PUBLIC HEALTH ASSESSMENT
U.S. NAVAL SUBMARINE BASE, NEW LONDON
GROTON, NEW LONDON COUNTY, CONNECTICUT
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
Contaminants discussed in the subsequent sections of this public health assessment will be evaluated to determine whether exposure to them has public health significance. All the contaminants detected at each site are not included in this document. Instead, ATSDR has selected certain contaminants that require further evaluation in this public health assessment.
ATSDR selects and discusses contaminants based on several factors: concentrations of environmental contaminants on and off the submarine base, field and laboratory data quality, sampling design, and comparison of chemical concentrations to health assessment comparison values for carcinogenic and non-carcinogenic health effects. Community health concerns are also considered when selecting the contaminants presented in this public health assessment.
Listing a chemical contaminant in the data tables that follow does not mean that it will cause adverse health effects. Instead, the list indicates which contaminants will be evaluated further in the public health assessment. The potential adverse health effects from those selected contaminants of health concern will be discussed in the Public Health Implications section of this document. When selected in one medium, a contaminant will be reported in all media in which it is found.
The comparison values for ATSDR public health assessments are developed by environmental and health agencies to provide an estimate of chemical concentrations present in each environmental medium (air, water, soil) that should be evaluated for possible health effects if exposure to the contaminants occurs. In many cases, the values have been derived from animal studies or occupational studies. Health effects are related to the exposure dose, the routes of entry into the body, and the amount of chemical absorbed by the body. ATSDR uses the following comparison values.
The data tables include the following abbreviations for these
comparison values.
| AL | Action Level. ALs represent levels at which the agency
(EPA) must take additional action under its control to
reduce the levels of the contaminant, and inform residents
about the action they can take to lower exposure. |
| CREG | Cancer Risk Evaluation Guide. CREGs are health assessment
comparison values that correspond to one excess cancer in a
million persons exposed over a lifetime. CREGs are
calculated from standard cancer risk, adult body weight,
adult ingestion rate, and EPA's cancer slope factor
(toxicity values for carcinogenic effects). |
| EMEG | Environmental Media Evaluation Guide. EMEGs are media-specific values that correspond to ATSDR's Minimal Risk
Level (MRL). They are calculated by using ATSDR's
conservative exposure assumptions that would protect the
most sensitive populations. |
| DWEL | Drinking Water Equivalent Level. DWELs are lifetime
exposure levels specific for drinking water at which
adverse health effects would not be expected to occur. |
| HA | Health Advisory. An HA is an estimate of acceptable
drinking water levels for a chemical substance based on
health effects information. A health advisory is not a
legally enforceable federal standard, but serves as a
technical guidance to assist federal, state, and local
officials. |
| LOAEL | Lowest Observed Adverse Effect Level. The LOAEL is the
dose of chemical in a study or group of studies that
clearly shows adverse health effects. |
| LTHA | Lifetime Health Advisory. LTHAs represent contaminant
concentrations that EPA deems protective of public health
over a lifetime (70 years) at an ingestion rate of two
liters of water per day. LTHAs are not legally enforceable
standards. |
| MCL | Maximum Contaminant Level. MCLs represent contaminant
concentrations that EPA deems protective of public health
(considering the availability and economics of water
treatment technology) over a lifetime (70 years) at an
ingestion rate of two liters of water per day. MCLs are
enforceable regulatory standards. |
| MCLG | Maximum Contaminant Level Goals. MCLGs are drinking water
health goals. MCLGs are set at a level at which no known
or anticipated adverse human health effects occur. MCLGs
are not enforceable standards. |
| MRL | Minimal Risk Level. Developed by ATSDR, MRLs are estimates
of daily exposure to a chemical that is not likely to cause
adverse non-carcinogenic health effects. MRLs are based on
the most current information available. |
| NOAEL | No Observed Adverse Effect Level. The NOAEL is a dose of
chemical in a study or group of studies that clearly shows
no adverse health effects. |
| RfD | Reference Dose. The EPA's RfD is an estimate (with uncertainty spanning perhaps a factor of ten) of the daily exposure of a person to a contaminant that is unlikely to cause adverse health effects. The RfD is operationally derived from the NOAEL (from animal and human studies) by a consistent application of uncertainty factors that reflect various types of data used to estimate RfDs and an additional modifying factor, which is based on a professional judgement of the entire database on the chemical. |
Additionally, individual chemicals may be grouped into general
chemical classifications based on their similar physical
properties. The following abbreviations are used in the sections
of the public health assessment that follow.
| PAHs | Polycyclic Aromatic Hydrocarbons. The chemicals in
this group include chemical constituents found in coal
tar and asphalt. PAHs are divided into two subgroups:
carcinogenic PAHs and non-carcinogenic PAHs.
Carcinogenic PAHs include benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene,
benzo(k)fluoranthene, indeno (1,2,3-cd)pyrene,
chrysene. Non-carcinogenic PAHs include naphthalene,
acenaphthylene, fluorene, anthracene, pyrene, and
others. Some PAHs are also considered Semi-Volatile
Organics. |
| PCBs | Polychlorinated Biphenyls. These chemicals are very
stable and persistent in the environment. They are
used as heat transfer liquids in transformers,
hydraulic fluids, lubricants, and in plasticizers,
surface coatings, inks, and adhesives. They are also
used as pesticide extenders and for microencapsulation
of dyes for carbonless duplicating paper. PCB 1260 is
a name for one specific chemical in this group. There
are 209 chemicals are classified as PCBs. |
| Pesticides | There are many different physical properties of
chemicals used to kill pests. In this public health
assessment, DDT and its breakdown products DDD and DDE
are included in this group of chemicals. |
| Inorganic Chemicals |
Organic chemicals contain carbon; inorganic chemicals do not contain carbon. VOCs, SVOs, PAHs,
PCBs, and some pesticides are organic chemicals.
Elemental metals such as lead, mercury, cadmium,
silver, nickel, and others are inorganic chemicals.
Other non-metal inorganic chemicals include boron,
antimony, and magnesium. |
| SVOs | Semi-Volatile Organics. The chemicals in this class
slowly evaporate when exposed to air. Chemicals in
the class include: 4-methylphenol, isophorone,
dibenzofuran, etc. Other chemicals in this class are
also PAHs, such as fluoranthracene, anthracene,
naphthalene, pyrene, etc. |
| VOCs | Volatile Organic Compounds. The chemicals in this group readily evaporate or volatilize into gases when exposed to air. This chemical class includes tetrachloroethane, chloroethane, trichloroethylene, dichloroethylene, benzene, toluene, xylenes, etc. |
An overview of the contamination found in soils, groundwater, surface water, and other environmental media may be helpful in understanding how the individual sites may be affecting the installation as a whole and the surrounding communities. For this reason, an overview is presented below and is followed by site-specific information. "Detected" denotes where contamination was found.
The information for this section was obtained from the Installation Restoration Study, Naval Submarine Base New London and the Phase I Remedial Investigation, Naval Submarine Base, New London as listed in the "References" section of this document.
Soil (3)
Surface soil samples have been collected and analyzed at six
of the installation sites. Contamination has been identified
in surface soil at four of the sites. Subsurface soil samples
have been collected and analyzed at nine sites. Contamination
was identified in subsurface soils at five of those sites.
The table that follows shows where surface and subsurface soil
contamination has been identified. PCBs, PAHs, and inorganic
chemicals are among the contaminants detected in both surface
and subsurface soils. Site-specific contaminants requiring
further evaluation within the public health assessment are
included in the On-Base Contamination section.
Table 1: Overview of Soil Contamination (3)
| Site | Surface Soil Contamination |
Subsurface Soil Contamination |
| CBU Drum Storage Area | ||
| Rubble Fill at Bunker A-86 | ||
| Torpedo Shops | ||
| Goss Cove Landfill | ||
| Over Bank Disposal Area | ||
| Spent Acid Storage and Disposal Area | ||
| Former Gasoline Station | ||
| Area A | ||
| DRMO | ||
| Lower Subase | ||
| North Lake | ||
| Rock Lake |
Groundwater (3)
Groundwater has been tested at five sites. Also, private
wells have been sampled in a neighborhood near Area A
Landfill. The shallow aquifer (overburden water table) has
been sampled at all five sites. The bedrock (deep) aquifer
has been sampled at three sites. A summary table of the on-site groundwater contamination follows. Contaminants detected
include inorganic chemicals and volatile organic chemicals.
The lists of selected contaminants and their concentrations
appear in the On-Base Contamination section.
Table 2: Overview of Groundwater Contamination (3)
| Site | Overburden Water Table Contamination |
Bedrock Aquifer Contamination |
| CBU Drum Storage Area | ||
| Rubble Fill at Bunker A-86 | ||
| Torpedo Shops | ||
| Goss Cove Landfill | ||
| Over Bank Disposal Area | ||
| Spent Acid Storage and Disposal Area | ||
| Former Gasoline Station | ||
| Area A | ||
| DRMO | ||
| Lower Subase | ||
| North Lake | ||
| Rock Lake |
Surface Water and Sediment (3)
Surface water samples have been tested at five on-base sites and two off-base areas (Thames River and a residential pond). Analysis of samples collected from Area A and the off-base Thames River identified contamination. Contaminated surface water was not detected at any other site.
Sediment samples have been collected at one on-base and two off-base sites. Contaminants were detected in the Area A and in the off-base area of a neighboring residence, but not in the Thames River. The specific contaminants identified in surface water and sediment samples are listed with their concentrations in the On-Base Contamination section.
Table 3: Overview of Surface Water and Sediment Contamination (3)
| Site | Surface Water Contamination |
Sediment Contamination |
| CBU Drum Storage Area | ||
| Rubble Fill at Bunker A-86 | ||
| Torpedo Shops | ||
| Thames River near Goss Cove | ||
| Over Bank Disposal Area | ||
| Spent Acid Storage and Disposal Area | ||
| Former Gasoline Station | ||
| Area A | ||
| Thames River near DRMO | ||
| Lower Subase | ||
| North Lake | ||
| Rock Lake | ||
| Off-base Thames River | ||
| Off-base residential area | |
Air (3)
No air monitoring has been performed at any site. Soil gas screening has been conducted at six sites. Levels of VOCs were reported as "high," "moderate," "low," or "trace." Measurements were recorded as volt/seconds (Vs), which represent relative quantities as compared to other measurements. A reading of greater than (>) >300 Vs was considered "high," a reading of 50.1 - 300 Vs was considered "moderate," a reading of 2.1 - 50 Vs was considered "low," a reading of 0.3 - 2.0 Vs was considered "trace," and a reading less than (<) <0.3 Vs was considered as "not detected." High and moderate levels of benzene and/or other VOCs were reported at five sites. A summary table of sites where high and moderate levels of VOCs were identified follows.
Table 4: Overview of Soil Gas Screening (3)
| CBU Drum Storage Area | |
| Rubble Fill at Bunker A-86 | |
| Torpedo Shops | |
| Goss Cove Landfill | |
| Over Bank Disposal Area | |
| Spent Acid Storage and Disposal Area | |
| Former Gasoline Station | |
| Area A Landfill | |
| DRMO | |
| Lower Subase | |
| North Lake | |
| Rock Lake |
Biota (3)
Frog and bird (catbird fledgling) tissues were collected from the Area A Wetland and analyzed for inorganic chemicals and pesticides. No contaminants were detected in the tissue samples. No other biota have been sampled at any other site.
Contamination detected within the installation boundaries is considered on-base contamination. Contamination found at each site on the submarine base is discussed in this site-specific information. Although the specific sampling dates were not provided, all samples were collected and analyzed in 1990.
CBU Drum Storage Area (3)
Surface soil was the environmental medium sampled at the CBU Drum Storage Area.
