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AMENDMENT TO OWNER-ENGINEER AGREEMENT NO. 1 – ATTACHMENT NO. 2 <br />WesTech Gravity Filter Media Analysis Overview <br />The below information was shared with Owner and United Consulting on December 1, 2023. Pricing <br />and information provided below are subject to change. Owner will be alerted of any changes to the <br />below details as soon as they become known to Engineer, if any. <br />FILTER MEDIA CORE SAMPLING PROCEDURE <br />The filter media must be thoroughly backwashed prior to collecting any sample. After <br />backwashing the media, drain the filter completely. Remove the manway cover if required. It is a <br />good idea to have a new manway gasket on hand. <br /> Using a sanitized 1¼” to 1½” diameter by 4’ to 6’ long (depending on the bed depth and amount <br />of freeboard) piece of thin wall tubing, insert the tube approximately six inches into the media <br />with a twisting motion. Empty the media into a clean bucket by tapping the side of the <br />tube. Repeat this procedure, being sure to sample the same hole, at six-inch increments until the <br />entire media bed has been sampled and the gravel or gravel retaining screen, if such has been <br />installed in the unit, has been intersected. <br /> The composited sample should then be thoroughly mixed to obtain a representative sample and <br />no less than one quart of the material forwarded to us for laboratory evaluation. If one core <br />sample does not yield a full quart, a second core sample should be obtained and mixed together <br />with the first so that a full quart is available for analysis. <br />CAUTION: Be sure to sample only the filtering media. DO NOT force the sample tube into the <br />sub-fill or the underdrain. <br />Mud balls or foreign material on or in the media should be included in the core sample. A <br />separate sample of any foreign material or mud balls should be sent along with the core samples. <br />Note the depth of the filter media (by inserting a ruler into the sample hole) and the general <br />condition of the bed surface. Note observations such as the media level, media mounding, and <br />fissures (channels) on the media surface. <br />Include with sample: <br />•Person, Company, Address, Phone Number <br />•Type of Media sample (Greensand, Anthracite, etc.) <br />•Date sampled <br />•Reason for sample (low capacity, poor quality, etc.) <br />•Purchase Order Number