidney problems. In the elderly, fluoride has been associated with an increased incidence of bone fractures in areas other than the back and neck. Skeletal fluorosis is associated with malnutrition (deficiencies of calcium, magnesium, and/or vitamin C). In India, the contributing factors of tea consumption (tea contains fluoride) and high water intake are seen in skeletal fluorosis (ATSDR, 1993). Cardiovascular (heart and blood circulation) disease can be worsened by fluoride because it inhibits glycolysis (the use of sugar in muscles when oxygen supply is not sufficient). Kidney disease reduces the body's ability to rid itself of fluoride (ATSDR, 1993).


Lead
In addition to children, population subgroups more susceptible to lead's toxic effects include pregnant women, the elderly, smokers, alcoholics, people with malnutrition, kidney or nerve problems, or genetic diseases affecting red blood cell production. Pregnancy releases lead from women's bones which can increase the amount available in the body (this increases the total dose for the mother and may harm the developing fetus). The elderly are more susceptible than adults to the effects of lead in the blood production system. Smokers ingesting lead are adding to the heavy metals they are exposed to through tobacco smoke (tobacco smoke contains lead, cadmium and mercury). Lead acts with alcohol to inhibit the production of key components of the blood and nervous systems. In malnutrition, insufficient levels of calcium increase the uptake of lead from the diet; while not enough iron and zinc increase the adverse effects lead has on the production of red blood cells. The nervous system and kidneys are the primary target organs for lead's toxic effects, so disease or dysfunction in either system can promote toxicity at lower levels than would occur in a healthy person. People with inheritable genetic diseases of the system which makes new red blood cells are unusually susceptible to anemia following lead exposure.


Nickel
Individuals sensitized to nickel may be unusually susceptible because exposure to nickel by any route may trigger an allergic response. Epidemiology studies indicated that blacks have a higher nickel sensitivity than whites and that women of both racial groups have higher reaction rates that men. The incidences of reactions may be higher in women because they generally wear more jewelry than men, and skin contact may be the main exposure route. Further studies are required to determine if there are true gender and racial differences in nickel sensitivity, or if there is a difference in rates of exposure. Nickel that has been absorbed into the blood stream is primarily excreted in the urine. Therefore, individuals with kidney dysfunction are likely to be more sensitive to nickel. The increased sensitivity of persons with kidney dysfunction is also suggested by increased serum (blood) concentrations of nickel in dialysis in patients. Because diabetics often have kidney damage, and because of the hyperglycemic effects of nickel observed in animal studies, the sensitivity of diabetics to nickel is also likely to be increased.


Trichloroethene
Elderly people or other people with weakening organ functions (especially the kidney and liver systems) may show increased susceptibility to the toxic effects of trichloroethene (ATSDR, 1997b). People who consume alcohol or who are treated with disulfuram may be at greater risk of trichloroethene poisoning because ethanol and disulfuram can both inhibit the metabolism of trichloroethene and can cause it to accumulate in the bloodstream, potentiating its effects on the nervous system (ATSDR, 1997b).

5.0 COMMUNITY HEALTH CONCERNS

On June 30, 1999, the EPA answered questions about this and other area hazardous waste sites (BMI/Textron, Solitron Devices and some currently operating industrial sites) at a Public Availability Open House. They held the Open House at the Riviera Beach Public Library at 600 West Blue Heron Boulevard. Julie Smith (DOH) recorded questions from community residents and officials. Former EPA Community Involvement Coordinator, Rose Jackson, also reported some community health concerns to DOH (Ms. Jackson now coordinates community education for the ATSDR). DOH paraphrased these early concerns and addresses them below:

Are there private wells west of Old Dixie Highway and the railroad tracks that could intercept contaminated groundwater?