Soil
Surface soil samples were collected to identify contaminants present in the top 18 inches of soil. Seven samples were collected from three on-site locations. The samples were collected at depths of 0 - 6 inches and at 12 - 18 inches. One sample was a composite of surface soil (0 - 6 inches) from two sampling locations at the site. VOCs, SVOs, pesticides, PCBs, total petroleum hydrocarbons (individual chemicals were not specified), and inorganic chemicals were analyzed. Only the composite sample was analyzed for inorganic chemicals. Lead was the only contaminant identified above comparison values. Cadmium was detected at 2,100 parts per billion (ppb), which is below health comparison values for soil.
Table 5: Contaminant in Surface Soil at CBU Drum Storage Area (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| Lead | NAb - 59,300 | 53,200c | Regional Background |
No other environmental medium has been sampled for analyses at this site.
Rubble Fill at Bunker A-86 (3)
Surface soil was the environmental medium sampled at the Rubble Fill at Bunker A-86.
Soil
Five soil samples were collected and analyzed from two sampling locations north (downgradient) of the site. Not all samples were analyzed for every chemical group. One of the five samples was a composite of soil from the two sampling locations. Only the composite sample (0 - 6 inches) was analyzed for SVOs, PAHs, inorganic chemicals, and pesticides. The inorganic chemicals, lead and cadmium were detected at low levels not exceeding comparison values. Three samples were analyzed for VOCs. No VOCs exceeded comparison values. Two surface soil (0 - 6 inches) samples were analyzed for PCBs. PCBs were not detected.
Table 6: Contaminants in Surface Soil at Rubble Fill at Bunker A-86 (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| Benzo(a)anthracene | CREGc | ||
| Benzo(a)pyrene | CREG | ||
| Chrysene | CREG | ||
Torpedo Shops (3)
Environmental media sampled for this site consisted of subsurface soil, groundwater, and soil gas.
Soil
Nine soil samples were collected from the two former septic tank drainage line fields for Buildings 450 and 325. Building 450 lines are considered the North System while Building 325 lines are designated the South System. All nine samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals.
Three subsurface (2 - 4 feet) soil samples were collected from the North System area. Five subsurface (4 - 8 feet) soil samples were collected from the South System area. One surface/subsurface sample (0 - 2 feet) was collected from an upgradient area east of the site to represent possible background levels at this location on the submarine base. PAHs were detected at higher concentrations in the sample taken from the upgradient well boring location, adjacent to the Torpedo Shops. The levels of PAHs detected in soil were below comparison values. The PCB contaminant, PCB 1254 was detected in one of the nine subsurface soil samples analyzed for PCBs.
Antimony was detected in six of the nine subsurface soil samples. Samples containing antimony were identified from the upgradient well location, from one of three samples taken from the North System at a depth of 2 - 4 feet, and from four of the five samples taken from the South System. All samples containing antimony were identified at concentrations below comparison values.
Table 7: Contaminants in Soil at the Torpedo Shops (3)
| Chemical | (ppba) |
|||
| North System | South System | Concentration (ppb) |
Source | |
| PCB 1254b | ||||
Groundwater
Three groundwater monitoring wells were installed at the Torpedo Shops. One well was installed in each system (North and South) and one well in the upgradient sampling area. The upgradient well was drilled into the bedrock and screened at a depth of 11 feet because of the shallow depth of bedrock in that area. The other wells are shallow overburden wells screened at 10 and 7 feet. Groundwater was analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals.
Antimony was only detected in the one well in the South System. Lead and cadmium were detected at trace levels, below comparison values in all samples including the laboratory blanks, indicating a possible low level background concentration.
Table 8: Contaminants in Groundwater at the Torpedo Shops (3)
| Chemical | Concentration (ppba) |
Comparison Value | ||
| North System | South System | Concentration (ppb) |
Source | |
| Antimony | from RfDd | |||
Soil Gas
Twenty-eight soil gas measurements were taken at the site. However, the data were not reported as concentrations. Measurements were recorded as volt/seconds (Vs) which represent relative quantities as compared to other measurements. A reading of greater than (>) >300 Vs was considered "high," a reading of 50.1 - 300 Vs was considered "moderate," a reading of 2.1 - 50 Vs was considered "low," a reading of 0.3 - 2.0 Vs was considered "trace," and a reading less than (<) <0.3 Vs was considered as "not detected." The only "high" reading was an "unknown" compound that was speculated to be toluene. Benzene was recorded at "trace-low" readings. Benzene may have been present in other positive readings.
Goss Cove Landfill (3)
The field investigations at this site consisted of radiation, geophysical, and soil gas surveys. Additionally, samples were collected from soil, groundwater, and surface water.
At Goss Cove, 458 measurements for radiation were made at ground surface or at waist level. No readings were detected above normal background levels.
A geophysical survey consisting of a combination of magnetometry, electromagnetic conductivity (EM), and ground penetrating radar (GPR) was conducted on the ground surface to determine if drums or other metal objects were buried on the site. Buried metal objects were identified at three locations between 10 - 25 feet beneath ground surface.
Soil
Seven soil samples collected at depths ranging from 4 - 12 feet were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Oil stains and sheens were noted on approximately half the soil borings taken.
The soil borings showed the depth of fill to range from 10 to 20 feet. All soil samples were collected from within the landfill material, and generally at or below the water table.
PCBs were detected in three of seven samples collected. The PAHs, benzo(a)anthracene and chrysene were detected in all of the seven soil samples collected. Benzo(a)pyrene was detected in four of the seven samples collected. Indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene were detected in one of the seven soil samples collected. Both benzo(b)fluoroanthene and benzo(k)fluoroanthene were detected in five of seven samples collected. Since Goss Cove Landfill is asphalt covered, the source of these PAHs is questionable and could come from the asphalt covering. Lead was detected at estimated levels above background in six samples. PCB 1248 was detected in three of seven samples collected.
DDE, and DDD were detected in two of the seven samples analyzed. The levels of DDE and DDD were below the health related comparison values. DDT was detected in four samples. DDT was detected at levels below 100 ppb in three separate locations. Another sample identified DDT at an estimated concentration of 3,400 ppb.
Table 9: Selected Contaminants in Subsurface Soil at Goss Cove Landfill (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| PCB 1248 | EMEGd | ||
| Benzo(a)anthracene | CREGf | ||
| Benzo(a)pyrene | CREGf | ||
| Benzo(b)fluoranthene | CREGf | ||
| Benzo(k)fluoranthene | CREGf | ||
| Chrysene | CREGf | ||
| DDT | CREGf | ||
| Indeno(1,2,3-cd)pyrene | CREGf | ||
| Lead | 26,500J - 3,020,000J | 53,200g | Regional Background |
Groundwater
Four monitoring wells, all screened in the overburden water table, were sampled for VOCs, SVOs, pesticides, PCBs, inorganic chemicals, and gross alpha and beta radiation. Three of the wells are located within the former landfill, while one well is upgradient of the site.
Naphthalene was detected in two of four groundwater samples collected. Gross alpha radiation was detected in three of four groundwater samples. Gross beta radiation was detected in three of four groundwater samples. In one of those samples, gross beta radiation exceeded comparison values.
Table 10: Selected Contaminants in Groundwater at the Goss Cove Landfill (3)
| Chemical | Concentration | Comparison Value | |
| Concentration | |||
| Naphthalene | LTHAc | ||
| Gross Alpha Radiation | MCLe | ||
| Gross Beta Radiation | MCLf | ||
Surface Water
One surface water sample was collected from the Thames River downstream from the Goss Cove Landfill. The sample was analyzed for VOCs, SVOs, pesticides, PCBs, inorganic chemicals, and gross alpha and beta radiation. No selected contaminants were detected above comparison values.
Soil Gas
Sixty-four soil gas points were analyzed. Most of the samples were taken from the area beneath the paved parking lot. Sampling results do not include analysis for methane gas. Methane gas is a naturally occurring gas produced during the decay process present in landfills. It is highly explosive and elevated concentrations may become trapped in confined areas such as cabinets or closets. Phase II sampling will include analysis for methane gas.
Trace to low levels of the VOCs, tetrachloroethylene, 1,2-dichloroethylene, trichloroethylene, benzene, and toluene were detected. Actual sampling results were not included in the Installation Restoration Study (3).
Three samples containing moderate to high levels of unidentified compounds mixed with benzene, toluene, and xylenes were identified. Further analysis indicates the presence of a petroleum product (3). These elevated levels of VOCs are in the vicinity where elevated soil concentrations of petroleum hydrocarbons were detected.
Over Bank Disposal Area (3)
Soil and sediment were sampled at this site. The discussion of sediment sampling is included in the Area A Downstream Watercourses section that follows.
Soil
Five soil samples were collected from two locations at the site. Three of the samples were collected at depths of 0 - 6 inches, and two samples were collected at depths of 12 - 18 inches. One of the samples collected at the 0 to 6 - inch depth was a composite sample of the two locations. The 12 to 18-inch samples were analyzed for VOCs only. The composite sample was analyzed for SVOs, pesticides, PCBs, and inorganic chemicals. The other two 0 to 6-inch samples were analyzed for selected inorganic chemicals only. Lead and cadmium were detected at low levels below health related comparison values.
Spent Acid Storage and Disposal Area (3)
Soil was the medium sampled at the Spent Acid Storage and Disposal Area.
Soil
Six soil samples were collected at depths of 0 - 4 feet and 4 - 8 feet. One additional sample was collected from the gravel used to fill the spent acid tank. One sample collected near the sanitary sewer line was analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. The other samples were analyzed for a selected number of inorganic chemicals only. No contaminants were detected at levels above health comparison values.
Former Gasoline Station (3)
Investigations at this site included geophysical survey, soil, and soil gas sampling.
A geophysical survey using GPR indicated that only one of the three underground storage tanks remains below the ground.
Soil
Five subsurface soil samples were collected at depths ranging from 8 - 16 feet. The samples were analyzed for VOCs and inorganic chemicals. Samples were collected to the north, east, and southwest of that location. Cadmium and lead were detected in all samples at trace concentrations not exceeding health comparison values.
Soil Gas
Eleven soil gas samples all collected beneath the paved road were analyzed. No VOCs were detected at moderate or high levels.
Area A (3)
Area A is divided into three areas: Area A Landfill, Area A Wetland, and Area A Downstream Watercourses.
The Step II investigations of Area A consisted of a radiation, geophysical, and soil gas survey within the former landfill only. Soil, groundwater, surface water, and soil gas sampling was performed throughout Area A. All groundwater data for Area A is combined in Table 14.
Area A Landfill (3)
A total of 1,272 measurements were taken for radiation. Radiation detected was determined to be naturally occurring.
Geophysical investigations using GPR, magnetic and electromagnetic conductivity were conducted at ground surface. Metal objects, some of which were "large," were determined to be at depths of 5 feet and 8 feet below ground surface (3).
Soil
Twelve subsurface soil samples were collected from eight locations in the landfill area. Two surface soil samples were also analyzed. The samples were collected at the site and analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals.
In subsurface soil samples, benzo(a)anthracene was detected in three of twelve samples analyzed. Benzo(b)fluoranthene, benzo(k)fluoranthene, and chrysene were detected in approximately six of twelve samples collected. Benzo(a)pyrene was detected in three of twelve samples collected. Cadmium was detected at low levels not exceeding health related comparison values. Landfill materials were encountered during drilling to an approximate depth of 10 - 12 feet, which was beneath dredged sediment from the Area A Wetland.
In surface soil samples, PCBs, DDT, and lead were detected in both samples analyzed. Benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and chrysene were detected in one of two samples collected.
Table 11: Selected Contaminants in Soil at Area A Landfill (3)
| Chemical | Concentration (ppba) | Comparison Value | ||
| Surface Soil | Subsurface Soil | Concentration (ppb) |
Source | |
| PCB 1260 | 350J - 12,000 | ND | 91 | CREG |
| Benzo(a)anthracene | ND - 130J | CREGd | ||
| Benzo(a)pyrene | ND | CREGd | ||
| Benzo(b)fluoranthene | ND - 220J | CREGd | ||
| Benzo(k)fluoranthene | ND - 96J | CREGd | ||
| Chrysene | ND - 160J | CREGd | ||
| DDT | 71J - 23,000 | ND - 83XJ | 2,100 | CREG |
| Lead | 36,200 - 85,700 | Regional Background | ||
Area A Wetland (3)
Investigations at the Area A Wetland included soil, sediment, surface water, and groundwater analysis. All groundwater data for Area A is combined in Table 14.
