FREEMONT, SANDUSKY COUNTY, OHIO
The Health Assessment Section (HAS) with the Ohio Department of Health received a request September 7, 2001, from the United States Environmental Protection Agency (US EPA) Region V Office to evaluate the Greiner's Lagoon site near Fremont in Sandusky County, Ohio. Specifically, US EPA's Remedial Project Manager for this site asked the Agency for Toxic Substances and Disease Registry (ATSDR) or its representative in Ohio (HAS) to evaluate the long-term risk associated with the site, particularly in light of the proposed remedial alternative selected for the site (capping with solidification and groundwater monitoring). Background materials with regard to the Greiner's Lagoon site (Engineering Evaluation/Cost Analysis Report, September 2000) were received from US EPA Remedial Project Manager in December 2001 and January 2002.
The Greiner's Lagoon site (GLS) is in a rural, agricultural portion of Ballville Township, in south-central Sandusky County, 5 miles south of the city of Fremont (Figure 1). The site consists of four former waste lagoons occupying a 10-acre rectangular plot of land in a level, open field ½ mile due west of the intersection of South Tiffin Road (County Road 53) and Shaw Road (County Road 181). There are approximately 35 primarily single-family residences within a one-mile radius of the site. The closest residences are ½ mile to the east along South Tiffin Road and a ½ mile to the south along Deran Road (Figure 2). Row-crop agriculture is the main landuse in the area.
Prevailing winds in this area are primarily from the west-southwest most of the year, blowing from the northwest during winter months. The Sandusky River, ½ mile southwest of the site, flows north into Lake Erie. Surface waters from the site, however, appear to drain into a shallow ditch at the east edge of the site, then through an underground drain to a larger, open ditch that transports the water north to Indian Creek, a northwest flowing tributary of the Sandusky River located northeast of the site (Figures 2 and 3).
The GLS is in the Huron-Erie Lake Plains physiographic region of Ohio, a flat, low-lying portion of the state underlain by a thin cover of glacial lacustrine clays and beach ridge sands that overlie limestone or dolomite bedrock. Borings at the GLS indicate 8-10 feet of surficial silty sand underlain by roughly 25 feet of silty clay and clay. Limestone or dolomite bedrock is encountered at a depth of 35 feet below the ground surface (ERM, 2000). Limited amounts of "perched" groundwater occur about four feet below the ground surface in the upper sand unit with more sustainable water yields obtainable from the deeper limestone bedrock. Well logs for residential wells drilled in the surrounding area indicate that all of the nearby residents obtain their drinking water from wells 60 to 125 feet in depth and cased into the bedrock (Ohio Dept. of Natural Resources, well logs). The limestone/dolomite bedrock is the main regional groundwater aquifer in the area, and the primary source of drinking water in this portion of south-central Sandusky County with yields in private wells averaging 10 to 25 gallons per minute.
Groundwater flow in the upper sand unit is radially from the site to the west. Groundwater flow in the bedrock aquifer at the GLS is to the east-northeast at a very low gradient (ERM, 2000). The intervening 25 feet of largely impermeable clay separates the groundwater in the upper perched sand layer from the groundwater in the limestone bedrock, causing the deeper bedrock aquifer to function as a confined aquifer system. At the GLS site, there is no evidence of a hydrological link between the upper perched sand aquifer and the underlying bedrock aquifer. The lateral extent of the perched upper sand layer off-site is not known. However, there is no evidence that the limited water supply obtainable from the upper sand unit is being used for any purposes by nearby residences (ERM, 2000).
The Greiner's Lagoon site was developed in 1954 and consisted of four lagoons used to store waste oil from nearby industries. Site operations prompted a number of complaints from area residents with regard to odors and spills from the lagoons. A 1980 legal decision required the then-current owner to clean up the site which he failed to do. US EPA instigated removal actions at the site in 1981, 1982, and from 1986-1988. These consisted of reinforcement of lagoon dikes, surface oil removal, liquids treatment, sludge solidification, lagoon backfilling, and placement of a soil cover over closed and filled lagoons. Lagoon 4 was dewatered, filled, and capped by US EPA in 1982. Between 1982 and 1985, the Ohio EPA facilitated the filling of lagoons 1 and 2 with sand and gravel washings from a sugar beet processing operation (ERM, 2000).