DOH identified private wells on both sides of Old Dixie Highway and the railroad. Seacoast Utilities personnel helped us find three homes east of Old Dixie Highway that have private wells. Since this northern area of groundwater contamination has been adequately evaluated, we concluded that these three private wells would not have contaminated water from Trans Circuits. They are too far away from the site. Rolous Frazier and Fred Lott, both DOH Environmental Specialists, visited the northernmost part of Riviera Beach in February 2000. This part of the city is between the Trans Circuits and Solitron Devices sites. They visited the addresses the City of Riviera Beach Utilities billing department gave us (as billing addresses that might have private wells) and then asked if the residents used private wells. They found and sampled seven private wells for groundwater contamination. The analyses did not detect any chemicals related to Trans Circuits or Solitron Devices nor did they find other chemicals at levels of concern for health.

What is the nature of underground contamination at the site?

Site investigations show the main concern for underground contamination is groundwater (FDER, 1985, 1992; GZA, 1987, 1989; BVSPC, 1999). The underground areas of concern depend on the amount and toxicity of the chemicals found there, and how they move in groundwater. Smaller areas near the site have groundwater that contains lead, nickel and fluoride, while trichloroethene can be found in groundwater ½ mile from the site. These chemicals are present at high enough levels to cause concern for drinking and other household uses of groundwater. Because of their chemical characteristics, lead, nickel and fluoride bind with soil, while trichloroethene moves more freely in groundwater.

Accordingly, the area of groundwater with elevated lead is small (Appendix B, Figure 2, the area covered by the black rectangle labeled Trans Circuits). The area with elevated nickel and fluoride is larger (same figure, dashed insets), while trichloroethene has moved 2,300 feet to the southeast (same figure, largest plume area associated with Trans Circuits).

Exposure to soil contaminants is more likely to occur with surface soil (0 - 3" deep). In the case of lead exposure, someone could either swallow dirt that they touched and then accidently got in their mouth, or they could breathe in dust, if they were digging in this area when the soil was dry. The dose calculated for the one soil sample with elevated lead from along the railroad spur (BVSPC, 1999) was not likely to cause illness, even when assuming daily, lifelong intake. The highest soil lead levels were found in deep soil (between 2.5 and 5 feet) beneath the former percolation pond.

Polynuclear aromatic hydrocarbons (PAHs) were found in the background surface soil and in all the on-site surface soil samples but one. PAHs are the remnants of incompletely burned organic material and so can be naturally occurring as well as man-made. PAHs are also present in asphalt roadways and parking lots, roofing tar and other building materials, so we attributed these soil PAH levels to the site's urban setting rather than the use of site-related chemicals. Although PAHs are not included in the table of on-site soil contaminants, we did a dose calculation for the highest PAH level found on site. This dose was not associated with adverse health effects except for a minimal increase in the probability of stomach and skin cancer.

All of our calculations for exposure assume that an adult will eat 100 milligrams of soil per day (the weight of a postage stamp), and a child will eat 200 milligrams per day, every day (the weight of two postage stamps). Such exposures are unlikely with present site use (or future industrial site use), and the site is some distance from local residences. Therefore, lead, fluoride, nickel and trichloroethene in groundwater are the underground contaminants that concern us for potential health effects related to the Trans Circuits site. However, we have been unable to find anyone who is drinking this water untreated; therefore, we are unaware of any current completed exposure pathway.

Has airborne contamination been associated with the site?

Site surface soil conditions and contaminant levels do not indicate a present-day source for airborne contamination. Accounts of past site practices indicate that workers diluted acids outside on a frequent basis. It is reported that clouds of hydrochloric acid would be emitted when the acid was being mixed with water. We have no past air measurements for the site and so we cannot assess the likelihood of illness from exposure to hydrochloric or other acid vapors. Concentrated hydrochloric acid is quite corrosive and can be dangerous if the vapors are inhaled or if the liquid is spilled on the skin. However, when diluted, it is fairly harmless. For example, dilute hydrochloric acid is present in the stomach and serves to aid the digestion of food.