Soil and Sediment
Thirty-three subsurface soil samples were collected from twelve locations within the Area A Wetland. The sampling depths taken ranged from 0 - 2 feet to 16 - 18 feet. Benzo(a)anthracene and chrysene were detected in 15 of 33 samples collected. Benzo(a)pyrene was detected in six of 33 samples collected. Benzo(b)fluoranthene and benzo(k)fluoranthene were each detected in 11 of 33 samples collected. Lead was detected above naturally occurring background levels in three of 33 samples collected. Nine sediment samples were also collected. All samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Benzo(a)pyrene, indeno(1,2,3-cd)pyrene, benzo(g,h,i)perylene were each detected in one of nine samples collected. Benzo(a)anthracene and DDE were each detected in two of nine samples collected. Benzo(b)fluoranthene, and benzo(k)fluoranthene, and chrysene were detected in three of the samples. Lead was detected above naturally occurring background levels in four of nine samples collected. Cadmium was not detected above naturally occurring background levels.
Table 12: Selected Contaminants in Soil and Sediment at Area A Wetland (3)
| Chemical | Concentration (ppba) | Comparison Value | ||
| Subsurface Soil | Sediment | Concentration (ppb) |
Source | |
| Benzo(a)anthracene | CREGd | |||
| Benzo(a)pyrene | CREGd | |||
| Benzo(b)fluoranthene | CREGd | |||
| Benzo(k)fluoranthene | CREGd | |||
| Benzo(g,h,i)perylene | ND | ND - 23,000 | 120 | CREGd |
| Chrysene | ND - 600J | ND - 42,000 | 120 | CREGd |
| Indeno(1,2,3-cd)pyrene | 270J | ND - 23,000 | 120 | CREGd |
| Lead | 3,600 - 298,000 | Regional Background | ||
Area A Downstream Watercourses and Overbank Disposal Area (3)
Investigations at this site included geophysical evaluation (reported in under Area A geophysical evaluation), soil, and sediment analysis.
Soil and Sediment
Five subsurface soil samples were collected from five monitoring well locations. These sampling depths ranged from 0 - 3 feet to 3 - 5 feet. All samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Benzo(k)fluoranthene and DDD were detected in one of five subsurface soil samples. DDE and DDT were detected in two of five subsurface soil samples. Lead levels detected in the five samples did not exceed naturally occurring background levels.
Twenty-three sediment samples were collected from the Area A Downstream Watercourses, OBDA, and associated ponds. The samples were collected from 18 sampling locations. The samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Benzo(a)anthracene, and chrysene were detected in nine of 23 samples collected. Benzo(b)fluoranthene was detected in eight samples collected. Benzo(a)pyrene, and benzo(k)fluoranthene were detected in six samples collected. Lead was detected above naturally occurring regional background levels in six samples. Indeno(1,2,3-cd)pyrene, was detected in four samples. DDD, DDE, DDT were detected in 18 samples. PCB 1260 was detected in one sample collected.
Table 13: Selected Contaminants in Soil and Sediment at Area A Downstream
Watercourses and Overbank Disposal Areas (3)
| Chemical | Concentration (ppba) | Comparison Value | ||
| Subsurface Soil | Sediment | Concentration (ppb) |
Source | |
| Benzo(a)anthracene | ND | CREGd | ||
| Benzo(a)pyrene | ND | CREGd | ||
| Benzo(b)fluoranthene | ND | CREGd | ||
| Benzo(k)fluoranthene | ND - 50JY | CREGd | ||
| Indeno(1,2,3-cd)pyrene | ND | CREGd | ||
| Chrysene | ND | CREGd | ||
| DDDe | ND - 61 | CREGf | ||
| DDEg | ND - 28JY | CREG | ||
| DDTh | ND - 74 | ND - 240,000J | 2,100 | CREG |
| Lead | 5,100 - 28,000 | 5,000J - 223,000 | 53,200i | Regional Background |
| PCB 1260 | ND | ND - 280JX | 91 | CREG |
Twenty-eight monitoring wells were installed throughout Area A Landfill, Area A Wetland, and the Area A Downstream Watercourses. Eleven of these wells are in the shallow, overburden water table. The other 17 wells are screened in the bedrock aquifer. Samples were analyzed for VOCs, SVOs, pesticides, PCBs, inorganic chemicals, and radiation. Benzene, cadmium, 1,4-dichlorobenzene, lead, PCB 1254, 1,1,2,2-tetrachloroethane, trichloroethylene, and gross Beta radiation were each detected in one of 28 samples analyzed.
Gross Alpha radiation was detected in five of the 28 samples. Manganese was detected in three of the 28 samples. Sodium was detected at levels above health comparison values in 20 of the 28 samples analyzed.
Table 14: Selected Contaminants in Groundwater at Area A
Landfill, Area A Wetland, and Area A Downstream Watercourses (3)
| Chemical | Concentration | Comparison Value | |
| Concentration | Source | ||
| Benzene | ND - 10Ja ppbb | 0 ppb | Carcinogen |
| Cadmium | NDc - 44.8J ppb | 2 ppb | EMEGd |
| 1,4-Dichlorobenzene | ND - 99J ppb | 75 ppb | LTHAe |
| Lead | ND - 22.4J ppb | 15 ppb | Action Levelf |
| Manganese | 2.3 - 8,130 ppb | 3,000 ppb | RfDg |
| PCB 1254 | ND - 150Xh ppb | 0.05 ppb | EMEG |
| Sodium | 9,000 - 1,360,000 ppb | 20,000 ppb | DWELi |
| 1,1,2,2-Tetrachloroethane | ND - 140 ppb | 0.175 ppb | CREGj |
| Trichloroethylene | ND - 17 ppb | 0 ppb | MCLGk |
| Gross Alpha Radiation | 0 - 42.2 pCi/Ll | 15 pCi/L | MCLm |
| Gross Beta Radiation | 2.8 - 56.3 pCi/L | 50 pCi/L | MCLn |
Surface Water
Fifteen surface water samples were collected. Seven from Area A Wetland, six from Area A Downstream Watercourses, and two from the Thames River. The samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Four of the 15 samples analyzed for radiation detected levels below health comparison values. Cadmium was detected above health comparison values for drinking water in one of the 15 samples analyzed. DDD was detected in one of 15 samples analyzed. Lead was detected in 11 of the 15 samples analyzed.
Table 15: Selected Contaminants in Surface Water at Area A Wetland,
Area A Downstream Watercourses, and the Thames River (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| Cadmium | NDb - 126Jc | 2 | EMEGd |
| DDD | ND - 1.9 | 0.15 | CREGe |
| Lead | ND - 7 | 15 | Action Levelf |
Soil Gas
Soil gas measurements were taken at 160 locations in the Area A Landfill. "High" readings were detected at 20 locations. The compounds detected in the "high" range are believed to include benzene, toluene, trichloroethylene, tetrachloroethylene, dichloroethylene, and xylenes.
Biota
Frog and bird (catbird fledgling) tissues from the Area A Wetland were analyzed only for metals and pesticides. No contaminants were detected.
DRMO (3)
The Step II investigations at this site consisted of radiation, geophysical, and soil gas surveys. Soil, groundwater, and surface water were the media sampled.
A total of 372 radiation measurements were made. All were within the naturally occurring background radiation levels for this region.
Because of the extensive surface metals (buildings and objects those awaiting auction) present at this site, the applicability of magnetic measuring methods is limited.
Soil
Four surface soil samples were collected at depths of 0 - 0.5 feet. All samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Benzo(b)fluoranthene and benzo(k)fluoranthene were detected in one of the four surface soil samples analyzed. Benzo(a)anthracene, chrysene, and lead were each detected in two of the four surface soil samples analyzed. PCB 1260 was detected in all four surface soil samples analyzed. Lead was detected above naturally occurring background levels in two of the four samples analyzed.
Twenty-four subsurface soil samples were collected at depths ranging from 0 - 2 feet to 8 - 10 feet. All samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. PCB 1260 was detected in 12 of 24 subsurface soil samples analyzed. Benzo(a)anthracene and chrysene were each detected in 18 of 24 samples analyzed. Benzo(a)pyrene was detected in ten of 24 samples analyzed. Benzo(b)fluoranthene was detected in 16 of 24 samples analyzed. Benzo(k)fluoranthene was detected in 11 of 24 samples analyzed. DDD, DDE, DDT, and 1,1,2,2-tetrachloroethane were detected in one subsurface soil sample analyzed. Indeno(1,2,3-cd)pyrene was detected in six of 24 samples analyzed. Lead was detected above naturally occurring background levels in 14 of 24 surface soil samples analyzed.
| Chemical | Concentration (ppba) |
Comparison Value | ||
| Surface Soil | Subsurface Soil | Concentration (ppb) |
Source | |
| PCB 1260 | CREGd | |||
| Benzo(a)anthracene | CREGe | |||
| Benzo(a)pyrene | CREGe | |||
| Benzo(b)fluoranthene | CREGe | |||
| Benzo(k)fluoranthene | CREGe | |||
| Chrysene | CREGe | |||
| DDD | CREGd | |||
| DDE | CREGd | |||
| DDT | CREGd | |||
| Indeno(1,2,3-cd)pyrene | CREGe | |||
| Lead | 20,700J - 204,000 | 2,900J - 8,130,000 | 53,200 | Regional
Background |
| 1,1,2,2-Tetrachloroethane | CREGd | |||
Groundwater
Six monitoring well samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Five of the wells are screened in the overburden water table and one is screened in the bedrock aquifer.
Surface Water
One surface water sample was collected from the Thames River and analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals.
Soil Gas
A soil gas survey was performed at the site. One "high" reading was detected; the chemicals detected are believed to include benzene, toluene, and other unknown constituents.
Lower Subase (3)
Field investigations consisted of a utility manhole inspection and waterfront bulkhead inspection for evidence of contamination sources/residuals. Other sampling included a soil gas survey, soil, and groundwater sampling. No radiological survey was performed at the Lower Subase.
A total of 212 utility manholes were inspected on two days in December 1990, and two days in April 1991. The utility manholes consisted of storm sewer, sanitary sewer, steam, electric, telephone, and sand manholes. Inspection consisted of removing manhole covers to note manhole type, and any visible evidence of oil contamination such as oil sheens on water or discolored sediment, or any petroleum odors. Neither air nor soil sampling was performed in the manholes. No oil sheens were observed along the waterfront.
Contamination sources in all but one manhole appear to be from product releases from underground fuel lines and storage tank leaks. Oil in one manhole possibly originated from the former waste oil pits in Building 79 (3).
Soil
Subsurface soil samples were collected from 17 borings and analyzed for VOCs, total petroleum hydrocarbons, and inorganic chemicals. The sampling depths ranged from 2 - 4 feet and 14 - 16 feet. In addition to those samples, five test borings were made at Building 79. Samples were screened for organic vapors and were visually inspected for contamination, but they were not analyzed for chemical constituents. Lead was detected in only one sample above background concentrations. Total petroleum hydrocarbons were detected at concentrations ranging from not detected - 14,000,000 parts per billion. Although the individual constituents of "total petroleum hydrocarbons" were not provided, fluorescence spectroscopy data indicate the presence of waste lubricating oils, Number 2 fuel/diesel oil, asphalt/tar, and waste oil/heavy residual fuel oil (such as Number 6 fuel oil) mixture. No other contaminants above health comparison values were identified.
