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I. Description of Waste Treatment System <br /> The City owns and operates a water treatment facility designed to primarily remove arsenic <br /> from groundwater using Ferric Chloride. Water is treated with Sodium Hypochlorite for <br /> disinfection and oxidation along with Ferric Chloride as a coagulant (to remove Arsenic). <br /> Treated water is then filtered through four vessels. As filters accumulate material, they are <br /> backwashed which generates a Ferric Chloride sludge bound with the removed Arsenic ions. <br /> Solids residual is sent to a recovery tank for settling and thickening. Once sludge is settled <br /> in the backwash recovery tank, it is then moved on for further treatment through use of a <br /> filter press. The filter press system includes a sludge batch tank, air compressor, pneumatic <br /> diaphragm pump, and a sidebar filter press, which provides dewatering of the liquid sludge <br /> with approximately 1.0%- 2.0%solids concentration by mass to a filter cake material that is <br /> then stored (no more than 90-days maximum) in a lined roll-off bin until the material is <br /> hauled to an appropriate disposal site. Water from the treatment process is recycled back <br /> into the headworks. <br /> 11. Constituents to be Analyzed <br /> The Filter Cake produced from this treatment process is known to be a Non-RCRAHazardous <br /> Waste, primarily due to the removal of arsenic from the water treatment process. This was <br /> established when the plant was first put into service around 2012-2013. The wastestream <br /> was originally profiled then and was analyzed for CAM 17 metals. The physical state is <br /> considered solid but does have some portion of liquid. Samples will be analyzed"as-is" and <br /> will not be dried further to ensure sample is representative. <br /> Since no significant changes in process or treatment technology have occurred at the <br /> treatment plant since it was put into service, future samples will also be analyzed for CAM <br /> 17 metals. If a significant change in process occurs (i.e., change in coagulant chemical, <br /> addition of a new chemical or treatment process, change in source water),the filter cake will <br /> be analyzed for additional indicator parameters, and the waste profile will be updated <br /> accordingly. <br /> III. Sampling <br /> a. Location(s) <br /> Samples will be collected from the filter cake disposal bin at a time when the bin is <br /> near-full and ready for disposal (within the 90-day timeframe for large quantity <br />