Department of the Environment

Modeling to Support the Development of Nutrient TMDLs in Baltimore Harbor

Miao-Li Chang

Maryland Department of the Environment

Acknowledgment

Special thanks to the following individuals for data compilation, model setup/simulations, and document reviews: Nauth Panday, Dinorah Damalsy, Hui Liu and Dr. Harry Wang (Virginia Institute of Marine Science).

Watershed Characteristics

The watershed The watershed is home to 1.5 is home to 1.5 million peoplemillion people

Landuse is Landuse is predominantly predominantly industrial, industrial, commercial commercial and residential and residential (55 %)(55 %)

Mixed Agriculture

15%

Urban55%

Water1%

Forest and Other Herbaceous - 29%

General Information

There are more than 100 industrial facilities with wastewater or There are more than 100 industrial facilities with wastewater or cooling water discharges to Baltimore Harborcooling water discharges to Baltimore Harbor

The Baltimore Harbor is a very complex system with The Baltimore Harbor is a very complex system with a unique 3-layer hydrodynamic flow pattern. The a unique 3-layer hydrodynamic flow pattern. The upper and lower layers flow inward to the head of the upper and lower layers flow inward to the head of the Harbor, and the middle layer flows outward.Harbor, and the middle layer flows outward.

Spatially variable elevated levels of nutrients, metals Spatially variable elevated levels of nutrients, metals and organics in water, sediments and bottom-feeding and organics in water, sediments and bottom-feeding species of fish.species of fish.

This complexity necessitates a comprehensive This complexity necessitates a comprehensive monitoring and modeling program.monitoring and modeling program.

Harbor Eutrophication Modeling Framework

Watershed Model - HSPF MDE Model used Patapsco/Back CBP Model used for Upper Bay

Hydrodynamic Model - CH3D

Water Quality Model - CE-QUAL-ICM

Sediment Fluxes - Chesapeake Bay Sediment Flux Model

Consistent with CBP modeling framework for Tributary Strategy Finer resolution and more local data for calibration

Harbor Eutrophication Modeling FrameworkWatershed ModelHSPFHydrology (flow, TSS)

Hydrodynamic ModelCH3D Velocity, Diffusion, Surface Elevation,Salinity, Temperature

Water Quality ModelCE-QUAL-ICMTemperature, Salinity, Total Suspended Solid, Cyanobacteria/Diatoms/Algae, Carbon, Nitrogen, Phosphorus, COD, DO, Silica

Watershed ModelHSPFnutrients, sediments

Sediment Diagenesis ModelSediment initial condition, Sediment settling rate

Point Source and other loads

Water Quality Prediction

Point Source Locations

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PB1PB2

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PSW1

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PNW4PNW5

PNW6PNW7 PNW8 PNW9

PE1

PE2

PE3

PB1 = Back RiverPB2 = Eastern StainlessPP1 = CongoleumPP2 = Freedom DistrictPP3 = ChemetalsPP4 = W.R. GracePP5 = PatapscoPP6 = Cox CreekPP7-PP13 = Bethelehem Steel

Nonpoint Source Load –Nonpoint Source Load –Watershed Model - Watershed Model - HSPF Segmentation

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Hydrodynamic Model

CH3D - Curvilinear Hydrodynamic 3-dimensionVelocity, Diffusion, Surface elevation, Salinity, Temperature on an intratidal time scale.

Model physical processes impacting bay-wide circulation and vertical mixing

Baltimore Harbor

Back River

Gunpowder River

Bush River

Susquehanna River

Magothy River

Severn River

South River

Chester River

Sassafras River

Bohemia River

Choptank River

Water Quality Model

§ CE-QUAL-ICM

§ Integrated compartment box model

 

§ Boxes correspond to cells in x-y-z space on the CH3D grid (3029 cells - 2 km 0.5 km 1.7 m in the surface plane, 8970 cells – 2 to 15 cells in the vertical)

 

§ Finite difference method using QUICKEST algorithm (Leonard, 1979) in the horizontal directions and a Crank-Nicolson scheme in the vertical direction

 

§ Kinetics are computed using a temporal dimension of days

 

22 state variables, 140 parametersTemperatureSalinityTotal suspended solid3 algae groups : Dinoflagelete , Diatoms, Other (green) algaeCarbon cycle : DOC, LPOC, RPOCNitrogen cycle :  Ammonium, Nitrate-nitrite, LPON, RPONPhosphorus cycle : Total phosphate, DOP, LPOP, RPOPSilica cycle : Available Silica, Particulate Biogenic SilicaCODDO

