Camp Perry Landfill Ecological Risk Assessment

Site Description/History

Environmental Setting

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.

Site Description

The site is an inactive 20-acre landfill in a rural area of Port Clinton, Ottawa County, Ohio. Lacarpe Creek flows south and east of the site to Lake Erie, which is about 1 mile to the north. The site is bordered by wetlands to the east, carp ponds to the north, a lagoon to the south with a military base landfill on the opposite side, and the Camp Perry military base to the west. The landfill is unlined and has no leachate collection system or any other form of containment. An unnamed ditch extends from the landfill east to Lacarpe Creek, and a boat channel extends northeast from the carp ponds.

The landfill received a variety of wastes including sewage sludge, commercial, municipal, household, industrial and medical wastes. Industrial waste sources included iron and steel foundries and plating and polishing operations. Wastes were landfilled to a depth below that of the groundwater. Landfill operations ended after the site flooded in 1974.

Sensitive Habitats

The landfill was constructed in a marshy area and is bordered by wetlands to the east. The Ottawa National Wildlife Refuge is less than one-half mile east of the site.

Threatened and Endangered Species

Table 1. Threatened and Endangered Species: Animals
Species Common Name	Scientific Name	Status*	Thumbnail Image (click for larger image)
Bald Eagle	Haliaeetus leucocephalus	FT
American bittern	Botaurus lentiginosus	SE
Least bittern	Ixobrychus exilis	SE	n.a.
King rail	Rallus elegans	SE
Black tern	Chlidonias niger	SE
The Bald Eagle is present in the Ottawa National Wildlife Refuge. The other bird species may be present in the refuge and surrounding wetlands.
*Status: FT = Federally threatened; SE = state-listed as endangered

Table 2. Threatened and Endangered Species: Plants
Species Common Name	Scientific Name	Status*	Thumbnail image (click for larger image)
Southern wapato	Lophotocarpus (=Sagittaria) calycinus	ST	n.a.
Slender goosefoot	Chenopodium leptophyllum	SE	n.a.
Smith's bulrush	Scirpus smithii	SE	n.a.
The wetland plant, Southern wapato, (a type of arrow-head plant), may be present. Two other plants recorded in the Lacarne and Port Clinton quadrangles, Slender goosefoot and Smith's bulrush are unlikely to be near the site because of habitat requirements and restricted distribution, respectively (Cooperrider 1982).
* Status: ST = state-listed as threatened; SE = state-listed as endangered

SLERA (Screening Level Risk Assessment):
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)

The following COPECs are likely to contribute to the potential ecological risks of the site:

Chromium (Cr) in water and soil;
Lead (Pb) in water and sediment;
Mercury (Hg) in sediment;
Copper (Cu) in sediment.

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.

Exposure Pathways and Potential Receptors

Release of landfill contaminants may occur through leachate/runoff, erosion, flooding, or discharge of contaminated groundwater to the surrounding lagoon, wetlands, carp ponds or ditch. Contaminants may adsorb or precipitate to sediments, or remain in solution. Sediment contaminants are directly available to benthic organisms and bottom feeders; and, for chemicals that biomagnify, are indirectly available to piscivores (fish-eaters), aquatic insectivores (insect-eaters), and higher predators through food chain exposures. Sediment contaminants are transported downstream via adsorption to suspended particles and by mass flow (erosion). Dissolved contaminants are directly available to aquatic organisms.

The plants and animals most likely to be affected by Contaminants of Potential Ecological Concern (COPECs) that do not biomagnify (chromium, copper, and lead) include benthic invertebrates, and the embryos and fingerlings of freshwater fish and amphibians. Animals that are most likely affected by COPECs that biomagnify (e.g., mercury) also include piscivores such as kingfishers, herons, egrets, bald eagles, or mink; and aquatic invertebrate consumers such as rails, bitterns, and raccoon.

Figure 1. Aquatic Conceptual Site Model
(arrows indicate the flow of contaminants through the system)

image of aquatic conceptual site model

SLERA: Risk Calculations/Exposure Estimates (Step 2)

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.

The following (nonregulatory) guidelines were used in this Screening Level Ecological Risk Assessment (SLERA) (See Screening Benchmarks page for more information on the guidelines used in this ERA):

Sediment - Ontario Provincial Sediment Quality Guidelines (Persaud, et al. 1993) and New York State Department of Environmental Conservation Technical Guidance for Screening Contaminated Sediment (NYSDEC 1993);
Soil - Netherlands Soil Cleanup (Interim) Act and Soil Cleanup Criteria for Quebec (Beyer 1990);
Surface water - U.S. EPA Water Quality Criteria protective of aquatic life (U.S. EPA 1986).