DEP permits air-strippers like the one used to treat groundwater at the site in the past. Air strippers at the City of Riviera Beach Utilities currently treat water with low levels of chemicals associated with this site. Air strippers remove the chemicals from the water and release them to the air. Daryl Graziani of the Palm Beach County Health Department analyzed air near the air strippers on August 8, 2000. He did calculations based on these measurements to estimate what 24-hour and annual chemicals levels were likely to be. He found all estimated chemical releases to be below annual and 24-hour state standards. Therefore, by rule, the city air strippers are exempt from any state permitting requirements. State air emissions standards are based on health considerations.

Has the community been exposed to contaminants in our water supplied by the city? If so, would our exposure be expected to have adverse health effects?

Contaminants from Trans Circuits have not been found in Seacoast Utilities public supply wells which supply the Town of Lake Park.

Table 4 lists the levels of site-related contaminants found in the City of Riviera Beach "Finished Water" from 1981 to 1986, and the latest analyses from 1999. The City of Riviera Beach's finished water, which they routinely analyze, has not had VOCs above the analytical detection limit since 1986. Apparently even before the air strippers were operating, chlorinated solvents and their breakdown products were either removed in the sulfide aeration tower or diluted below detection levels by blending contaminated water with uncontaminated water from other wells.

The only time City of Riviera Beach "Finished Water" (tap water) exceeded a health-based screening level was in July 1982: four micrograms per liter (µg/L) of vinyl chloride were detected. This chemical may have come from the Solitron Devices hazardous waste site (FDER, 1985). People would not have smelled vinyl chloride at this level (vinyl chloride has a mild sweet odor and an odor threshold of 3,000 µg/L). Four µg/L is slightly above the standard for long-term (lifelong) ingestion of vinyl chloride in drinking water. Because the next "Finished Water" quality data are from January the next year, and the prior analyses were done in August 1991, we estimated that the community could have been drinking water with vinyl chloride at this level for at most 18 months (11 before and 7 after). This level of vinyl chloride gives a dose 157 times less than the level found to cause changes in liver cells (not cancer) in rats (Til et al., 1983, 1991). Because we are comparing an 18-month possible exposure with exposures for a lifelong study, and because people's estimated daily dose for that time was so much lower than the animals in this study, we do not expect to see any illness from this exposure. Again, we need to remember for this 18-month period we don't know when and for how long vinyl chloride was above the drinking water standard, nor do we know what affect mixing of city well water and alternate use of city wells had on the daily levels.

The additional amount of vinyl chloride that a person could breathe from showering or from other household uses of this water could be 1.5-6 times higher than the contribution from drinking alone (McKone, 1987). We compared our highest estimated vinyl chloride air level with vinyl chloride inhalation studies. The amount of vinyl chloride likely to volatilize from groundwater with vinyl chloride at four µg/L would have been 1,283 times less than the level associated with breast cancer in a lifelong inhalation study of female rats. Breathing this level for 18 months is not expected to add sufficiently to the risk of illness.

Although citizens notified the city utilities staff about odors from City of Riviera Beach municipal water in the 1970s, we cannot evaluate the likelihood of illness for possible exposures during this time because no water samples were analyzed before 1981. We don't know what chemicals people smelled, or what level the odor-causing chemicals may have been present at.

DOH learned of additional community concerns from the following:

  • Public Meetings the EPA held on August 14, 2000, and September 19, 2000 for the Solitron Devices site,
  • A meeting Connie Garrett (DOH) had with Riviera Beach city officials and utilities managers on September 19, 2000, and
  • Citizens responses to DOH facts sheets. We prepared these fact sheets for the Public Comment Drafts of the Public Health Assessments for the Trans Circuits and Solitron Devices sites. They summarized DOH's public health concerns for both sites. The fact sheets were distributed to the nearby community by mail before DOH's Public Availability Meeting for the Trans Circuits and Solitron Devices sites. We held this meeting on November 28, 2000 at the Riviera Beach City Council Chambers at 600 West Blue Heron Boulevard. Before and after the meeting, these fact sheets were also distributed by the Northwest Riviera Beach Community Redevelopment Corporation who helped DOH find private wells that we were then able to sample.

