WET WEATHER FLOWS 2010...KDHE Annual Water & Wastewater School August 5, 2010 Wet-weather flows are...
Transcript of WET WEATHER FLOWS 2010...KDHE Annual Water & Wastewater School August 5, 2010 Wet-weather flows are...
91st Annual Water andWastewater School
August 3 - 6 2010
WetWet--Weather FlowsWeather Flows
Jim Fitzpatrick
KDHE Annual Water & Wastewater School August 5, 2010
Overview
Wet-Weather Flow Treatment Challenges
Auxiliary Treatment Strategy
High-Rate Treatment Processes and Technologies
Closing Thoughts
B&V - 2
KDHE Annual Water & Wastewater School
Wet-Weather Flow Treatment Challenges
Wet-Weather Flow Treatment Challenges
Totally different set of technical and ecological issues than dry-weather flow treatment
Totally different set of technical and ecological issues than dry-weather flow treatment
KDHE Annual Water & Wastewater School August 5, 2010
Aggressive SSO or CSO control usually results in higher peak flows to treat
Realistic long-term I/I removal goalsOld sewers leak…new sewers will leak when they get old.
Significant effort and continuous expense. Year after year afteryear…after year...after year…
Private property issues
Increased storage may not eliminate need for high-rate treatment
Storage dewatering rates, back-to-back storms, etc.
Too much storage may be more detrimental to environment
Cost/benefit of I/I removal vs. conveyance & treatment determined through comprehensive analysis
B&V - 4
KDHE Annual Water & Wastewater School August 5, 2010
Wet-weather flows are generally highly variable and infrequent…
Mill Creek WWTP (Cincinnati, OH)Influent Flow Probability Curve
0
50
100
150
200
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300
350
400
450
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percentage of Data At or Below Value
Raw
Influ
ent F
low
, M
GD
Daily Average Data (1/1/03 - 11/24/08)Annual Average Design CapacityMaximum Monthly Average Design CapacityPeak Daily Average Design Capacity
Lawrence, KS WWTP Influent Excess Flows
0
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0 5 10 15 20 25 30 35 40 45 50 55 60 65 70Run time, hrs
Flow
, mgd
0
20
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Flow
, ML/
d
30-Aug-03 13-Sep-03 4-Mar-0410-Mar-04 13-May-04 25-May-042-Jul-04 7-Jul-04 16-Jul-0426-Jul-04 27-Jul-04 29-Jul-0417-Aug-04 18-Aug-04 24-Aug-0428-Aug-04 8-Oct-04 5-Jan-057-Feb-05 13-Feb-05 13-May-051-Jun-05 3-Jun-05 11-Jun-0512-Jun-05 13-Aug-05 20-Aug-0526-Aug-05 23-Sep-05 20-Oct-0530-Apr-06 1-May-06 28-Aug-0622-Mar-07 12-Apr-07 14-Apr-076-May-07 19-Jun-07 30-Jun-074-Oct-07 17-Oct-07 18-Oct-0717-Feb-08 3-Mar-08 17-Mar-0819-Mar-08 9-Jun-08 13-Jun-0813-Sep-08 8-Mar-09 27-Apr-0930-Apr-09 16-May-09
QPKHR ≈ 5 to 10 x QAA
Similar for other CSS and SSS communities
Site-specific climatesB&V - 5
KDHE Annual Water & Wastewater School August 5, 2010
…with highly variable influent qualityMill Creek WWTP (Cincinnati, OH)
Influent Characteristics (Jan '03 - Nov '08)
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50 100 150 200 250 300 350 400 450
Raw Influent Flow, MGD
Raw
Influ
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once
ntra
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mg/
L
Annual Average Design CapacityDaily Average TSSDaily Average BODBest Fit (TSS)Best Fit (BOD)
Nelson WWTP Complex (Johnson County, KS)Influent Characteristics (Jan '03 - Nov '08)
0
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0 1 2 3 4 5 6 7Sewershed Flow Peaking Factor (Daily Average/30-day Average)
Influ
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OD
, mg/
L
No PEFTF OperationPEFTF OperationTrendline (y=ax^b)
C << CAA after first flush
Similar for other CSS and SSS communities
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KDHE Annual Water & Wastewater School August 5, 2010
Pollutants of concern are generally different than normal dry-weather conditions
D.O. sags generally much less of a concern vs. dry weather.High flows/volumes, turbulence, etc. in receiving stream
Larger assimilative capacity
Main wet-weather POCs are generally:Floatables. Trash, plastics, etc. Ingestion and entanglement by wildlife. Aesthetics
Solids. Prevent silt and sediments from burying eggs and larvae.
Biological pathogens (bacteria, viruses, etc.). Human health concern vs. aquatic toxicity concern.
Predominantly non-point sourcesB&V - 7
KDHE Annual Water & Wastewater School August 5, 2010
Biological treatment processes can be optimized, but have inherent limitations
Wet-weather capacity is inexact. Different storm-to-storm, antecedent conditions, etc.Cold influent (snowmelt) challenges.Building more biological treatment units will not necessarily increase wet weather capacity. Biomass has finite capacity.Save Your Biomass
Absolutely critical component of POTWRecovery can take weeks or monthsBNR biomass are particularly sensitive
Capacity bottleneck is usually existing clarifiers and/or filters (physical/chemical process units)
Don’t Upset Your Bugs!
