TEMPERATURE EFFECTS ON
ASSIMILATIVE CAPACITY OF RIVERS, LAKES AND ESTUARIES
2016 Georgia-Pacific Environmental Conference
Atlanta Airport Marriott Gateway Hotel
October 18, 2016
Michael R. Corn, P.E., BCEEAquAeTer, IncBrentwood, TN
Grand Ole OpryHome of Country Music
Beech Grove near Nashville, Tennessee
FEDERAL WATER POLLUTION CONTROL ACT AMENDMENTS OF 1972
(CLEAN WATER ACT)1. RESTORATION AND MAINTENANCE OF CHEMICAL, PHYSICAL
AND BIOLOGICAL INTEGRITY OF NATION’S WATERS;a. discharge of pollutants into the navigable waters be eliminated by 1985;b. protection and propagation of fish, shellfish, and wildlife and provides
for recreation in and on the water be achieved by July 1, 1983;c. discharge of toxic pollutants in toxic amounts be prohibited; andd. control of nonpoint sources of pollution be developed and implemented
in an expeditious manner.
CLEAN WATER ACT OF 1972WATER QUALITY-BASED PERMIT LIMITS
WATER QUALITYBASED LIMITS FOR
DO
TECHNOLOGYBASED LIMITS
WHOLE EFFLUENTWATER QUALITY
BASED LIMITS
BAT ANDEFFLUENT LIMITS
GUIDELINES
CONVENTIONALAND
PRIORITY POLLUTANTS
ANTIBACKSLIDINGPROVISION
END OF PIPE
NUMERIC STANDARD
(TYPICALLY 5 mg/L)
IODPROTECTIONOF AQUATICRESOURCES
BOD5LIMITS
NH3,4 LIMITS
HUMANHEALTH
CRITERIA
ACUTETOXICITYCRITERIA
CHRONICTOXICITYCRITERIA
ANTIBACKSLIDINGPROVISION
ANTIDEGRADATIONPROVISION
MIXING ZONE
1987 WATER QUALITY
ACT
END OF PIPE
Impacts to Receiving Stream Water Qualityfrom Municipal and Industrial Discharges
o Typical impairments identified downstream from Discharges DO standard not being met Nutrient enrichment (DO sag or nuisance algal blooms) Metals (typically Hg, Pb, As, Cu) Dioxins Sedimentation (silvicultural activities) Other Toxins – Carcinogens, Non-Carcinogens,
Teratogens
HOW DOES TEMPERATURE AFFECTTREATMENT AND EFFLUENT LIMITS
1. Max T for Aerobic Treatment ~ 104°F (40°C);2. Min T for Nitrification ~ 59°F (15°C);3. DO saturation decreases per degree T increase;4. Oxygen depletion increases per degree T increase;5. Reaeration Rates increase per degree T increase;6. Net Effect:
a. Lower BOD5 limits per degree T increase;b. Lower Nitrogen limits per degree T increase;c. More oxygen supply per degree T increase; andd. More stress on aquatic resources per degree T increase.
