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LA SALLE COUNTY
NAPLATE
Congressional District # 11
OTTAWA TOWNSHIP FLAT GLASS SITE
EPA ID# ILD005468616Last Updated: August, 2009
Site Description
The Ottawa Township Flat Glass (OTFG) site is located in Naplate, La Salle County, Illinois, about 60 miles southwest of downtown Chicago. The OTFG site is also known as the “Libbey-Owens-Ford (LOF) Plants 5&7” site. The 228-acre site consists of the property containing a glass manufacturing facility ("Plant #5" (active) and "Plant #7" (currently inactive)) located on the north side of the Illinois River plus former silica sand quarries, wastewater disposal areas, and a 56-acre undeveloped parcel of land. It also includes additional former silica sand quarries and wastewater disposal areas across from the facility on the south side of the river.
The manufacturing plant has been making flat glass products since about 1907. Arsenic trioxide was a minor ingredient in the manufacturing process from 1907 until 1970 when its use was discontinued. The final step in the manufacturing process involved grinding and polishing cast glass with fine silica sand and water. The process generated a waste slurry containing mostly sand, water, and glass particles (containing arsenic) which was discharged into the former quarries for settling of solids and discharge of overflow water into the Illinois River. The slurried waste in the settling areas contains appreciable levels of arsenic and is a source of arsenic contamination in local area groundwater as well as being a direct contact or ingestion threat to human and ecological receptors.
EPA has divided the OTFG site into four portions, called "operable units" (OU), for ease of investigating and addressing site contaminant levels and potential health risks. These include the Residential Soils (OU #1), Illinois River Sediment (OU #2), Groundwater and Source Areas south of the river (OU #3), and Groundwater and Source Areas north of the river (OU #4).
Pilkington North America, Inc. (PNA) purchased the glass manufacturing facility from LOF in 1986, about 16 years after the use of arsenic in the glass-making process was discontinued. PNA continues to operate the glass manufacturing plant to date.
Site Responsibility
The OTFG site is being addressed through federal, state, and potentially responsible party actions.
The OTFG site is a potentially responsible party (PRP)-lead site. To date, under EPA oversight, Pilkington North America (PNA) has performed a time critical removal action, a remedial investigation, and several baseline human health and ecological risk assessments. In addition, PNA has begun feasibility studies for the groundwater operable units that are scheduled to be completed in fall 2009 and fall 2010.
Threats and Contaminants
Arsenic is the contaminant of concern at the site. It is a poison in high doses and a potential human carcinogen through prolonged exposure to much lower amounts, although it may also be an essential micro-nutrient. People or animals that come into contact with arsenic-contaminated soil or that drink arsenic-contaminated water could be at risk, depending on duration and arsenic exposure levels as well as other factors.
Elevated levels of arsenic were found in the soil of the yards of two residences in Naplate near the glass plant, prompting a look at almost all yards within the village. The settling areas are located adjacent to the Illinois River, causing a concern that river sediment may have been contaminated with arsenic. Arsenic is found at very high levels in the settling areas and in the shallow groundwater aquifer beneath the settling areas, but it has not impacted Naplate's water supply (derived from a separate aquifer) based on results of historic sampling efforts by the village.
Very high levels of arsenic in residential yards could be an immediate and/or long-term threat to human health through ingestion, inhalation, or dermal absorption. Arsenic contamination in river sediment could impact ecological receptors. Arsenic in the settling areas could be an immediate and/or long-term threat to human health and the environment through ingestion, inhalation, or dermal contact. The arsenic-contaminated groundwater is a potential threat to human health through ingestion should the contaminated water be used for potable purposes.
Cleanup Progress
Illinois EPA initially managed site investigations from the early 1980s until it referred the site to U.S. EPA in the late 1990s. U.S. EPA reached an agreement with PNA in September 2001 whereby the site would be handled as if it were listed on the Superfund National Priorities List but would not have to go through the listing process. U.S. EPA and PNA signed an Administrative Order on Consent ("AOC") under which PNA would conduct a remedial investigation ("RI") and feasibility study ("FS") at the site under U.S. EPA oversight. Remedial investigation activities are underway to determine the nature and extent of (arsenic) contamination in area groundwater, soil, and sediment.
