FINAL ORDINANCE NO. 97-022 - Laserfiche WebLink

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B. Groundwater. Treatment cells shall have a minimum of 3 feet between the bottom of the cell and the ground water table. Drain tile or French drains shall not be used to artificially lower the groundwater table. Subd. 3 System Design. A. Designer. Wetland treatment systems shall be designed by a Registered Professional Engineer with experience and specific training in the design of these types of systems. B. Design Flow. Wetland treatment systems shall be sized based on a minimum of 50 gallons per day per person. C. Level of Treatment. Wetland treatment systems shall be designed to remove Total Suspended Solids (TSS), Phosphorous (P), Total Nitrogen (TN), and Fecal Coliforms (FC), and reduce the 5-Day Carbonaceous Biochemical Oxygen Demand (CBODS). Calculations showing the design level of treatment shall be submitted. Prior to discharge into the infiltration cell, the following discharge limits shall be met: CBODS 50mg/l TSS 20mg/l TN 15mg/1 N114 10mg/l TP 5mg/1 FC 200mg/1 In the ground water below the infiltration cell, the following discharge limits shall be met: TN 10mg/1 FC 4 c/100 ml D. Insection Points. Inspection and monitoring ports shall be located within the system such that the water level can be determined, and a water sample can be easily taken in each treatment cell, and 1- foot below the infiltration cell. E. Operating Plan. An operating plan shall be developed by the designer. This plan shall include standard operating procedures and maintenance of the system. F. Monitoring Plan. Systems designed for greater than 1500 gallons per day shall have a monitoring plan developed by the designer. It shall include monitoring of sludge and scum levels in the septic tanks and pumping stations, effluent flow into the system. Water quality exiting the fast treatment cell shall be monitored to insure that it meets the design level of treatment. Monitoring of the groundwater below the second treatment cell shall also be performed. Monitoring shall be conducted annually. The City shall be sent a copy of all test results. An annual fee shall be charged by the City to review these test results. This fee shall be set from time to time by resolution of the City Council. G. Mitigation Plan. The system designer shall develop a plan to follow in case expansion or abandonment of the system is necessary.