Surface Water Quality
Dr. Martin T. Auer
MTU Department of Civil & Environmental Engineering
Surface Water Quality Management
• water supply
• recreation
• wastewater discharge
In A Watershed Everyone Lives Downstream
Add Clark
Surface Water Quality Management
• wastewater discharge
• recreation
• water supply
Temperature and the Density of Water
1.0000
0.9995
Density (g∙cm3)
0.9990
Maximum
Density
3.94 °C
0.9985
0.9980
0.9975
0.9970
0.9965
0.9960
0.9955
0.9950
0
5
10
15
20
Temperature (°C)
25
30
Thermal Stratification
spring
summer
Temperature (°C)
Thermal Stratification
Seasonality in Stratification and Mixing
 = °C
Dollar Bay - Temperature
0
1
1
2
2
Depth (m)
Depth (m)
0
3
3
4
4
5
6
M
A
M
J
J
A
S
O
N
D
5
6
7
7 8
8
Temperature (°C)
0
5
10
15
20
You are what you eat. For example, there’s this lake …
… and there’s that lake.
Trophic State
Oligotrophic
Eutrophic
Low in algae
High in algae
High transparency
Low transparency
Cold water fishery
Warm water fishery
The Limiting Nutrient Concept
The Product
The Supplies
The Divided Lake
Productivity and Oxygen
Trophic State and Oxygen Profiles
Eutrophic Lake
Oligotrophic Lake
Clinograde (°C)
Temperature
Orthograde (°C)
Temperature
5
10
15
20
0
25
0
0
2
2
4
4
6
6
8
8
10
12
Depth (m)
Depth (m)
0
10
12
14
14
16
16
18
18
20
20
5
10
15
20
25
Dollar Bay - Temperature
0
1
1
2
2
Depth (m)
0
3
3
4
4
5
6
M
A
M
J
J
A
S
O
N
D
5
6
7
7 8
8
Temperature (°C)
0
5
10
15
20
Dollar Bay – Dissolved Oxygen
M
0
A
M
J
J
A
S
O
N
D
1
Depth (m)
2
3
4
5
6
7
8
Dissolved Oxygen (mg∙L-1)
0
2
4
6
8
10
12
Onondaga Lake – Dissolved Oxygen
Oneida Lake – Dissolved Oxygen
Lake Erie – Dissolved Oxygen
Gulf of Mexico – Dissolved Oxygen
Aerobic and Anaerobic Metabolism
Aerobic (oxygen available)
C ( H 2O )  O2  CO2  H 2O
Anaerobic (oxygen not available)
C ( H 2O )  NO3  CO2  H 2O  N 2  HCO3
C ( H 2O )  Mn 4  CO2  H 2O  Mn 2
C ( H 2O )  Fe3  CO2  H 2O  Fe 2
C ( H 2O )  SO42  CO2  H 2O  H 2 S
C ( H 2O )  CO2  CH 4
Oligotrophic
Eutrophic
Low in nutrients, TP<10
High in nutrients, TP>20
Low in algae
High in algae
Oxygen at saturation
Oxygen (+, epi), (-, hyp)
High transparency
Low transparency
Cold water fishery
Warm water fishery
Deep lakes with steep
sides and infertile, often
rocky watersheds.
Shallow lakes with gently
sloping sides and cultivated,
fertile watersheds.
Natural Eutrophication
Cultural Eutrophication
Lakes: Loss of Beneficial Use
• Nutrients – aesthetics, recreation, drinking water
• Microorganisms – recreation, drinking water
• Toxics – wildlife, drinking water
• heavy metals: cadmium, lead, mercury
• synthetic organic chemicals: DDT, PCB, dioxin
Engineering Approaches for Lake Management
(Phosphorus)
1. Lake Protection
• Point source control (advanced waste treatment)
• Nonpoint source control
Engineering Approaches for Lake Management
(Phosphorus)
1. Lake Protection
• Point source control
• Nonpoint source control (land use management)
Engineering Approaches for Lake Management
(Phosphorus)
2. Diversion
Seneca River
Onondaga Lake
METRO
Engineering Approaches for Lake Management
(Phosphorus)
3. Hypolimnetic Aeration
Support Raft
Gas Vent
Support
Cables
Contact
Chamber
Air Line &
Diffuser
Ballast
Engineering Approaches for Lake Management
(Phosphorus)
4. Sediment Inactivation
Engineering Approaches for Lake Management
(Phosphorus)
5. Dredging
Engineering Approaches for Lake Management
(Phosphorus)
6. Algicides
Engineering Approaches for Lake Management
(Phosphorus)
7. Biomanipulation
River Water Quality
In A Watershed Everyone Lives Downstream
Add Clark
Biochemical Oxygen Demand
BOD exerted, y
BOD remaining, L
Dissolved Oxygen (mg/L, ppm)
Dissolved Oxygen Saturation and Deficit
16.0
14.0
12.0
10.0
8.0
6.0
0
5
10
15
20
Temperature (°C)
25
30
35
Dissolved Oxygen Sag Curve
Change in oxygen concentration =
inputs from reaeration – losses to deoxygenation
Stream Zones and Biota
Organism Diversity and Abundance