Residential Soils
PNA conducted soil sampling in a few Naplate residential areas in late 2002 and discovered elevated levels of arsenic in shallow (0 to 6 inches) and deep (greater than 12 inches) sampling points on two lots (417 and 419 22nd Ave.) located close to the factory. Soil arsenic levels were found to be as high as 44,800 milligrams per kilogram (mg/kg or "parts per million" or "ppm") on parts of these lots. (In contrast, EPA’s removal action trigger point for arsenic levels in residential soil is about 100 ppm.) It was later determined that settling area fill material had been removed from the facility and used to fill in low spots on the lots so that a home could be built on one of them.
PNA, under EPA oversight, began a time-critical removal action at the two yards in December 2003, excavating arsenic-impacted soil above about 20-40 ppm. PNA safely excavated a total of 3,325 cubic yards of soil and G&P slurry material and disposed of it in an off-site landfill. While this work was being done the residents of the two homes were temporarily relocated to a local hotel. After sampling the edges and bottoms of the excavations to confirm that all impacted soils had been removed, PNA placed clean soil backfill into the excavations and reseeded the lots. The removal action was completed in June 2004. The homes were also found to have above-normal levels of arsenic-laden dust inside and PNA performed an interior cleanup action in 2004 for the home at 419 22nd Ave. and in 2006 for the home at 417 22nd Ave. to reduce the interior arsenic levels to safe levels.
PNA also expanded the residential sampling program in 2003 to include additional testing at residences located very near the area of the two impacted properties. The residential soil sampling program was expanded again in fall 2005 to cover almost all of the lots in the village. Over 2000 soil samples were taken by PNA from about 210 Naplate residential lots and analyzed for arsenic. (About 21 residential lots and 3 commercial properties were not sampled either because access was not granted or there were no exposed soil areas to sample.) Results of the soil analyses were tabulated and presented in the Remedial Investigation Report for the Residential Soils Operable Unit (August 2007). Results indicate that G&P slurry material has not been placed as fill on any other village lots and that no immediate health threats were present.
The arsenic concentration trends in the residential area soil samples showed that the composite soil arsenic levels were less than or equal to 10 ppm in a great majority (approximately 65 percent) of the sampled areas. Another 33 percent of the sampled areas had composite soil arsenic concentrations of 10 ppm to 20 ppm. In comparison, the composite soil arsenic levels of 98 percent of sampled areas are consistent with the state’s published background level of 11-13 ppm. Since 11-13 ppm is an average background soil arsenic level due to anthropogenic sources, EPA believes it is reasonable to assume that some areas would be slightly higher than 11-13 ppm arsenic and some lower. Hence a range of 10-20 ppm for the composite samples can generally be thought of as being consistent with this value.
The last 2 percent of the sampled areas, or seven residential yards and one area in an alley, had composite arsenic concentrations of 20 ppm to 30 ppm or more. In these 8 areas, an individual sample arsenic concentration in the range of 50 ppm to 109 ppm was found, yielding the slightly higher composite results. The highest composite result for arsenic was 35 ppm. PNA conducted a final removal action in these 8 yards in September 2008. Soil was removed from around the sampled areas that exceeded 50 ppm arsenic and taken off site for disposal. The cleanup resulted in the composite arsenic levels for these 8 properties to fall within the composite arsenic values for the rest of the Village of Naplate.
The health risks associated with the composite residential soil arsenic levels were calculated to not exceed cancer-causing and non-cancer-causing levels. Therefore, EPA issued a proposed plan for public comment that called for no further cleanup action to take place in the residential soils operable unit. EPA opened a public comment period on the proposed plan from June 16, 2008 to July 16, 2008. We held a public meeting on June 24, 2008 at the Naplate Village Hall to present the proposed plan and take public comment and we later signed a Record of Decision (ROD) in September 2008. EPA selected "No Further Action" as the final cleanup approach for the residential soils.
