upper milwaukee river tmdls

7/29/2019 Upper Milwaukee River TMDLs

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Upper Milwaukee River

Basin Water Quality Forum

Milwaukee River Basin TMDLs

January 23, 2013

Steve Heinz, P.E.

Milwaukee Metropolitan Sewerage District


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Presentation Outline

Background

Who, What, Where, When, and Why

Process

How


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Background- Who

The TMDL Development Team

WDNR and USEPA will provide

Review and comment during process

Final approvals

Southeastern Wisconsin Regional PlanningCommission (SEWRPC) for technicalassistance


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Background - Who

The TMDL Development Team

Southeastern Wisconsin Watersheds Trust

(SWWT) for public outreach assistance

CDM Smith leads technical consultant team

Milwaukee Metropolitan Sewerage District(MMSD) is sponsoring the effort


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Background - What

TMDL = Total Maximum Daily Load

The amount of pollutant a water bodycan receive and still meet its waterquality standard (WQS)

Also referred to as allowable load

loading capacity


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Background - What

Objective of a TMDL study is to

1. Identify pollutant reductions needed tomeet WQS and

2. Determine a pollutant allocation foreach pollutant source


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Background - What

Goal of a TMDL is to delist water bodieson the 303(d) list of impaired waters

Pollutants to be addressed by this TMDL

Phosphorous (TP)

Sediment (TSS)

Bacteria Fecal coliform for 3 rivers

E. colifor estuary


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Background - What

A TMDL is

A calculation

A planning tool to delist impaired waters

A TMDL is not

A regulation

A permit


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Background - What

Will also develop an Implementation Plan

Not required

Intended to provide options, not requirements,

to help dischargers meet their allocations

Options will include Green infrastructure

Pollutant trading

Will reference findings of Discovery Farms

and Discovery Watersheds


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Background - Where

Milwaukee River Basin

Milwaukee River watershed

Menomonee River watershed

Kinnickinnic River watershed

Milwaukee Harbor Estuary


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Background - Where


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Background - When

TMDL Report to DNR April 30, 2013 Four workshops held to date

Two more workshops planned

Implementation Plan September 2013

Three workshops planned

For Workshop proceedings: MMSD.com

On left side, click on Water Quality Research


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Background - Why

Cuz Congress said so in the Clean

Water Act of 1972

USEPA delegated responsibility for

TMDLs to the states (DNR in Wisconsin)

MMSD is sponsoring this TMDL study as a

third party on behalf of DNR


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Process

Using models from the Water Quality Initiative,

a joint planning effort completed in 2007 for

SEWRPCs Regional Water Quality Management

Plan Update (Planning Report #50) MMSDs 2020 Facilities Plan

Models also used for Watershed Restoration

Plans for the Kinnickinnic and Menomonee

Rivers, both completed in 2010


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Process

Models were built, calibrated, and validated

using eight years of monitored data

Models then revised to reflect 2020 land use

Models are run with continuous precipitation

data for the ten year period of 1988 1997 This period statistically representative of the

63-year period 1940 - 2002


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Process

Water Quality Standards to be met

Phosphorus (TP) 0.1 mg/l for rivers and estuary

0.075 mg/l for streams

Sediment (TSS) Has a narrative WQS instead of a numerical WQS

Will be 12 mg/l for this TMDL study not state wide standard

Based on biological response variables, similar to how

phosphorous standard was developed


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Process

Water Quality Standards to be met Bacteria

Fecal Coliform

400 colony forming units (cfu)/100 ml (< 10% of samples) 200 cfu/100 ml (30-day geometric mean)

Some waters have a variance of 1,000 cfu/100 ml (30-

day) and 2,000 cfu/100 ml (10% of samples)

E. colistandards apply to the outer harbor 126 cfu/100 ml (30-day geometric mean)

235 cfu/100 ml maximum


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Process

Determine

loadingcapacity

Calculate

baseline loadcontributions

Allocate loadsto sources

Calculate

instreamconcentrations

TMDL LA, WLA

Slide courtesy of CDM Smith


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Process

Determine

loadingcapacity

Calculate


Allocate loadsto sources

Calculate


TMDL LA, WLA



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Process

Loading capacity = allowable load = TMDL Expressed in pounds or CFUs per day

Can be implemented on monthly or seasonal basis

For each reach (water body segment):

Load = Concentration * Flow

Loading capacity = Water Quality Target * Flow

Loads and loading capacities vary with flow


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Process

Determined flow regimes per EPA guidance,for each reach and month

Q Low = 5th percentile

Q Dry = 25th percentile

Q Mid = 50th percentile

Q Moist = 75th percentile

Q High = 95th percentile

Also determined Q Min and Q Max

Based on ten (10) years of modeled flows


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Slide courtesyof CDM Smith


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Process

Phosphorous and Sediment TMDLs Applies to all twelve months

Use the 25th percentile flow (QDry)

One allowable load per month per reach

To be consistent with other Wisconsin TMDLs

Bacteria TMDL

Applies May to Sept - recreation standard in force

Calculate using 10% standard; verify geomean met

Use load duration methodology per EPA guidance

Five allowable loads per reach for the 5 month period


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Process

Determine

loadingcapacity

Calculatebaseline

loadcontributions

Allocate loads

to sources

Calculate


TMDL LA, WLA



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Process

Baseline loads are set to represent compliancewith existing regulations and permit limits

Baseline is notExistingor Current

Baseline loads only used to allocate allowable

loads to sources -- they do notdetermine the

allowable loads Allowable load = Water Quality Target * Flow


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Process

Baseline loads will be set as follows

Discharges that are not permitted

Baseline load = 0 = WLA

SSOs CAFO production areas

Manure spreading accounted for in LA

Nonpoint sources (LA) Loads and flows per WQI models

Loads broken out by land use

Ag modeled as partial compliance w/ NR 151


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Process

Baseline loads for point sources

Individual Permitted Point Sources (Industry & POTWs)

If numeric limit: permit concentration * design flow

No numeric limit: measured concentration * flow

General Permitted Point Sources

Will be a portion of the urban load (portion TBD)

If within MS4 - included in MS4s WLA

If outside MS4 - % of non-permitted urban load

Non-contact cooling water gets WLA if contains P


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Process

Baseline loads for point sources

CSOs: permitted 6 / year

Baseline load = 0* = WLA

0* because CSOs already covered by LTCP

MS4s: per NR 151 TSS reductions required

20% on existing development,

40% on redevelopment, and

80% on new development


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Process

Determine

loadingcapacity

Calculate


Allocate

loads tosources

Calculate


TMDL LA, WLA



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Process

TMDL = LA + WLA + MOS + RC

LA = Load Allocation (Nonpoint Sources)

WLA = Wasteload Allocation (Permitted Point Sources)

MOS = Margin of Safety (accounts for uncertainty)

RC = Reserve Capacity (accounts for future discharges)


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Process

LA

WLA

MOS

RC

Loading Capacity

BackgroundAgricultural

Non permitted Urban

General Permitted

Municipal Storm Sewer (MS4)

Wastewater Treatment Plants

Industrial

Margin of Safety

Reserve Capacity



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Process

Allowable loads for each reach will bedivided proportionally according to the

sources baseline load contribution

Ag,35%

PS,30%

MS4,20%

NPU,15%

Allowable Load

Ag, 35%

PS,30%

MS4,20%

NPU,15%

Baseline Load



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Process

Determine

loadingcapacity

Calculate


Allocate loads

to sources

Calculate


TMDL LA, WLA



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Questions ?

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