Groundwater
Groundwater samples were collected from 24 monitoring wells and analyzed for volatile organic chemicals, total petroleum hydrocarbons, and inorganic chemicals. All wells were screened in the overburden water table. Total petroleum hydrocarbons were detected in one sample at a concentration of 5,400 parts per billion. The individual constituents of "total petroleum hydrocarbons" were not provided, but fluorescence spectroscopy data indicate the presence of waste oil/heavy residual fuel oil (such as Number 6 fuel oil) mixture, Number 2 diesel oil, waste lubricating oils, and heavy residual fuel oil. The other selected contaminants are listed in the following table.
Table 17: Selected Contaminants in Groundwater at Lower Subase (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| Benzene | |||
| Cadmium | EMEGe | ||
| Lead | |||
Soil Gas
A soil gas survey was conducted on the site. A total of 127 locations were sampled. Two "high" readings were identified. Benzene, toluene, and xylenes (among other unknown constituents) were the chemicals believed to cause these readings.
North Lake (7)
Soil and surface water were investigated at this site.
Soil
Sixteen soil (beach and sediment) samples at North Lake were collected in 1988 and 1990. Samples were analyzed for VOCs, SVOs, phthalate esters, pesticides, PCBs, and inorganic chemicals. The samples were all designated as "soil" samples without distinguishing which were from the beach area and which were sediments. No contaminants detected were above health comparison values.
Surface Water
Surface water samples were collected in 1988, 1990, and 1991 and analyzed for VOCs, SVOs, phthalate esters, pesticides, PCBs, and inorganic chemicals. No contaminants detected were above health comparison values.
Rock Lake
Surface water was the medium sampled at this site.
Surface Water
Samples were collected in 1991 and analyzed for the same parameters as the North Lake samples: VOCs, SVOs, phthalate esters, pesticides, PCBs, and inorganic chemicals. No contaminants above health comparison values were detected in the samples.
During the assessment of the New London Submarine Base, the preparers of this document searched the Toxic Chemical Release Inventory (TRI) to determine other sources of chemical releases into the environment in the areas near New London Submarine Base. The TRI is an on-line database, maintained by EPA, that contains information (self-reported by chemical manufacturers and other industries) about more than 320 different chemicals released into the environment. Data has been compiled for the period between 1987 and 1990. The New London Submarine Base is not a manufacturing facility and, therefore, is not subject to reporting releases to the TRI. However, the submarine base must comply with all other state and federal reporting requirements for actual chemical releases.
TRI database reported chemical releases made to air, land, and surface water points for VOCs and inorganic chemicals such as heavy metals from industrial sources within the zip code areas of New London, Groton, and Norwich, Connecticut.
Residential Wells
A total of twenty-three residential wells were sampled to evaluate overall groundwater quality and to determine if on-base contaminants have migrated off base, impacting neighboring areas. Depths of residential wells vary widely from a surface spring to a 300-feet deep bedrock well. Wells are designated by the letters OSW followed by a number.
Groundwater
The first round of sampling in 1991 included analysis of 14 wells for VOCs, SVOs, inorganic chemicals, pesticides, and PCBs. Sampling locations were chosen based on proximity to the submarine base and willingness of individual homeowners to have their wells tested (7). Generally, the residential wells were located on roads closest to the Area A and DRMO sites: Sleepy Hollow, Pinelock Drive, Long Cove Road, and Route 12.
The second round of sampling in 1991 included confirmatory analysis of inorganic chemicals in four wells plus the inorganic chemical analysis on eight additional wells. One well from round 1 had only VOC analysis performed during the second round. The second round of sampling extended the sampling area to the east of Baldwin Hill Road and North Pleasant Valley Road.
The third round of sampling in 1991 included confirmatory inorganic chemical analysis on six wells from round 2 sampling plus total analysis (VOCs, SVOCs, inorganic chemicals, pesticides, and PCBs) on one additional well not previously sampled.
In August of 1992, the Connecticut State Department of Environmental Protection in conjunction with the Connecticut State Department of Health Services analyzed 10 of those previously sampled wells for VOCs and inorganic chemicals.
In September of 1992, the Navy performed boron analysis on two of those wells previously sampled by the state and eight residential wells previously sampled in the first round. Boron levels were near or below detection limits.
During the first sampling round, lead was detected above the action level of 15 ppb in OSW 10 (39 ppb). In the second sampling round, lead was detected above 15 ppb in OSW 23 (32 ppb), OSW 21 (18 ppb), and OSW 6 (estimated at 17 ppb).
Subsequent confirmatory sampling showed lead levels to be below the action level in all but two wells, OSW 10 and OSW 23. Concern for lead levels in those private wells prompted the Navy to performed detailed lead analysis. Water was taken at the well head and at the tap prior to flushing, then again after a five minute flushing at both locations. Well OSW 10 showed lead levels to be below the detection limit of 3 ppb in all four samplings. Further analysis by another lab showed the actual lead concentration to be 1.7 ppb. Well OSW 23 showed lead levels ranging from < 3 ppb to 37 ppb. This residential well showed lead levels to be lowest (< 3 ppb) after flushing the line for five minutes and highest prior to flushing. Overall, lead levels in private wells were higher than the levels found in groundwater at the Area A Landfill on base.
The VOCs, methylene chloride and total xylenes were detected at trace levels, below health comparison values in one residential well (OSW 15) during the first round. Chloromethane, another VOC, was also detected in that residential well at an estimated value above health comparison values for drinking water. This well was resampled during the second round of sampling and again by CTDHS; no VOCs were detected. Chloromethane has not been detected in groundwater at any of the sites on the installation.
Cadmium was detected during the first sampling round in residential well OSW 6. However, cadmium was not detected in that residential well in the second and third sampling rounds or by CTDHS. Cadmium was detected at trace levels in samples from seven other wells; however, the presence of cadmium in the wells is questionable because cadmium was also detected in the laboratory control samples.
Sodium was detected at levels above the health comparison value in six of the 23 residential wells tested.
Contaminants detected in private residential wells were found to be hydrogeologically unconnected, (depths of wells varied from shallow to deep) and geographically unconnected (homes not adjacent to each other). No defined plume of contamination has been identified beneath the submarine base. The source(s) of contamination in residential wells has not been identified.
Table 18: Selected Contaminants in Private Wells Located Off Base Near
Area A Landfill (3)
| Chemical | Concentration (ppba) |
Comparison Value | |
| Concentration (ppb) |
Source | ||
| Chloromethane | LTHAd | ||
| Cadmium | EMEGe | ||
| Lead | Action Levelf | ||
| Sodium | |||
Residential Property (7)
An investigation consisting of surface water and sediment sampling was conducted as part of the RI/FS to determine if on-base contaminants have migrated off base, impacting neighboring areas.
Surface Water
Three sampling points were selected in an off-base stream originating along the perimeter road at the northern portion of the base and flowing off-base to the north. One round of sampling was conducted. All samples were analyzed for VOCs, SVOs, inorganic chemicals, pesticides, and PCBs. No contaminants were detected above health comparison values.
Sediment
Three sediment samples were collected from a stream bed, which flows from the submarine base, (north of the Area A Landfill/Wetland) north to off-base residential areas. The samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. Pesticides DDE and DDD were detected in the sediment of the stream bed at the sampling point at the submarine base perimeter. The second sampling point further off base (north) and downgradient of surface water flow, detected only trace amounts of DDE and no DDD. The third sampling point off base in the residential area downgradient from the submarine base did not detect any pesticides. The levels of pesticides detected were below health comparison values for children. Lead was detected in sediment nearest the residential area at background levels. No chemicals were detected at levels above health comparison values.
Thames River (7)
An investigation consisting of surface water and sediment sampling was conducted at points adjacent to on-base areas of contamination to determine if on-base contaminants have migrated off base, impacting the Thames River.
Surface Water
Four surface water sampling points were selected in the Thames River adjacent to on-base surface drainage outfalls. One surface water sample was collected from the Thames River downstream from the Goss Cove Landfill. One sample was collected from an up-stream area at the DRMO site. Two samples were collected from outfalls of the Area A Downstream Watercourses. All samples were analyzed for VOCs, SVOs, pesticides, PCBs, inorganic chemicals, and gross alpha and beta radiation.
Sediment
Two sediment samples were collected from the Thames River, adjacent to on-base areas of contamination. The samples were analyzed for VOCs, SVOs, pesticides, PCBs, and inorganic chemicals. No chemicals were detected at levels above health comparison values.
D. Quality Assurance and Quality Control
The quality assurance/quality control (QA/QC) report was presented in Appendix C, Remedial Investigation, Naval Submarine Base New London, Groton, Connecticut. Sample collections and analyses followed proposed protocols. The data provided to ATSDR for review consisted primarily of laboratory summaries rather than actual laboratory reports. ATSDR's conclusions concerning the sites on this installation are determined by the accuracy of the data summaries when actual laboratory data were not available. ATSDR has determined that the data evaluated for this public health assessment are valid. Qualified data are indicated by a corresponding footnote.
Prompted by public concern over elevated boron levels, the Navy investigation revealed laboratory error caused by interference of sulfur in boron analysis samples (11). Surface water and groundwater samples were reanalyzed using two different labs and split sampling techniques. Confirmatory sampling revealed that boron concentrations in surface water and groundwater were not elevated.
Physical Hazards
Soil gas concentrations of volatile organic compounds including benzene, toluene, and xylenes were detected at the Goss Cove Landfill. However, samples were not analyzed for methane, a gas produced by decaying matter, common at landfills. Since the Nautilus Museum is built on top of the landfill, soil gases may accumulate in the utility tunnel and mechanical room of the museum building potentially creating a physical explosive hazard. Proposed Phase II sampling will include methane analysis.
Other Hazards
Military housing reported that lead paints and asbestos were
used on the housing units, some within the family housing
areas. Navy personnel are currently working to eliminate the
problem.
To determine whether humans are exposed to contaminants migrating from a site, ATSDR evaluates the environmental and human components that lead to human exposure. This evaluation or pathways analysis consists of five elements: source of contamination, environmental medium in which contaminants may be present or may migrate, points of human exposure such as a private water well, a route of human exposure such as ingestion, inhalation or dermal contact, and a receptor population (people who are exposed or potentially exposed).
ATSDR identifies exposure pathways as completed, potential, or eliminated. For a completed pathway to exist, all of the five elements must be present to provide evidence that exposure to a contaminant has occurred in the past, is occurring or will occur in the future. A potential pathway indicates that at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred, could be occurring or could occur in the future. Pathways are eliminated when at least one of the five elements is missing and will never be present.
Past, present, and future exposure pathways that may present a public health hazard are discussed in this section.
A. Completed Exposure Pathways
Private Well Pathway
A past, current, and future completed exposure pathway exists for residents who drink contaminated water or use it for other household purposes. Exposures to lead, cadmium, and sodium occur through the route of ingestion. Exposures to VOCs occur mainly through the route of ingestion; however, skin absorption and inhalation of contaminants may also occur.
During the first sampling round, lead was detected above the action level of 15 ppb in OSW 10 (39 ppb). In the second sampling round, lead was detected above 15 ppb in OSW 23 (32 ppb), OSW 21 (18 ppb), and OSW 6 (estimated at 17 ppb).
Subsequent confirmatory sampling showed lead levels to be below the action level in all but two wells, OSW 10 and OSW 23. The Navy then performed detailed lead analysis in those two wells. Water was taken at the well head and at the tap prior to flushing, then again after a five minute flushing at both locations. Well OSW 10 showed lead levels to be below the detection limit of 3 ppb in all four samplings. Further analysis by another lab showed the actual lead concentration to be 1.7 ppb. Well OSW 23 showed lead levels ranging from < 3 ppb to 37 ppb. This residential well showed lead levels to be lowest (< 3 ppb) after flushing the line for five minutes and highest prior to flushing.
There are 11 estimated residences exposed to lead concentrations above the action level (OSW 10 serves 10 residences) from wells OSW 10 and OSW 23. Because lead levels fluctuated above and below the action level of 15 ppb, exposure to lead at concentrations above the health comparison value is intermittent, but could potentially last for longer than one year.