Primary Data Requirements for Determining Assimilative Capacity
1. Statistical Flow and Temperature Scenarios2. River Hydraulics3. Background Water Quality Conditions
a) Time of travelb) Bathymetry
4. Effluent Variability and Characteristicsa) Flowsb) Quality
5. Oxygen Rates (per day)a) Atmospheric Reaeration Rateb) Algal Productivity and Respiration
6. River Deoxygenation Rates (per day)a) Ultimate Carbonaceous Biochemical Oxygen Demand (CBODu) decay rateb) Organic nitrogen decay ratec) Ammonia nitrogen decay rated) Sediment oxygen demand
7. Calibration/Verification Modeling8. Predictive Modeling to Establish Wasteland Allocations
Schematic of the Oxygen BalanceCalculations In QUAL2E
OXYGEN DEMANDSIN
CBODuNITROGEN SERIES
IOD
OXYGEN DEMANDSOUT
CBODuNITROGEN SERIES
IOD
O2 IN O2 OUT
NUTRIENTS NUTRIENTS
O2 BALANCE = ASSETS – LIABILITIES = DO – OXYGEN DEMANDS
-O2AMMONIFICATION
Org N NH3
-O2NITRIFICATIONNH3 NO2 + NO3
-NO3, -CBODuDENITRIFICATION
@ANOXICCONDITIONS
-O2CBODu
+O2SUSPENDED ALGAE(PRODUCTION AND
RESPIRATION)
-O2IOD
NUTRIENTSTOTAL NTOTAL P CBODu
NUTRIENTS
+O2
ATTACHED ALGAEAND AQUATIC PLANTS
(PRODUCTION ANDRESPIRATION)
DENITRIFICATION BENTHICOXYGEN
DEMANDS
CBODuNUTRIENTS
SOD
ATMOSPHERICREAERATION +O2
-CBODu, NO3
AUGUST 27, 1998 CALIBRATION MODELOUACHITA RIVER NEAR CROSSETT, AR
0
1
2
3
4
5
6
7
8
190195200205210215220225230
ORM
DISS
OLV
ED O
XYGE
N (m
g/L)
PREDICTED DO AVERAGE DOMAX DO MIN DOOBS DO PREDICTED DO NO GP DISCHARGEUSEPA DO
PREDICTED DO, NO DISCHARGE
Ouachita River Calibration Model
QUAL2E Sensitivity Analyses
-25 % +25 %4
5
6
7
8
9
10
PERCENT OF CALIBRATION VALUE
MIN
IMU
M S
TR
EA
M D
O (m
g/L
)
Chl-A/Algae Flow Temperature K2, Rearation Rate k3, SOD rate k1, CBOD Decay Rate k(org-N)/k(NH3) BG DO
BG BODu Inc. Inflow BODU CC Flow CC DO CC BODu Algal Settling Rate Non-algal Light Ext. Chlorophyll-a
WHAT AFFECTS DO IN RIVER1. Temperature;2. Flow;3. Background DO; and4. Reaeration Rate
WHAT HAPPENS IN THE STREAM AT HIGHER TEMPERATURES
1. Decreasing DO with Increasing Temperature;2. Essential to match Q and T that occur at same time;3. Higher reaeration rates @ high T;4. Higher O2 depletion @ high T;5. Optimum T for algae ~27.5°C or 81.5°F; and6. Blue-green algae max T ~72°C or 163°F.
Monthly Temperatures
Tombigbee finished 1984
WHAT IS THE PROJECTION FOR AMBIENT AIR TEMPERATURE TRENDS IN THE
SOUTHEAST1. Avg Annual Temperature increased in SE by ~2°F since 1970;2. By 2100, Avg temperature to rise 4 to 8°F or 2.2 to 4.4°C;3. Number of days over 95°F or 35°C to increase (2041-2070)
https://www3.epa.gov/climatechange/southeheast.html
FLOW & TEMPERATURE
DO CONCENTRATION AND SATURATIONVS TEMPERATURE
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
120.00%
0.000
2.000
4.000
6.000
8.000
10.000
12.000
14.000
16.000
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0
SAT
UR
ATIO
N V
S 0.