Exposure Estimates

The SLERA was performed with the following conservative assumptions (See SLERA Step 2 for more information on these commonly used assumptions):

Bioavailability - 100%, with the exceptions of the influence of sediment total organic carbon (TOC - assumed to be 1% in the absence of site-specific information) and water hardness (calculated to be 140, 220, and 244 mg/l as CaCO3 for Lacarpe Creek, the wetland, and Darby Pool, respectively, by the following equation:

Total hardness = 2.5 x (Ca++) + 4.1 x (Mg++) (Freeze and Cherry 1979));
Area use factor - 100%;
Contaminant level - highest sample concentration.

Exposure Calculations

Comparisons of the concentrations of Contaminants of Potential Ecological Concern (COPECs) with ecological benchmark guidelines are given in Tables 2-4.

Table 3. Comparison of Landfill Soil Contaminant Data with Soil Quality Criteria (SQC)
Substance	SQC		Maximum Detected Contaminant Concentration	Hazard Quotient
Substance	B	C	Maximum Detected Contaminant Concentration	B	C
Chloroform	5	50	0.004	0.0001
1,1,2,2-Tetrachloroethane	5	50	0.0008	0.0002
Ethylbenzene	5	50	0.028	0.006
Total xylene	5	50	0.091	0.02
N-Nitrosodiphenylamine	15*		1.2	0.1
DEHP	70**		3.7	0.05
Heptachlor	0.5	5	0.039	0.1
DDE	0.5	5	0.065	0.1
Arsenic (As)	30	50	13.9	0.5
Barium (Ba)	400	2000	210	0.5
Chromium (Cr)	250	800	560	2	0.7
Lead (Pb)	150	600	21.8	0.1
Mercury (Hg)	2	10	0.14	0.1
The Soil Quality Criteria (SQC) are based on the Netherlands and Quebec soil guidelines (Beyer 1990). Criteria B refer to moderate soil contamination that requires additional study. Criteria C refer to severe soil contamination. * Based on a 2-week LC50 for earthworm (Neuhauser et al. 1985) divided by 10. ** Lowest of range of acceptable on-site soil cleanup criteria for oil refineries approved by the Ontario Ministry of the Environment based on human health (Beyer 1990).

Table 4. Comparison of Surface Water and Leachate Contaminant Data with Ambient Water Quality Criteria (AWQC)
Substance	Location	Maximum Detected Contaminant Concentration (ug/L)	AWQC	Hazard Quotient
Antimony (Sb)	Darby pool	20.5	1600	0.013
Arsenic (As)	Darby pool	11	48	0.23
Barium (Ba)	Darby pool	249	50,000	0.005
Beryllium (Be)	Darby pool	1.5	5.3	0.28
Cadmium (Cd)	wetland	2.4	8.6	0.30
Chromium (Cr)	leachate	50	16	3.1
Chromium (Cr)	Darby pool	20.2	16	1.3
Copper (Cu)	Darby pool	35.7	34	1.1
Lead (Pb)	Darby pool	200	125	1.6
Nickel (Ni)	Darby pool	42	3100	0.014
Zinc (Zn)	Darby pool	141	570	0.25

Table 5. Comparison of Sediment Contaminant Data with Sediment Quality Criteria (SQC)
Substance	SQC		Maximum Detection	Location	HQ
Substance	LEL	SEL	Maximum Detection	Location	LEL	SEL
DEHP	2a		3	wetland	2
Methoxychlor	0.006a		0.11	lagoon	18
Copper (Cu)	16	110	45	Lacarpe Creek	3	0.4
Lead (Pb)	31	250	40.3	Lacarpe Creek	1	0.2
Mercury (Hg)	0.2	2	0.28	Lacarpe Cr./lagoon	1	0.1
The Sediment Quality Criteria (SQC) are based on the Ontario Provincial Sediment Quality Guidelines (Persaud, et al. 1994), except where noted. Lowest Effect Level (LEL) refers to marginally polluted sediments in which ecotoxic effects become apparent, but the majority of sediment-dwelling organisms are not affected. Severe Effect Level (SEL) refers to heavily polluted sediments likely to affect the health of sediment-dwelling organisms. Hazard Quotient (HQ) = sample concentration / SQC, and rounded to one significant digit. a - LEL for DEHP & methoxychlor = chronic criterion calculated assuming 1% total organic carbon (TOC) (NYSDEC 1993).

