House's Junk Yard Revised Ecological Risk Assessment
In this section, the history of the site, along with endangered species known (or suspected) to be at the site, is described. Information about the historical and current land-use, as well as types of habitats, and known or suspected sources of contamination.
House's Junkyard (HJY) is an active automobile scrap yard on a 2-acre site along Clark Road, Gary, Lake County, Indiana. The surrounding area is primarily industrial and contains several other CERCLIS-listed sites. HJY is located on the Calumet Lacustrine Plain approximately 1600 feet from the Grand Calumet River. Surface water runoff drains into an unnamed ditch along the eastern boundary of the site that discharges into a 20-acre Palustrine Emergent wetland (the wetland) associated with the Grand Calumet River. There are no containment or leachate collection systems at the site. The watertable of a surficial aquifer, the Calumet Aquifer, is located between 34 and 50 feet below the surface. The regional groundwater flow gradient is either towards the Grand Calumet River or Lake Michigan.
Additional wetlands are located downstream from HJY along the Grand Calumet River and the Indiana Harbor Canal. The direction of flow in the canal depends on wind and Lake Michigan water levels, so the canal is both a tributary and a discharge of the Grand Calumet River.
The soil at House's Junkyard (HJY) is contaminated with volatile and semivolatile organic compounds, PCBs, and heavy metals. The same classes of contaminates are present in the sediments of the unnamed ditch adjacent to HJY. The lower ditch and wetland sediments are primarily contaminated with metals.
An area without vegetation located west of the ditch between HJY and the wetland was noted during the site visit. The area, approximately 25 feet in diameter, is covered with a gray substance cracked in a polygon pattern, and contains several rusted out drums. The surrounding area is thickly vegetated up to the edge of the gray material, but no vegetation grows within. This area is not marked on the maps in the reports reviewed.
Threatened and Endangered Species
Threatened and endangered species are present in several areas near HJY and along the Grand Calumet River (Table 1).
SLERA (Screening Level Risk Assessment):
Screening Level Problem Formulation
Screening Level Problem Formulation (Step 1)
For this site, the Region 5 ecologist (James Chapman) performed the Ecological Risk Assessment, including calculation of Hazard Quotients (HQ), deciding on potential assessment endpoints and conceptual site models (See ERA Guidance Step 3 for more information on endpoints and site models).
This section describes the likely sources of contamination, what the contaminants are, and what plants and animals at the site are likely to be affected by those contaminants and in what manner.
Contaminants of Potential Ecological Concern (COPECs)
- Total aliphatic hydrocarbons
- Total chlorobenzene
- Total organochlorinated pesticides
- Total Polycyclic Aromatic Hydrocarbons (PAHs)
- Total Polychlorinated Benzenes (PCBs)
- Arsenic (As)
- Beryllium (Be)
- Cobalt (Co)
- Chromium (Cr)
- Copper (Cu)
- Nickel (Ni)
- Lead (Pb)
- Selenium (Se)
- Vanadium (V)
- Zinc (Zn)
Fate, Transport, and Ecotoxicity
Only those chemicals likely to contribute to the potential ecological risks of the site are discussed in this section. This procedure is followed because the screening level ecological risk assessment (SLERA) is based on a screening comparison of the concentrations of COPECs with benchmark guidelines by media (soil, sediment, or surface water). This numerical comparison results in a Hazard Quotient; if the HQ is greater than one, the potential for ecological risk by that COPEC is present. (See Step 2 of the Guidance for more details.)
The benchmark values are sufficiently conservative so that chemicals detected at concentrations below the guidelines are not expected to exhibit significant ecological effects, even if fully bioavailable. Since fate, transport and toxicity variables do not modify the outcome of the screening (these effects are embedded in the derivation of the particular guidelines), discussions of these processes for the chemicals screened out are unlikely to contribute meaningful information to the SLERA.
Potential onsite exposure pathways include direct contact with soil contaminants and dietary exposure via consumption of soil-inhabiting organisms. The offsite exposure pathways are related to runoff into the ditch, wetland, and Grand Calumet River. There were no descriptions of plants or animals in these habitats.
House's Junkyard (HJY) is a highly disturbed and mostly barren industrial site with patches of weedy invasive vegetation. It is unlikely to contain sensitive ecosystems or species of special concern.
Aquatic and terrestrial plants and animals may be exposed to ditch contaminants. There are substantial populations of duckweed (Lemna sp.) and green algae (Chlorophyta) in the ditch. Rooted plants are also present, for example, cursed crowfoot (Ranunculus sceleratus forma natans). All of these species are eaten by waterfowl; duckweed is also eaten by muskrat, algae by deer, and crowfoot by rails (Martin et al. 1951; Fassett 1957). There is a disturbed second-growth woods along the ditch bank between HJY and the wetland, dominated by eastern cottonwood (Populus deltoides) with an understory of red osier (Cornus stolonifera), bramble (Rubus sp.), and bracken fern (Pteridium aquilinum). Reed grass (Phragmites australis) lines portions of the ditch bank. A den with several burrow openings is located on the ditch bank downstream from HJY, probably constructed by muskrat (Ondatra zibethicus). Other animal signs (tracks, scat, fur) were not observed, but this should not be considered evidence that animals are not present because conditions were not conducive for detection (season, rain, no snow cover, thick leaf litter layer, and absence of mud flats along the ditch). A potential terrestial receptor of special concern documented in the adjacent areas is the Franklin's Ground Squirrel (Table 1), however, the area under consideration does not provide appropriate habitat (Nowak 1991).