In July 1991, Lubrizol, one of the companies who disposed of waste oil at the site, entered into an administrative order of consent with US EPA to take over corrective and remedial activities at the GLS. These activities included improving surface water drainage, installing a fence to reduce access to the site, repair leaking lagoon dikes, and developing and carrying out an Engineering Evaluation/Cost Analysis investigation to determine the extent of contamination at the GLS and make recommendations with regard to the clean up of the site. Soil and groundwater sampling was conducted at the site in 1996 and 1998. Eight monitoring wells have been installed at the site; three developed in the deep bedrock aquifer and the other five in the upper perched water-bearing sand layer. Another six monitoring wells were installed in this upper perched sand layer outside of the actual waste disposal area and around the perimeter of the site in 1998 (Figure 3). An additional 17 shallow soil and groundwater samples were collected, also from areas just outside of the waste disposal area, using Geoprobe technology as part of the second phase of the EE/CA investigation. A limited number of surface water and sediment samples were collected from the drainage ditch at the eastern edge of the waste disposal area in 1997.
The EE/CA report summarizing the results of the investigations at the GLS was completed in September 2000. Several volatile organic compounds (VOCs), semi-volatile organics (SVOCs), and a number of metals whose concentrations exceeded natural background levels for the region, were detected in both shallow subsurface soils and shallow perched groundwater at the site. US EPA proposed a clean up plan for the site at a public meeting in Fremont August 29, 2001. This plan called for an engineered cap over the former waste disposal area, solidification and stabilization of fill materials in the former lagoon area, and regular groundwater monitoring at the site (US EPA RPM, 9/07/01). Residents raised a number of issues in response to the cleanup plan, but were especially concerned about the long-term health threat that might result if contaminated soil and groundwater are left in place at the site. These community concerns are the basis for this health consultation.
Area residents have to come into physical contact with the hazardous materials disposed of at the Greiner's Lagoon site in order for exposure to these chemicals to result in possible adverse health effects. In order for residents to come into contact with site-related chemicals, there must be a completed exposure pathway linking the residents with the on-site chemicals. A completed exposure pathway consists of five elements that must all be present for chemical exposure to occur. These include: (1) a source of the toxic chemicals of concern, the site; (2) a method of environmental transport or a way to transport the chemicals from the site to the residents [soil, air, groundwater, surface water]; (3) a point of exposure which is a place where a resident comes into direct contact with the chemical [on-site versus off-site]; (4) a route of exposure which is how the resident comes into contact with the chemical [drinking it, eating it, breathing it, or touching it]; and, (5) people who could be exposed which are the people living near or who are working on the site who are most likely to come into contact with site-related chemicals. If any of these elements is missing, the exposure pathway will be incomplete, physical contact with the chemicals of concern will not occur, and no residents would be exposed. Exposure pathways are complete if all five elements are present. This could result in physical contact between residents and the chemicals of concern at the site and exposure might occur.
Physical contact with a chemical contaminant in and of itself does not necessarily result in adverse health effects. A chemical's ability to affect a resident's health is also controlled by a number of other factors including:
- How much of the chemical a person is exposed to [ the dose]?
- How long a person is exposed to the chemical [the duration of exposure]?
- How often a person is exposed to the chemical [acute versus chronic]?
Other factors affecting a chemical's likelihood of causing adverse health effects upon contact include the resident's:
- History of past chemical exposures,
- Smoking, drinking alcohol, or taking certain medications or drugs,
- Current health status,
- Sensitivity to certain substances,
- Age and/or sex, and
- Family medical history.
The chemicals of concern at the Greiner's Lagoon site include a number of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and metals that have been found in shallow subsurface soils and shallow, perched groundwater in and immediately surrounding the former waste oil disposal lagoons (Tables 1-3).
The VOCs of concern at the GLS include acetone, 4-methyl 2-pentanone, 2-butanone (methyl ethyl ketone), and, to a lesser extent, benzene.
Acetone, 4-methyl 2-pentanone, and 2-butanone all occur as liquids that will vaporize readily upon exposure to the atmosphere. These chemicals are quite mobile in soils, rarely absorbing to soil particles and often leaching down into underground water supplies. All three chemicals are classified by US EPA as "Class D Carcinogens" - chemicals that are either not classifiable as to their cancer-causing ability or which have been tested on animals in the laboratory and failed to demonstrate any relationship to the onset of cancer. US EPA has not established Maximum Contaminant Levels (MCLs) for public drinking water supplies for these three chemicals. US EPA has established "Removal Action Levels" (RALs) for two of these chemicals in groundwater at Superfund hazardous waste sites. These levels are 3,500 ppb for acetone and 200 ppb for 2-butanone (Table 2).