B&V - 8
KDHE Annual Water & Wastewater School August 5, 2010B&V - 9
KDHE Annual Water & Wastewater School August 5, 2010
???????????????
Misinterpretation of “Secondary Treatment”
BiologicalProcess
BiologicalProcess
Auxiliary Treatment Facilities for Wet Weather
Excess FlowsSecondary ≠ Biological. Unintended consequence from focusing only on dry weather.
SecondaryTreatment
PrimaryClarifier
PrimaryClarifier
PrimaryTreatment
SecondaryClarifier
SecondaryClarifier
SecondaryTreatment
PrimaryTreatment
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KDHE Annual Water & Wastewater School August 5, 2010
We don’t currently have technology-based effluent limits for wet-weather conditions
40 CFR 133 assumes long-term average influent…TSS/BOD = 200/200 mg/L.Long-term effluent from entire POTW…not short-term performance criteria for biological trains…not wet-weather influent conditions.Narrative allowances in 40 CFR 133 and 122(m) for wet weather.
Parameter Units
40 CFR 133.102 40 CFR 133.105
Secondary Treatment Equivalent to Secondary Treatment
Max Min Weekly Average
Monthly Average Max Min Weekly
AverageMonthly Average
pH SU 9.0 6.0 - - 9.0 6.0 - -
TSSmg/L - - ≤45 ≤30 - - ≤65 ≤45
% Removal - - - ≥85% A - - - ≥65% A
BOD5mg/L - - ≤45 ≤30 - - ≤65 ≤45
% Removal - - - ≥85% A - - - ≥65% A
Notes:A. Based on monthly average influent and effluent concentrations only. Special considerations for
lower requirements with combined sewers and less concentrated influent for separate sewers.B&V - 11
KDHE Annual Water & Wastewater School August 5, 2010
Primary Treatment Secondary Treatment
“Secondary Treatment” per 40 CFR 133 & 122.41(m)
BulkSolids
Removal
BiologicalProcess
Liquid/Solid Separation
BulkSolids
Removal
BiologicalProcess
Liquid/Solid Separation
Auxiliary Treatment Facilities for Wet Weather
Excess Flows
SecondaryTreatment
Optional
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KDHE Annual Water & Wastewater School
Auxiliary Treatment StrategyAuxiliary Treatment StrategyA proven strategy for treating wet-weather flows…
…while minimizing SSOs or CSOs
A proven strategy for treating wet-weather flows…
…while minimizing SSOs or CSOs
KDHE Annual Water & Wastewater School
Parallel auxiliary treatment has a long track record as an effective wet-weather strategy
Complement the inherent wet-weather limitations of biological processes
Auxiliary treatment facilities optimized for wet weather influent
Enable POTW to achieve secondary treatment effluent quality during both dry and wet weather
Biological Treatment Facilities
River
Auxiliary Treatment Facilities
Qpeak
~2Qavg
QXS
August 5, 2010B&V - 14
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Some lessons learned from CSO control…R
iver
QpeakFlow
Control
QXS
Reduce via NMCOptimize per NMC
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
t
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KDHE Annual Water & Wastewater School August 5, 2010
Additional treatment presumed by USEPA 1994 CSO Control Policy Minimum Required, Except:
(i) ≤ 4 to 6 events per yearOR
(ii) ≤ 15% of system-wide annual average collected volume
KDHE Annual Water & Wastewater School August 5, 2010
Additional treatment per CSO Control Policy...R
iver
QpeakFlow
Control
QXS
QXS2
Reduce per LTCP
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
t
LTCP implementation scenario that many POTWs are now tackling.
QXS1
Wet-Weather Auxiliary Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
Flow Control
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KDHE Annual Water & Wastewater School August 5, 2010
Integrated CSO Pollution Control FacilitiesR
iver
QpeakFlow
Control
QXS2
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
tWet-Weather Auxiliary
Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1Flow Control
Optimal design in many cases for event response, operations, maintenance, etc….
…so, may be optimal design for water quality protection.B&V - 18
KDHE Annual Water & Wastewater School August 5, 2010
How far can we go with integrated facilities?R
iver
QpeakFlow
Control
QXS2
Site-specific design constraints (levees, effluent pumping, etc.) may make single outfall desirable.
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
tWet-Weather Auxiliary
Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1Flow Control
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KDHE Annual Water & Wastewater School August 5, 2010
How far can we go with integrated facilities?R
iver
QpeakFlow
Control
QXS2
Instead of separate monitoring sites, specify separate monitoring conditions
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
tWet-Weather Auxiliary
Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1Flow Control
Dis
infe
ctio
n
Combined disinfection facilities may be optimal design alternative.
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How far can we go with integrated facilities?R
iver
QpeakFlow
Control
QXS2
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
tWet-Weather Auxiliary
Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1Flow Control
Dis
infe
ctio
n
Combined preliminary treatment facilities (screening & grit removal) may be optimal design alternative.