The wetland that receives the ditch drainage is an ecosystem of special concern. Potential receptors include benthic organisms, fish, amphibians, and avian or mammalian consumers of aquatic organisms. Several state-listed threatened and endangered species have been recently documented in the area surrounding HJY (Table 1). There is a substantial likelihood that American bitterns, King Rails, Black Terns and spotted turtles are potential wetland receptors, based on their presence in the Clark & Pine Natural Area and Nature Preserve adjacent to HJY. The bird species are insectivorous, and the former two prey on amphibians, crayfish, and small fish as well (Martin, et al. 1951). Spotted turtles are omnivorous. The wetland is dominated by cattail (Thypha latifolia) and reed grass. Both are important food sources for muskrat. Geese and, to a lesser extent, ducks feed on cattails, but reed grass has minimal wildlife food value for species other than muskrat (Martin et al. 1951; Fassett 1957).
Complete exposure pathways to the contaminants at SD03-01 are probably present for local populations of benthic invertebrates, amphibians, and muskrat. The primary ecotoxicological concerns are reproductive impairment caused by direct contact with methoxychlor and systemic effects caused by contact with dichlorobenzene, naphthalene, and DEHP. Although the area of contamination of all but the latter compound is apparently limited, the presence of volatile compounds indicates that there is an ongoing release of contaminants at this sample location.
Figure 1. Possible and Partial Wetlands Conceptual Site Model
(arrow indicate flow of contaminants through the system)
This section includes calculations of Hazard Quotients and calculated estimations of risk by COPECs to potential receptors in different media (soil, sediment, surface water). This step involves the comparison of the concentrations of COPECs with benchmark guidelines by media (sediment, soil, surface water). If the maximum concentration of a chemical found at the site exceeds the screening benchmark guideline, then there is the potential for risk and further study is needed to clarify that risk. (See SLERA Step 2 for more information on the screening process, including calculating Hazard Quotients.)
Ecotoxicological Benchmark Values
The Screening Level Ecological Risk Assessment (SLERA) is based on a screening comparison of the concentrations of COPECs with benchmark guidelines by media.
- Netherland Soil Quality Guidelines
- Ontario Lowest Effect Levels (sediments)
- Ontario Severe Effect Levels (sediments)
Selected sediment organic contaminant data for the ditch sample (SD03-01) immediately adjacent to HJY are given in Table 2 with Netherland soil quality guidelines that serve as benchmarks for preliminary evaluation of potential risk. Hazard quotients, the maximum contaminant concentration (sample ) divided by screening level benchmark (Criteria B or C), are also presented in Table 2.
|Compound||Sample concentration*||Criteria B**||Criteria C***||HQ B||HQ C|
|Total aliphatic hydrocarbons (4)||2.25||7||70||0.3|
|Total chlorobenzene (5)||26.03||2||20||10||
|Total organochlorinated pesticides (6)||35.9||1||10||40||4|
Soil quality guidelines are used as benchmark values because sediment quality guidelines have not been developed most of the contaminants at this sample location.
* Sample SD03-01 is located at the probable point of entry of contaminants from HJY to the ditch (Weston 1994).
** Criteria B refer to moderate soil contamination that requires additional study (Beyer 1990).
*** Criteria C refer to threshold values that require immediate cleanup (Beyer 1990).
(4) Total of vinyl chloride (0.028), 1,1-dichloroethane (0.24), 1,2-dichloroethene (1.6EJ), 1,1,1-trichloroethane (0.31), trichloroethene (0.017) and tetrachloroethene (0.059).
(5) Total of 1,2-dichlorobenzene (26) and chlorobenzene (0.027).
(6) Total of 4,4-DDE (0.26J), endosulfan II (0.12J), methoxychlor (35J), and chlordane (0.54).
J - estimated value.
|Contaminant||Concentration in Wetlands||Concentration in Ditch||Ontario LEL*||Ontario SEL*||WDNR|
|Chromium (Cr)||654 J||232||26||110||100|
|Copper (Cu)||394||136 J||16||110||100|
|Lead (Pb)||1370 J||541 J||31||250||50|
|Selenium (Se)||3.4 J||1.3||1|
|Zinc (Zn)||365 J||927||120||820||100|
|Total PAHs**||94.6 J||4||100|
J - estimated value;
- The following compounds meet or exceed the (nonregulatory) threshold for immediate cleanup:
- total chlorobenzene (primarily 1,2-dichlorobenzene)
- total organochlorinated pesticides (primarily methoxyclor).
