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FIELD PROTOCOL Conventional Sampling Technique Before the static groundwater level from the Monitoring Wells is measured, wells are opened and allowed to equilibrate. The Depth To Water (DTW) and floating product level, if present, in each well that contained water is then measured with a Solonist Water level Indicator and a KECK Interface Probe — 100', respectively. These instruments are accurate to the nearest 0.01 foot. If necessary, groundwater depths are subtracted from wellhead evaluations, including corrections for product thickness, for gradient evaluation by multiplying product thickness (PT) by a correction factor 0.8 and subtracting from the DTW (Adjusted DTW=DTW— [PT x 0.8]). Water samples collected for subjective evaluation, i.e. measurable floating hydrocarbon product (if present), are collected by gently lowering approximately half the length of a new disposable bailer past the air-water interface (if possible) and collecting a sample from near the surface of 1 the water in the well. Prior to collection of groundwater samples, at least three well casing volumes are purged with either a powered pump or bailers. Temperature, pH and conductivity are measured with a Horiba Water Quality Monitor Model U-22XD for each well casing volume. When the measured parameters are stabilized, the groundwater sample is collected. The quantity of water purged from each well is calculated as follows: 1 Well Casing Volume (gal) =n x r2 x h x 7.48 h=Total Well Depth—DTW. where r is radius of the well casing (feet), h is column of water in the well (feet) and 7.48 is the conversion factor from cubic feet to gallons. The number of well casing volumes removed=total gallons of water purged/gallons in 1 well casing volume. ' After purging, each well is allowed to recharge to at least 80% of the initial water level. Water samples are collected with a new disposable bailer, and carefully poured into 40-milliliter (ml) glass vials preserved with hydrochloric acid. The vials are filled so as to produce a positive meniscus and sealed with a cap containing a Teflon® septum, and examined for air bubbles to avoid headspace that would allow volatilization to occur. The labeled samples are promptly transported on ice in a thermally insulated ice chest, accompanied by a Chain of Custody Record, ' to a California-certified laboratory. 1