South Hill Geology Ian Toevs, and Brett Gleitsmann Cornell Students

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1 South Hill Geology Ian Toevs, and Brett Gleitsmann Cornell Students In order to more accurately describe the movement of water or a contaminate in the subsurface it is essential to understand the underlying geology. Geological features play an influential role in the fate of subsurface fluids. Some of the factors that are affected include the rate of infiltration or percolation through the ground and how deep it will go. The rate of movement is also dependant on the type of material and its subsequent conductivity. The geology of the South Hill area in Ithaca is consistent with that of the Finger Lakes Region in general. The geological formations that we see every day in the surrounding area were formed from many layers of sediment deposition which were compacted to make layered shale. Other layers were deposited on top of this shale and the later broken up when the Appalachian Mountains formed. Then during the last ice age glaciers moved through the area scouring off the surface soil layers leaving exposed shale. The Paleontological Research Institute (PRI) of Ithaca has a webpage describing this geology in more detail, the link is listed below. < Figure 1: layered shale along Spencer Street

2 In Figure 1 it is possible to see the layered shale that has been exposed from the latest road construction project along Spencer Street. This picture is located directly down slope from the Emerson plant. The water that is visibly seeping out of the rock is infiltrating somewhere uphill, percolating down through fractures in the layers of shale, and then resurfacing where the layer is exposed. If present in the subsurface as a liquid, contaminates could discharge here as well. As I mentioned above, the conductivity of the subsurface material plays a huge role in the rate and direction of movement of a liquid. Shale has a very low hydraulic conductivity which means that the movement of liquid would be very slow ( ft/day, from USGS Water-Resources Investigations Report Unfortunately, the shale on South Hill is fractured and layered; these two factors greatly accelerate the rate of movement. Liquid will always seek out the path of least resistance and the fractures in the shale layers accommodate this nicely. Therefore as liquid infiltrate into the very shallow layer of soil on the surface and comes to a shale layer it will flow along the plane of the layer until there is a fracture, then a portion of the liquid will go down to the next layer. For South Hill this equilibrium point is essentially the point where the liquid meets the water table from Six Mile Creek. 2 N 1 Figure 2: additional test sites

3 Based on the observable geological evidence and the existing TCE test results a few additional points of interest for testing are shown in Figure 2. The rationalization for picking these sites is based upon the down slope gradient from Emerson as well as the dipping direction for the underlying shale layers. If in fact the fire reservoir was one of the main sources of contamination, the houses along Spencer Street appear to be directly in the path of the contaminate plume. Therefore Additional Test Site #1 would be a wise place to monitor and/or mitigate. It is very hard to explain the presence of TCE in the houses along South Hill Terrace and Turner Place from only the fire reservoir contamination. That is why it is believed that the Research and Development (R & D) Lab may have been a contributor as well. Figure 3 shows the view from the Research and Development Lab down towards South Hill Terrace. Figure 3: R & D Lab This picture shows that the top of these houses is approximately even with the parking lot of the R & D Lab. The pink house in the center of the picture as well as the house further down the hill both tested positive for TCE. This appears to

4 be a logical place for liquid in the subsurface to flow. Figure 4 shows the carport of the pink house. Figure 4: carport Upon close inspection it is apparent that water seeps through the railroad ties and the white plastic pipe at the top right corner of the carport serves to drain excess water coming down the hill. This is another example of where some of the layers of shale have surfaced bringing water and the potential for more TCE. As a result of the two potential contamination sources and the TCE findings associated with each of those sources, Additional Test Site #2 would be a wise addition to the monitoring/mitigation planning. Site #2 is located in between the two potential contaminate pathways making it a very unlikely site to avoid TCE contamination.

5 Storm Drainage Network on South Hill Jens Liebe Cornell Student Seep Emerson R&D Lab Fire reservoir An accurate prediction of the transport of water and TCE through the shale that makes up the South Hill residential area is almost impossible. Yet storm drains, or their construction beds, may act as preferential flow paths which facilitate the transport of water and chemicals. The above map shows the storm drainage pipes in blue, and an open surface drain (dashed) on the upper reach of South Cayuga Street, which is fed from the Emerson plant and ties into the buried drainage pipe at the intersection of South Cayuga/South Hill Terrace. On South Hill Terrace, residents reported of a draining pipe, which exact course is not known (residential drain, dotted), but probably connects to a seep identified on the parking of the Emerson Research & Development Lab. The network of storm drainage pipes (solid blue) shows no indication of being responsible for a distinct pattern of high TCE levels found in the sampled houses. Yet, the residential drain (dotted) that runs between Emerson s Research & Development Lab and South Cayuga Street lies in the area of high TCE levels. It may be the case that this residential drain, or its bed, might facilitate the transport of TCE.

6 Sources: GIS Data: TCE Data: Seep location: Environmental Strategies Consulting, Reston, VA (2005): Proposed Offsite Monitoring Well Locations. Emerson Power Transmission. Accessible through Tompkins County Library; Storm Drainage: City of Ithaca (Pipe) & own observation (open drain; residential drain). Note: Ithaca s storm drainage map for the South Hill Area is not yet complete.