Sediment
PNA and others began testing the Illinois River environment for arsenic before the 2001 RI/FS AOC was signed. PNA both collected sediment samples and conducted bathymetric surveys. PNA had characterized arsenic content in local river sediment in 2000. Data indicated an area of potential concern along the north side of the Illinois River next to the site. Over 100 sediment samples were taken from along the north shoreline, with arsenic values ranging from ND to 428 ppm. The average was about 50 ppm, although half the samples were less than 18 ppm. The above-background values indicate that the sediment along the north shoreline is somewhat impacted by arsenic contamination from the site.
PNA took 33 sediment samples upstream of the OTFG site. These samples were considered to be background samples or those unaffected by the site. Arsenic values ranged from not detected (ND) to 13 ppm, averaging about 5 ppm, verifying that the upstream area sediment is not impacted by arsenic from the site.
Over 100 samples were taken from the south side of the river near the glass plant location and also downstream. Arsenic values ranged from ND to 29 ppm, averaging about 4 ppm, which verifies that the sediment in these areas is not impacted by arsenic from the site.
The U.S. Geologic Survey also has sampled sediment in the Illinois River over the last 10 years or so. According to a USGS on-line database, samples taken a few miles upstream (near the Marseilles lock-and-dam) had arsenic values ranging from 1 ppm to 7 ppm. Downstream sediment samples (from the Starved Rock lock-and-dam area) had arsenic values at about 1 ppm. This data also indicates that the sediment in these areas is not impacted by the site.
PNA also looked at water quality data for the river from samples taken by others in the 1990s. These sample results showed that there were no measurable levels of arsenic from the site in river water.
PNA conducted radioisotope studies on the north shorline-area sediment and that data suggest that the sediment deposit was laid down in the 1950s. It also suggests that the deposit is stable and not subject to wash out by yearly flooding.
Illinois EPA conducted bioassay studies on the north shoreline-area sediment in about 1990. Data showed that the sediment imparted no acute toxicity effects on the sensitive test organisms. PNA conducted tests in 2002 on benthic organisms and data showed some chronic effects; however, there was no discernible difference between upstream and downstream chronic toxicity effects on test benthic organisms. Thus, no fish sampling was done because literature suggests that health impacts on fish occur at arsenic levels that are at least an order-of-magnitude above that of benthic organisms.
EPA therefore concluded that the arsenic-impacted sediment in the Illinois River along the north shoreline next to the site is very stable – it wouldn’t be prone to being washed away by river water, that it has very little or no effect on river water quality, and that it displays very little or no toxicity (attributable to arsenic) to aquatic organisms.
The health risks associated with the sediment arsenic levels were calculated to not exceed cancer-causing and non-cancer-causing levels. Therefore, EPA issued a proposed plan for public comment that called for no cleanup action to take place in the Illinois River sediment operable unit. EPA opened a public comment period on the proposed plan from June 16, 2008 to July 16, 2008. We held a public meeting on June 24, 2008 at the Naplate Village Hall to present the proposed plan and take public comment and we later signed a Record of Decision (ROD) in September 2008. EPA selected "No Action" as the final cleanup approach for the Illinois River Sediment.