Lead found in these private wells does not appear to be originating from contaminant sources on base because 1) flushing of the pipes causes a drastic decrease in the concentration of lead from 37 ppb to < 3 ppb, 2) the location of wells containing lead are geographically isolated, and 3) because of the hydrogeology which shows that the varying depths of the wells tap different aquifers: shallow aquifer or bedrock aquifer.
Lead is a common contaminant of household water in the New England area because lead plumbing and/or lead solder were used in older houses. The natural acidity of the groundwater may cause the lead in pipes to leach into the water. Because the lead detected in OSW 23 dropped to < 3 ppb after flushing indicates that lead is not originating from the groundwater, but from piping leading to the home.
The VOCs, methylene chloride and total xylenes were detected at trace levels, below health comparison values in one residential well (OSW 15) during the first round. Chloromethane, another VOC, was also detected in that residential well at an estimated value above health comparison values for drinking water. This well was resampled during the second round of sampling and again by CTDHS; no VOCs were detected. Chloromethane has not been detected in groundwater at any of the sites on the installation. Because VOCs were detected in only one sampling event and not in any other subsequent samplings, exposure to VOCs is considered to be short-term to intermediate in duration.
Cadmium was detected during the first sampling round in residential well OSW 6. However, cadmium was not detected in that residential well in the second and third sampling rounds or by CTDHS. Because cadmium was detected in only one sampling event and not in any other subsequent samplings, exposure to cadmium is considered to be short-term to intermediate in duration.
Sodium was detected at levels above the health comparison values in four of the 23 residential wells tested. Past, current, and future exposure to sodium is considered to be long-term in duration.
Sodium is a naturally occurring contaminant in wells located in coastal areas. Saltwater intrusion of well water is a result of varying depths at which saltwater and fresh water meet. Depending on the rate at which underground freshwater moves and several other factors, such as underground sediment characteristics, wells contaminated with sodium, if not pumped, will over time, flush out saltwater contamination. Human activities also contribute sodium to natural waters. Sodium chloride used as a deicing agent on roads may also enter water supplies as runoff from both roads and storage depots.
Even though a definitive source has not been established for lead and sodium contamination, residents who use private wells for drinking water and household purposes have been and are being exposed to lead and sodium in their well water.
Preliminary findings from the Installation Restoration Study indicate that the shallow aquifer (overburden water table) generally flows toward the Thames River to the west of the installation. However, the flow may vary slightly at each site. Hydraulic connection between the shallow aquifer (overburden water table) and the deep (bedrock) aquifer has not been confirmed. The bedrock aquifer may flow in a northwest/southeast orientation at some areas of the installation (a small section of Area A Landfill), but the complex fracture structure of granite makes flow direction difficult to predict for all areas of the submarine base. The overburden water table is contaminated at several sites on the installation.
Soil Pathway
The DRMO site is an open-air site partially covered by dirt and gravel with some asphalt covered areas. This site is used as a holding area for scrap materials before they are sold at auction. Materials are placed in rows on the dirt, gravel, and asphalt covered areas by hand, trucks, and large lifting equipment. This continuous activity as well as wind from the Thames River frequently cause dust particles to be stirred up. Surface soil is contaminated with PCBs, PAHs, pesticides, and lead. There are three full-time employees at the DRMO site. Human contact with contaminated soil represents a past, current, and future completed exposure pathway through the routes of inhalation, dermal absorption, and unintentional ingestion of surface soil dust for workers.
Once a month, public auctions are held at the DRMO site. Public attendance ranges from approximately five to 50 people, including children. An intermittent, short-term completed exposure pathway exists for people who contact surface soil contaminants through inhalation, dermal contact, and unintentional ingestion of surface soil dust.
Surface Water and Sediment Pathways
Area A is comprised of Area A Landfill, Area A Wetland and Area A Downstream Watercourses. The Area A Landfill received all of the waste material from the submarine base until it was closed and partially paved in 1973. Area A Wetland is a man-made wetland adjacent to the landfill. Leachate from the landfill and surface drainage from the Rubble Fill at Bunker A-86 flows into the Area A Wetland. Surface water drainage flows through streams originating from the wetland. Several divergent streams known as Area A Downstream Watercourses flow through the Over Bank Disposal Area and around the Torpedo Shops past the North Lake recreational area, and the golf course to the Thames River.
A fence has been installed between the Area A Wetland, and another fence is under construction around the Area A Landfill to prevent people from walking through the wetland area closest to the landfill.
Prior to the installation of the fence, children were known to play in the streams near the recreational areas that abut the wetland and landfill. Those children and any adults coming in contact with surface water and creek sediment have been, in the past, exposed to contaminants in those areas.
The selected contaminants in surface water and sediment samples collected at Area A Landfill and in the downstream water courses include the PAHs: benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno (1,2,3-cd)pyrene, and chrysene; DDT and its breakdown products: DDD and DDE; lead, cadmium, and PCBs. Exposure routes of those chemical were through dermal absorption, inhalation of volatilized materials, and unintentional ingestion of surface water and sediment.
Area A Landfill runoff accumulates in the Area A Wetlands region before draining toward the river. Contaminants in the water or in sediment can be washed through the stream systems to the river. Sediment contaminants may also stay in a localized area and be covered by new deposits of sediment.
B. Potential Exposure Pathways
Soil Pathway
The August 1991, Installation Restoration Study describes soil on the submarine base as generally having moderate to moderately rapid permeability. Therefore, vertical migration of surface contaminants is possible.
Runoff is rapid to very rapid and the pH is strongly to moderately acidic. The erosion hazard is considered severe. Drainage generally occurs toward the Thames River, west of the submarine base, but extensive filling has altered the topography at various locations on the submarine base. Surface soil is contaminated at the CBU Drum Storage Area, the Rubble Fill at Bunker A-86, the Area A Landfill, and DRMO.
Subsurface soil is contaminated at the Torpedo Shops, the Goss Cove Landfill, Area A Landfill, the DRMO, the Spent Acid Storage and Disposal Area, and the Lower Subase.
No completed exposure pathway through human contact with contaminated soil at the CBU Drum Storage Area, the Rubble Fill at Bunker A-86, the Area A Landfill, the Torpedo Shops, the Goss Cove Landfill, and the Lower Subase has been documented.
Access to the sites is currently restricted. However, people performing remedial or removal work on the sites may be exposed to contaminants in the surface and subsurface soil. Those workers could be exposed to the contaminants through incidental ingestion of contaminated soil particles, through inhalation of entrained particles and volatiles, and through dermal contact with contaminated soil.
Potential exposure of workers can be prevented or mitigated through use of protective equipment and by maintaining the current site restriction policy. Additionally, if excavation of the Goss Cove Landfill occurs, during the proposed future use plan, construction workers and people visiting the Nautilus Museum could be exposed to contaminants.
Surface Water and Sediment Pathways
Three distinct areas present potential exposure pathways.
The installation is located on the Thames River within the Thames River Watershed. Approximately 1,400 square miles of eastern Connecticut are drained by the Thames River and its tributaries. Surface water from the submarine base drains west toward the river by way of streams and storm sewers. The on-base streams and lakes located in the north central portion of the installation discharge to the Thames River at the DRMO site, the Lower Subase, and the Goss Cove Landfill. People who come into contact with contaminated surface water and sediment may be exposed to contaminants through the routes of incidental ingestion, inhalation of volatile compounds and aerosols, and dermal absorption.
Migration of sediment contaminated with DDE from on base to off-base residential areas has occurred. The adjacent off-base residential area consists of lush, densely vegetated areas with large trees, rhododendron, and ferns. However, actual ground cover is minimal. Residences in this area are downhill from the submarine base. A stream and underground spring feed a small pond between the submarine base perimeter and one of the homes. Sediment accumulated in the off-base residential pond from runoff associated with on-base road construction activities. Sediment from the pond were sampled and found to contain trace levels of DDE. The Navy dredged the pond in December 1991. In August 1992, the Navy resampled sediment from this pond for pesticides and PCBs. No contamination was detected. Children swim in the pond in the summer. The pond is also used as an emergency source of water in case of fire. That home uses spring water (surface expression of groundwater) as its drinking water source. If any contaminated sediment interact with drinking water, this resident's drinking water may potentially become contaminated.
Currently, concentrations of contaminants detected in the unfenced portion of the Area A Downstream Watercourses do not pose a health threat for children. However, because sediment movement may occur over time due to natural occurrences, and because children are known to play in the stream alongside the road to the North Lake recreational area, a potential exposure pathway exists for children who come in contact with surface water and sediment contaminants.
Air and Soil Gas Pathway
Prevailing winds are southwesterly in the summer and northwesterly in the winter with an average wind speed of 10 miles per hour. The area is subject to storms, some of hurricane intensity, that travel up the Atlantic coast.
Soil gas surveys have detected VOCs at several sites (see Environmental Contamination section). No air monitoring data have been collected to determine concentrations of contaminants that may be present in the air as volatilized chemicals or as entrained particles. No completed exposure pathway has been identified as a result of air contamination.
Potential exposure pathways exist for on-site workers entering visibly contaminated manholes. Confined areas may cause a build up of volatile organic compounds creating a potential for human exposure through inhalation and skin contact. Additionally, because the Nautilus Museum is built on top of an old landfill, methane gas and other soil gases if present could potentially build up in the confined areas of the museum. Exposure of museum workers and incidental exposure of museum visitors would represent the most likely receptor population.
Future land use at the Goss Cove Landfill may present another potential exposure pathway depending on its actual use and/or future construction plans.
Biota Pathways
Species of local flora and fauna have been identified and are listed in the Installation Restoration Study Naval Submarine Base-New London Groton, Connecticut, Appendix F. People are not allowed to hunt or fish on the submarine base. However, people do fish in the Thames River. Despite the advisory on shellfish harvesting in the Thames River, it is known to occur. Several commercial shellfish beds are located north of the submarine base on the Thames River. All commercial shellfish are depurated for 30 days in approved waters to cleanse the shellfish of bacteria. However, this treatment does not removed chemical contaminants that may have accumulated in the shellfish tissue. Even though no contaminants were detected in river water and contaminants detected in river sediment were below health comparison values, shellfish may accumulate and concentrate any contamination that was present over time prior to sampling. If contaminants are detected in the shellfish, people who ingest contaminated shellfish would be exposed.
C. Eliminated Exposure Pathways
Surface Water and Sediment Pathways
North Lake and Rock Lake water and sediment have been sampled extensively. No selected contaminants have been identified in the samples. Therefore, no exposures exist for people who swim and play in the lakes.
Biota Pathways
The Connecticut Department of Health Services has issued an area-wide advisory warning residents not to consume striped bass and bluefish caught in Long Island Sound due to PCB contamination. The advisory is not linked to contaminants found on base. Human exposure to contaminated fish is eliminated if people do not consume striped bass and bluefish caught in the Long Island Sound. No farming or livestock operations are reported to occur within a 1-mile radius of the submarine base.
Appendix F of the Installation Restoration Study provides an
ecological risk assessment based on surface water, sediment, and
soil data. Although no fish tissue was analyzed, tissue data
from frogs and birds (species not usually consumed) were
collected from Area A Wetlands. No pesticides were detected in
samples. Consumption of biota may result in a completed
exposure pathway.
Completed Exposure Pathways
| PATHWAY NAME | CONTAMINANT | EXPOSURE PATHWAY ELEMENTS | TIME | COMMENTS | ||||
| SOURCE | ENVIRONMENTAL MEDIA |
POINT OF EXPOSURE |
ROUTE OF EXPOSURE |
EXPOSED POPULATION |
||||
| Private Wells | Chloromethane, Lead, Cadmium, Sodium |
Unknown | Groundwater | Resident's tap | Ingestion, Inhalation, Skin Absorption |
Residents, including children and pregnant women |
Past Present Future |
No groundwater contamination plume has been defined at the submarine base. |
| Surface Soil | PCBs, PAHs, Lead | DRMO site | Surface Soil | Contaminated surface soil at the DRMO Site | Unintentional Ingestion, Inhalation, Skin Absorption | Workers at the DRMO
site
Children playing in the soil during monthly public auction Adults attending monthly public auction |
Past Present Future |
Three full time
workers are
present at the
DRMO site.
