urban point sources nutrient loads: relationship of point...
TRANSCRIPT
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Urban Point Sources Nutrient Loads: Relationship of
Point Source to Total Downstream
Dale White, Ohio EPA – Division of Surface Water – Modeling and Assessment
Ohio Nutrient Forum - November 14, 2012
Approach • 3 watersheds (Cuyahoga, Great Miami,
Sandusky)
– CSO exists
– Long-term, in-stream chemical monitoring exists
– Compare high urban to high non-urban
• Watershed-scale estimates
• Worst-case Scenario – will over-predict PS loads
– In-stream processing ignored
– CSO concentrations on high end of range
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Location of Study Areas
Land Use (% of total) Upstream Gage
Station (Drainage
Basin)
Agriculture Grass/Hay/Pasture
Urban Forest, Water, Wetland,
Other
Cuyahoga 9 12 40 39
Great Miami 65 8 17 10
Sandusky 78 4 8 10
(source: NCWQR)
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Distribution of WWTP
Drainage Basin
Area (mi2)
# Majors (Design Flow
> 1 MGD)
# Significant minors
(Design Flow > 0.5 MGD)
Largest Sources (MGD)
Cuyahoga 707 13 3 Cleveland-Southerly (175) Akron (90)
Great Miami 2710 25 4 Dayton (72) Middletown (36) Springfield (25)
Sandusky 1251 4 2 Fremont (7.6)
Approach
• Annual Total Load
– Mass of pollutant discharged into water-body in one year
– Measured from long-term data obtained from gage data at downstream station
• Point Source Load
– Calculated from WWTPs effluent data
– CSO load from typical discharge and estimated concentration (high-end of range)
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Nature of the Point Source
• Point Sources defined…
– discharges from WWTPs and municipal sewer overflows
– WWTPs: wastewater treatment plant discharge
• 24/7, 365 days/y
• In this study…primarily municipal but some industrial
– CSO: municipal sewer overflows
• Episodic, storm-related discharges
Comparison Among Basins – TP 2006-2011 period
Cuyahoga Sandusky Great Miami
0
200
400
600
800
1000
1200
1400
Load
(m
ton
s/y)
Total @ Gage
CSO
WWTP
Dst WW+CSO
P-Task Force I Ohio L.E.
WWTP = 585 All Urban = 796
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Comparison Among Basins – TN 2006-2011 period
Cuyahoga Sandusky Great Miami
0
2000
4000
6000
8000
10000
12000
14000
16000
Load
(m
ton
s/y)
Total @ Gage
CSO
WWTP
Dst WW+CSO
Comparison Among Dry/Wet Year – TP 2010 vs. 2011
Cuy2010
Cuy2011
San2010
San2011
GMR2010
GMR2011
0
200
400
600
800
1000
1200
1400
1600
Load
(m
ton
s/y)
Total @ Gage
CSO
WWTP
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Comparison Among Dry/Wet Year – TN 2010 vs. 2011
Cuy2010
Cuy2011
San2010
San2011
GMR2010
GMR2011
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
Load
(m
ton
s/y)
Total @ Gage
CSO
WWTP
Percent of Total Load by Urban PS
2011 water year (wet)
Basin TN NO23 TP
Cuyahoga 67 100 42
Great Miami 12 14 19
Sandusky 2 1 3
2010 water year (dry)
Basin TN NO23 TP
Cuyahoga 87 100 64
Great Miami 18 21 37
Sandusky 2 2 5
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Point Source Improvements
• Cities Spending Billions of Dollars to Eliminate CSOs and Upgrade WWTPs
– NEORSD: $2.5 Billion
– Akron: $900 million
– Toledo: $316 million
• Toledo, Akron and Cleveland CSO Control Projects Ongoing
– Most Projects Fully Implemented by 2030
Use this in Chart…
– By 2017 Over Half of All CSO Communities Will Have Fully Implemented Their Required CSO Control Projects and Most CSO Communities Will Have Fully Implemented CSO Control Projects by 2030
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Current Program: LTCP Implementation
• When will LTCP Construction be Complete?
Year of Completion
Number of Communities
Already Complete
20
2012 3 (23)
2013 7 (30)
2014 2 (32)
2015 2 (34)
2016 2 (36)
2017 7 (43)
Year of Completion
Number of Communities
2018 3 (46)
2019 4 (50)
2020 3 (53)
2021 1 (54)
2025 4 (58)
2030 10 (68)
Thanks to…
• Ohio EPA CSO program staff and lead
• National Center for Water Quality Research (esp. Dave Baker)
• Regulated community…for self-monitoring
Contact [email protected]
614-644-2159
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Extra Slides – For Discussion
Questions to consider…
1) What is the relative contribution of CSO and WWTP of TP and TN to large endpoints (Lake Erie, Ohio River)?
2) What projections exist for reduction and elimination of CSO load?
