Assessing Bay Criteria

1

Assessing Bay Criteria

Assessment method reminder‘Relative Model’ method

Direct model assessmentResults

2

Criteria Assessment

3

Gather and interpolate WQ Data

4

Separate Open Water from Deep Water from Deep Channel using the pycnocline

5

Assess violations of the criterion each month for three years

Ass

essm

ent

Per

iod

March 1999

April 1999

May 1999

June 1999

March 2000

Apr 2000

May 2000

6

Create and Evaluate the CFDs

Allowable exceedences

Unallowable exceedences

7

Dissolved Oxygen Criteria

• Green – evaluated using data

• Otherwise not evaluated for 303d

8

2003 DO Criteria Assessment

• Use the model in a relative sense to re-generate ‘observed’ data sets for different scenarios

• Model output not directly assessed

• Model response to scenarios overlaid on observed data to create “what we would have observed given scenario inputs”

9

Monitoring Team

1985 - 1994Observed Data

Observed CriteriaAchievement

CalibratedModel

ModelE3

Scenario

Monitoring Team

E3“Observations”

Criteria AchievementUnder E3

Modeling Team

10

Frequency of DO, CB5, Summer, Bottom

0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

percent less than

mg

/l

Data

Model (cal)

11

Frequency of DO, CB5, Summer, Bottom

0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

percent less than

mg

/l

Data

Model (cal)

12

Frequency of DO, CB5, Summer

0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

percent less than

mg

/l

Data

Model (cal)

Model (3E)

13

EEE scenario

y = 0.8059x + 1.4603

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6 7 8

Calibration

EE

E

[E3] = 0.8 * [calibration] + 1.5

14


0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

percent less than

mg

/l

Data

Data (3E)

15


0

1

2

3

4

5

6

7

8

9

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

percent less than

mg

/l

Data

Data (3E)

16

One regression for each pointfor each month

17

2008 Proposed MethodDO Criteria Assessment

• 2003 method – use the model in a relative sense to re-generate ‘observed’ data sets

• Direct assessment from the model

18

Monitoring Team

1991 - 2000Observed Data

Criteria AchievementFor 8 3-year periods

CalibratedModel

ModelE3

Scenario

Monitoring Team

E3“Observations”

Criteria AchievementUnder E3

Modeling Team

CriteriaAchievement

Directly Evaluated

For all criteria

19

Proposed DO Criteria Assessment

• Use the direct model assessment to determine whether the 3 relative-model assessments are more or less difficult to achieve– Question 1 – Which criteria are ‘limiting’?

• Use the model in a relative sense (2003 method) for the TMDL– Question 2 – What is the TMDL?

20

MODEL ONLY -- Various Scenarios -- Non-Attainment Mainstem Average

0%

5%

10%

15%

20%

25%

30%

Observed Bad Trib Strat BTS+40%

no

n-a

ttai

nm

ent

DO Open Water non-summer Monthly

DO Open Water Summer Instantaneous

DO Open Water Summer Monthly

DO Deep Water Instantaneous

DO Deep Water Daily

DO Deep Water Monthly

DO Deep Channel Instantaneous

Calibration - 340/24 244/21 146/13

1996-1998

21

MODEL ONLY -- Various Scenarios -- Non-Attainment Mainstem Average

0%

5%

10%

15%

20%

25%

30%

Observed Bad Trib Strat BTS+40%

no

n-a

ttai

nm

ent

DO Open Water non-summer Monthly

DO Open Water Summer Instantaneous


DO Deep Water Instantaneous

DO Deep Water Daily

DO Deep Water Monthly

DO Deep Channel Instantaneous

Assessable Criteria are Limiting!!

