Challenges for Ethanol Fuels Contaminated Sites Assessment
Student Presenter
Juliana G. de Freitas, Dept. of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada
James F. Barker, Dept. of Earth and Environmental Sciences, University of Waterloo , Waterloo , ON , Canada
Ioannis Chatzis, Chemical Engineering, University of Waterloo , Waterloo , ON , Canada

Ambient Groundwater Quality in the Lower Hudson Valley of Southeastern New York State
Student Presenter
Steven Parisio, Regional Solid Waste Geologist, New York State Department of Environmental Conservation, New Paltz , NY
Eva M. Knoth, New York State Department of Environmental Conservation, New Paltz, NY
Michael Rispoli, Student Intern, New York State Department of Environmental Conservation, New Paltz, NY

Challenges for Ethanol Fuels Contaminated Sites Assessment
Student Presenter
Juliana G. de Freitas, Dept. of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada, Tel: 519-888-4567 ext.35284, Fax: 519-746-7484, Email: jgardena@scimail.uwaterloo.ca
James F. Barker, Dept. of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada, Tel: 519-888-4567 ext. 32103, Fax: 519-746-7484, Email: jfbarker@sciborg.uwaterloo.ca
Ioannis Chatzis, Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada, 519-888-4567 ext.33306, Fax: 519-746-7484, Email: ichatzis@uwaterloo.ca

The use of ethanol as an additive in gasoline is increasing significantly in North America , raising concerns about the consequences of ethanol usage when monitoring the subsurface for groundwater contamination. One piece of the problem is the effect of ethanol on contaminant distribution in the source zone. Ethanol can change important properties of the system which can result in an unexpected distribution of the gasoline contaminants. Ethanol can also enhance the solubility of aromatic hydrocarbons such as benzene.

In 2D visualization experiments gasoline was injected in the top of the unsaturated zone and then ethanol was injected in the same position. It was shown that ethanol can mobilize the gasoline and alter its distribution significantly. The visualization experiments also indicate that ethanol stays mainly in the capillary fringe, being transported above the water table along with cosolubilized hydrocarbons. However, typical monitoring techniques applied at fuel contaminated sites are not intended to sample the capillary fringe. Although under some conditions a typical monitoring well may draw some ethanol contaminated water, providing an indication of contamination, the sample will be diluted and therefore the measured concentration may be significantly smaller than the actual concentration in the capillary fringe. Therefore, the horizontal transport of high concentrations of hydrocarbons and ethanol in the capillary fringe at field scale presents significant challenges for monitoring. For example, since sampling in the vadose zone requires suction, volatile losses are more likely to happen when sampling water from the vadose zone. Laboratory experiments showed that the use of ceramic suction samplers may result in loss of volatile organics of up to 30%, depending on the pressure applied and compound properties. The concentration of ethanol in the aqueous phase was also shown to interfere with the sample bias.

Ambient Groundwater Quality in the Lower Hudson Valley of Southeastern New York State
Student Presenter
Steven Parisio, New York State Department of Environmental Conservation, Region 3 Office, New Paltz, NY 12561, USA, Tel: 845-256-3126, Fax: 845-255-3414; Email: sxparisi@gw.dec.state.ny.us
Eva M. Knoth, New York State Department of Environmental Conservation, Region 3 Office, New Paltz, NY 12561, USA, Tel: 845-256-3142, Fax: 845-255-3414; Email: emknoth@gw.dec.state.ny.us
Michael Rispoli, New York State Department of Environmental Conservation, Region 3 Office, New Paltz, NY 12561 , USA , Tel: 845-256-3142, Fax: 845-255-3414 Email: rispol36@newpaltz.edu

A large volume of groundwater quality monitoring data has been collected in connection with solid waste landfills which are regulated by the New York State Department of Environmental Conservation.  The data set for the seven counties which comprise the study area in southeastern New York State includes more than sixty monitored landfills.  Most sites have at least one upgradient monitoring well which is located outside of the potential zone of influence for landfill-derived groundwater contamination and is used to establish ambient groundwater quality for the site.  At the typical site, between fifteen and thirty rounds of  sampling have been completed with a list of more than forty water quality parameters being analyzed during each round of sampling.  Although sampling personnel and analytical laboratories are different for each site, a high degree of uniformity in methods used is assured by State regulations which govern environmental monitoring at solid waste landfills.  In this study, data for selected parameters was pooled from a large number of sites to develop a basis for characterizing ambient groundwater quality variability on a regional basis.  Parameters selected for this study are those which are considered to be the most useful in detecting landfill-derived groundwater contamination and include alkalinity, ammonia, arsenic, chloride, chemical oxygen demand, hardness, iron, manganese, phenols and total dissolved solids.  Comparisons are made with data from monitoring wells downgradient of the landfills and with other available data sets. Special emphasis is placed on whether parameters exceed applicable water quality standards in ambient groundwater and whether the parameters selected are reliable indicators of landfill-derived groundwater contamination. This study should be particularly useful in cases where topography, property boundaries or other site constraints make it impossible to site a valid upgradient monitoring point or where groundwater quality impact assessments must be made using a single monitoring point.