In this exercise you will be asked to create maps that represent ground water samples from a contaminated site on Long Island. You will receive little guidance about how to create these maps, other than purpose for creating the maps.
Introduction to the Problem
The following is a narrative regarding the site taken from the EPA National Priorities Listing Site.
Conditions at Proposal (October 22, 1999): The 124.6-acre Lawrence Aviation Industries, Inc. (LAI) site in Port Jefferson Station, Suffolk County, New York is an active manufacturer of titanium sheeting for the aeronautics industry. The company was founded at its present location in 1959. The property was previously a turkey farm owned by LAI's corporate predecessor, Ledkote Products Co. of New York. In approximately 1991, LAI indicated that its titanium mill was operating in a 200,000 square-foot plant complex on a 160-acre site. The site is located on a topographic high point and is surrounded by residential areas and a few commercial properties. The Village of Port Jefferson is located to the north.
LAI has been cited by the Suffolk County Department of Health Services (SCDHS) and the New York State Department of Environmental Conservation (NYSDEC) for numerous violations. LAI wrote in February 1971 that liquid wastes from non-acid tanks were drained directly to the sump, which the company reported to be 37,500 square feet. In August 1970, the owner of an adjacent property told SCDHS that the sump occasionally overflowed onto his property, killing the plants. Samples collected from the sump in 1970 and 1972 revealed the presence of hexavalent chromium, nitrates, and fluoride at concentrations in excess of permissible limits for discharge to ground water. In February 1973, LAI had used an earthen berm to divide the sump into stormwater and industrial wastewater sections. SCDHS referred to the two separated sections as the North and South lagoons in 1980, at which time both contained liquid and were receiving discharges.
In 1980, the company crushed more than 1,600 drums and allowed the liquid contents to spill on unprotected soil prior to drum removal. SCDHS interfered with the procedure to prevent additional drums from being perforated. The drums contained trichloroethylene (TCE), tetrachloroethylene (PCE), spent acid sump sludges, salt wastes, hydraulic oils, Zyglo penetrant, hydrofluoric acid, nitric acid, and other plant wastes. SCDHS also observed numerous discharges from various plant activities to the ground surface and to two unlined lagoons. SCDHS collected a number of samples and issued Notices of Violation to LAI for the discharges. TCE was detected in liquid samples collected from the North Lagoon. Samples collected from the North and South lagoons in April 1985 contained elevated levels of fluorides. The North Lagoon was backfilled sometime after 1985. In July 1990, the NYSDEC Resource Conservation and Recovery Act program discovered more than 2,000 drums stored on the site. Drum contents included waste solvents, acetone, acids, oil, salty base, ink, and untreated acidic sludge, as well as numerous types of solid waste. NYSDEC cited LAI for violating numerous hazardous waste regulations, and provided oversight for drum removal in 1990 and 1991.
Ground water from the Upper Glacial/Magothy aquifer is the only source of water supply in the site vicinity. From 1979 to 1997, TCE was detected in 11 residential wells located between 0.22 and 1.05 miles north of the site. Residences with private drinking water wells located north of the site have been connected to the public water supply to eliminate the presence or threat of exposure to TCE contamination. The drinking water wells where TCE was detected are considered to be subject to actual contamination because they were closed as a result of contamination from the site. There are 47 public supply wells, serving an estimated 120,508 people, screened in the Upper Glacial/Magothy aquifer within 4 miles of the site.
Status (February 2000): EPA is considering various alternatives for this site.
Since this time a ground water sampling initiative has been undertaken to determine the extent of contamination and ultimate fate of the contaminants in the ground water. Your objective is to create a preliminary map of the TCE analysis. These concentrations were collected from multilevel (multiport) wells but only the maximum concentration at any depth will be examined in this exercise.
You will find the windows zipped dataset available on the web site. TCE data are provided in the Excel worksheet MPW_TCE_2004.xls. Various base GIS shapefile data are also provided, including roads, hydrography, well locations, the LAI site boundary. Department of transportation topographic and plan raster data are also provided, along with a DEM of the area.
Analyze the data using two methods: (1) a classified symbol map and (2) a contour map. Do not attempt to perform geostatistics on this data set. You will be graded both on the representation of the data and the presentation of your map so make sure you include all the required information on the map. Construct a web page that presents your maps along with a brief narrative that interprets the data. The interpretation need not address the underlying contamination and transport problem, but should address the spatial distribution of the measured data.