Calibration - 340/24 244/21 146/13

1996-1998

22

Monthly is Limiting in all Deep Water Cases

Cbseg

DO Deep Water

Monthly

DO Deep Water Daily

DO Deep Water

Instantaneous LimitingCB3MH 1.86% 0.60% 0.29% MonthlyCB4MH 11.45% 10.21% 3.00% MonthlyCB5MH 2.22% 1.55% 0.01% MonthlyCB6PH 0.00% 0.00% 0.00% -CB7PH 2.21% 0.99% 0.77% MonthlyCHSMH 14.31% 12.37% 6.60% MonthlyEASMH 18.11% 16.84% 9.91% MonthlyMD5MH 6.08% 5.52% 0.01% MonthlyPA1MH 0.11% 0.00% 0.00% MonthlyPA2MH 8.11% 7.82% 3.44% MonthlyPA3MH 0.00% 0.00% 0.00% -PA5MH 0.00% 0.00% 0.00% -PATMH 29.12% 27.75% 19.75% MonthlyPAXMH 0.63% 0.00% 0.10% MonthlyPOMMH 0.08% 0.00% 0.00% MonthlyPOMMH 0.08% 0.00% 0.00% MonthlyPOTMH 0.08% 0.00% 0.00% MonthlyPOVMH 0.00% 0.00% 0.00% -POVMH 0.00% 0.00% 0.00% -RPPMH 0.01% 0.00% 0.00% MonthlySBEMH 42.50% 35.44% 22.34% MonthlyVA5MH 0.00% 0.00% 0.00% -YRKPH 0.00% 0.00% 0.00% -

Trib Strategy

Model direct output

1996-1998

23

Monthly is Limiting in all Open Water Cases

Trib Strategy

Model direct output

1996-1998

Cbseg

DO Open Water

Summer Monthly

DO Open Water

Summer Weekly

DO Open Water Summer Instantaneous Limiting

CB1TF 0.03% 0.00% 0.00% MonthlyCB2OH 1.48% 0.00% 0.10% MonthlyCB5MH 0.01% 0.00% 0.00% MonthlyCB6PH 0.24% 0.00% 0.00% MonthlyCB7PH 0.57% 0.00% 0.00% MonthlyCHOMH1 7.24% 1.96% 2.53% MonthlyCHOMH2 34.10% 28.45% 25.47% MonthlyCHOOH 28.04% 24.18% 23.20% MonthlyCHOTF 20.32% 14.31% 13.96% MonthlyCHSMH 0.65% 0.00% 0.12% MonthlyCHSOH 46.68% 36.62% 34.53% MonthlyJMSPH 1.07% 0.00% 0.00% MonthlyJMSTF 0.22% 0.00% 0.13% MonthlyJMSTFL 0.27% 0.00% 0.17% MonthlyMAGMH 3.74% 0.00% 0.00% MonthlyMOBPH 1.26% 0.00% 0.02% MonthlyNANMH 5.70% 3.09% 3.95% MonthlyNANOH 0.04% 0.00% 0.00% MonthlyPAXOH 10.68% 0.49% 0.03% MonthlyPAXTF 0.95% 0.00% 0.00% MonthlyPIAMH 1.93% 0.00% 0.00% MonthlyPOCMH 1.14% 0.03% 0.41% MonthlyPOTOH 3.55% 0.00% 0.03% MonthlySASOH 9.95% 1.27% 1.81% MonthlySEVMH 4.38% 0.77% 1.54% MonthlyTANMH 12.85% 6.76% 6.66% MonthlyYRKMH 7.42% 2.89% 3.19% Monthly

Plus 26 more monthly limited

Plus 66 More no violation

24

Data Only - DO criteria -- average of mainstem segments

0

0.05

0.1

0.15

0.2

0.25

1994-1996 1995-1997 1996-1998 1997-1999 1998-2000

non-

atta

inm

ent

DO Open Water Summer MonthlyDO Deep Water Summer MonthlyDO Deep Channel Summer Instantaneous

Change among 3-year periods

25

Data and relative model - DO sensitivity1996-1998

0%

5%

10%

15%

20%

25%

Observed 244/21 146/13

non-

atta

inm

ent


DO Deep Water Summer Monthly

DO Deep Channel Summer Instantaneous

26

Relative and Direct Model - DO sensitivity1996-1998

0%

5%

10%

15%

20%

25%

30%

Observed 244/21(Relative)

146/13(Relative)

Calibration(model)

244/21(model)

146/13(model)

non-

atta

inm

ent


DO Deep Water Summer Monthly

DO Deep Channel Summer Instantaneous

27

Initial Observations

• Model predicts that the most restrictive criteria are the ones that we can measure and assess through the relative model method

• The relative model method is sensitive to load reductions

28

Decision Requested

• Agreement on proceeding forward with the recommended procedures for assessing the full suite of Bay criteria adopted by the states into their water quality standards regulations pending further understanding of which sets of criteria are driving the allocations.

Documents

Assessing Bay Criteria