Prestige Environmental became the official maintenance company to check for groundwater sampling. They check the wells surrounding the site for volatile organic compounds (VOC’s), changes in water level, and general maintenance. Each area of maintenance wells contains three wells of varying depths. Each well is tested to measure levels in the top aquifer, the middle soil, and the lower aquifer (Prestige, 2018). They use a photoionization detector to complete their preliminary assessments of the sites. This will measure any VOC’s and other gases that are emitted from the wells. They complete this by immediately placing the sensor by the opening of the well when they open the cover. Concentrations are measured by parts per billion. On site analysis during the interview showed that there were no VOC’s or other gases present at the locations visited. Prestige Environmental also tested the depths of the water in the well to determine the health of the aquifer and if the plume may affect it if the water level were to raise. If all preliminary assessment reading are within range, they return the following week to do more in-depth water sampling and test for; vinyl chloride, meththylene chloride, 1,2 dichloroethane, thrichloroethene, benzene, mercury, tetrachloroethene, chlorobenzene, and many others (Dickerson, 2018). This site has not been deleted from the NPL list.