Prel
imin
ary
Trea
tmen
t
B&V - 21
KDHE Annual Water & Wastewater School August 5, 2010
How far can we go with integrated facilities?R
iver
QpeakFlow
Control
QXS2
~2Qavg
BiologicalTreatmentFacilities D
isin
fect
ion
Wet-Weather Auxiliary Treatment
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1
Dis
infe
ctio
n
Same as previous slide, except flow split is after preliminary treatment.
Prel
imin
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Trea
tmen
t
Flow
Con
trol
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KDHE Annual Water & Wastewater School
Wet-weather events lend themselves to a parallel auxiliary treatment strategy
Complement the inherent wet-weather limitations of biological processes
Auxiliary treatment facilities optimized for wet weather influent
Enable POTW to achieve secondary treatment effluent quality during both dry and wet weather
Biological Treatment Facilities
River
Auxiliary Treatment Facilities
Qpeak
~2Qavg
QXS
August 5, 2010B&V - 23
KDHE Annual Water & Wastewater School August 5, 2010
What are “auxiliary treatment facilities”?
Permitted use implied at 40 CFR 122.41(m)(4)(i)(B)
Wet-weather influent characteristics are amenable to advanced physical or chemical treatment and not optimal for biological treatment.
USEPA (2008), Emerging Technologies for Wastewater Treatment and In-Plant Wet Weather Flow Management, EPA 832-R-06-006
USEPA (2007), Wastewater Management Fact Sheet, In-Plant Wet Weather Peak Flow Management, EPA 832-F-07-016
WEF (2006), Guide to Managing Peak Wet Weather Flows in Municipal Wastewater Collection and Treatment Systems
USEPA (2004), Report to Congress, Impacts and Control of CSOs and SSOs, EPA 833-R-04-001
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Some perspective on auxiliary treatment technologies…
Conventional Sedimentation + DisinfectionLong understood by POTWs to generally support CWA and codified secondary effluent quality (40 CFR 133)General consensus among scientists and engineers in the treatment profession. Perhaps some site specific exceptions.Supported by USEPA 1994 CSO Control Policy
Today’s Advanced HRT AlternativesBuilt upon proven physical/chemical mechanismsProduce very high quality wet-weather effluentSmall footprint…high capacity
B&V - 25
KDHE Annual Water & Wastewater School
High-Rate Treatment Technologies
High-Rate Treatment Technologies
Today’s advanced physical or chemical technologies were not envisioned by the
NPDES program when “blending” or “bypassing” was defined.
Today’s advanced physical or chemical technologies were not envisioned by the
NPDES program when “blending” or “bypassing” was defined.
KDHE Annual Water & Wastewater School August 5, 2010
Auxiliary treatment facilities generally consist of multiple process units
Influent or Effluent Pumping
Screening
Grit Removal
BOD & TSS Removal
Effluent Disinfection
Solids Handling
Considerations
Various technology and design
alternatives for each process unit
B&V - 27
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Effluent DisinfectionEffluent Disinfection
KDHE Annual Water & Wastewater School August 5, 2010
Effluent Disinfection Alternatives Include…
Chlorination
Gas vs. HypochloriteOnsite generation?
UVLow Pressure High Output
Medium Pressure
Open Channel
Closed Vessel
Other? O3, ClO2, PAA, BCDMHB&V - 29
KDHE Annual Water & Wastewater School
BOD & TSS RemovalBOD & TSS Removal
KDHE Annual Water & Wastewater School August 5, 2010
Many of today’s HRT technologies weren’t available when NPDES regulations were formed
Sedimentation(a.k.a. Clarification)
Filtration
Conventional
Chemically Enhanced
Lamella Settlers
Sludge Recirculation
Ballasted Floc
Shallow Sand
Deep Sand
Cloth Media
Compressible Media
HRCHRF
High-Rate Treatment
(HRT)B&V - 31
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Conventional Sedimentation
Also known as:
Primary Clarification
Settling
Gravity Settling
Primary Treatment
B&V - 32
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1500 BC - Alum coagulation by Egyptians
1740 AD - Chemical sewage treatment in Paris
Today – a.k.a. CEPT (Chemically Enhanced Primary Treatment) or CEC (Chemically Enhanced Clarification) or CES (Chemically Enhanced Settling or Sedimentation)
Chemically enhanced sedimentation continues to prove its effectiveness
NoChemicals
AfterChemical
Dosing
FinalEffluent
2007 CEPT Trials at 75th & Nall PEFTF
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The 4 Basic Steps of CEPT
Step 1 – Coagulant Addition: Rapid mixing of metal salt and/or cationic polymer.
Step 3 – Flocculation: Low turbulence to agglomerate particles into floc.
Step 4 – Settling: Quiescent zone to separate floc from clarified effluent.
Turbulence
Step 2 – Flocculant Addition: Rapid mixing of anionic polymer. If ballast or other measures also taken, CEPT HRC.
B&V - 34
KDHE Annual Water & Wastewater School August 5, 2010
What are we trying to do with coagulants and flocculants?
Most particles in water tend to have a negative surface charge.
