This document summarizes Missouri's proposed 2015 lake nutrient criteria. It discusses the regional and site-specific criteria from 2009, and the new approaches for whole body contact recreation, drinking water supply protection, and aquatic life protection. The proposed criteria establish phosphorus, nitrogen, chlorophyll, and secchi depth values for different lake classes and ecoregions. Implementation of the new criteria could lead to impairments of over 80% of reservoirs and most major lakes, requiring numerous TMDLs and potential permit impacts. Issues for further discussion include the use of transparency in criteria setting and site-specific criteria development.

1. 2015 Missouri Lake
Nutrient Criteria
TRENT STOBER
2014 Water Seminar

2. 2009 Missouri Lake Nutrient Criteria
• Regional Criteria
– Regression Based
• Site-Specific Criteria
– 27 High Quality Reservoirs
– Existing Condition
• Tributary Arm Criteria
– Lake of the Ozarks
– Table Rock Lake

3. 2009 Regional Lake Nutrient Criteria
 Total Phosphorus Criteria
 Total Nitrogen Criteria – 20 x TP
 Chlorophyll Criteria
 Plains Chl:TP = 0.44
 Ozark Border and Ozark Highland
Chl:TP = 0.42

4. 2015 Lake Nutrient Criteria - Beneficial Uses
• Drinking Water Supply
– Taste & Odor
– Algal Toxins
• Whole Body Contact
Recreation
– Transparency
• Aquatic Life Protection
– Sport Fish Yields

5. Whole Body Contact Recreation Approach
• Differs by Ecoregion
• Transparency (Secchi
Depth)
• Change Point Analysis
• Algae-Nutrient
Relationships

6. Whole Body Contact Recreation Approach
WQC
WQC
WQC

7. Whole Body Contact Recreation Approach

8. Whole Body Contact Recreation Approach

9. Montana Algal Target
Scientific and Technical Basis for
Montana’s Numeric Nutrient Criteria

10. Drinking Water Supply Protection Approach
Algal Toxins
Microcystin in Missouri Reservoirs
Graham and Jones 2009

11. Drinking Water Supply Protection
Algal Toxins
Microcystin
Conc. (ug/L)
Total Phosphorus
(ug/L)
Total Nitrogen
(ug/L)
Chlorophyll
(ug/L)
Secchi Depth
(m)
ND 32 646 11 1.2
0.1-1 47 891 26 0.9
> 1 76 1170 46 0.7
Proposed DWS 20 450 10 1.2
Microcystin in Missouri Reservoirs
Graham and Jones 2009

12. Aquatic Life Protection Approach
Lake Ecoregion
Chl-a
(μg/L)
Secchi
depth (m)
Plains 30 0.6
Ozark Border 22 0.7
Ozark
Highlands
15 0.9

13. Proposed Lake Nutrient Criteria
Table L: General Ecoregional nutrient criteria
Lake
Lake Class TP
TN
Ecoregion
(μg/L)
(μg/L)
Chl-a
(μg/L)
Minimum
Secchi
Depth
(m)
Alternative
Criteria
TP
(μg/L)
TN
(μg/L)
Plains L1 20 450 10.0 1.2 30 650
L2 20 550 12.0 1.2 40 900
L3 (WBC-A) 30 600 17.0 1.2 50 850
L3 (WBC-B) 50 800 30.0 0.6 90 1,200
Ozark
Border
L1 20 450 10.0 1.5 30 650
L3 (WBC-A) 20 500 9.0 1.5 35 700
L3 (WBC-B) 40 650 22.0 0.7 80 1,050
Ozark
Highlands
L1 & L2 10 300 6.0 2.0 20 450
L3 (WBC-A) 10 300 6.0 2.0 20 450
L3 (WBC-B) 30 600 15.0 0.9 40 800

14. Potential Impacts of Proposed Lake Nutrient
Criteria
• Potential Impairments
• > 80% Reservoirs
• Most Major Reservoirs
– Lake of the Ozarks,
Truman, Pomme de Terre,
Stockton, Taneycomo,
Wappapello
– Mark Twain, Smithville
• Numerous TMDLs
• Permit Impacts

15. Issues for Further Discussion
• Use of Transparency to Set
Criteria
• Change Point Analysis
Approach
• Drinking Water Supply
Approach
• Site-Specific Criteria
Development
• Allowable Exceedance
Frequency
• Implementation Approaches

16. Incremental Cost of Nutrient Removal

17. Algal Production Potential v. Greenhouse Gas
Production
12,500
10,000
7,500
5,000
2,500
0
25,000
20,000
15,000
10,000
5,000
0
Level 1 (No N/P
Rem)
Level 2 Level 3 Level 4 Level 5
GHG Emissions (CO2 eq mt tons/yr)
Algae Production per Treatment Level (lb algae/d)
Algae Production GHG Emissions

18. The Fun is Just Beginning
2010 Draft Missouri Stream and River Nutrient Criteria
Stream Nutrient
Criteria Zone
Total Nitrogen
(ug/L)
Total Phosphorus
(ug/L)
I 900 75
II 700 35
III 500 31
IV 430 10
V 500 75

19. Thanks!
Trent Stober
HDR Engineering
3610 Buttonwood Drive, Suite 200
Columbia, MO 65201
573-489-5961
trent.stober@hdrinc.com