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ARCADIS <br />ARCADIS' drilling subcontractor (Layne) began the well redevelopment by brushing <br />the screened interval of the well to loosen any debris. Layne continued to brush and <br />surge the well for approximately 1.5 hours. During the brushing process rubber <br />gaskets were added to the scrubber to increase the surge block affect. The recharge <br />rate was observed to be approximately 1 foot every 10 minutes and the water was <br />observed to be cloudy, gray and contained fine sediments. Next, the well was <br />surged block and then bailed followed by airlifting. <br />Compressed air was used to lift and lower water across the screened section of the <br />well to free the well screen of particulates that were clogging the filter pack. Airlifting <br />activities were performed for approximately one hour until conditions did not appear <br />to improve. The recharge rate increased to approximately 1.5 feet every 10 minutes <br />and the water was less cloudy than during the scrubbing process. <br />After airlifting a final bailing operation was completed with a 15 foot long metal bailer. <br />The well was completely dewatered during the final bailing operation. ARCADIS <br />documented well development activities on a daily log. A copy of the daily log is <br />provided in Attachment 1. <br />Groundwater Sampling and Analysis <br />Groundwater samples were collected from MW -7 on September 28, 2012. Due to the <br />slow recharge in MW -7, three well volumes were not able to be purged from MW -7. <br />MW -7 was purged dry and left to recharge prior to collecting the sample. <br />While MW -7 was recharging, a round of water levels was collected from the <br />monitoring wells and piezometers at the site. This data is provided in Table 1 and <br />shown on Figure 1. Overall groundwater elevations and flow direction have not <br />changed significantly from measurements collected in March 2012. <br />The field water quality parameters including temperature, pH and specific <br />conductivity were stable (i.e., less than a 10 percent change between readings) <br />before samples were collected from MW -7 using a disposable bailer. Groundwater <br />samples were placed directly into laboratory- supplied containers and kept on ice in a <br />cooler. <br />Groundwater samples were submitted to the ACZ Laboratories, Inc. (ACZ) Facility <br />located in Steamboat Springs, Colorado for laboratory analysis of metals (iron, <br />manganese, potassium and sodium), TDS and sulfate. Samples for total dissolved <br />C l ser ■usku Doiuncnt, Hol nm 2012 MW -7 Redevelop Summat} Letter 2012 1217 Holcun Portland R ell De, Sampling Summat■ Letter doc <br />Mr. Justin Andrews <br />December 17, 2012 <br />Page. <br />2/5 <br />