Monthly auction attracts 5 - 50 people for a few hours at a time. |
| Surface Water | Cadmium, Lead, Pesticides | Area A Landfill | Surface Water | Area A Downstream Watercourses | Unintentional Ingestion, Inhalation, and Skin Absorption | Children playing in the
streams and nearby
recreational areas
Adults using the recreational areas |
Past | Access to Area A
Wetland is
prevented by a
7-foot fence.
Access to the Area A Downstream Watercourses is not prevented. |
| Sediment | Lead, PAHs, PCBs, Pesticides | Sediment | ||||||
| Sediment | DDE | On-base Areas | Sediment | Off-base Residential Areas | Residents coming in contact with contaminated sediment | Past | Latest sampling results did not detect any contaminants | |
Chemicals released into the environment do not always result in human exposure. Human exposure to a chemical contaminant can only occur if people come in contact with the contaminant either by ingestion (eating or drinking a substance containing the chemical), inhalation (breathing air containing the chemical), or by dermal absorption (skin contact of a substance containing the chemical).
To understand the type and severity of health effects that may be caused from exposure to a specific chemical contaminant, several factors related to the interaction of the chemical with the individual must be considered. Such factors include the amount or chemical dose to which a person is exposed, the frequency and duration of exposure, the route the chemical enters the body (ingestion, inhalation or dermal absorption), and the multiplicity (combination of chemicals) of exposure.
Health effects are also related to such characteristics as age, sex, nutritional and health status, life style, and family traits, all of which may influence how a specific chemical is absorbed (taken up by the body); metabolized (broken down by the body); and excreted (eliminated from the body).
To determine the possible health effects produced by specific chemicals, ATSDR considers physical and biological factors as well as a variety of information, such as scientific literature, research reports, and reports from other federal agencies.
The following sections evaluate the potential health effects from contaminant exposure at New London Submarine Base. The toxicological evaluation of each contaminant assesses probable health effects from exposure to the contaminant. Health effects are related to contaminant concentration exposure route, exposure frequency, and potential exposed population. Populations known or suspected of being sensitive to the contaminant are included. Information will be presented in relation to those pathways identified as completed exposure pathways.
Cadmium
Cadmium is an element that occurs naturally in the earth's surface. Pure cadmium is a soft, silver-white metal; however, cadmium is not usually found in the environment as a metal. It is usually found as a mineral combined with other elements such as oxygen (cadmium oxide), chlorine (cadmium chloride), or sulfur (cadmium sulfate, cadmium sulfide). Those compounds are solids that may dissolve in water, but do not evaporate or break down in the environment. A common use of cadmium is to electroplate steel to improve its corrosion resistance. Cadmium is also used in nickel-cadmium batteries, nuclear control rods and metal coatings. It is used as the basis of color pigments in ceramic glazes (12).
Cadmium was detected during the first sampling round in one of the 14 well samples at a maximum concentration of 26 ppb. However, cadmium was not detected in the second and third sampling rounds or by CTDHS sampling of that residential well. It is unknown why the contamination in the well was not detected upon resampling. Cadmium was detected at trace levels in seven other samples; however, the laboratory blanks also contained trace levels of cadmium suggesting a quality problem in the blank sample. If cadmium was present in the well sample, exposure of residents would be intermittent, short-term exposure through ingestion of contaminated well water.
EPA has suggested the concentrations of cadmium in drinking water that would not be expected to cause adverse health effects are 20 ppb for children for 1 - 10 day (short-term) exposure and 5 ppb for children for long-term exposure (over one year). For adults, a concentration of 40 ppb for 1 - 10 day exposure and 5 ppb for long-term exposure has been suggested (13).
The maximum detected concentration of cadmium converted to an estimated daily exposure dose is 0.002 mg/kg/day for children using a one liter per day water ingestion rate and 0.001 mg/kg/day for adults using a two liters per day water ingestion rate. Short-term exposure to cadmium at 0.1 mg/kg/day (50 - 100 times higher than the estimated dose from the level detected in residential well water) can cause stomach irritation, nausea, and vomiting. The Lowest Observed Adverse Effect Level is 0.01 mg/kg/day. Long-term exposure to cadmium at (LOAEL) 0.01 mg/kg/day can cause detectable adverse kidney effects. The LOAEL dose is five to ten times higher than the estimated dose from residential well water (12).
Comparison of the estimated daily exposure dose to EPA's reference dose of 0.0005 mg/kg/day for chronic exposure (RfD, an estimate of the daily exposure to a contaminant that is unlikely to cause adverse health effects) and ATSDR's minimal risk level for chronic exposure of 0.0002 mg/kg/day, (MRL, an estimate of daily exposure to a chemical that is likely to be without adverse non-carcinogenic health effects) indicates that adverse non-carcinogenic health effects may occur for both children and adults who ingest drinking water containing cadmium at a concentration of 26 ppb for longer than 1 year. However, cadmium was not detected in the residential drinking water well in the second and third sampling rounds, indicating that cadmium is not always present and therefore, long term exposure to 26 ppb cadmium in drinking water is unlikely. Based on that information, cadmium at a concentration of 26 ppb in the residential drinking water well does not pose a health hazard.
Chloromethane
Chloromethane, also called methyl chloride is a colorless gas at room temperature. It is a naturally occurring chemical that is prevalent in oceans and is produced by some plants and rotting wood, and when grass, wood, charcoal, and coal are burned. Chloromethane is commonly found in tap water that has been chlorinated (14). When present in soil or water, chloromethane evaporates quickly.
Chloromethane was detected in one residential well at an estimated concentration of 27 ppb. Other VOCs were detected at estimated trace levels below health comparison values. Resampling of this residential well did not detect chloromethane or any other VOCs. Resampling indicates that chloromethane is not always present in drinking water, so long term exposure to chloromethane in drinking water is unlikely. Therefore, exposure to chloromethane from the drinking water well represents an intermittent, short-term exposure through ingestion, inhalation, and dermal contact. Chloromethane has not been detected at any of the other residential wells sampled nor at any of the sites at the submarine base.
Inhalation of volatilized chloromethane from heated water used for showering represents an inhalation exposure to chloromethane. Short-term inhalation exposure to levels one thousand times greater (200,000 ppb) than the level detected in well water has resulted in impaired ability to perform simple tasks (14). Long-term inhalation exposure to 265,000 ppb chloromethane has caused central nervous system effects such as blurry vision, dizziness, staggering, and confusion (14). The health comparison value used for chloromethane in drinking water is EPA's Child Longer Term Health Advisory (CLTHA) value of 400 ppb. The CLTHA is 16 times higher than the levels detected in private drinking water.
ATSDR was unable to identify any studies in the scientific literature regarding absorption of chloromethane in people or animals that ingested food or water containing chloromethane. The health effects resulting from short-term or long-term exposure of animals or people to water containing specific levels of chloromethane are unknown. However, EPA has established a Lifetime Health Advisory (LTHA) level of 3 ppb in drinking water. LTHAs represent contaminant concentrations that EPA deems protective of public health for people over a lifetime (70 years) at an ingestion rate of two liters of water per day. The LTHAs are not legally enforceable standards, but guidelines to assist health professional. The LTHA is used as a guideline that assumes a person will drink two liters of water containing 3 ppb chloromethane per day, everyday, for 70 years without any adverse human health effects. Little information is available on short-term or long-term oral exposure to chloromethane. Therefore, the resulting adverse human health effects cannot be predicted.
Lead
Lead is a naturally occurring bluish-gray metal found in small amounts of the earth's surface. It is used to produce some batteries, pipes, solder, and paints. The amount and wide-range use of lead has decreased over the last several years because of the harmful effects of lead in people and animals (15).
Lead was detected above the action level of 15 ppb in OSW 10 (39 ppb) during the first sampling round and in OSW 23 (32 ppb), OSW 21 (18 ppb), and OSW 6 (estimated at 17 ppb) in the second sampling round.
Subsequent confirmatory sampling showed lead levels to be below the action level in all but two wells, OSW 10 and OSW 23. Concern for lead levels in those private wells prompted the Navy to performed detailed lead analysis. Water was taken at the well head and at the tap prior to flushing, then again after a five minute flushing at both locations. Well OSW 10 showed lead levels to be below the detection limit of 3 ppb in all four samplings. Further analysis by another lab showed the actual lead concentration to be 1.7 ppb. Well OSW 23 showed lead levels ranging from < 3 ppb to 37 ppb. This residential well showed lead levels to be lowest (< 3 ppb) after flushing the line for five minutes and highest prior to flushing. Overall, lead levels in private wells were higher than the levels found in groundwater at the Area A Landfill on base.
Exposure of residents would be through ingestion. Lead is not easily absorbed through the skin, or inhaled from contaminated water. Exposure to lead is particularly dangerous to the unborn and children less than 6 years old. Exposure to lead can cause deficiencies in a child's mental development and ability.
There are 11 residences with lead concentrations above the action level (OSW 10 serves 10 residences) from wells OSW 10 and OSW 23. Because lead levels fluctuated above and below the action level of 15 ppb, human exposure to lead at concentrations above the health comparison value is intermittent, but could potentially last for longer than one year.
Normal baseline blood lead levels in children range from 3 - 8 µg lead per deciliter of blood (µg/dL) (15). The actual blood lead measurement is dependent on several factors including the sampling procedure, the analysis method, the variability in the laboratory, and the age of the child (16).
Epidemiologic studies have identified some children with blood lead levels as low as 10 µg/dL without distinctive symptoms that show signs of decreased intelligence and impaired neurobehavioral development (16). Maternal and cord blood lead levels of 10 - 15 µg/dL appear to be associated with reduced gestational age and reduced weight at birth (15). Additionally, women of child bearing age who may have an accumulation of lead in their bone marrow, when pregnant, can pull the stored lead from the bone marrow into the blood and can increase the amount of lead reaching the unborn child.
Increases in blood lead resulting from the ingestion of 39 ppb lead in drinking water are estimated to be between 2 - 4 µg/dL in children and 1 - 2 µg/dL in adults. Therefore, a child with a baseline blood lead level of 8 µg/dL who drinks water containing 39 ppb lead may develop a blood lead level of 12 ppb. Because lead is a common element in the natural environment, any additional exposure to lead that increases blood lead concentrations in children to levels greater than 10 µg/dL may result in adverse health effects. For children whose blood lead levels are between 10 - 14 µg/dL, ATSDR/CDC recommends intervention in preventing and reducing exposure. Therefore, ATSDR considers the lead concentrations present in drinking water wells to pose a health hazard for fetuses and young children.
Contact with lead contaminated sediment at the Area A Downstream Watercourses represents a past complete exposure pathway. Lead was detected at a maximum concentration of 223,000 ppb in the sediment of the Area A Downstream Watercourses. Because small children often ingest sediment as a result of hand-to-mouth activities, children generally receive greater doses of lead than do adults. Based on the estimated exposure dose for adults at this site, lead does not pose a health hazard to adults. Exposure of children who played in the area would have been short-term, intermittent exposure through incidental ingestion of sediment mainly through hand-to-mouth action. That short-term, intermittent exposure to the concentrations of lead present in sediment could have potentially cause an increase in the blood lead levels of children. Therefore, exposure to sediment at the Area A Downstream Watercourses posed a public health concern for young children. Since the area has been fenced, it no longer poses a health hazard to children.