Acetone has been found in subsurface soils (4-12 feet below the ground surface) surrounding the former waste lagoon area at levels up to 190 parts per million (ppm). Levels in groundwater sampled from borings made in the shallow, perched, sand aquifer (Boring SM-8) in 1996 ranged up to 170,000 parts per billion (ppb) and acetone levels in on-site monitoring wells developed in the same aquifer ranged up to 58,000 ppb (monitoring well MW-7) [ERM, 2000]. It should be noted that acetone is a commonly detected laboratory artifact often contaminating environmental samples. However, trip blanks collected as part of the 1996 sampling of groundwater monitoring wells at the site had no detects of acetone indicating that laboratory contamination was not a factor in the detections of acetone in these wells in the 1996 sampling (ERM, 2000).
4-Methyl 2-pentanone has been also found at elevated levels (up to 150 ppm) in subsurface soils (6-12 feet bgs) surrounding the former waste lagoon area. Groundwater levels for this chemical were equally elevated in both on-site borings (up to 120,000 ppb in SM-1) and on-site monitoring wells (up to 36,000 ppb in MW-7), both of which were drilled into the upper perched sand layer (ERM, 2000).
Low levels of MEK (< 2 ppm) were detected in subsurface soils on-site (depths of 4-12 feet bgs). Elevated levels of MEK (up to 22,000 ppb) were detected in a groundwater sample recovered from a boring in the former waste area (SM-4).
In contrast to the other three VOCs of concern, benzene is a known human cancer-causing chemical (Class A Carcinogen). Benzene, like the other three VOCs, will vaporize readily upon exposure to the air and will be quite mobile in most types of soils and readily leach into underground water supplies. Levels detected in subsurface soils (4-8 feet bgs) in the waste disposal area were, however, low (< 2 ppm). Similarly, levels detected in groundwater in the perched sand unit in the waste disposal area were also low (ND-63 ppb) and only rarely exceeded federal public drinking water standards for this chemical (MCL = 5 ppb).
Only one semi-volatile organic compound was commonly detected in soils and shallow groundwater at the site at levels of possible health concern.
Phenol is another chemical that is a "Class D Carcinogen," is rather mobile in soils, and readily leaches into groundwater. In contrast to acetone, 4-methyl 2-pentanone, and MEK, phenol does not readily vaporize upon exposure to the air. Phenol was detected in subsurface soils (6-12 feet bgs) adjacent to the former lagoon area at levels up to 200 ppm. Concentrations of phenol up to 320,000 ppb were detected in groundwater collected from an on-site boring (SM-8) and levels up to 36,000 ppb from an on-site monitoring well (MW-6). No public drinking water standard (MCL) has been established by US EPA for phenol. The US EPA has established a Removal Action Level for phenol of 6,000 ppb.
A number of metals where detected in on-site subsurface soils in the former waste disposal area at concentrations that exceeded the background levels for these metals in native soils in north-central Ohio. These included lead (up to 811 ppm), cadmium (up to 44 ppm), chromium (up to 37 ppm) and nickel (up to 33 ppm).
Metals concentrations elevated above natural background levels were also detected in the shallow, perched groundwater on-site, including arsenic (up to 160 ppb), chromium (up to 100 ppb), lead (up to 96 ppb), and nickel (up to 210 ppb). Metals are generally not very mobile in groundwater in north-central Ohio due to the typically high pH of groundwater in this area.
The EE/CA investigation report (ERM, 2000; Table 5-1) identified a number of possible exposure pathways with the potential to link chemicals of concern at the Greiner's Lagoon site with on-site trespassers, on-site workers, and/or off-site residents.
Direct contact/ingestion of contaminated soils/inhalation of vapors or dust
The bulk of the contamination detected in soils at and adjacent to the site occur at depths greater than 2 feet below the ground surface. Surface soils on-site consist primarily of clean fill materials. Placement of an engineered cap over the former waste disposal area would further reduce the likelihood that contaminated subsurface soils would be exposed at the surface. As a result, following site remediation it is unlikely that incidental trespassers at the site would come into contact with the contaminated soil on-site. The existing fencing surrounding the site would also limit incidental trespass onto the site.
