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Start <br />Stormwater Pond <br />is periodically <br />inspected <br />Minnesota Stormwater <br />Manual Appendix D has a <br />Stormwater Pond/Wetland <br />Operation & Maintenance <br />Checklist (see rule of <br />thumb) <br />Inspect the <br />embankment and <br />emergency <br />spillway <br />Inspect inlet riser <br />and principle <br />spillway or outlet <br />structure <br />Inspect outfall <br />locations <br />Measure the <br />amount of <br />sedimentation <br />buildup <br />Is volume of sediment <br />approaching 50% of the <br />capacity of the pond ** <br />inhibiting pond effectiness? <br />No <br />Take sample (s) of <br />sediment to <br />determine particle <br />size distribution <br />Yes <br />Determine percent <br />of sample that is <br />retained on a #200 <br />sieve <br />Is 93% or more of <br />sediment retained on a <br />#200 sieve ?Yes <br />Have samples <br />analyzed for <br />contaminate <br />concentrations <br />No <br />Evaluate Lab <br />results: Determine <br />Management level <br />Dredge Management level <br />does not need to be <br />determined. It is assumed <br />to be management level 1 <br />See Sediment <br />Placement process <br />flow chart <br />Sediment Volume <br />(Cubic yds) <br />Recommended # of <br />samples <br />0 to 100 1 <br />100 to 500 2 <br />500- to 3,000 3 <br />3,000-30,000 4 <br />30,000-100,000 5 <br />100,000-500,000 6 <br />500,000-1,000,000 7 <br />1,000,000 8 + <br />** or less than 3 feet of water at the inlet half of pond <br />wq-strm4-13 Minnesota Pollution Control Agency 6/1