Lab 5: Suitability Analysis

Kettleman Hills

The Kettleman Hills polychlorinated biphenyl (PCB) disposal facility is only one of ten in the nation. PCBs are highly toxic and have found to be carcinogenic in animals. Furthermore, the EPA suspects them to be cancer-causing in humans. In a 2010 report, the EPA found that the Kettleman Hills facility was improperly disposing of PCB materials—local air, soils, biota, and vegetation samples exceeded legal PCB levels by 2 to 400 times. For this reason, lawmakers have been hesitant to allow the facility to expand until further PCB research has been conducted. GIS and suitability analysis can be very helpful in objectifying whether the Kettleman Hills facility can be safely expanded given certain safety requirements.

A key concern among the Kettleman community is that an abnormally high rate of birth defects is linked to groundwater contamination from the PCB facility. I could analyze the problem with ARCGIS by performing a buffer analysis on the town’s aquifer to see if the facility is nearby existing water supplies. The region could incorporate slope (in relation to runoff), water table height, distance from aquifers, distance from population centers, and vegetation type, and soil permeability into a suitability analysis of the region surrounding the facility.

Each variable could also be individually weighted to reflect higher importance. The proposed expansion area around the Kettleman Hills facility could then be evaluated based on this suitability analysis.The Kettleman Hills facility suitability analysis could then be compared to other potential PCB disposal sites. These potential locations should be subjected to the same analysis to keep the figures consistent and to determine whether or not another area is more suitable. One difficult factor to measure is that the Kettleman PCB facility is only 3 miles from Kettleman city—a popular stop on CA Interstate 5. Although few residents live in the community, many people depend on its water.

In order to analyze the total effect of the PCB facility, Kettleman satellite images from before the facility was opened could be compared to Kettleman satellite images after the facility was opened. The vegetation cover could be made into polygons in each period and the change in land cover could be analyzed. This may prove to be useful in the case that some plants are especially susceptible to PCB contamination. If this method is effective, it would also show the range of PCB contamination.

GIS can help lawmakers make better decisions by summarizing scientific data in a condense and visual way. Although more complex layers can be at work, GIS helps identify and objectify the most immediate and pressing concerns. The above image is an example of results that could be reproduced for the Kettleman site.