Future workers at the site could possibly come into contact with contaminated soils if they dig into the former disposal areas down to depths greater than 2 or 3 feet below the ground surface. Dermal contact would likely be limited by outerwear worn by workers. The main potential threat to workers trenching or excavating soils at the site would be from the incidental inhalation of volatilized organic compounds or inhalation of contaminated dirt or soil particles (dust). Use of respirators by on-site workers would eliminate this potential threat.
Direct contact/ingestion/inhalation of volatile chemicals from the contaminated,
perched groundwater on-site
As contaminated groundwater in the upper perched sand unit occurs roughly 4 feet below the ground surface and access to the site is limited by fencing, it is unlikely that incidental trespassers would come into contact with contaminated groundwater at the site. Placement of an engineered cap over the former waste disposal area would also further isolate contaminated, perched groundwater and also reduce the influx of rainwater through the roof of the disposal area and down into the shallow groundwater, eventually reducing the volume of contaminated perched groundwater at the site.
As in the above scenario, on-site workers excavating or trenching soils in the former waste disposal area might become at risk of exposure to toxic chemicals if they penetrate the cap and dig any greater than two or four feet below the ground surface. The main routes of exposure would be via inhalation of volatile organic compounds and, less significantly, dermal contact with the contaminated groundwater. Proper protective gear on site workers would insure against exposure through either potential route.
Direct contact/ingestion/inhalation of contaminants in on-site surface waters
Sampling of surface water and sediment collected from four locations along the drainage ditch that borders the eastern edge of the former waste disposal area at the site in 1997 failed to detect any volatile or semi-volatile organic compounds in either surface water or sediment at levels above the laboratory detection limits (ERN, 2000). No metals were detected in surface water samples. Metals did occur in sediment samples, although at levels far below US EPA generic screening values for these metals in soils.
Risk via the inhalation route is minimal due to the lack to volatiles in either surface water or sediments and the limited potential for wet, muddy sediments to be entrained into the air as dust.
Ingestion/direct contact with Off-site perched groundwater
The lateral extent and continuity of the upper perched sand layer present on-site has not been determined off-site. Groundwater contamination on-site is largely limited to this sand unit. Monitoring wells installed outside the perimeter of the former waste lagoon area and sampled in 1998 showed only minimal contamination (Table 3). There is no evidence that nearby residents are using the groundwater in this perched unit off-site for any purpose. All nearby residential wells are cased into the limestone/dolomite bedrock, limiting the likelihood that contaminated water from the upper sand aquifer could impact off-site residential wells. (ERM, 2000; ODNR, well logs).
As no one is currently using this groundwater for any purpose and groundwater yields from this sand layer would be limited in comparison to the deeper bedrock aquifer in this area, it is unlikely that this exposure pathway would be complete beyond the boundaries of the site.
Ingestion/Direct Contact with Off-site Bedrock Groundwater
The bedrock aquifer is the primary source of drinking water used by area residents. The same limestone/dolomite bedrock aquifer that underlies the site underlies this entire portion of south-central Sandusky County (Schmidt, 1980; ODNR Division of Water well logs).
Currently there is no evidence that the site has significantly impacted the underlying bedrock aquifer. Sampling of the three bedrock wells that bracket the former waste disposal area in 1996 and 1998 provided no confirmed detections of site-related chemicals-of-concern in wells MW-1 and MW-2. Bedrock well MW-3 had a detection of acetone at 37 ppb in 1996 with no detections of the same chemical in 1998. The same well had estimated trace levels of both 4-methyl-2 pentanone and bis(2-ethylhexyl)phthalate in 1996 and no detections in 1998. As these are estimated values, it is questionable as to whether the low levels of chemicals detected are actually indicative of the presence of these chemicals in the bedrock aquifer under the site.
The closest residential wells are at least 0.5 miles east and south of the site and are all cased into the bedrock. Calculated levels at which non-cancer adverse health effects might occur as the result of contact with VOCs and SVOCs found in on-site groundwater range from 4,000 to 20,000 ppb for adults and 1,000 to 6,000 ppb for children. It is unlikely that these contaminants in the groundwater on-site would be able to migrate 0.5 miles without significant attenuation, diffusion, and dispersion of the contaminant plume. As a result, even if site-related chemicals were able to migrate off-site to area drinking water wells, it is unlikely that concentrations of these chemicals at the point of exposure (resident's well) would be high enough to cause adverse health effects. In addition, sampling of on-site monitoring wells in 1998 indicated a significant decline in the levels of the contaminants of concern detected in the perched aquifer (Table 2).
