The groundwater in the well is sampled for characteristics (hereinafter ???groundwater characteristics???), such as, but not limited to, water quality parameters; groundwater level; and contaminants such as benzene, toluene, ethyl-benzene, xylenes (BTEX), aromatic hydrocarbons and chlorinated solvents such as trichloroethylene (TCE), tetrachloroethylene (PCE) and their degradation products, dichlo