Although many people expressed their concerns, often they had similar concerns, or they asked questions that we responded to above. We grouped the similar concerns that we have not already addressed and responded to them below:

How will the Trans Circuits and Solitron Devices sites affect my health and my family's health? Will I get sick?

DOH looks at all the information available for each hazardous waste site. We look at what amounts of chemicals are present and try to determine if there is a way for people to be exposed to these chemicals. Based on what is known about both these sites, it is unlikely anyone will get sick.

Soil contamination is mainly known to be present on the sites (one sediment sample from the canal next to the Solitron site had elevated chromium). To meet the conditions we assume for the doses we calculated, people would either have to inhale dust daily from the sites or accidentally eat soil from the sites, daily, for long periods of time. This soil would also have to have the highest levels that were detected during the sampling of the sites. We are not aware of anyone who has had this kind of long-term exposure to soil from either site.

Based on what we know, chemicals in groundwater were present at relatively low levels before the City of Riviera Beach began treating it. Currently, the city treats all the groundwater they supply, and we have not found anyone using private wells that have contaminated water. However, we do not have any information on drinking water quality in the 1970s when people reportedly could smell chemicals in the city water.

Are there any long term health effects or cancer expected from site-related contaminants?

Based on what we know, the answer is no, we do not expect long-term health effects nor do we expect an increase in cancers. To address the possibility of health effects from contaminants that could have been in City of Riviera Beach municipal water before any testing was done, DOH is comparing the rates of specific cancer types (cancers that could be linked with site-related chemicals) with rates for those same cancers in other Florida communities.

Are there any precautions that the residents should take?

People in Riviera Beach who use private wells should have them tested, if they have not been tested recently. People using private wells in Lake Park probably do not need to have their wells tested: only three private wells are in southern Lake Park and they are not near the area of groundwater contamination.

The Palm Beach County Health Department has worked with the city utilities of Lake Park and Riviera Beach, along with the Northwest Riviera Beach Community Redevelopment Corporation to locate and sample a total of 25 private wells. Analyses of samples from private wells near the Trans Circuits and Solitron Devices sites (the first seven private wells we tested and discussed above) did not show site-related chemicals or any other harmful chemicals at elevated levels. However, testing of 18 additional private wells (located further from the site) did identify elevated levels of chemicals in two wells. This contamination was related to another area of groundwater contamination about 1 and ½ miles south of Blue Heron Boulevard. DEP either connects residences using wells with elevated chemicals to city water, or provides a filter for the well.

City of Riviera Beach municipal water is tested and treated by the City of Riviera Beach utilities. It is safe to drink. Seacoast Utilities supplies water for Lake Park. They also test their water. They have not had contamination from Trans Circuits impact any of their city wells, so the municipal water is safe to drink in Lake Park, as well.

Most residents will probably not have to worry about contaminated soil exposure. Only workers on either site that were disturbing the soil would be likely to accidentally inhale contaminated dust or accidentally eat contaminated soil.

Will the present testing identify other types of water contamination if it is present?

The present testing is designed to identify other types of water contamination, if present. Municipal water suppliers, like Seacoast Utilities who supply water to Lake Park, are required by state regulations enacted in 1985 to sample their wells every three years for an extensive list of chemicals. Water suppliers with wells showing violations of state drinking water regulations are required to sample more frequently, and must show that the water they are supplying is safe. The City of Riviera Beach samples their wells every three months.

Have any of the residents become sick, been harmed or otherwise been affected by this site?

At this time, DOH is not aware of anyone with illnesses we can link to exposures to site-related chemicals. Our evaluation of what people may have been exposed to in the past is based on a limited number of groundwater and soil analyses, from a limited time period.

Community members also expressed others concerns about the Trans Circuits and Solitron Devices sites. DOH does not set policy, regulate hazardous wastes, or oversee cleanups. Therefore, although we acknowledge these concerns, we do not address them here. Again, many community members had similar concerns which we grouped into the following questions:

  • How could this contamination happen in the first place, and how can we keep it from happening again in our communities?
  • Who can citizens take their hazardous waste concerns to?
  • When will these sites be cleaned up and why has the cleanup process has taken so long?