Another complete exposure pathway exists for people who have contact with lead contaminated surface soil at the DRMO site. Lead has been detected at a maximum concentration of 204,000 ppb in surface soil. Exposure of full-time workers would be long-term, chronic exposure through inhalation and incidental ingestion of surface soil, and surface soil dust. Visitors to the DRMO site during the monthly-held auction would be exposed to lead contaminated surface soil and surface soil dust for a short, intermittent duration.
Adults are less sensitive to the effects of lead because adults do not absorb lead as readily as do children, and adults are not as sensitive to the toxic effects of lead as are developing children. It is estimated that 15% of the lead that adults are exposed to is absorbed. Children, however, absorb approximately 50% of the lead from exposure (17).
Health effects associated with increases in blood lead levels of 35 - 100 ug/dL blood above normal levels include decreased reaction time, decreased memory, weakness in fingers and ankles, anemia, and colic (17). Estimated increases in blood lead levels for adult full-time workers would be approximately 2 ug/dL. Therefore, exposure of DRMO full-time workers to lead at the concentrations detected is not a public health concern.
Estimated increases in blood lead levels in children and adults from intermittent exposures to lead at the levels detected in DRMO surface soil are less than 1 µg/dL blood. No adverse health effects would be expected as a result of short-term, intermittent exposures of visitors to the levels of lead detected in surface soil at the DRMO site.
PCB 1260 - (Polychlorinated Biphenyls)
Polychlorinated Biphenyls represent a class of complex chemical mixtures that are formulated when biphenyls are chlorinated. The composition of the end product is determined by the degree of chlorination. The name PCB 1260 refers to a specific PCB chemical. The individual PCB mixtures are identified by four digits: the first two digits of most PCB formulations indicate that the preparation is a mixture; the second two digits denote the approximate chlorine content by weight percent. For example, PCB 1260 is a mixture with a 60% average chlorine content.
PCB compounds are very inert, thermally and chemically stable compounds with dielectric properties. They have been used in as heat transfer liquids in transformers, hydraulic fluids, and lubricants. PCBs have also been used in plasticizers, surface coatings, inks, adhesives, pesticide extenders, and for microencapsulation of dyes for carbonless duplicating paper (18).
PCB 1260 has been detected at a maximum estimated concentration of 3,100 ppb in surface soil at the DRMO site. Exposure of full-time workers would be long-term, chronic exposure through dermal absorption, inhalation, and incidental ingestion of surface soil dust.
Adults attending the monthly auction would be exposed to contaminants for a short duration. Children, who may also attend the monthly auction, may have a greater exposure dose if they are allowed to play in the DRMO area. Exposure of visiting adults and children would be through dermal absorption, inhalation, and incidental ingestion of surface soil dust.
Studies have shown that concentrations 1,300 times (3,436,000 ppb) greater than those present in surface soil at the DRMO site have not resulted in elevated blood levels of PCBs (19). Short-term exposure to PCBs at higher levels (35,000 ppb) than detected at the DRMO site has resulted in skin irritation. Skin irritation is the only known acute adverse health effect from exposure to PCBs (20).
EPA has classified PCBs as probable human carcinogens based on evidence from animal studies that show PCBs cause cancer in some animals. Long-term exposure to PCBs has been associated with carcinogenic health effects. When evaluated using the cancer risk values, the maximum PCB concentration detected is not expected to cause any increased cases of cancer in full-time workers or in adults and children who visit the base monthly. Based on that information, PCBs at the levels detected at the DRMO site do not pose a public health hazard.
A complete exposure pathway exists for children playing in sediment in the Area A Downstream Watercourses. PCB 1260 was detected in sediment samples from the Area A Downstream Watercourses at an estimated maximum concentration of 280 ppb.
Exposure of children playing in those areas would be short-term, intermittent exposure through dermal contact and incidental ingestion of sediment mainly through hand-to-mouth action. Those short-term, intermittent exposures to the concentrations of PCB 1260 present in sediment are not expected to cause adverse health effects.
Polycyclic Aromatic Hydrocarbons (PAHs)
PAHs are a group of chemicals that are formed during the incomplete burning of coal, oil and gas, garbage or other organic substances. PAHs can occur naturally or be man-made. Only a few of the more than one hundred PAH compounds have known uses. However, PAHs are found throughout the environment. They are present in tobacco smoke, smoke from wood, creosote-treated wood products, cereals, grains, flour, and meat. Cooking meat or other foods at high temperatures such as during grilling, increases the amount of PAHs in the food (21).
PAHs are divided into two groups: carcinogenic PAHs and non-carcinogenic PAHs. Carcinogenic PAHs include benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno (1,2,3-cd)pyrene, and chrysene. Non-carcinogenic PAHs include naphthalene, acenaphthylene, fluorocene, anthracene, pyrene, and others.
PAHs can enter the body quickly and easily by all routes of exposure: ingestion, inhalation, and dermal absorption. PAHs tend to be stored in fatty tissue and organs such as kidneys, the liver and spleen. Results from animal studies show that PAHs are not stored in the body for a long time. Instead, PAHs that enter the body are eliminated within a few days, primarily in the feces and urine (21).
Although there is little information that describes the effects of PAHs on humans, inhalation and dermal contact exposure have been associated with cancer in humans (21).
PAHs have been detected in the sediment of the Area A Downstream Watercourses at the following estimated concentrations: 850 ppb benzo(a)anthracene, 640 ppb benzo(a)pyrene, 750 ppb benzo(b)fluoranthene, 320 ppb benzo(k)fluoranthene, 1,200 ppb indeno (1,2,3-cd)pyrene, 1,200 ppb chrysene. Exposure of children playing in the sediment of the Area A Downstream Watercourses would be short-term, intermittent exposure through dermal absorption, inhalation, and incidental ingestion of sediment.
When evaluated using the cancer risk values, the maximum concentration of PAHs detected would not be expected to cause any increased cases of cancer in children playing in the sediment from the Area A Downstream Watercourses. Based on that information, PAHs at the levels detected in the Area A Downstream Watercourses do not pose a public health hazard.
A complete exposure pathway exists for full-time workers and visitors to the DRMO site. PAHs have been detected at the following estimated concentrations: 570 ppb benzo(a)anthracene, 440 ppb benzo(b)fluoranthene, 310 ppb benzo(k)fluoranthene, 560 ppb chrysene. Exposure of full-time workers at the DRMO site would be long-term, chronic exposure through dermal absorption, inhalation, and incidental ingestion of surface soil dust.
Adults attending the monthly auction would be exposed to contaminants for a short duration. Children, who may also attend the monthly auction, may have a greater exposure dose if they are allowed to play in the DRMO area. Exposure of adults and children would be through dermal absorption, inhalation, and incidental ingestion of surface soil dust.
When estimated long-term exposure doses for full-time workers (based on an exposure duration of 40 hours per week for 20 years) are evaluated using the cancer risk values, the maximum concentrations of PAHs detected are not expected to cause any increased cases of cancer in full-time workers. When estimated short-term exposure doses for visiting adults and children (based on exposure duration of two hours per month for five years) are evaluated using the cancer risk values, the maximum concentrations of PAHs detected are not expected to cause any increased cases of cancer in those adults or children. Based on that information, PAHs at the levels detected at the DRMO site do not pose a public health hazard.
Pesticides DDT, DDD, DDE
DDT - p,p'-dichlorodiphenyltrichloroethane
From 1946 to 1972, DDT was one of the most widely used agricultural insecticides in the world. As of January 1, 1973, all uses of DDT were banned from the United States and Canada, but it is still used in Mexico and many tropical countries. DDT does not readily dissolve in water, instead it adsorbs to soil, and organic matter (22). DDE is the major degradation product in aerobic soil (in the presence of oxygen). Under anaerobic conditions (in the absence of oxygen), DDD is the major metabolite (22).
In people, DDT is metabolized by two pathways. A small percent is converted to DDE, which does not undergo further biotransformation, but is stored in the fat (adipose) tissues. The major detoxification pathway is via dechlorination to DDD, which is readily degraded to a water soluble metabolite, DDA and is rapidly excreted into the urine (23).
DDT has been detected in sediment along the Area A Downstream Watercourses at an estimated concentration of 240,000 ppb. Because the area is now fenced, past exposure of children who played in the Area A Downstream Watercourses to DDT would have been through ingestion and dermal contact with contaminated sediment for an intermediate duration (14 - 365 days). Dermal exposure to DDT has not been associated with any illness or irritation (24).
EPA has classified DDT as a probable human carcinogen based on evidence that it causes cancer in animals and insufficient evidence that it causes cancer in humans.
Symptoms of DDT poisoning in people are abnormally increased sensitivity of the mouth and lower part of the face, which is followed by a burning or prickling sensation, and tremor of the extremities, confusion, malaise, headache, fatigue and delayed vomiting (23). It is reported that human poisoning has only occurred through ingestion of DDT. In general, symptoms occur as soon as 30 minutes after a large dose (unspecified concentration) or as late as 6 hours after a small dose (unspecified concentration) (24). In acute, short-term exposure, recovery is usually complete or well advanced in 24 hours. In severe cases, complete recovery may take a week or more (25).
The estimated exposure dose for children exposed to DDT contaminated sediment is 0.007 mg/kg/day. The Lowest Observed Adverse Effect Level (LOAEL) for intermediate human exposure was 0.07 mg/kg/day (10 times higher than the estimated dose for children) (26). The No Observed Adverse Effect Level (NOAEL) for DDT has not been established. A single oral dose of 10 mg/kg body weight produced illness in some persons, but no vomiting or convulsions occurred. When the dose was 16 mg/kg body weight or greater, convulsions occurred frequently. Generally, smaller doses did not produce illness although a dose of 6 mg/kg produced perspiration, headache and nausea in one man. Doses as high as 20 mg/kg might be taken without effect; however, doses that high have led to immediate vomiting so that the amount actually retained could not accurately be determined (23).
Since the difference in the estimated exposure dose for children and the LOAEL is only 10 fold, estimates for uncertainty (uncertainty factors) would make the doses equivalent, indicating a potential for adverse health effects. Based on that information, past exposure to DDT posed a public health concern for children exposed to DDT contaminated sediment in the Area A Downstream Watercourses. When estimated intermediate doses for children are evaluated using the cancer risk values, the maximum concentrations of DDT detected would not be expected to cause any increase cases of cancer in those exposed children. No long-term adverse health effects (carcinogenic or non-carcinogenic) are expected to occur as a result of exposure to DDT contaminated sediment in the Area A Wetland and Area A Downstream Watercourses.
DDD - p,p'-dichlorodiphenyldichloroethane
In animals, DDD is less toxic than DDT. DDD poisonings also have a slower onset and a longer duration in contrast to DDT poisonings. Lethargy is more prominent in DDD poisonings, and convulsions are less frequent (27). The main action of DDD is on the liver, where it stimulates the hepatic microsomal oxygenation of drugs and corticosteriods (28).
DDD has been detected along the Area A Downstream Watercourses sediment at an estimated concentration of 1,700,000 ppb. Past exposure of children playing in sediment in the Area A Downstream Watercourses would have been intermediate, intermittent exposure to DDD through dermal contact, and ingestion of contaminated sediment.
A purified form of DDD used at high levels (usually 8 - 10 grams or 8,000,000 - 10,000,000 mg) therapeutically in humans to treat adrenal cortical carcinomas and Cushing's syndrome, produce some toxic effects, but were completely reversed when DDD exposure ended (29).
The estimated exposure dose for children is 0.005 mg/kg/day. Doses of 110 - 114 mg/kg/day did not produce any detectable injury to the liver, kidney or bone marrow, doses as high as 7500 mg/kg/day may also be tolerated without discernable side effects (30). No LOAEL or NOAEL has been determined for DDD exposure in humans (26).
When the estimated intermediate dose for children is evaluated using the cancer risk values, the maximum concentrations of DDD detected would not be expected to cause any increase cases of cancer in those exposed children. Exposure to DDD through ingestion of sediment is not expected to present any short-term or long-term adverse health effects. Therefore, exposure to DDD contaminated sediment in the Area A Downstream Watercourses does not pose a public health hazard.