Coagulants result in cations adsorbing to particle, canceling repulsive forces.
Flocculants help to compensate for coagulant overdosing and imperfect flocculation conditions. Glue particles together into a floc. “Sweep floc coagulation”
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CEPT can be implemented different ways
2°Peak
Q
River
2 – 2.5 Avg Q
DisinfectHead-works
Coagulant
DisinfectCEPT
Flocculant
1°
Additional CEPT Facilities
CEPT with Existing Facilities
2°Peak
Q
River
2 – 2.5 Avg Q
1° DisinfectHead-works
Coagulant
Flocculant
“Split Treatment”concept.
Potential enhancement for existing peak flow clarifiers.
B&V - 36
KDHE Annual Water & Wastewater School August 5, 2010
Sludge Recirculation and Ballasted Flocculation
Same chemical enhancements as CEPT, but:
Use lamella settlers to decrease settling tank footprint
Recirculate solids to further enhance flocculation
Add ballast or other mechanism to create denser floc
Generally higher chemical dose than CEPT, but not always
Also known as Chemically Enhanced High Rate Settling, Ballasted Flocculation (and others).
B&V - 37
KDHE Annual Water & Wastewater School August 5, 2010
HRC - Ballasted Flocculation (Sand)
CSO/SSO43 worldwide, 15 U.S. (July, 2008)
1 2 3 41 2 3 4
B&V - 38
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HRC - Ballasted Flocculation (Magnetite)
CoMagTM
B&V - 39
MagSep
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence, Kansas Excess Flow Treatment Upgrades
Main WWTP
Splitter/Screening Facility
Chemical Feed Facility
Actiflo® Treatment Basins
Chlorine Contact BasinDechlorination Basin
(Shared)
XS Flow
XS Flow Pump Station
B&V - 40
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence Wet Weather Flow Schematic
65mgdWWTP
Course Screening
SodiumBisulfite
Splitter / Screening
Facility
25mgd
40 mgd
65mgd
20mgd
20mgd
ACTIFLO
Chlorine ContactBasin
Ferric ChlorideSodiumBisulfite
Sludge Sludge/Microsand
Microsand
FineScreening
Polymer
Kansas River
Main WWTP
Course Screening
Splitter / Screening
Facility
Actiflo® Units
Chlorine ContactBasin
Ferric Chloride
Sludge Sludge/MicrosandMicrosand
FineScreening
Polymer
Excess Flow Treatment
95 ML/d(25 mgd)
246 ML/d(65 mgd)
151 ML/d(40 mgd)
75.7 ML/d(20 mgd)
246 ML/d(65 mgd)
B&V - 41
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence Wet Weather Flows
0
5
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65A
ug-0
3N
ov-0
3Fe
b-04
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-04
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-04
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-04
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ay-0
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ug-0
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ov-0
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ay-0
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ug-0
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ov-0
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ay-0
9
Flow
, mgd
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Total Plant Influent (Hourly Average)Annual Average Total Plant Influent
B&V - 42
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence Wet Weather Influent TSS
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0 5 10 15 20 25 30 35 40 45 50 55 60 65 70Run time, hrs
Con
cent
ratio
n, m
g/L
30-Aug-03 13-Sep-03 4-Mar-0410-Mar-04 13-May-04 25-May-042-Jul-04 7-Jul-04 16-Jul-0426-Jul-04 27-Jul-04 29-Jul-0417-Aug-04 18-Aug-04 24-Aug-0428-Aug-04 8-Oct-04 5-Jan-057-Feb-05 13-Feb-05 13-May-051-Jun-05 3-Jun-05 11-Jun-0512-Jun-05 13-Aug-05 20-Aug-0526-Aug-05 23-Sep-05 20-Oct-0530-Apr-06 1-May-06 28-Aug-0622-Mar-07 12-Apr-07 14-Apr-076-May-07 19-Jun-07 30-Jun-074-Oct-07 17-Oct-07 18-Oct-0717-Feb-08 3-Mar-08 17-Mar-0819-Mar-08 9-Jun-08 13-Jun-0813-Sep-08 8-Mar-09 27-Apr-0930-Apr-09 16-May-09
B&V - 43
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence Wet Weather Effluent TSS
0
10
20
30
40
50
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70Se
p-03
Mar
-04
May
-04
Jul-0
4Ju
l-04
Jul-0
4A
ug-0
4A
ug-0
4Ja
n-05
Feb-
05Ju
n-05
Jun-
05A
ug-0
5A
ug-0
5O
ct-0
5M
ay-0
6A
pr-0
7M
ay-0
7Ju
n-07
Oct
-07
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ar-0
8Ju
n-08
Sep-
08A
pr-0
9M
ay-0
9Volu
me-
Wei
ghte
d Ev
ent A
vera
ge C
once
ntra
tion,
mg/
L
HRC Effluent TSSOverall POTW Effluent TSSNPDES Permit Weekly Average TSS Limit
FeCl3 contaminated with ferrous iron (Fe2+)
B&V - 44
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0
20
40
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160Se
p-03
Mar
-04
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4Ju
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4A
ug-0
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ug-0
4Ja
n-05
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ug-0
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ay-0
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n-08
Sep-
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ay-0
9Volu
me-
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ghte
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ent A
vera
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once
ntra
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mg/
L
HRC Effluent COD
Overall POTW Effluent COD
Lawrence Wet Weather Effluent COD
52 events in 70 months of operation.