 

6.0 CONCLUSIONS

We classify this site as "no apparent public health hazard". We are not aware of any nearby residents currently exposed to site-related contaminants. Past exposure levels are either not likely to have caused illness, or we cannot evaluate them--because there are no data for us to estimate exposure levels from. Nevertheless, people should not drink untreated groundwater from areas of groundwater contamination on or near the site. Disturbance of the lead-contaminated subsoil below the former percolation pond is also a possible future exposure pathway.

Currently, the City of Riviera Beach treats groundwater with air strippers to remove contaminants before using it for municipal supply. The neighborhoods and businesses around the site have access to municipal water, although not every home is hooked up to it. As a part of this public health assessment, DOH staff investigated the neighborhoods and business near the site to find and sample any private drinking water wells currently in use. They identified and sampled seven private wells between Trans Circuits and another source of groundwater contamination, Solitron Devices, in February 2000. The analytical results showed that none of these private wells contained site-related chemicals, or any other chemicals at levels of health concern. Although no one has precisely delineated the area of offsite groundwater contamination, we know its general area and only one of the seven wells is near this area.

Only one analysis of the City of Riviera Beach Utilities "Finished Water" (tap water) exceeded Florida's drinking water standard for lifelong exposure. DOH's dose calculation did not show expected illness from vinyl chloride at the low level detected, even when we compared it to lifetime exposure studies. We estimate a total exposure period of 18 months or less because the July 1982 sample is the only sample with vinyl chloride above state standards. However, samples with no detectable vinyl chloride taken earlier in August 1981 and later in January 1983, bracket the possible time frame. We do not know the actual period vinyl chloride was present, but we do know that since the city mixes half the wells every day, to prevent saltwater from moving in from the ocean. It is possible the contaminated wells were only used every other day. Although citizens notified city utilities staff about tap water odors before 1981, we cannot evaluate the likelihood of illness for such exposures, if any, because no one analyzed "Finished Water" (tap water) before 1981.

Between 1976 and 1985, an unknown number of workers could have been exposed to chemicals, vapors and dust inside and outside the Etched Products/Trans Circuits building. This public health assessment does not estimate exposures or the possibility of illnesses for these workers. Worker's health and safety are the responsibility of the federal Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH).

Our specific conclusions follow:

  1. In the future, people should not use contaminated (untreated) groundwater from on or near this site as a source of drinking water. People drinking this water probably could not smell or taste the lead, fluoride, nickel or trichloroethene in the water.


  2. Under current site conditions, lead in the subsoils is not a public health threat. If, in the future, anyone disturbs soil beneath the percolation pond, they should avoid ingestion or inhalation exposure due to possible high levels of lead.


  3. The building is easily accessible because someone has removed most of the doors. We saw glass from broken fluorescent light bulbs inside the building. If children were to go inside the building, they could cut themselves on broken glass.

7.0 RECOMMENDATIONS

  1. Ensure that people do not drink untreated contaminated groundwater by resampling nearby private wells yearly.


  2. Control dust generation during any future cleanup, remodeling, utilities or construction work that would disturb subsurface soils and create dust from the area below the percolation pond. Analyze additional soil samples for lead before disturbing this soil.


  3. Limit building access to prevent children from contacting broken glass.

8.0 PUBLIC HEALTH ACTION PLAN

This section describes what ATSDR and DOH plan to do at this site. The purpose of a Public Health Action Plan is to reduce any existing health hazards and to prevent any from occurring in the future. ATSDR and DOH will do the following:

  1. DOH, Bureau of Environmental Epidemiology will inform and educate nearby residents about the public health threats associated with this site.


  2. DOH Bureau of Environmental Epidemiology will notify FDEP and the South Florida Water Management District so that any new private wells installed will have to fulfill the requirements for wells in areas of delineated groundwater contamination. Of the seven private wells found nearest the site, one was closer to the area of groundwater contamination than the others. The Palm Beach County Health Department should sample this well yearly, for at least five years, or until we have a better idea of the location of groundwater contamination related to the Solitron Devices site (the area of groundwater contamination near the Trans Circuits site is known). Although the six other nearby private wells are probably far enough from the area of contamination not to have immediate concerns, DOH may also want to sample them yearly.


