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than 20% during an operational period, additional jar testing shall be performed, and <br /> dose rates reviewed. <br /> City of Everett <br /> EVERETT Reviewed for Permit 10/20/2021 <br /> W FSHINGTON <br /> 3.2.2 Chitosan/ Chemical Dose Rate Calibration <br /> The dose rate of chitosan will be determined using the standard jar test and then <br /> calibrating the LMI pump by timing the uptake of chitosan (through the metering pump) <br /> from a graduated cylinder and noting the flow rate of the sand filter. The metering pump <br /> will be calibrated at least daily and every 4 hours throughout the day (or if the dose is <br /> changed in response to changing conditions during treatment). <br /> It is important to use the treatability testing procedure so the operator uses the minimum <br /> amount of chitosan/ chemical necessary to achieve results. <br /> 3.2.3 pH Neutralization <br /> Depending on soil and water conditions, pH neutralization will be available as needed <br /> throughout the project. A CO2 tank with a line heater and regulator assembly has been <br /> added as part of the water Quality monitoring box. A flow splitter and pair of needle <br /> valves would be used to individually control gas flow to an injector on the incoming <br /> pretreatment line as well as before the sand media filter. Sample ports on both lines <br /> allow the operator to measure and adjust gas flow as necessary. <br /> pH of the discharge will be adjusted to minimum of 6.5 and maximum of 8.5. <br /> 3.2.4 Treatment System Operation Sequence <br /> The filter system operator will follow the sequence outlined below for system operation: <br /> • Jar testing of the water in the tanks will determine/ confirm treatability and <br /> necessary Chitosan dose rates as well as pH neutralization. <br /> • The discharge volume totalizer should be read and recorded in the daily <br /> treatment operations log before starting the system. <br /> • Start the Chitosan acetate metering pump (if required) and check to ensure <br /> Chitosan is being delivered at the proper dose rate with the calibration tube. <br /> • Turn on the in line CO2 heater and adjust the gas flow as needed for pH <br /> adjustment <br /> • Start the filter system feed pump with the system in manual re-cycle, measure <br /> and record the influent flow rate, turbidity, and pH in the daily log. <br /> • Collect a sample of filtered water and measure and record the turbidity, pH and <br /> Chitosan residual test results in the log <br /> 11 <br />