2015 Missouri Lake Nutrient Criteria

TRENT STOBER

2014 Water Seminar

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

2009 Regional Lake Nutrient Criteria

Total Nitrogen Criteria – 20 x TP Chlorophyll Criteria

Plains Chl:TP = 0.44 Ozark Border and Ozark Highland

Chl:TP = 0.42

Total Phosphorus Criteria

2015 Lake Nutrient Criteria - Beneficial Uses

• Drinking Water Supply

– Taste & Odor

– Algal Toxins

• Whole Body Contact Recreation

– Transparency

• Aquatic Life Protection

– Sport Fish Yields

Whole Body Contact Recreation Approach

• Differs by Ecoregion

• Transparency (Secchi Depth)

• Change Point Analysis

• Algae-Nutrient Relationships

Whole Body Contact Recreation Approach

WQCWQCWQC

Whole Body Contact Recreation Approach

Whole Body Contact Recreation Approach

Montana Algal Target

Scientific and Technical Basis for Montana’s Numeric Nutrient Criteria

Microcystin in Missouri ReservoirsGraham and Jones 2009

Drinking Water Supply Protection ApproachAlgal 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 ReservoirsGraham and Jones 2009

Drinking Water Supply ProtectionAlgal Toxins

Aquatic Life Protection Approach

Lake EcoregionChl-a (µg/L)

Secchi depth (m)

Plains 30 0.6

Ozark Border 22 0.7

Ozark Highlands

15 0.9

Proposed Lake Nutrient Criteria

Table L: General Ecoregional nutrient criteria Lake Ecoregion

Lake Class TP (µg/L)

TN (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

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

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

Incremental Cost of Nutrient Removal

Algal Production Potential v. Greenhouse Gas Production

0

2,500

5,000

7,500

10,000

12,500

0

5,000

10,000

15,000

20,000

25,000

Level 1 (No N/P Rem)

Level 2 Level 3 Level 4 Level 5

GH

G E

mis

sio

ns

(CO

2 eq

mt

ton

s/yr

)

Alg

ae P

rod

uct

ion

per

Tre

atm

ent

Lev

el (

lb a

lgae

/d)

Algae Production GHG Emissions

The Fun is Just Beginning

Stream Nutrient Criteria Zone

Total Nitrogen (ug/L)

Total Phosphorus (ug/L)

I 900 75II 700 35III 500 31IV 430 10V 500 75

2010 Draft Missouri Stream and River Nutrient Criteria

Thanks!

Trent StoberHDR Engineering3610 Buttonwood Drive, Suite 200Columbia, MO 65201573-489-5961trent.stober@hdrinc.com