  3. DOH, Bureau of Environmental Epidemiology will continue to work with the EPA and FDEP to ensure that the site is cleaned up to protect public health. The EPA will warn future owners of the property (via deed restrictions) about the possibility of metals in the subsoil beneath the percolation pond. This will protect future construction or utility workers and workers at nearby business from possible exposures to lead in soil and airborne dust.


  4. DOH will ask the EPA to prevent building access so that children are not able to come in contact with broken glass that could cause cuts.

The conclusions and recommendations in this report are based on the information reviewed. When additional information becomes available, DOH, Bureau of Environmental Epidemiology staff will evaluate it to determine what additional recommendations to make, if any.


9.0 SITE TEAM/AUTHORS

Florida Department of Health Author
Connie Garrett
Bureau of Environmental Epidemiology
Division of Environmental Health
(850) 245-4299


ATSDR Technical Project Officer
Debra Gable
Division of Health Assessment and Consultation
State Program Section


The ATSDR Regional Representative:
Bob Safay
Regional Services
Office of the Assistant Administrator


10.0 REFERENCES

ATSDR 1992. Public Health Assessment Guidance Manual (March). Agency for Toxic Substances and Disease Registry, U.S. Public Health Service. Atlanta, GA.

ATSDR 1993. Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1996a. Toxicological Profile for 1,2-Dichloroethene. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1997a. Toxicological Profile for Tetrachloroethene. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1997b. Toxicological Profile for Trichloroethene. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1997c. Toxicological Profile for Vinyl Chloride. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1998. Guidance on Including Child Health Issues in Division of Health Assessment and Consultation Documents. Agency for Toxic Substances and Disease Registry. Atlanta, GA. July 2, 1998.

ATSDR 1999a. Soil and Water Comparison Values. Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

ATSDR 1999b. Draft Toxicological Profile for Lead (Update). Agency for Toxic Substances and Disease Registry, U.S. Department of Health and Human Services.

Black and Veatch, 1999. Volume I - Quality Assurance Project Plan, Remedial Investigation/Feasibility Study, Trans Circuits, Inc. Site, Lake Park, Palm Beach County, Florida, March 1999.

Black and Veatch, 1999. Work Plan Volume I - Technical Approach, Remedial Investigation/Feasibility Study, Trans Circuits, Inc. Site, Lake Park, Palm Beach County, Florida, April 1999.

Black and Veatch, 1999. Work Plan Volume II - Field Sampling Plan, Remedial Investigation/Feasibility Study, Trans Circuits, Inc. Site, Lake Park, Palm Beach County, Florida, April 1999.

Black and Veatch, 1999. Draft Screening - Level Ecological Risk Assessment of the Trans Circuits, Inc. Site, Lake Park, Palm Beach County, Florida, April 1999.

Black and Veatch, 1992. Final Site Inspection Prioritization for Trans Circuits, Inc. Lake Park, Palm Beach County, Florida, November, 1992.

Department of Environmental Regulation, 1982, Letter from Drinking Water Administrator to Jack Walden, City of Riviera Beach, public supply well system - water quality analysis results from G.M. Dykes, November 30, 1982.

Department of Environmental Regulation, 1985, Riviera Beach Wellfield Contamination, Palm Beach County, by G.B. Watts, N.A. Brown, September 1985.

Department of Environmental Regulation, 1987, Supplementary Contamination Report Riviera Beach Wellfield Contamination, Palm Beach County, by G.B. Watts, R.W. Hicks, W.A. Martin, Jr., January 1997.

Department of Environmental Regulation, 1992, Groundwater Investigation Supplementary Contamination Report, Trans Circuits, Inc. Lake Park, Florida, Palm Beach County, by William A. Martin, P.G., Robert Cilek and Mark A. Murray, March, 1992.

