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Use of ATP to identify poor-performing filters . Al Parrella Western Lake Superior Sanitary District Duluth, MN. Add bleach here. Final effluent. Problem statement:. Bacteria increases across effluent filters Seems to be a seasonal phenomenon (worse towards end of season).
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Use of ATP to identify poor-performing filters Al Parrella Western Lake Superior Sanitary District Duluth, MN
Add bleach here Final effluent
Problem statement: • Bacteria increases across effluent filters • Seems to be a seasonal phenomenon (worse towards end of season)
Fecal coliform, before and after filtersMonthly geometric mean
Fecal coliform, before and after filtersMonthly geometric mean Limit Problem
Troubleshooting • Use of ATP pen • Test ATP at various location including the effluent of each filter • Results reported as difference between “total” and “free”
Results • Clearly there was a problem with number 11 filter • Found several mechanical issues related to backwash system
Conclusion • It’s hard to clean 100+ tons of media
Steps • Start meter • Obtain sample • Submerge pen • Break ampule • Mix • Obtain reading • Units are in “relative light units”
Thanks to… • …Roger Sandstrom, Treatment Plant Operator • Kathy Hamel, PE, Operations and Maintenance Supervisor, Clean Water Production