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Geolo&A17,eduda bu. Page 3 Groundwater Monitoring Report Project No. 750.2 ( November 18,2003 Figure 2 shows the location of the well cluster used for calculating g vertical groundwater 1 gradient in this report, MW-1 and MW-10 L Table 1 shows a Summary of Water Level and Gradients Slope and Bearing and Table 3 shows the calculated vertical gradients. The information used in the calculations is shown below. + Vertical gradient calculation formulas are as follows: • vertical correction for gradient: [(gw gradient slope) x (distance)=vertical correction] • vertical head: [(head of deep well) (head of shallow+ correction) =vertical head] vertical gradient: [(vertical head) /(vertical distance) =vertical gradient]• 3 For the September 6, 2003, groundwater measurement, the vertical gradient was calculated for the MW-1/MW-101 pair. The vertical gradient was negative (a downward direction). However, it was insignificant as head difference between MW-1 and MW-101 was only 0.03-feet. Generally, the magnitude of.the vertical gradient has progressively decreased # since February 2001. As required under AB2886, the depth to groundwater data was submitted electronically to GeoT racker-on November 7, 2003, withconfirmation number 27.11598038. I , 1.2 Groundwater Sampling Procedure On September 6, 2003, Don Light. of Del-Tech mobilized to the site to conduct a groundwater-monitoring event.- Del-Tech personnel opened the wells and measured the depth to water with an electrically actuated sounding tape. The water level reading was recorded to an accuracy, of 0.01 foot. No floating product was detected during the I. , monitoring event. Stagnant water in the well casing g was purged ged using a Waterra pump and dedicated tubing. The rate of well purging was. monitored. The well was purged of at least three casing volumes until the groundwater parameters (temperature, conductivity and pH) had stabilized r (Appendix Q indicating that water representative of actual aquifer conditions was entering y the well. Groundwater parameter stabilization was characterized by three successive readings within 10%. L Before a sample w ' p as collected, the wells water level was.allowed to recharge to at least 80% of its initial level. All water removed from the monitoring well and not used as a i sample was placed in a 55 gallon DOT approved container that is properly labeled and temporarily stored on-site. A Waterra pump and dedicated tubing were used to collect each sample. Extreme care was Iexercised while collecting samples to prevent agitation of the water contained in the r, ✓ Waterra pump. With minimal sample aeration, water samples were transferred from the