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3.1.4 <br />3.2 <br />4 <br />Filters <br />The SEH Pilot Water Plant contains four filter columns (filters) that each measure 8 inches in <br />diameter and 72 inches tall. The resulting surface area for filtration of each filter is 0.35 ft2. The <br />filters each have a 0.75 inch inlet, 1.5 inch backwash waste outlets, underdrains, air release <br />system, rate of flow meters, sample taps, and filter media. Pressure taps are located on the inlet <br />and outlet of each filter to obtain filter head loss by comparing the two pressures. For the <br />Ramsey pilot study, Filters 1 and 2 (Train 1) were operated without aeration and detention. <br />Filters 3 and 4 (Train 2) were operated with aeration and detention. Each filter was supplied 1.05 <br />gpnn to achieve a target filtration rate of 3.0 gprnift2 for this study. Each type of filter media used <br />in the study was new and had not been used in other studies_ The filters were backwashed with <br />a combination of air and water between filter runs. <br />Table 1— Pilot Study Filter Characteristics <br />Filter <br />, <br />Media <br />Filtration Rate <br />(gpmfft2) <br />Effective Si <br />(mm) <br />Media Depth (in) <br />1 <br />Greensand <br />' <br />3 <br />0_30-0.35 <br />18 <br />, <br />Anthracite <br />0.9-1.0 <br />12 <br />2 <br />Silica Sand <br />3 <br />0.45-0.55 <br />' 18 <br />i <br />Anthracite <br />0.9-1.0 <br />12 <br />3 <br />. <br />Greensand <br />, <br />3 <br />0.30-0.35 <br />, 18 <br />Anthracite <br />0,9-1,0 <br />12 <br />4 <br />Silica Sand <br />3 <br />0.45-0.55 <br />18 <br />Anthracite <br />0.9-1.0 <br />12 <br />Sampling and Analysis <br />Sampling and analysis was completed by the onsite SEH pilot plant operator. Field testing for <br />iron and manganese was conducted using a Hach DR/890 Portable Colorimeter, and was done <br />for the raw water and from the effluent of each filter. Testing for iron was conducted using the <br />Hach Method 8147 (DR800 FerroZine Solution Pillow), which has a range of 0-1.3 mg/L iron (Fe), <br />and an estimated detection limit of 0.011 mg/L Fe. Testing for manganese was conducted using <br />the Hach Method 8149 (DR800 PAN), which has a range of 0-0.70 mg/L manganese (Mn), and <br />an estimated detection limit of 0.020 mg/L Mn. Temperature and pH analyses were conducted <br />using a Hach HQ 40 pH meter, and was done for the raw water. Samples for the analysis of <br />chlorine were collected from the effluent of each filter and analyzed using the Hach DR/890 <br />Portable Colorimeter. The chlorine demand was calculated by subtracting the residual chlorine <br />after filtration from the dose of chlorine added to the raw water to oxidize iron. The results of the <br />sampling and subsequent analysis are presented in the remainder of this report. <br />Pilot Study Results <br />As discussed, the pilot study was conducted for Ramsey's Wells No. 3 and 4 to establish the <br />efficiency and reliability of the two treatment processes, as well as the two filter media types, to <br />remove iron and manganese. Identical pilot studies were conducted at both wells. The purpose <br />of this was to determine how well the treatment processes would do with more than one source <br />PILOT STUDY REPORT RAMSY 154354 <br />Page 4 <br />