Sediment Flux ModelA

CT

IVE

SE

DIM

EN

T

LA

YE

R

Aerobic layer

Anaerobic layer

POM Dissolved

POM Dissolved

Particle mixing

Dissolved mixing

Burial

Depositional flux

Fluxes of O2, H2S, NH4, NO3, PO4, Si

WATER COLUMN

Sedimentation Diffusion

Sedimentation

PartioningReactions

PartioningReactionsDiagenesis

WQ Calibration

Baltimore Harbor

Algal bloom

Hypoxia/anoxia

Very eutrophication

Water Quality Data

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M1M2

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MDGT

FYBR

CTBY

INHB

RVBH

WCPT

HMCK

FFOF

DPCK

#S Water column data stations$ Benthic flux data stations

Water columnMDE 94-95Baltimore City Department of Public Work 97

Benthic fluxUniversity of Maryland 94, 95, 97

Upper BayChesapeake Bay Program 82~

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CB1.0

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EE1.1

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ET1.1

ET2.1

ET2.2ET2.3

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ET4.2 ET5.0

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WT1.1

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CB4.1ECB4.1W

CB4.2CCB4.2E

CB4.3W

XGG8251

WT8.3

CB4.3CCB4.3E

CB4.2E

CB4.1C

WQ Calibration

Technical Review Update

Reviewed by State Agencies, Baltimore County and Baltimore City

Reviewed by Chesapeake Bay Program Modeling Subcommittee

Reviewed by SAG Modeling Technical Group

Percentages of Average Annual Loads in the Baltimore Harbor

Total Nitrogen 1995-1997

Municipal & Industrial Point Sources

71%

Urban-Stormwater 12%

Mixed Agriculture

12%

Other 5%

Total Phosphorus 1995-1997

Municipal & Industrial Point

Sources 58%

Urban-Stormwater 29%

Mixed Agriculture

8%

Other 6%

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Curtis Bay

M23

M22

M16

M26

M28

M8

M13M14

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M12

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M6

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M21

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M24

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M18M25

Grid091002_all_prj.shpopen waterdeep waterdeep channel

# Boynton_bf_fttomtr_md.shp# Mdeloc_edit_fttomtr_md.shp

Harbor Designated Uses

Target TMDL water quality goals

Ensure that minimum DO concentrations specified for each designated use of the Baltimore Harbor are maintained;

Resolve violations of narrative Chla criteria. MDE has determined, per Thomann and Mueller, that it is acceptable

to maintain Chla concentrations below a maximum of 100 µg/L, and to target, with some flexibility depending on waterbody characteristics, a 30-day rolling average of approximately 50 µg/L.

Baltimore Harbor Designated Uses and DO criterion

1.0DC

1.72.33.0DW

3.04.05.0OW

5.0MF

Instantaneous minimum

1-day mean

7-day mean

30-day mean

DesignatedUse

Open Water(OW)

Deep Channel(DC)

Migratory Fish(MF)

Lower Pycnocline - Bottom

Open Water(OW)

Deep Water(DW)

Migratory Fish (MF)

Upper – Lower pycnocline

Open Water(OW)

Open Water(OW)

Migratory Fish(MF)

0 – Upper Pycnocline

Oct 1 –Jan 30June 1 –Sept 30Feb 1 –May 31

DO Attainment Check

Solid Line = CBP Reference CurveDotted Line = MDE Attainment CurvePercent Nonattainment = 2%

Area blew the CBO Reference Curve representing an approximately 10 percent allowable exceedance equally distributed between time and space (CBP, 2003

Sensitivity Scenarios

1. No Point Sources – 100% removal of point source loads in Harbor area: To test the impact of point sources.

2. No Nonpoint Sources -- 100% removal of nonpoint source loads in Harbor area: To test the impact of nonpoint sources.

3. No Anthropogenic Loads - 100% removal of point and nonpoint source loads: To test the impact of human activities (point + nonpoint source loads)

4. Clean Sediment -- Start model with clean sediment initially: To test the impact of internal source (pollutant loads from bottom sediments)

5. Bay Influences -- 100% removal of point and nonpoint source loads and start model with clean sediment initially: To test the impact of loads from Chesapeake Bay to Baltimore Harbor.

Sensitivity Model Scenarios

Baltimore Harbor DO Percent non-attainment Sensitivity Scenarios

Deep Water June to

September

Deep Channel June to September

Open Water June to

September

Migratory Fish February to May

Open Water October to

January

Calibration 29 87 1 4 1

Zero Point Source Loads

14 60.9 0 0 0

Zero Nonpoint Source Loads

12 61 0 0 0

Zero Point Source + Zero Nonpoint

Source Loads 9 57.8 0 0 0

Zero Sediments Initial Conditions

10 44.2 0 0 0

Zero Point Source + Zero Nonpoint

Source Loads + Zero Sediments Initial Conditions

4 37.2 0 0 0

BALTIMORE HARBOR OTHER SCENARIOSLOADINGS and DO Attainment Check

SCENARIO

% Violation

MIGRATORY FISH

% Violation

OPEN WATER

(June-Sept)

% Violation

OPEN WATER (Oct-Jan)

% Violation

DEEP WATER

% Violation

DEEP CHANNEL*

Calibration 4 1 1 29 87

CBP Allocation 0 0 0 16 63.5

MDE NPS, CBP Allocation PS

0 0 0 16 63.5

PS = permit limits MDE NPS

Upper Bay = CBP 0 0 0 18 65.3

PS = E3 MDE NPS

Upper Bay = CBP 0 0 0 14 60.7

PS = ENR MDE NPS

Upper Bay = CBP 0 0 0 7.8 80

Baltimore Harbor Possible TMDL Scenario Run

Point Source : Flow: Maximum permit flow

ENR to Municipal - TN: 4 mg/L annual average

(3 mg/L in May - October, 5 mg/L in November - April), TP: 0.3 mg/L

Industrial PS – Best Possible Control loads

Nonpoint Source: 15 % reduction in controllable loads (urban storm water and

agriculture loads)

Progress to Date

Model developments – Completed

Technical Review – Completed

Draft TMDL numbers – Completed

Plan: TMDL submittal in 2006