Direct contact with/ingestion of surface water and/or sediment off-site
There is the potential for a completed pathway through the surface water and sediment route via the on-site ditch, the enclosed culvert open drainage ditch, and Indian Creek. It is feasible that site-related contaminants could be transported via the surface water route off-site where residents may come into contact with these chemicals. However, no chemicals of concern were detected in surface water and only low levels of metals were detected in the on-site ditch sediments. It is unlikely then, based on current data (ERM, 2000), that this pathway would be an important conduit for transporting significant quantities of contaminants off-site. Capping of the former waste area would further limit the likelihood of site chemicals washing into the on-site ditch.
HAS recognizes that children may be more sensitive to exposures to toxic chemicals in the environment than adults. Reviews of the toxicology of the chemicals of concern at this site included screening values and health-based standards calculated by the Agency for Toxic Substances and Disease Registry (ATSDR) and US EPA specifically for children.
Based on current conditions at the site, if the remedy preferred by US EPA for this site is put in place (engineered cap + solidification/stabilization of soils + groundwater monitoring), it is unlikely that the Greiner's Lagoon site would pose a significant public health threat to nearby residents in the future. No completed exposure pathways linking off-site residents to contaminants at the site have been documented. As a result, the site currently does not constitute a public health hazard to area residents.
The main pathways of concern with regard to off-site residents would be the potential for the more mobile contaminants on-site (acetone, 4-methyl 2-pentanone, 2-butanone, benzene, and phenol) to seep into the regional bedrock aquifer and migrate off-site to the nearest residential drinking water wells. However, currently there is no evidence that contamination on-site has impacted the deep bedrock aquifer under the site. The emplacement of an engineered cap over the former waste lagoon area would further reduce the likelihood that these contaminants would impact the bedrock aquifer on-site by limiting the recharge of the groundwater in the upper sand layer through minimizing the amount of rainwater percolating through surface soil into this sand.
1. Carry out the proposed remedial activities at the Greiner's Lagoon site. These actions should minimize or eliminate any future threats the site might pose to the public health of nearby residents.
2. Continue to monitor on-site groundwater to confirm that levels of contamination in the upper sand layer decline over time and to insure that the regional bedrock aquifer at the site remains unaffected by on-site contamination.
Health Assessment Section
Robert C. Frey, Ph. D., Geologist
Eric Yates, Environmental Specialist
ENVIRONMENTAL RESOURCES MANAGEMENT (ERM). 2000. Engineering Evaluation/ Cost Analysis Report (for the) Greiner's Lagoon Site, Fremont, Ohio, September, 2000. 136 p. + Figures and Tables.
OHIO DEPARTMENT OF NATURAL RESOURCES (ODNR). Division of Water Resources, well logs from the vicinity of the Greiner's Lagoon site, Ballville Township, Sandusky County, Ohio.
SCHMIDT, J. J. 1980. Groundwater Resources of Sandusky County. Ohio Department of Natural Resources, Division of Water (Map, one sheet).
|Chemical||0-2 ft||2-4 ft||4-6 ft||6-8 ft||8-10 ft||10-12 ft|
|Bis(2-Ethylhexyl) phthalate||580J||610J||840 J||3,600||540J||630J|
0-2 ft = depth below the ground surface
ND = Chemical not detected
J = Estimated value
|Chemical||Perched Sand Wells
|Perched Sand Wells
|US EPA MCL||US EPA RAL|
MCL = US EPA Maximum Contaminant Level
RAL = US EPA Removal Action Level
ND = Chemical not detected
J = Estimated value
NA =Not available
ND =Chemical not detected
J =Estimated value
MCL =US EPA Maximum Contaminant Level
* = US EPA Action Level at the tap
This Greiner's Lagoon Health Consultation was prepared by the Ohio Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the health consultation was begun.
Alan W. Yarbrough
Technical Project Officer, SPS, SSAB, DHAC, ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health consultation and concurs with the findings.
Chief, State Program Section, SSAB, DHAC, ATSDR