Coordinated operation of HRC and activated sludge trains always achieved NPDES permit limits.
Handled wet-weather peak flows >6 times annual average flow.
Don’t extrapolate AS performance too far. It was protected by HRC from upset.
B&V - 45
KDHE Annual Water & Wastewater School August 5, 2010
Lawrence WWTP Monthly Average Results
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Jan-0
0Ju
l-00
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l-01
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Jan-0
4Ju
l-04
Jan-0
5Ju
l-05
Jan-0
6Ju
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Jan-0
7Ju
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ent C
once
ntra
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(mg/
L)
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Rem
oval
(%)
Effluent TSSEffluent BODTSS RemovalBOD Removal
Parallel excess flow treatment system commissioned in summer 2003
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KDHE Annual Water & Wastewater School August 5, 2010
1 2 3 41 2 3 4
HRC - Sludge Recirculation
CSO/SSO11 worldwide, 2 U.S. (July, 2008)
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KDHE Annual Water & Wastewater School August 5, 2010
Excess Flow Treatment at Bay View WWTP (Toledo, Ohio)
232 MGD HRC17 MG
EQ
4 MG EQ 4 MG
EQ
B&V - 48
KDHE Annual Water & Wastewater School August 5, 2010
Toledo DensaDeg HRC System
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BAY VIEW PUMP
STATION
GRITREMOVAL
SKIMMINGSREMOVAL
PRIMARYCLARIFIERS
AERATION BASINS
CHLORINECONTACT
BASIN
SECONDARYCLARIFIERS
EQ BASIN
SCREENING& GRIT
REMOVAL
High Rate Clarification
CHLORINECONTACT
&REAERATION
EFFLUENTPUMPING
636 ML/d(168 mgd)
878 ML/d(232 mgd)
UP TO1514 ML/d(400 mgd)
UP TO738 ML/d(195 mgd)
102 ML/d(27 mgd) UP TO
776 ML/d(205 mgd)
PRIMARYCLARIFIERS UP TO
1514 ML/d(400 mgd)
Bay View WWTP Wet Weather Flow Schematic
B&V - 50
KDHE Annual Water & Wastewater School August 5, 2010
Bay View WWTP Wet Weather Flows
0
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350A
pr-0
7
May
-07
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Flow
, mgd
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, ML/
d
Total Plant Influent Daily AverageAnnual Average ~70 mgd
B&V - 51
KDHE Annual Water & Wastewater School August 5, 2010
0
100
200
300
400
500
600
mg/L
1/5/07 1/6/07 1/15/07 1/16/07 3/2/07 4/25/07 4/26/07 6/3/07 6/4/07 8/20/07
Date
Wet Weather Event TSS Concentrations
Influent AS Effluent HRC Effluent
Toledo Parallel Excess Flow Treatment
Better than overstressed activated sludge (1/15 & 4/25)
All under 40 mg/L, all but 2 under 30 mg/L
Consistently achieved permit limits
2007 = 3rd wettest year on record in Toledo
Don’t extrapolate AS performance too far. It was protected by HRC from upset.
B&V - 52
KDHE Annual Water & Wastewater School
HRF alternatives offer similar TSS & BOD as HRC, but no chemicals required
Schreiber Fuzzy FilterSchreiber Fuzzy Filter
CMF Media
SchreiberWWETCO
2000 BC - Granular filtration in ancient Sanskrit writings
TodayDeep-bed granular mediaCompressible mediaCloth media
Compressed Media Filter
Varies with Filter Cell Size
Varies with Number of Filter Cells
WWETCO Filter
August 5, 2010B&V - 53
KDHE Annual Water & Wastewater School
Full-scale CMF wet-weather treatment facilities
West Point Lake
GA
AtlantaAtlanta
Columbus, GAColumbus, GA
Chattahoochee River Chattahoochee River WatershedWatershed
Walter F. George Reservoir
www.cleanwateratlanta.org
www.cwwga.org
Atlanta, GAAtlanta, GA
ALGA
FL
August 5, 2010B&V - 54
KDHE Annual Water & Wastewater School
CMF
August 5, 2010B&V - 55
KDHE Annual Water & Wastewater School August 5, 2010
Columbus LTCP Implementation and Keys to Compliance Success
1990 to 1995: CSO Control Program Development
1996 to 2001: Regional Watershed Studies
2001 to Present Day: Watershed Controls Implementation and DemonstrationsSatellite auxiliary treatment facilities
Monthly monitoring and reporting of events, bacteria, TSS and phosphorous
Demonstration approach. Comprehensive multi-year post-construction watershed monitoring and modeling study and water quality compliance analysis.
