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Staff Report-PW Staff Report Date of Meeting: 4/27/2022 For: Wastewater Committee From: Charles Fischer – Director of Public Works Subject: Staff Report Bliss System: Since the beginning of the year the Bliss System has been operating well. The only issue that we have faced is a control panel having triggered an alarm twice in the same week. This issue has been monitored and no alarms have been triggered recently. The alarms which were triggered are believed to be from the Spring snow melt as the covers to the settling and pump tank were covered by deep snow and are placed near a drainage valley on the property. Possibility of I&I is likely the issue and the pump was not able to keep up with the infiltration. The flow meters installed in late February have been operating normally and effluent flows from the sand filters are now measured more accurately. The meters also indicate flow rates in GPM while the pumps are running which allow Public Works to monitor any significant change in pump operation or when it is required to recalibrate the meters. The meters will need to be recalibrated on a yearly basis and will be performed by Quality Flow for two years from the installation date. After two years from the installation date Public Works can look for other vendors or continue with Quality Flow for yearly recalibration. The infiltration trenches have been switched from mounds A and C to B and C. By changing the flow to specific mounds, we are able to build in resting periods for each mound. Typically, one of the three trenches will rest for one year. Well water monitoring has continued to show lower Nitrogen levels under 20mg/L but still above the 10mg/L set by the MPCA. Uptown System: The Uptown System has been operating between 2000-2500 gallons per day on average since January of 2021. The I&I coming into this system between 2021 and 2022 has been marginal in April of 2021 and February of 2022 which were the melting periods following the winter of each year. Although there was infiltration noticed in the pump run times the average flow for each month continued to stay below the average per day for the respective month. In the graphs provided you will see a two-day window in July where the flows went above the average per day and was due to drawing down the tank for inspection. A/E System: The A/E system throughout 2021 operated under the average flow per day for the calendar year. Although operation has been below this mark the system is close to operating at the designed average per day capacity. I&I has continued within the system as well and can be noticed in the abrupt spikes in March and April of 2021. The Spring weather of 2022 and the shaded nature of the neighborhood drew out the period in which the frost subsided and made for a more continual I&I timeframe recorded between February and March, which daily flows were at or above average per day flow set by the County permit. The April flows represented in the chart do not represent the actual flow of the system. Pump 1 in the lift stations has been experiencing operational issues and inspections of the pump have taken place. The pump has been inspected and found to be running at normal operation and flow. The issue has been noted in the control panel. Further investigation of the control panel is now taking place. Pump Inspection and Flow Testing: This year Public Works contracted Minnesota Pump Works to pull and inspect all the pumps in the major lift stations within each system. The number of major lift stations are: four in the Bliss, two in the Uptown and one in the A/E. Each lift station has two pumps which pump independently during normal flow or together during a high flow situation. Also, during the inspections motor oil was drained and filled and any necessary repair, parts replacement or adjustments were also to be made. The inspections and flow testing were performed Monday, April 25th and Tuesday, April 26th. The final office report is being generated and should be available soon. Verbal confirmation from the technician noted that all pumps are in normal operating condition. The office report will have further information for any abnormality or if any pumps should be considered for future replacement.