Post on 28-Mar-2015
transcript
Use of ATP to identify poor-performing filters
Al ParrellaWestern 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
April May June July August SeptemberOctober0
50
100
150
200
250
300
350
400
450
BeforeAfter
Fecal coliform, before and after filtersMonthly geometric mean
April May June July August SeptemberOctober0
50
100
150
200
250
300
350
400
450
BeforeAfter
Problem Limit
Troubleshooting
• Use of ATP pen• Test ATP at various location including the
effluent of each filter• Results reported as difference between “total”
and “free”
Seco
ndary Effl
uent
Floc T
ank I
nfluent
Filter
Effluen
t 1
Filter
Effluen
t 2
Filter
Effluen
t 3
Filter
Effluen
t 4
Filter
Effluen
t 5
Filter
Effluen
t 6
Filter
Effluen
t 7
Filter
Effluen
t 8
Filter
Effluen
t 9
Filter
Effluen
t 10
Filter
Effluen
t 11
Filter
Effluen
t 12
Final
Effluen
t0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
ATP Assessment October 2, 2013
Results
• Clearly there was a problem with number 11 filter
• Found several mechanical issues related to backwash system
Seco
ndary Effl
uent*
Floc T
ank I
nfluent
Filter
Effluen
t 1
Filter
Effluen
t 2
Filter
Effluen
t 3
Filter
Effluen
t 4
Filter
Effluen
t 5
Filter
Effluen
t 6
Filter
Effluen
t 7
Filter
Effluen
t 8
Filter
Effluen
t 9
Filter
Effluen
t 10
Filter
Effluen
t 11
Filter
Effluen
t 12
Backwash
Wate
r
Final
Effluen
t0
500
1000
1500
2000
2500
3000
3500
4000
4500
ATP AssessmentOctober 15, 2013
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