Development of science-based frequency criteria for WQS
Impaired water definitions from USEPA Guidance for 2006 Assessment, Listing and Reporting Requirements, p. 67http://www.epa.gov/owow/tmdl/2006IRG/report/2006irg-report.pdf
TMDL evaluation and implementation plan with Georgia reasonable potential analysis. Columbus LTCP has no reasonable potential to violate WQS. CSO control facilities have no numerical effluent limits.
Columbus will be able to show the Chattahoochee River at Columbus is not impaired and request a Record of Decision to be removed from the impaired water classification (next impairment cycle is 2010)
B&V - 56
KDHE Annual Water & Wastewater School
CMF Media
SchreiberWWETCO
August 5, 2010B&V - 57
KDHE Annual Water & Wastewater School
CMF – Fuzzy Filter
August 5, 2010B&V - 58
KDHE Annual Water & Wastewater School
85 mgd Fuzzy Filter at West Area CSO Treatment Facility (Atlanta, Georgia)
August 5, 2010B&V - 59
KDHE Annual Water & Wastewater School
Compressible Media
Flexible Membrane
Filtered Water Underdrain
Air Supply for Backwashing
Filter Housing
Filter Basin
Backwash TroughsPerforated Plates
CMF – WWETCO
Uncompressed
Compressed
Fill & Compress
Filter Start
Filter EndDrain & Uncompress
Air Scour Backwash
August 5, 2010B&V - 60
KDHE Annual Water & Wastewater School
CMF Backwash
PHOTO AFTER PRIMARY INFLUENT FILTRATION.
PHOTO NEAR END OF BACKWASH
August 5, 2010B&V - 61
KDHE Annual Water & Wastewater School
10 mgd WWETCO Filter at Weracoba Creek Stormwater BMP (Columbus, Georgia)
UncompressedFilter Media
Bottom Perforated Plate
Top Perforated
PlateBackwash
Trough
Flexible Membrane
CompressedFilter Media
Compressible Filter Media
Top Perforated Plates
Backwash Trough
Filter Influent
CMF
August 5, 2010B&V - 62
KDHE Annual Water & Wastewater School
Triple bottom line evaluations of satellite PEFTFs in Johnson County, Kansas…
Belinder Road Peak Excess Flow Treatment FacilityJohnson County, Kansas
Sedimentation and Chlorination Basins
Diversion ChamberElectrical/Controls Fine ScreensPumpsChemicals
Bench-scale (Jar Testing)
HRC: CEPT, ballasted flocculation, sludge recirculation
Full-scale trials
CEPT
August 5, 2010B&V - 63
KDHE Annual Water & Wastewater School
Dynamic Tangential
Filter Unit
Compressible Media
Filter Unit
Influent Piping
Filter Feed Tank
Fine Screen Unit
Cloth Disc Filter Unit
Influent Sampler
Screenings and Pass-through Piping
…led to side-by-side HRF testing in 2008
August 5, 2010B&V - 64
KDHE Annual Water & Wastewater School August 5, 2010
Influent Characteristics - JCW 2008 Filter Pilot
0
50
100
150
200
250
300
350
40019
-May
21-M
ay
23-M
ay
25-M
ay
27-M
ay
29-M
ay
31-M
ay
2-Ju
n
4-Ju
n
6-Ju
n
8-Ju
n
10-J
un
12-J
un
14-J
un
16-J
un
18-J
un
Con
cent
ratio
n (m
g/L)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Prec
ipita
tion
(inch
es)
Mission Main WWTP Rain Influent TSS (Composite) Influent BOD5 (Composite) Influent Soluble BOD5 (Composite)
PE PI PE PI PE
B&V - 65
KDHE Annual Water & Wastewater School August 5, 2010
Effluent TSS - JCW 2008 Filter Pilot
0
50
100
150
200
250
300
350
400
19-M
ay21
-May
23-M
ay25
-May
27-M
ay29
-May
31-M
ay2-J
un4-J
un6-J
un8-J
un10
-Jun
12-Ju
n14
-Jun
16-Ju
n18
-Jun
Even
t Com
posi
te T
SS (m
g/L)
Influent
Dynamic Tangential Filter Effluent
Cloth Disc Filter Effluent
Compressible Media Filter Effluent
B&V - 66
KDHE Annual Water & Wastewater School August 5, 2010
Wet Weather Treatability Tests (St. Joseph, Missouri Water Protection Facility
Not used during actual wet-weather
conditions
Coarse Screened& Degritted
Influent
Secondary Effluent
Mixing Tee CMFTest Unit
Treated Effluent
Treated Effluent
CEPTTest Unit
HRCTest Unit
CompositeCollection
Tank
Treated Effluent
Collected during CMF test run for CEPT and
HRC jar tests
B&V - 67
KDHE Annual Water & Wastewater School August 5, 2010
April 2009 Wet-weather Treatability Testing (St. Joseph, MO)
Compressible Media Filter Test Unit
UntreatedTreated
B&V - 68
KDHE Annual Water & Wastewater School August 5, 2010
TSS and BOD – St. Joseph, MO (April, 2009)
106
127136
6
2113
27 2635
26
69
12 9 9
33
10
0
20
40
60
80
100
120
140
Untrea
ted (C
MF)Unt
reated
(HRC)
Untrea
ted (C
EPT)
CMF
HRC (ferr
ic) E
fflue
nt
HRC (alum) E
ffluen
t
CEPT (fer
ric) E
ffluen
t
CEPT (alum
) Effl
uent
Con
cent
ratio
n, m
g/L
TSS BOD5
B&V - 69
KDHE Annual Water & Wastewater School
Effluents were tested for both hypochlorite and UV dose response…
St. Joseph, MO Jar Tests (April 10, 2009)
1
10
100
1,000
10,000
100,000
1,000,000
0 1 3 5 10 15 30Contact Time After 6 mg/L Chlorine Dose (min)
E. C
oli C
ount
(MPN
/100
mL)
CMF CEPT- Ferric CEPT- Alum HRC- Ferric HRC- Alum
126 MPN/100 mL
St. Joseph, MO Jar Tests (April 10, 2009)
1
10
100
1,000
10,000
100,000
0 10 20 40 60 80Collimated Beam UV Dose (mJ/cm2)
E. C
oli C
ount
(MPN
/100
mL)
CMF CEPT- Ferric CEPT- Alum HRC- Ferric HRC- Alum
126 MPN/100 mL
August 5, 2010B&V - 70
KDHE Annual Water & Wastewater School
Screening and Grit RemovalScreening and Grit Removal
KDHE Annual Water & Wastewater School August 5, 2010
Screening and Grit Removal
Best alternatives are highly site-specific.