Department of Environmental Protection, 1991. Trans Circuits, Inc. groundwater sampling data. From Zoe Kulakowski, Site Bureau of Waste Cleanup to Saadi Motamedi, Southeast District Environmental Supervisor.

Department of Environmental Protection, 1991. Trans Circuits, Inc. Groundwater Sampling data. Memo from Bill Martin, Site Investigation Section to Saadi Motamedi, Southeast District Environmental Supervisor, December 16, 1991.

Department of Environmental Protection, 1995. Memo from Paul Wierzbicki to Vincent Paluso about the back door of the Trans Circuits Site being unsecured.

Department of Environmental Protection, November 8, 1995. Letter from Paul Wierzbicki to Steve Kennedy, Lake Park Building Official about the back door of the Trans Circuits Site being unsecured.

Environmental Protection Agency,1997. U.S. Environmental Protection Agency. Exposure Factors Handbook, Volumes I, II, and III. EPA/600/P-95/002Fa,b,c.

Environmental Protection Agency, 1999, Trans Circuits Site Fact Sheet, Lake Park, Palm Beach County, Florida.

Environmental Protection Agency, 1993, Letter to the former site owner advising him that the EPA was going to start a site investigation at the Trans Circuits, Inc. Site.

Environmental Protection Agency, 1984, Potential Hazardous Waste Site Preliminary Assessment, performed by David Troutman of E.C. Jordan Co., January 17, 1984.

Goldberg, Zoino and Associates, Inc, 1986. Contamination Assessment Plan, September 1986.

Goldberg, Zoino and Associates, Inc, 1987. Contamination Assessment Report and Remedial Action Plan, February 1987.

Goldberg, Zoino and Associates, Inc, 1989. Annual Summary and Project Status Report, April 1989.

Goldberg, Zoino and Associates, Inc, 1990. Summary of Remedial Action, April 9, 1990.

Jacobs Engineering Group, Inc., 1991. Screening Site Inspection, Trans Circuits, Inc., Lake Park, Florida, January 1991.

Kamrin 1988. Toxicology - A Primer on Toxicology Principles and Applications. Lewis Publishers. Chelsea MI.

McKone, T.E., 1987. Human exposure to volatile organic compounds in household tap water: the indoor inhalation pathway, Environmental Science & Toxicology 21:11941201.

NJDEP 1990. Improving Dialogue with Communities. New Jersey Department of Environmental Protection, Division of Science and Research, Trenton, NJ.

Riviera Beach, 1997. April 1996 and March 1997 analytical data for Riviera Beach Wells 4, 6, and 17 collected from City of Riviera Beach Utilities by Black and Veatch Special Project Corp. personnel during Trans Circuits, Inc., site reconnaissance, May 2, 1997.

Seacoast Utilities Authority, 1992. Phone call to Rim Bishop by Andrea Austin, Black and Veatch. Subject; Number of connection, population served, boundaries of area served and map request.

Stedman's 1990. Stedman's Medical Dictionary, 25th Edition, Illustrated. Williams & Wilkins, Baltimore, MD.

Sullivan, Brian, Public Works Building Department, 1997. Telephone conversation with Mr. Sullivan reported by Carol W. King, BVSPC, July 2, 1997. Subject: Storm drainage near the Trans Circuits, Inc. site.

Til, H.P., V.J. Feron and H.R. Immel, 1991. Lifetime (149-week) oral carcinogenicity study of vinyl chloride in rats, Food Chemistry and Toxicology 29(10):713-718.

Til, H.P., H.R. Immel and V.J. Feron, 1983 Lifespan oral carcinogenicity study of vinyl chloride in rats. Final report. Civo Institutes, TNO. Report No. V 93.285/291099.

USGS, 1983. U.S. Geological Survey, 7.5 Minute Series Topographic Quadrangle Maps for Florida: Riviera Beach 1949, (Photorevised (PR) 1983); Palm Beach 1946, (PR 1983, Bathymetry Added 1986); Delta 1945 (PR 1983), scale 1:24,000.

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