1. Phosphorus and Suspended Solids TMDL For the Lower Fox River/Green Bay Area of Concern – Putting the Pieces Together
Bud Harris, P. Sager,
D. Scheberle, V. Harris,
P. Baumgart, D. Robertson,
K. Fermanich, M. Finney,
J. Kennedy, J. V. Klump
UW Green Bay November 2-3, 2005
Looking upstream from the mouth of the Lower Fox River to the DePere dam, one can see the industrial and urban land uses that have destroyed fish and wildlife habitat and that are the source of the high concentrations nutrients, suspended solids and toxic substances.

2. Fox-Wolf Basin (16,500 km2) Three Sub-Basins Lower Fox (1,580 km2)
New London
Berlin
Oshkosh
Neenah/Menasha
Appleton
Wrightstown
DePere
Mouth
Fox-Wolf Basin (16,500 km2)
Three Sub-Basins
Lower Fox (1,580 km2)
41 Watersheds

3. Green Bay Area of Concern (approx 57.2 km2)

4. TMDL Requirements in Section 303(d)
Clean Water Act
TMDL Requirements in Section 303(d)
identify impaired/threatened waterbodies
(P listed in 303d in 2002)
develop TMDLs for those waters 4

5. TMDL Definition Sum WLA + Sum LA + {MOS} = TMDL
WLA = wasteload allocation
(point source loads)
LA = load allocation
(nonpoint source and background loads)
MOS = margin of safety (explicit or implicit)
TMDL = total maximum daily load

6. TMDLs 303(c) 303(d) 303(e) Water Quality Standards Water Quality
Controls*
TMDLs
* Water quality controls include regulatory as well as voluntary controls 6

7. Examples of how wq goals and TMDLs could be expressed
Nutrient TMDLs
Examples of how wq goals and TMDLs could be expressed
Water Quality
Water Quality
Controls
TMDL
Goals
nitrogen concentration
phosphorus concentration
chlorophyll-a conc.
macrophyte density
Carlson Trophic State Index
tons of in-lake algal biomass pH
transparency
biological indicators such as
health of fish or macroinvertebrates
dissolved oxygen
.....
annual or seasonal loading of nitrogen or phosphorus
percent reduction in nitrogen or phosphorus
..... 7

8. How did we get here? Some important benchmarks
1965 Federal Water Pollution Control Act
1970 First Load Estimate for P and SS
70-80’s Sea Grant Green Bay Subprogram
80-90’s GBMSD Monitoring Program
1988 Green Bay Remedial Action Plan
1990’s Priority Watershed Programs
1990 State of Bay Report
1992 NEWWT
2003 Lower Fox River Watershed Monitoring Program
SWAT modeling for load allocation

9. Changes? Total P in Green Bay

10. Changes? Average TSS in Green Bay

11. Changes? Secchi Disk in Green Bay

12. Target for TP Based on Algal Growth Rates in Green Bay
Algal growth begins to decline at 45 ug/l TP
At > 100 ug/l, growth rates do not increase

13. Defining the relationship between total phosphorous and algae
Present ambient phosphorous concentration ■
Target level ▲

14. Secchi Depth Model for Lower Green Bay (by Paul Sager)
Light penetration measured by secchi disk and light meter
Secchi depth = 0.80 – TSS – 0.17 VSS – 0.16 Chlor a
(r2 = .69)
Sea Grant and Paul Sager currently updating model using recent MSD data

15. Green Bay AOC TMDLs TMDL 15 riparian protection rotational grazing
Phosphorus (P) & Suspended Solids(SS)
Water Quality
Goals
Water Quality
Controls
TMDL
riparian protection
rotational grazing
conservation tillage
manure mgt
stormwater mgt
P rationing
construction site mgt
urban design
P target
SS target
Secchi disk depth
45µg/l
50% reduction in P load
7.5 mg/l
50% reduction in SS load
1.5 m 15

16. Basin Load Partitioning Data from GBMSD, DNR,USGS
New London
Berlin
Oshkosh
Neenah/Menasha
Appleton
Wrightstown
DePere
Mouth
Basin Load Partitioning
Data from GBMSD, DNR,USGS
Estimates by Dale Robertson USGS

17. Loads at Main Branch Sites

18. Smaller-scale monitoring to identify sources with greater confidence

19. Fox-Wolf Basin Point Source P Loads

22. TMDL Lower Fox River Basin (assume 50% reduction all sources)
TMDL (P) = sum WLA + sum LA + MOS
= 258,791 Kg/yr / 2
= 129,396 Kg/yr
TMDL (SS) = sum WLA + sum LA + MOS
= 81,600 mt/yr / 2
= 40,800 mt/yr

23. Possible Approaches STRATEGIES SS P SCENRARIO ONE SCENARIO TWO etc…
Phosphorus in Soil kept at a stable 40 parts per million
Vegetated Buffer Strip-installed on 100 percent of the 1:24k hydrology streams
Phosphorus in feed for dairy cows is reduced by 25 percent
Conservation Tillage current No Till (NT) the rest Mulch Till (MT), and all manure incorporated
Intensive Rotational grazing in which 40 percent of dairy farms adopt
SCENARIO TWO etc…
Individual % Reduction
SS P
0% 12.8%
3.5% 4.1%
0% 5.5%
18.7% 16.5%
14.1% 15.3%

24. Next Steps?
Satellite image May 19, 2000

25. Phosphorous Reduction Management Strategy
What is the likelihood of success?
Cost effectiveness
Social acceptability
Ecological integrity
True cost pricing
Political Will

26. TMDL Review Criteria 26 Is the TMDL approvable?
Identification of waterbody/pollutant of concern
Applicable water quality standards and numeric targets
Technical analysis/supporting documentation
Margin of safety & seasonality
TMDL/loading capacity
Wasteload & load allocations
Reasonable assurances nonpoint source controls will be implemented if point source WLAs rely on those controls
Public participation
Monitoring plan (for phased approach)
Implementation plan (not required) 26