urban point sources nutrient loads: relationship of point...

11/15/2012

1

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


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


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


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


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


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


Sandusky 2 2 2


Basin TN NO23 TP

Cuyahoga 76 94 61


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


Sandusky 2 1 3

2010 water year (dry)

Basin TN NO23 TP

Cuyahoga 87 100 64


Sandusky 2 2 5

CSO Facility Accomplishments

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Current Program: LTCP Implementation

• When will LTCP Construction be Complete?

Year of Completion


Already Complete

20

2012 3 (23)

2013 7 (30)

2014 2 (32)

2015 2 (34)

2016 2 (36)

2017 7 (43)

Year of Completion


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)


Basin TN NO23 TP

Cuyahoga 63 93 37


Sandusky 2 2 2


Basin TN NO23 TP

Cuyahoga 76 94 61


Sandusky 1 1 3

urban point sources nutrient loads: relationship of point...

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