- Arsenic (As)
- Chromium (Cr) (ditch and wetland)
- Copper (Cu) (ditch and wetland)
- Lead (Pb) (ditch and wetland)
- Zinc (Zn) (ditch)
- Nickel (Ni) (wetland)
- PCBs (wetland)
- PAHs (wetland) - fluorene, phenanthrene and chrysene meet or exceed individual SELs (HQs of 10, 3 and 1, respectively).
- Selenium (Se) (ditch and wetland)
- Zinc (Zn) (wetland).
- Beryllium (Be) and Vanadium (V) are within background concentrations.
Fluorene and phenanthrene partition to sediments where they are gradually biometabolized. They may bioaccumulate in benthic organisms and fish but do not biomagnify. Fluorene reduces reproduction of aquatic invertebrates, delays emergence of larval midges, and adversely affects the feeding and predation avoidance behavior of bluegill fingerlings. Fluorene, phenanthrene and chrysene are not carcinogenic (Eisler 1987b).
The threatened/endangered species that are potentially present in the wetland may be exposed to these contaminants through predation on insects (American bittern, king rail, black tern); or amphibians, crayfish, and small fish (American bittern, king rail, spotted turtle). Spotted turtles and muskrats may also be exposed through consumption of aquatic vegetation. These exposures are unlikely to result in significant toxicological effects (in the potential receptors listed above) from fluorene, phenanthrene, chrysene, chromium (Cr), lead (Pb), copper (Cu), or nickel (Ni) because these substances are not subject to biomagnification or significant bioaccumulation. Zinc (Zn) and selenium (Se) are subject to significant bioaccumulation; however, the sediment concentrations of these contaminants are unlikely to be sufficiently high to significantly impact upper trophic levels. The sole contaminants of potential concern for the threatened/endangered species are the PCBs because of their strong biomagnification potential and reproductive impact.
The main potential ecological impacts of the wetland contaminants result
from direct exposure of algae, benthic invertebrates, and embryos and fingerlings
of freshwater fish and amphibians to PAHs (fluorene, phenanthrene, chrysene),
chromium, lead, copper, nickel, zinc, and selenium. Potential endpoints include growth reductions and impaired survival.
Link to Toxicity Profiles for more information on the harmful effects of the various chemicals found at this site.
Conclusions and Recommendations
There are two areas of potential ecological concern near House's Junkyard (HJY), Gary, IN, differentiated by the type of contaminants present.
- There is a "hot spot" at sediment sample SD03-01, located at the probable point of entry of contaminants from HJY to the unnamed ditch, that is contaminated with a mixture of volatile and semi-volatile organic compounds and organochlorinated pesticides. Concentrations of toluene, xylene, dichlorobenzene, naphthalene, and methoxychlor exceed benchmark soil quality guidelines, and that of bis(2-ethylhexyl)phthalate greatly exceeds background concentrations. These contaminants present risks to benthic invertebrates, amphibians and muskrat. The presence of high concentrations of volatile compounds indicates there is a continuing release of contaminants at this site. Since the area of contamination appears to be limited, a removal action would resolve any ecological concerns. If a removal action is not taken, bulk sediment toxicity tests should be performed to determine the impact of the contaminant release.
- The second area of potential ecological concern encompasses the lower
ditch and the wetland into which it discharges, both of which are primarily
contaminated with metals and PCBs. The wetland is also contaminated with
low molecular weight PAHs. Contaminants that meet or exceed the benchmark
severe effect level of the Ontario sediment quality guidelines include chromium
(Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), Polycyclic Aromatic
Hydrocarbons (PAHs) (fluorene, phenanthrene, chrysene), and PCBs. Selenium
(Se) and arsenic (As) exceed benchmark Wisconsin Department of Natural Resources
sediment quality guidelines.
The primary potential ecotoxicological effects include reproductive impairment of wetland birds (potentially including three state-listed endangered species: American bittern, king rail and black tern) caused by biomagnification of PCBs; and growth and survival reductions of algae, benthic invertebrates, and fish and amphibian embryos and fry caused by direct exposure to PAHs, chromium, lead, selenium, zinc, nickel, and copper. The dosages to these potential receptors cannot be reliably estimated from the data presently available.
Therefore, further testing and sampling is recommended:
- sediment and water samples from the wetland (there are questions concerning the reliability of the prior samples) including measurements of pH and total organic carbon;
- bulk sediment toxicity tests to determine the effects on benthic organisms and freshwater fish fry (these should be performed with a series of dilutions to help establish cleanup goals); and
- analysis of tissue concentrations of PCBs in aquatic insects and small fish to determine the dosage to the potential endangered bird receptors.
- January 1, 1994 - Extended site assessment
- December 14, 1994 - Screening Level Ecological Risk Assessment completed
- August 24, 2000 - Removal action completed
- April 2, 2001 - Site reassessment complete