Transcript Use of ATP to identify poor

Use of ATP to identify poorperforming 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 filters
Monthly geometric mean
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Before
After
Fecal coliform, before and after filters
Monthly geometric mean
450
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350
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Problem
Limit
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100
50
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Before
After
Troubleshooting
• Use of ATP pen
• Test ATP at various location including the
effluent of each filter
• Results reported as difference between “total”
and “free”
ATP Assessment
October 2, 2013
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Results
• Clearly there was a problem with number 11
filter
• Found several mechanical issues related to
backwash system
ATP Assessment
October 15, 2013
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Conclusion
• It’s hard to clean 100+ tons of media
Steps
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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