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Sandusky River Basin - Detail
WWTP Specifics
• Design Flow ≥ 0.5 MGD: all majors, significant minors
• Examined these parameters:
– TSS, ammonia, Kjeldahl nitrogen (TKN), nitrate+nitrite, and TP
– Organic N: from TKN or 20% TSS
– Self-monitor data
• Median daily load: due to monitoring frequency, skewness, outliers
– TP: range from 2x/wk to 1x every 2 wk
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Annual Precipitation (1996-2001)
0
10
20
30
40
50
60
1996 1997 1998 1999 2000 2001
Tota
l (in
/y)
Cuyahoga
Sandusky
Great Miami
Annual Precipitation (2006-2011)
0
10
20
30
40
50
60
70
2006 2007 2008 2009 2010 2011
Tota
l (in
/y)
Cuyahoga
Sandusky
Great Miami
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CSO Specifics (1)
• 3 major CSOs – all below NCWQR gage
– NEORSD (some DD), Fremont, Middletown
• Typical Year (of Q)
– Difficult to measure Q: hazardous, planning, timing
– Long period of record (e.g., NEORSD 45 years)
– Considers rainfall depth and intensity, #storms per year
CSO Specifics (2)
• Chemical monitoring
– Concentrations reflect combination of storm-water and untreated sewage
– Variable due to First Flush: – Accumulated surface contaminants
– Re-suspend collection system sediment from low-flow periods
– Obtained from national studies
• Hence, CSO loads are fixed magnitudes by facility
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Akron CSO Program Reduction by Year: Overflow Volume & 2nd By-pass
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Cuyahoga Street Storage Facility
Ohio Canal Tunnel
Step Feed to 130 MGD 45% Cumulative Bypass Reduction
Step Feed to 170 MGD 100% Cumulative Bypass Reduction
BioEHRT at WPCS 73% Cumulative Bypass Reduction
Northside Tunnel & Ohio Canal High Rate Treatment
Page 26
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Comparison Among Basins – TP 1996-2001 averaging period
0
100
200
300
400
500
600
700
800
900
1000
Cuyahoga Sandusky Great Miami
Load
(m
ton
s/y)
Ambient - NCWQR
Urban Total
WWTP
CSO (high)
Urban Total (dst)
P-Task Force I Ohio L.E.
WWTP = 585 All Urban = 796
Dolan and McGunagle (2005)
Comparison Among Basins – TN 1996-2001 averaging period
0
2000
4000
6000
8000
10000
12000
14000
16000
Cuyahoga Sandusky Great Miami
Load
(m
ton
s/y)
Ambient - NCWQR
Urban Total
WWTP
CSO (high)
Urban Total (dst)
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Approach (2)
• Timeframe
– Older vs. newer (6-yr averages)
• 1996-2001 vs. 2006-2011
– Dry vs. wet year (annual precipitation)
• 2010 vs. 2011
• Parameters of interest:
– TP, TN, nitrate+nitrite
– Ortho-phosphate (reactive P): estimate not consistent
WWTP Specifics
• Design Flow ≥ 0.5 MGD: all majors, significant minors
• Examined these parameters:
– TSS, ammonia, Kjeldahl nitrogen (TKN), nitrate+nitrite, and TP
– Organic N: from TKN or 20% TSS
– Self-monitor data
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CSO Specifics (1)
• 3 major CSOs – all below NCWQR gage
• Typical Year (of Q)
– Difficult to measure Q: hazardous, planning, timing
– Long period of record (e.g., NEORSD 45 years)
– Considers rainfall depth and intensity, #storms per year
CSO Specifics (2)
• Chemical monitoring
– Concentrations reflect combination of storm-water and untreated sewage
– Variable due to First Flush: – Accumulated surface contaminants
– Re-suspend collection system sediment from low-flow periods
– Obtained from national studies
• Hence, CSO loads are fixed magnitudes by facility
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CSO Contaminant Concentrations
Source TP TN TKN
NEORSD 2.19 – –
USEPA (2004) 0.1 to 28, median = 0.7 – 0 to 82.1
USEPA (2001) 1 to 10 3 to 24 –
Metcalf and Eddy (2003) 1.2 to 2.8 – 4 to 17
Applied here Typical High
2.19
5
10 17
Notes: All concentrations in mg/L
Percent of Total Load Urban PS (CSO high)
2006 to 2011 averaging period
Basin TN NO23 TP
Cuyahoga 63 93 37
Great Miami 14 17 26
Sandusky 2 2 2
1996 to 2001 averaging period
Basin TN NO23 TP
Cuyahoga 76 94 61
Great Miami 16 16 30
Sandusky 1 1 3
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Percent of Total Load Urban PS (CSO high, 2011 2x)
2011 water year (wet)
Basin TN NO23 TP
Cuyahoga 67 100 42
Great Miami 12 14 19
Sandusky 2 1 3
2010 water year (dry)
Basin TN NO23 TP
Cuyahoga 87 100 64
Great Miami 18 21 37
Sandusky 2 2 5
CSO Facility Accomplishments
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Current Program: LTCP Implementation
• When will LTCP Construction be Complete?
Year of Completion
Number of Communities
Already Complete
20
2012 3 (23)
2013 7 (30)
2014 2 (32)
2015 2 (34)
2016 2 (36)
2017 7 (43)
Year of Completion
Number of Communities
2018 3 (46)
2019 4 (50)
2020 3 (53)
2021 1 (54)
2025 4 (58)
2030 10 (68)
Percent of Total Load Urban PS (CSO high)
2006 to 2011 averaging period
Basin TN NO23 TP
Cuyahoga 63 93 37
Great Miami 14 17 26
Sandusky 2 2 2
1996 to 2001 averaging period
Basin TN NO23 TP
Cuyahoga 76 94 61
Great Miami 16 16 30
Sandusky 1 1 3