Risk Characterization

Contaminants that meet or exceed benchmark values include chromium (landfill soil, leachate, and Darby Pool water), copper (Lacarpe Creek sediments and Darby Pool water), lead (leachate and Lacarpe Creek water), mercury (Lacarpe Creek and lagoon sediments), DEHP (wetland sediment), and methoxychlor (lagoon sediment). These Contaminants of Concern (COCs) are those that are likely to cause ecological risk at the site.

Two of the exceedances are of doubtful significance. DEHP exceeds the sediment benchmark value calculated with a conservative Total Organic Carbon (TOC) of 1%, but is under benchmark values calculated with TOC of 2% or greater. Wetland sediments are expected to have high TOC, so the DEHP exceedance in Table 5 is probably not likely. The methoxychlor sediment concentration is an estimated value. It probably does not represent a release from the site since it was detected in only one lagoon sediment sample located on the far side from the site (but adjacent to the Military Landfill) and was not detected in other samples.

Two contaminants exceed benchmark values at the landfill. Chromium (Cr) exceeds Ambient Water Quality Criteria (AWQC) in 2 of 3 leachate samples, and lead (Pb) in 1 of 3 (OEPA 1989). Chromium also exceeds the soil quality criterion in 1 of 4 samples taken on the landfill by Ohio Enivronmental Protection Agency (OEPA) (1992), but not in any of the 4 SSI landfill soil samples, or in any of the off-site sediment samples. Chromium met the AWQC in the SSI Darby Pool samples, but not in either of the Ohio Environmental Protection Agency (OEPA) (1992) surface water samples at the same location, or in any of the creek surface water samples. Lead does not exceed soil or surface water benchmark values, but there is one exceedance for creek sediments (SSI 1991). Lead levels are also elevated in the lagoon sediment near the landfill (OEPA 1992), but do not exceed the sediment benchmark. It appears that there are at least some releases of chromium and lead from the landfill in concentrations that are of potential ecological concern, but the releases have not (yet) resulted in significant off-site contamination.

Two contaminants exceed benchmark values in off-site locations, but not in landfill samples. Copper (Cu) exceeds the sediment guideline in 2 of 6 samples, and exceeds AWQC in 1 of 4 surface water samples (SSI 1991). Copper did not exceed AWQC when Darby Pool was resampled by OEPA (1992). It is unclear whether the copper contamination of Lacarpe Creek sediments can be attributed to the site. Mercury (Hg) meets the sediment criterion in 3 of 6 samples (2 in Lacarpe Creek and 1 in the near side of the lagoon by the site) (SSI 1991). Mercury is also elevated in 1 landfill soil sample, but does not exceed the soil guideline (SSI 1991). There are no instances of elevated mercuryin the later OEPA samples for any media (OEPA 1992). A provisional conclusion is that mercury may have been released from the site, but the ecological significance is uncertain because the exceedances just meet the Lowest Effect Level (LEL) of the sediment guidelines.

Uncertainty

Risks are intentionally overestimated by the conservative assumptions discussed in this section and in Ecological Risk Assessment Step 2 Estimating Exposure, and by the use of generic benchmark values. Background concentrations are not well characterized, particularly in regard to sediment metals in Lacarpe Creek.

Scientific-Management Decision Point (SMDP)

Conclusions and Recommendations

There is evidence that chromium (Cr) and lead (Pb) are being released from the Camp Perry Landfill at levels that are of potential ecological concern, but there is no evidence as yet that these releases have resulted in significant off-site contamination. Mercury (Hg) in off-site sediments just meets the Lowest Effect Level of the sediment guidelines, but the ecological significance and the relationship with the site and background are uncertain. Copper (Cu) is also elevated in off-site sediments, but there is no clear link with the site.

The landfill was not considered to be a high priority site based on immediate ecological risks. Chromium and mercury presented moderate potential risks to ecological receptors in the area around the site. Lead and Copper presented low potential ecological risks. The ecological concerns related more to the potential future behavior of the site as an unsecured landfill in the floodplain of an ecologically sensitive area, than they did to the then current impacts of the on- and off-site contamination. The primary justification for Superfund involvement at that time was be to have secured a source area to prevent the future development of significant ecological risks, and more expensive cleanup costs.

Risk Management SMDP/Current Status (Step 8)

September 1995 - Screening Level Ecological Risk Assessment completed.
At this point, no further ecological risk assessment was performed

Links to more information on this site

CERCLIS Hazardous Waste Sites Information: Camp Perry Landfill

Contacts for this site

James Chapman, Ecologist (chapman.james@epa.gov)