Depends upon downstream treatment technologies.
Something like a “rock box” + coarse screens may be fine for conventional processes…but some TSS removal designs need enhanced grit and screenings removal.
Many equipment alternatives to choose from.B&V - 72
KDHE Annual Water & Wastewater School August 5, 2010
Screen Geometry
Reference: Schier etal WEFTEC 2005
B&V - 73
KDHE Annual Water & Wastewater School August 5, 2010
Many grit removal alternatives
Level needed is highly site-specific.
Besides downstream liquids train, remember solids train (digesters, sludge pumps, etc.).
Some screens are sensitive to grit and some grit units are sensitive to screenings.
HeadworksSettling channel, stilling well, “rock box”
Detritus tank
Aerated basin
Vortex separator – hydraulic or mechanically induced
Detritus
B&V - 74
KDHE Annual Water & Wastewater School
Closing ThoughtsClosing Thoughts
KDHE Annual Water & Wastewater School August 5, 2010
Latest Regulatory Activities2005 draft Peak Wet Weather Discharge Policy
Has not been finalized.2009 - Numerous comments on Draft UA Guidance2010 – EPA public comment period on SSO and Peak Flows Policy
B&V - 76
KDHE Annual Water & Wastewater School
Source: USEPA, Sanitary Sewer Overflows and Peak Flows Listening Session, June 30, 2010
Many WWTPs also have a grit removal step…sometimes upstream of screening…sometimes downstream…sometimes on primary sludge. Various technology and design alternatives.
Parallel solids treatment processes not shown, but required. Various technology and design alternatives.
Various technology and design alternatives for screening, primary clarification, biological treatment and disinfection depending upon effluent quality goals.
“Secondary Treatment”per 40 CFR 133
Many WWTPs don’t have primary clarifiers. Various design alternatives.
B&V - 77
KDHE Annual Water & Wastewater School
Source: USEPA, Sanitary Sewer Overflows and Peak Flows Listening Session, June 30, 2010
B&V - 78
KDHE Annual Water & Wastewater School
Source: USEPA, Sanitary Sewer Overflows and Peak Flows Listening Session, June 30, 2010
B&V - 79
KDHE Annual Water & Wastewater School
Source: USEPA, Sanitary Sewer Overflows and Peak Flows Listening Session, June 30, 2010
“Secondary Treatment”per 40 CFR 133
This is “auxiliary treatment”…not “bypass”…not “blending”. Various technologies and design alternatives depending upon effluent quality goals.
B&V - 80
KDHE Annual Water & Wastewater School August 5, 2010
Holistic view is needed to stay focused on sustainable water quality protection
Primary Treatment Secondary Treatment
BulkSolids
Removal
BiologicalProcess
Liquid/Solid Separation
BulkSolids
Removal
BiologicalProcess
Liquid/Solid Separation
Auxiliary Treatment Facilities for Wet Weather
Excess Flows
SecondaryTreatment
Optional
40 CFR 133.102Secondary Treatment ≠ 100% Biological Treatment. It just so happens that biological treatment has proven to be the optimal technology for dry-weather influent characteristics.
40 CFR 122.41(m)Intended to prevent taking units out of service unnecessarily during dry weather (i.e. lower level of treatment).
Never intended to prevent from bringing additional units into service to provide higher level of treatment during wet weather.
Auxiliary treatment facilities are simply another treatment train within the overall secondary treatment boundary. Uses technologies optimized for wet-weather influent characteristics.
