Introduction and Importance of Reuse/Recycle Water and the ...
Transcript of Introduction and Importance of Reuse/Recycle Water and the ...
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Introduction and
Importance of
Reuse/Recycle Water and
the Use of Defined
Substrate Technology for
the Detection of Indicator
Bacteria Gil Dichter
World Wide Technical Support Manager, Water
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OBJECTIVES Introduction to Reuse Water
Importance of Reuse Water
Where is it being used?
Review of studies comparing Traditional
Methods to Colilert
Q & A
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- Drought
- Population growth
- Increased municipal, industrial, and agricultural demand
- Dependence on single source of supply
- Restrictions on wastewater discharges (nutrient limitations)
Factors Driving Water Reuse
2
Water
scarcity
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Guidelines for Water Reuse
EPA/625/R-04/108 Sept 2004 EPA 600/R-12/618 Sept 2012
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Categories of Water Reuse Applications
• Many states have rules, regulations or
guidelines for the range of reuse water
• Urban Reuse for non-potable applications.
• Agricultural Reuse
• Impoundments (recreational waters)
• Industrial Reuse
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Reclaimed/ Reuse Water
- Wastewater that has been treated to meet specific
water quality criteria used for a range of purposes
• Requirements for microbiological and chemical
parameters
- Varies from state to state (majority of states test for
fecal coliforms followed by total coliforms and several
for E.coli
Bacteria - total or fecal coliforms, E.coli or
enterococci
Pathogens - Cryptosporidium, Giardia, viruses
Chemistry: pH, Turbidity, BOD, COD, TSS
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Potential for Water Reuse
• About 7% of municipal wastewater effluent in the U.S. is reclaimed and beneficially reused
• Israel reuses more than 70%
• Singapore reuses 30%, up from 15% in recent years
• Australia, now at 8%, has a national goal of 30% by 2015
8
~7.3% Reclaimed
About 33 BGD of municipal effluent is produced annually in the U.S.
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Wastewater
Treatment
Drinking Water
Nonpotable Reuse (NPR)
Customers
Raw Water
Sources
Nonpotable Users
Irrigation
Industry
Cooling
Towers
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Wastewater
Treatment
(often with some
advanced treatment)
Water Treatment
Drinking Water
Indirect Potable Reuse (IPR)
Customers
Other Water
Sources
“Environmental
Buffer”
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Wastewater
Treatment
Water Treatment
Drinking Water
Direct Potable Reuse (DPR)
Customers
Other Water
Sources
Advanced
Treatment
X
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• Bacteria Indicator- E.coli
• Bacterial Limits:
- 30 Day Geometric Mean: 11/100 mL
- Reportable violation: 35/100 mL
- Uses: recreational areas - parks, golf
courses
Reuse Water- Virginia
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Multiple Tube Fermentation
Methods
Membrane Filtration
Enzymatic Methods
(Colilert & Colilert -18)
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Membrane Filtration
• Place filter on filter assembly
• Pour sample
• Apply vacuum
• Rinse filter assembly
• Remove filter and transfer
onto agar plate
• Cap, invert, and incubate
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Defined Substrate
Technology- Colilert or
Colilert-18 and Quanti-Tray
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Procedure for either P/A or Quantification
Blister Pack Add Reagent to Sample
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Quanti-Tray
Pour sample into Quanti-Tray Seal Quanti-Tray
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Incubate
Temperature
• Fecal Coliform
44.5°C ± 0.2° C
Total coliform/E.coli
35 ± 0.5° C
Time
• Colilert: 24 hours
• Colilert-18: 18 hours
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Positive Yellow Wells for Total
Coliforms or Fecal Coliforms
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E.coli- Blue Fluorescence- Quanti-Tray
under a 365nm UV Light
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Quanti-Tray 2000 MPN Table
No of large
wells giving
positive
reaction
No of small
wells giving
positive
reaction
MPN per
100ml
sample
95% Lower
Confidence
Limit
95% Upper
Confidence
Limit
10 2 13.2 7.1 22.0
30 12 64 46.8 85.1
47 40 509.9 393.4 652.5
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Quanti-Tray 51 MPN Table
No wells
giving
positive
reaction
MPN per
100ml
sample
95% Lower
Confidence
Limit
95% Upper
Confidence
Limit
0 <1 0 3.7
15 17.8 10.8 29.4
35 59.1 42 84.4
51 >200.5 146.1 infinity
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Studies
• California -
• Florida
• Oregon
• Idaho
• Washington
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Protocol for Comparing Methods
and Review of Several Studies
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Collect 250 ml sample
100mL for Colilert /Q-Tray-
Lab Method
100 mL for
MF or MPN
Incubate samples for required time & temperature
Read and record results
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California- Title 22
Requirement for Total Coliforms
• Total coliforms is the indicator bacteria required
for testing reuse water
- MTF 15 tube for total coliforms
- 2.2/100 mL 7 day median (if 4 consecutive days exceed
this, then 4th day is in violation)
- 23/100 mL not to exceed in more than 1 sample in a 30
day period
- 240/100 mL maximum for any one sample
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Site A • Secondary treatment for final effluent using
chlorination
• Samples tested over a 2 month period with n = 33
• All samples were tested in duplicate
• Positive & negative QC controls tested weekly
• All positive controls were within assigned range
• Negative controls were negative
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Site A 2X2 Table con’t
All results LTB-BGLB
Colilert + - Total
+ 3 11 14
- 0 52 52
Total 3 63 66
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Site A Tests Results Summary
LTB-BGLB
• 3 positives at 2/100
mL
Colilert
• 11 positives at 1/100
mL
• 3 positives at 2/100
mL
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Site B
• Tertiary treatment for final effluent using UV at
one plant and chlorination at the other plant
• Samples tested over a 1 month period
• Positive QC controls tested weekly
• Spiked sample tested
• All positive controls were within assigned
range
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Site B 2X2 Table con’t
All results LTB-BGLB
Colilert + - Total
+ 0 3 3
- 1 16 17
Total 1 19 20
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Site B Tests Results Summary UV Plant
LTB-BGLB
• 1 positive at 1/100
mL
Colilert
• 2 positives at 1/100
ML
• 1 positives at 2/100
mL
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Site C • Tertiary treatment for final effluent using
chlorination
• Samples tested over a 2 month period with n = 25
• Positive spiked control diluted in reuse water
tested weekly
• All positive controls were within assigned range
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Site C 2X2 Table con’t
All results LTB-BGLB
Colilert + - Total
+ 0 0 0
- 0 25 25
Total 0 25 25
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LTB-BGLB
Colilert + _ Total
+ 3 3 6
- 3 2 5
Total 6 5 11
Site X, OR 2 X 2 Table
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• 11 samples tested in parallel between Early May and mid-
August.
• Positive QC controls were tested and all were within the
assigned range.
• Reuse water spike with the positive control.
• PT was completed and passed.
• Results in 24 hours vs. 48-96 hours.
• Approval recommended by Certification Officer and permit
office issued permit action letter to allow use of Colilert.
Site X, OR
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Final Conclusions • Parallel testing at these sites indicates no significant
difference between the methods.
• Results can be obtained in18 or 24 hours compared to 48-96
hours
• Data from the sites suggest that Colilert can be used for
testing reuse water.
• Facilities in CA approved for using Colilert.
• Florida site using it for the past 2 years.
• Approved in Oregon. Can now use Colilert without further
approval. Same is true for Washington.
•Idaho Pending