DDE - p,p'-dichlorodiphenyldichloroethylene
DDE does not undergo any biotransformation in the human body, but is stored for an indefinite period in the fat (adipose) tissue (31). Other than several metabolic studies, there are no reports of acute human exposure to DDE.
DDE has been detected along the Area A Wetland and in the Area A Downstream Watercourses sediment at an estimated concentration of 28 ppb. Past exposure of children playing in sediment in the Area A Downstream Watercourses would have been intermediate, intermittent exposure to DDE through dermal contact, and ingestion of contaminated sediment.
The estimated exposure dose for children is 0.0003 mg/kg/day. Oral administration of 5 mg/kg DDE to one human volunteer for 92 days (intermediate exposure) produced no observed adverse health effects (32). When the estimated intermediate dose for children is evaluated using the cancer risk values, the maximum concentrations of DDE detected would not be expected to cause any increase cases of cancer in those exposed children. Based on the low estimated dose, past exposure to DDE through ingestion of sediment is not expected to cause any short-term or long-term adverse health effects.
Sodium
Sodium is a normal constituent of natural waters. It is derived geologically from the leaching of surface and underground deposits of salts such as sodium chloride, from the incorporation of evaporated ocean spray particles into rainfall, and from the intrusion of seawater into freshwater aquifers. Salt spray from the sea is often the largest contributor of sodium within 50 - 100 miles of seacoasts (34). Human activities also contribute sodium to natural waters. The sodium chloride used as a deicing agent on roads enters water supplies in runoff from both roads and storage depots.
Sodium has been detected in private residential wells at a maximum concentration of 34,600 ppb. Residents would be exposed by ingesting drinking water containing sodium.
A survey of 2,100 water supplies covering 50% of the population of the United States was taken between 1963 - 1966 by the CDC's Heart Disease Control Program, Division of Chronic Diseases of the U.S. Public Health Service. Concentrations of 20,000 - 49,990 ppb sodium in drinking water account for 19% of the water samples collected (35).
Sodium-restricted diets are required in the treatment of congestive cardiac failure, renal disease, cirrhosis of the liver, and toxemia of pregnancy (35)
A maximum level of sodium in drinking water of 20,000 ppb was suggested by the American Heart Association in 1957 (35). EPA's Drinking Water Equivalent Level is 20,000 ppb. Drinking Water Equivalent Levels are lifetime exposure levels specific for drinking water at which adverse health effects are not expected to occur.
The level of sodium in drinking water may influence blood pressure and may be associated with hypertension (36). Twenty percent of the adult U.S. population has hypertension (Intersociety Commission for Heart Disease Resources, 1971). In the treatment of essential hypertension, restriction of dietary sodium leads to a drop in blood pressure (35).
Sodium is added to many foods during processing. Although sodium is required for normal body functions, the average American's intake of sodium exceeds the body's need by 10 times or more.
Based on a representative survey of 15,778 persons aged 12 - 74 years, the National Center for Health Statistics estimated that 2.8% or approximately 6.2 million Americans are on low-sodium diets prescribed for reasons of illness. The low-sodium diets most commonly prescribed limit the patient to either 1.0 or 0.5 grams (g) of sodium per day. Where water supplies contain more than 20,000 ppb sodium, dietary sodium restriction to less than 1.0 g/day is difficult to achieve and maintain. Therefore, the presence of sodium at levels above 20,000 ppb represents a public health concern for persons on salt-restricted diets.
B. Health Outcome Data Evaluation
ATSDR has identified a completed exposure pathway for off-base residents who drink contaminated well water. The source of the contamination has not yet been determined. Another completed exposure pathway exists for people who had contact with sediment and surface water in the Area A Downstream Watercourses.
In evaluating the potential correlation between cancers observed in a population and the cause of those cancers, two factors must be addressed. First, there must be a causative chemical agent, or environmental chemical contamination at concentrations that would cause an increased risk of cancer. Secondly, a completed exposure pathway must exist for people to come in contact with that contamination.
After evaluation of these completed exposure pathways, no increase in cancer rates is expected because of the low estimated exposure dose. However, ATSDR has evaluated the Connecticut Tumor Registry Data Base information to determine if an elevated cancer incidence exists within the submarine base area towns of Groton and Ledyard as compared the state of Connecticut in order to address community concerns about local cancer rates. The Connecticut Department of Health Services maintains one of the nation's most extensive Tumor Registry Data Bases. Information has been collected since 1935.
Cancer rates (Appendix B) are slightly elevated for the male "All Types" category in Groton and Ledyard as compared to the State of Connecticut. All types refers to the combined types of cancers. Many factors affect cancer rates, such as dietary influences, hereditary predisposition, and environmental exposure. In general, cancer represents a group of diseases with a variety of causes. Since it has not been determined that any singular cause of all types of cancer exists, the "All Types" category cannot be accurately evaluated.
For the other cancers such as lung and rectal, ATSDR does not have any information on the specific human risk factors such as smoking or diet. Those factors are important when evaluating cancer rates.
Only a few types of cancers have been linked with chemical specific environmental contamination. Among these, is the association of vinyl chloride with liver cancer and the association of benzene with certain types of leukemia.
At this time, it is not possible to link an elevation of cancer rates to an environmental source of contamination such as the New London Submarine Base.
C. Community Concerns Evaluation
In meetings with officials from the Town of Ledyard and City of Groton, a local physician, and an advisor to the City of Groton, the following concerns were expressed.
Military Highway, running north of the submarine base, is in the town of Ledyard. Cancer data were provided to ATSDR from the State of Connecticut Department of Health Services. Cancer Incidence data from the Ledyard was compared to that of Connecticut. However, ATSDR is not able to narrow the information down to the specific population along Military Highway. At this time, it is not possible to link any elevation of cancer rates to an environmental source of contamination such as the New London Submarine Base.
The incidence of cancer for the Groton area was evaluated. Lung cancer rates were slightly elevated for Groton in the period from 1979-1981, but not in the later time period. Many factors such as smoking and occupation add to a persons risk for lung cancer. At this time, it is not possible to link elevated cancer rates to an environmental source of contamination such as the New London Submarine Base.
Four surface water and two sediment samples from various locations on the Thames River were analyzed. As yet, the Navy has not sampled any edible biota. However, Connecticut Department of Environmental Protection routinely sample edible biota in the Thames River. The Connecticut Department of Environmental Protection in conjunction with the Connecticut Department of Health Services has issued health advisories for shellfish caught in the Thames River due to high fecal coliform counts, but no health advisories exist for fish caught on the Thames River. Other health advisories exist for fish and shellfish caught in Long Island Sound due to PCB contamination of the region.
The New London Submarine Base has sampled 23 private wells within 1 mile of the submarine base. Contamination has been found (see Environmental Contamination section of this public health assessment) in private wells near the submarine base. Contaminants detected include cadmium, chloromethane, lead, and sodium. The source of contamination has not been identified. The municipal wells and reservoirs are routinely sampled according to the Safe Drinking Water Act of 1974, as amended in 1986. To date, no contamination has been detected in those municipal wells or reservoirs.
After additional sampling of the North Lake area, mercury contamination was found in only one of the 13 samples taken from the North Lake recreational area. Because only one isolated case contained a low level of mercury, ATSDR has determined that the North Lake swimming area does not represent a health hazard.
One surface water and one sediment sample from the Thames River have been analyzed from the Goss Cove Landfill. No contaminants were detected above health comparison values. However, because of proposed future changes in land use at the Goss Cove Landfill area, ATSDR has recommended additional sampling of sediment and surface water in those Goss Cove areas where people could come in contact with potentially contaminated environmental media.
ATSDR recommends the Navy address the deposition of dredged river sediment, its location, its level of contamination, and the potential for human contact with the dredged material.
ATSDR has recommended in this public health assessment that further characterization of the river near the submarine base be incorporated in future sampling plans in order to assess the potential for human exposure.
During the public health assessment process, ATSDR reviewed the information contained in the 1989 Plan of Action as well as the sampling results from the Phase I Remedial Investigation. In this public health assessment ATSDR identified specific data gaps, and made recommendations for further sampling in order to better characterize the extent of contamination and the potential for human exposure.
During informal one-on-one meetings with residents, the following concerns were expressed:
Two samples were taken from that residential well. Sodium was the only contaminant detected above health comparison values. Sources of the sodium have not yet been identified; however, it is likely that salt water has intruded the well.
Because of the community concerns and the one sample that showed mercury contamination from the Navy's data obtained in September 1990, the New London Submarine Base conducted further sampling to better characterize contamination in the North Lake swimming area. Beach sand, sediment and surface soil were analyzed. The additional sampling results did not detect any contamination in the North Lake swimming area. During summer months, routine sampling of surface water in the North Lake is analyzed for contamination. To date, no further contamination has been found.
North Lake is filled each year with city water before the swimming season and is subsequently drained to a low-water level at the end of the season. City water is chlorinated on base before North Lake is filled.
Additional sampling results did not detect any contamination in the North Lake swimming area; therefore, there is no threat to public health.
See above
ATSDR has referred this concern to OSHA for further
investigation:
Occupational Safety and Health Administration (OSHA)
Regional Office
133 Portland Street
Boston, MA 02114
617-565-7164
The Navy recommends that past employees who are concerned about their exposure contact the servicing industrial hygiene department at Naval Hospital, New London. Industrial Hygiene surveys done in the past, along with past air monitoring results should give the employees some indication of their past exposure to chemical stressors at their old work place on the base.
The Connecticut Department of Environmental Protection routinely samples surface water and edible biota from the Thames River. The Connecticut Department of Environmental Protection in conjunction with the Connecticut Department of Health Services has issued health advisories for the shellfish caught in the Thames River due to high fecal coliform bacteria count from sewage discharge, but no health advisories exist for fish caught on the Thames River. Other health advisories exist for fish and shellfish caught in Long Island Sound due to PCB contamination of the region.
Four surface water and two sediment samples from various locations on the Thames River were analyzed. No contaminants were detected in the Thames River.
A public meeting, conducted by the Navy personnel, was held on July 26, 1990. The following additional concerns were expressed during the meeting:
Currently toxic waste is taken off base to a regulated hazardous waste disposal area (37).
Solid radioactive waste materials associated with maintenance and operation of naval nuclear-powered warships are packaged in federally approved containers and taken off base to U.S. Nuclear Regulatory Commission (NRC) licensed disposal areas (37).
No, all surface water and runoff from the New London Submarine Base drain into culverts that empty into the Thames River (3).
Leachate drainage into the Thames River is regulated by the Clean Water Act, which controls the direct discharge of pollutants to surface waters through the National Pollutant Discharge Elimination System (NPDES) program. NPDES requires permits for direct discharges to surface water. The permits contain limits based upon either effluent (discharge) standards or, if they are more stringent, ambient (overall water quality) standards. NPDES permits are issued, monitored, and enforced by EPA, or by a state agency authorized by EPA to administer an equivalent state program (36). New London Submarine Base has applied for and received several NPDES permits.
The submarine base has received water from the city of Groton since the 1940s.
ATSDR held a public meeting on August 18, 1992 to answer residents' questions about the health hazards associated with elevated boron levels found in their drinking water wells. The following question concerns residents the most.
More information on boron in drinking water can be found in ATSDR's health consultation, August 1992. A copy of the health consultation is available at local document repositories or a copy can be requested from ATSDR.
Prompted by concern over elevated boron levels, the Navy investigation revealed laboratory error caused by interference of sulfur in boron analysis samples (11).
Surface water and groundwater samples were reanalyzed using two different labs and split sampling techniques. All confirmatory sampling revealed that boron concentrations in surface water and groundwater were not elevated.
Because of boron's wide use and the estimated amount of boron normally ingested by people, the low levels of boron detected in private wells are not expected to substantially increase the relative body burden of boron. The amount of boron detected in private well water is not expected to cause any adverse health effects for children or adults. Therefore, water from these private wells is safe to drink.
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