7 Some Facts About the Emerson Spill Gabriel B. Lewis Cornell Student What we know Spills containing TCE at Emerson are polluting the groundwater and moving downhill towards the residents and the stream. TCE is also vaporizing out of the soil and seeping into homes in the same way that Radon seeps into basements. The TCE pollution moves through the groundwater, and may continue to move for years. This further complicates detection and means that a house may be polluted one year and not the next. Extensive sampling could be a solution, but an accredited sampling of a home by itself costs approximately 1,500 to 2,500 dollars. According to Janet Snoyer, Emerson Power is paying 2,500 dollars to install a vapor mitigation system at some contaminated homes. The ventilation system can cost over 2,500 dollars depending on the quality and type of the basement. ( l). Ventilating the air out of homes is sure to prevent contamination, but it can also reduce the value of the home, a major concern for area residents. However, extensive sampling may be prohibitively expensive and mitigation is the only reliable way to prevent TCE indoor air quality problems. What we don t know We do not have data to identify specific soil and subsurface characteristics. This means that we do not know exactly how the pollution is moving in the groundwater or where TCE vapor may be found. Because the area is so fractured and steep it is difficult to predict where TCE will move next and how fast it will move. It is also possible for pools of TCE to sit on the bottom of the groundwater and continue to release TCE into the groundwater from unknown locations. It is difficult to find the extent of the pollution because we do not know exactly where on the Emerson site the TCE is coming from.

8 Properties of Some Chemicals Andrew Neil Cornell Student All chemicals found at the Emerson site in Ithaca, NY have relatively low vapor pressures the highest is 350mmHg for methylene chloride on the order of mmHg. The proportion of the chemicals in the air just above the pure liquid is equal to the vapor pressure of the chemical divided atmosphere pressure (760 mm Hg). Thus air above a pure chemical with a vapor pressure of 100 mmhg will contain ~12% of the chemical. All of these chemicals listed in Table 1 have specific gravities greater than 1 (ranging from ) and as such would be capped by any water above them in shallow groundwater tables. The specific gravity of a compound is a measure of its density relative to water: a specific gravity greater than one indicates density greater than water. However, it is likely that, in the case of groundwater on South Hill, that there would not be enough depth of water above a chemical pulse to create a standing cap over these gases. Specific gravities are also summarized in Table 1. These chemicals are moderately soluble to insoluble in water as well, and are likely to evaporate readily from surface waters. Those with slightly higher solubility preferences may leach to groundwater, and then evaporate from the soil. This is likely the case on South Hill, where shallow subsurface flow can move rapidly down the steep slope, before any of these chemicals can volatilize out of solution. Solubility data are shown in Table 1, as a function of percent chemical dissolved relative to water as the solvent. Chemical Vapor Pressure Specific Gravity Solubility (%) (mmhg) 1,1, Trichloroethane 1, Dichloroethane cis-1, Dichloroethane Methylene chloride Tetrachloroethene Trichloroethene Table 1. Physical properties of the major chemicals found related to the Emerson site, South Hill, Ithaca, NY. Data from NIOSH, Trichloroethane and its related compounds tend not to decompose in soils, either by natural degradation or by biological processes (USEPA 2005). The half-life of 1,1-trichloroethane was found to be between 200 and 300 days, relatively long

9 lived for a chemical in soil (ATSDR 2004). Because these compounds do not degrade, they can be retained in soils for long periods of time. However, the log octanol/water partition coefficient of trichloroethane is 2.49 while the log partition coefficient for octanol alone is , indicating that trichloroethane prefers dissolution in water to sorption to organic material in soils. Trichloroethane is not taken up by plants or other organisms in the soil and seems only to be a threat via inhalation of vapors (ATSDR 2004). The physical characteristics of trichloroethane and its related compounds show that the transport of this suite of chemicals could occur in a location like the Emerson site in Ithaca. The chemicals have the capacity to leach into groundwater and subsequently evaporate out of solution in the soil. Trichloroethane is relatively persistent in the soil and will only leach out of soil when there is enough rainfall to dissolve it and flush it from the soil. References Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological profile for 1,1,1-trichloroethane (Draft for Public Comment). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. USEPA List of Drinking Water Contaminants and MCLs: Drinking Water Contaminant Factsheet for Trichloroethylene. Washington, DC: U.S. Environmental Protection Agency.

10 Health Hazard? Craig Weinstein Cornell Student Chemicals likely not related to Emerson spill Chemical Name EPA Minimum Risk Level (Indoor Air Concentration, ug/m3) Level found in *Brad's house, ug/m3 Acetone 3.50E E+01 Benzene 1.30E E-01 m-xylene 7.00E E-01 MTBE 3.00E E-01 Toluene 4.00E E-01 Health Affects* Eye/ear/nose irritation, gastrointestinal hemorraging, headache, dizziness Death, cancer, throat/nasal/skin irritation, immunological effects, dizziness, headache Nausea, vomiting, eye irritation, impaired shortterm memory/reaction time/equilibrium Respiratory effects, eye/nose/throat irritation, dizziness, nausea, vomiting Respiratory/eye/skin irritation, dizziness, headache, impaired intellectual, psychomotor, neuromuscular effects * These affects were taken from and it should be noted that concentrations on South Hill may not be the same as those from this source. The risk, however, still remains. Chemicals likely not related to Emerson spill

11 Chemicals likely related to Emerson spill Chemicals likely related to Emerson spill TCE (1,1,1- Trichloroethane) PERC (Tetrachloroethene) NYS DOH Guideline (concentration, ug/m 3 ) Levels found at Brett s house (South Hill Terrace, ug/m 3 ) Health Risks* 100 <0.83 Death (at high concentrations), impaired psychophysiological functions, dizziness, skin/eye irritation Death (at high concentrations), respiratory/eye irritation, liver/kidney damage, possible reproductive effects * These affects were taken from