1994 CSO Control Policy does not even require “secondary treatment” of excess flows
B&V - 81
KDHE Annual Water & Wastewater School
Potential regulatory disconnects without holistic view…
August 5, 2010
River
QpeakFlow
Control
QXS2
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
t
Wet-Weather Auxiliary Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
QXS1Flow Control
River
QpeakFlow
Control
QXS
QXS2
~2Qavg BiologicalTreatmentFacilities D
isin
fect
ion
Prel
imin
ary
Trea
tmen
t
QXS1
Wet-Weather Auxiliary Treatment Facilities
Floa
tabl
esR
emov
al
BO
D &
TSS
Rem
oval
Dis
infe
ctio
n
Flow Control
Parallel auxiliary wet-weather treatment approach is allowed and encouraged by the 1994 CSO Control Policy…
…but integrating the same or higher levels of water quality protection into a WWTP is discouraged by recent interpretations of the 2005 draft Peak Flow Discharge Policy.
B&V - 82
KDHE Annual Water & Wastewater School August 5, 2010
Summary and Conclusions
Sewer systems will always have significant wet weather peaking factors.
The 2005 proposed Peak Wet Weather Discharge Policy has not been enacted…EPA considering new SSO and Peak Flows Policy rulemaking.
Clean Water Act regulations focus on dry-weather and have not established science-based wet weather water quality criteria, treatment standards or effluent limitations
Floatables, solids and biological pathogens are the primary pollutants of concern
Auxiliary treatment of excess flows with physical or chemical technologies is a proven and sound approach
B&V - 83
KDHE Annual Water & Wastewater School August 5, 2010
For Additional Information…
Jim FitzpatrickWet Weather Treatment [email protected]
Larry JaworskiWet Weather Practice Leaderand Former WEF President
Matt BondWastewater Treatment Practice
B&V - 84
Mike OrthClient Account ManagerLower [email protected]
KDHE Annual Water & Wastewater School
DiscussionDiscussion
- 2
Creek
Effluent from Activated SludgeFacilities at POTW
Effluent from Peak Wet-WeatherLagoons at POTW
B&V - 85
KDHE Annual Water & Wastewater School
ExtrasExtras
KDHE Annual Water & Wastewater School August 5, 2010
Parallel excess flow treatment ≠ bypass (cont’d)
Diversion involves decreasing flows. Parallel treatment concept does not decrease flows to any
portion of the treatment facility. We are increasing flows to all portions
of the treatment facility.
40 CFR 122.41(m)(1)(i)
KDHE Annual Water & Wastewater School August 5, 2010
Parallel excess flow treatment ≠ bypass (cont’d)
The use of auxiliary treatment facilities is a feasible alternative
to a bypass; therefore, using them can’t be a bypass
40 CFR 122.41(m)(4)(i)(B)
KDHE Annual Water & Wastewater School August 5, 2010
Parallel excess flow treatment ≠ bypass (cont’d)
Parallel excess flow treatment is not bypass, but does provide
essential maintenance of biomass to assure efficient operation.
40 CFR 122.41(m)(2)
KDHE Annual Water & Wastewater School
Biological treatment probably has many more unknowns than other technology alternatives
Filtration2000 BC - Granular filtration in Greece and IndiaToday - Particle size distribution data or pilot trials to confirm solids loading rates, hydraulic loading rates, backwash frequencies, etc.
Sedimentation1500 BC - Alum coagulation by Egyptians1740 AD - Chemical sewage treatment in ParisToday - Jar tests to optimize chemicals. Pilot and full-scale stress tests to confirm design SOR for CEPT.
BiologicalEarly 1900’s - First activated sludge WWTPsToday - Wet-weather capacity is inherently inexact. Many, many variables affect biomass behavior.
Site-Specific R&D
Process R&D
KDHE Annual Water & Wastewater School 11/04/2009B&V - 91
High-Rate Contact Stabilization Concept
Activated Sludge System
Receiving Stream
CEPT,HRC, HRF, DAF, etc.
~2Qavg
BioContact
RAS Sludge/Backwash
Ye olde contact stabilization configuration of activated sludge…with high-rate solid/liquid separation technologies.
Another parallel auxiliary treatment strategy.
QXS
Qpeak
KDHE Annual Water & Wastewater School 11/04/2009B&V - 92
Potential R&D needs for high-rate contact stabilization concept
Actual wet-weather influent (vs. surrogate influent).
Repeatable results from site to site?
Concerns about extrapolating and generalizing results based on statistically small dataset.
Is claimed biological uptake significant?
Conventional “soluble” BOD includes colloidal fraction largely removed by advanced phys/chem.
What about adsorption onto hydrous metal complexes similar to the latest thinking on chemical phosphorus removal?
KDHE Annual Water & Wastewater School 11/04/2009B&V - 93
Potential R&D needs for high-rate contact stabilization concept (cont’d)
Capacity of available biomass must be considered.Any added risk to biomass health?
What about BNR bugs or unintended inhibition to BNR processes?
May not be able to truly assess biomass impacts without auxiliary treatment facilities at same scale as dry-weather activated sludge facilities.
Piloting to date limited to activated sludge operated in contact-stabilization mode.
What about fixed-film (TF, MBBR, IFAS, BAF, SAF)?
What about other AS operating modes or configurations?
Any significant water quality benefits to warrant the significant additional complexity and expense above and beyond today’s advanced physical/chemical alternatives?