Source Areas and Groundwater
PNA installed a number of groundwater monitoring wells in 2002-04 in and around the site and has sampled nearby private wells to determine the nature and extent of groundwater contamination beneath the site. Results indicate that there are two groundwater aquifers of immediate concern below the site. The upper aquifer, the St. Peter Sandstone, is a regional unconfined aquifer that has been impacted by arsenic contamination from the site. The lower aquifer, the New Richmond Sandstone, has not been found to have been impacted by arsenic contamination. Between the two aquifers lies the Shakopee Dolomite, a 150-200 foot thick aquitard that forms an effective barrier between the St. Peter Sandstone and New Richmond Sandstone. Arsenic levels in the St. Peter Sandstone range from a few parts per billion ("ppb") at the edges of the contaminant plume to several ppm in the center, about 400 times higher than the maximum contaminant level for arsenic (10 ppb) under the Safe Drinking Water Act. The St. Peter Sandstone, however, is not used for potable purposes in the site area. Also, the Village of Naplate public water supply well draws water from the deeper New Richmond Sandstone aquifer and thus is not at risk of arsenic contamination.
PNA collected soil samples on the facility property and results indicate that elevated levels of arsenic are in the settling areas, primarily the former quarries and waste disposal areas where the polishing slurry was discharged. These areas act as sources of arsenic contamination in the upper aquifer. A human health and ecological risk assessment is being prepared to evaluate arsenic impacts with results due in early 2009. Future work will likely consist of gathering data to design soil covers (or “caps”) to place over the source areas that would help prevent further leaching of arsenic into the groundwater, because the volume of source material may be too great to dig up and move to an off-site landfill.
Future Work
PNA will prepare RI reports for the two groundwater operable units by early 2009 and a FS report for each shortly thereafter. The FS reports will examine cleanup methods for arsenic contamination as appropriate based on the human health and ecological risk assessment results to be presented in the RI reports. However, we will also examine whether early actions can be taken to address the arsenic in the groundwater as appropriate.
EPA is planning to issue a proposed cleanup plan for groundwater operable unit 3 in late summer 2009 and to sign a ROD for this area in fall 2009. Afterwards, we will work with PNA to conduct the selected cleanup remedies. EPA is also planning to issue a proposed cleanup plan for groundwater operable unit 4 in late fall 2010 and to sign a ROD for this area in winter 2010.
Success Story
Under EPA oversight, PNA safely and successfully cleaned up the two highly-impacted residential lots in 2004 and cleaned the interiors of the homes shortly thereafter. In 2008 PNA safely and successfully removed additional soil from the residential areas to bring down composite arsenic levels to equal those found on the rest of the lots in Naplate. The results of the soil sampling and cleanup work allowed EPA to issue a "No Further Action" ROD for the residential soils operable unit.Community Involvement
EPA issued a proposed plan fact sheet for the Residential Soils and Illinois River Sediment operable units of the OTFG site to the public for review and comment in June 2008. EPA placed the proposed plan and other site documents into the Administrative Record file and the information repository maintained at the U.S. EPA Records Center (U.S. EPA Region 5, 77 W. Jackson Blvd., Chicago, IL) and at the Reddick Library (1010 Canal St., Ottawa, IL). We placed a notice of the availability of the proposed plan and other documents in the Ottawa Times, an area newspaper of wide circulation, also in June 2008.
EPA opened a public comment period on the proposed plan from June 16, 2008 to July 16, 2008. We held a public meeting on June 24, 2008 at the Naplate Village Hall to present the proposed plan and take public comment. We answered questions at the meeting about the actual or potential health risks posed by contaminants at the site and why we proposed that the No Action alternative be our response action for these two operable units. We signed the Record of Decision in September 2008. Our responses to public comments received during the comment period are included in the Responsiveness Summary section of the Record of Decision.
In about late summer 2009 EPA plans to issue a proposed plan for cleanup of groundwater operable unit 3 for public comment and we will again hold a public meeting in the area to present the plan and take public comments.
Property Reuse
The 56-acre undeveloped parcel that is considered part of the site has been sampled and shown to be not impacted by arsenic on the surface. Thus, the property likely is eligible for reuse, although we project that groundwater-use restrictions may have to be placed on the land to be protective of human health and the environment because arsenic is found in the groundwater beneath the site.
The interior of the impacted residences at 417 and 419 22nd Ave. have been cleaned of arsenic residue and are available for reuse.