0 (%
)
CO
NC
EN
TR
ATIO
N (m
g/L
)
TEMPERATURE (deg C)
DO vsTemperature
Percent Saturation vs 0.0°C
DO vs Temperature
From Standard Methods
-0.2 to -0.3 mg/L per 1°C T rise~250 lbs/day of BOD5
Comparison Between Measured and Calculated Reaeration Coefficients
STREAMREACH
1
2
3
4
5
6
1
2
3
DEPTH(feet)
0.375
0.706
0.620
1.700
0.860
0.440
1.140
1.280
1.420
VELOCITY(fps)
0.0620
0.0490
0.0530
0.0096
0.0450
0.0620
0.4300
0.4000
0.3300
REAERATIONRATE (K )
4.194
2.890
2.840
0.277
1.950
2.817
1.500
1.380
1.250
O'CONNOR
14.050
4.810
6.080
0.573
3.580
11.000
6.950
5.630
4.380
OWENS
20.700
5.450
7.310
0.361
3.580
15.310
9.630
7.400
5.370
CHURCHILL
4.040
1.020
1.370
0.053
0.670
2.830
4.010
7.400
5.370
LANGBIEN
1.750
0.028
0.763
0.036
0.420
1.408
2.750
2.260
1.580
2
FIELD MEASURED VALUES EMPIRICAL PREDICTIONS OF K
SAN GABRIEL RIVER
2
BRUSHY CREEK
REAERATION RATE INCREASES WITH TEMPERATURE
k2 = c*ΔhTOT
k2 @ 29.5°C = 1.72/dayk2 @ 20°C = 1.72/day * 1.02220 -29.5
k2 @ 20°C = 1.40/day
From GP Red River Waste Assimilative Capacity Study on Red River (Jernigan and Corn June 1992; March 1993)
Reaeration is a function of turbulence not depth
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0
k 2(p
er d
ay)
WATER TEMPERATURE (°C)
REAERATION RATE, k2, vs TEMPERATURE
GROWTH RATE FOR ALGAE
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
120.00%
0 5 10 15 20 25 30 35 40
GR
OW
TH
RAT
E (%
)
TEMPERATURE (deg C)
Algae growth vs Temperature
MAXIMUM GROWTH RATE @ 27.5°C(100% as compared to other temperatures)
(Cassidy, K.O. 2011. "Evaluating Algal Growth at Different Temperatures", UK)
IMPACT OF TEMPERATURE INCREASE
1. Increasing Temperature, DO instream decreases;2. Reaeration rate increases – but water cannot hold as
much oxygen;3. Algae – 16 to 30°C optimum; > 30°C conducive to blue-
green algae
DEOXYGENATION RATES ARE TEMPERATURE DEPENDENT
1. Temperature Correction Factor for deoxygenation rates is 1.047 (Empirically determined)
2. For CBODu, k1, of 0.1/day at 30°C, the rate converted to 20°C is:
k1 @ 20°C = 0.1/day @ 30°C * 1.04720-30 = 0.06/day k1 @ 35°C = 0.1/day @ 30°C * 1.04735-30 = 0.13/day
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0
k 1(p
er d
ay)
WATER TEMPERATURE (°C)
DEOXYGENATION RATE, k1, vs TEMPERATURE
Determination of River CBODu and Ammonia Deoxygenation Rates
Note: Calibration kr=0.44/day
Verification kr=0.40/day
Sediment Oxygen Demand
Monthly BOD5 Loadings Ouachita River Downstream from Coffee Creek
MONTH 7Q10 90th PERCENTILE WLA GP PERMITWATER BOD5 BOD5
TEMPERATURE(cfs) (°C) (lbs/day) (lbs/day)
January 2,658 <18 53,539 8,000February 5,269 <18 102,142 8,000March 4,037 <18 79,435 8,000April 2,436 25.1 24,614 8,000May 1,591 26.5 21,591 8,000June 1,049 31.0 22,706 8,000July 894 31.9 14,605 8,000August 802 31.6 8,069 7,262September 829 29.8 6,568 5,911October 822 25.1 10,423 8,000November 1,231 18.0 25,888 8,000December 2,059 <18 42,071 8,000
Note: CBODu/BOD5 = 4
y = 339.08x0.5866
R² = 0.9973y = 375.52x0.5582
R² = 0.9954
y = 438.37x0.5226
R² = 0.993
y = 558.52x0.4743
R² = 0.9835
y = 739.8x0.4203
R² = 0.9732
y = 1215.4x0.337
R² = 0.9437
10000800
BO
D5
LO
AD
ING
(lbs
/day
)
FLOW (cfs)
BOD5 LOADING VS FLOW & TEMPERATURE
22 deg C
24 deg C
26 deg C
28 deg C
30 deg C
32 deg C
Power (22 deg C)
Power (24 deg C)
Power (26 deg C)
Power (28 deg C)
Power (30 deg C)
Power (32 deg C)
22°C
24°C
26°C28°C
30°C
32°C
Each 2°C Temperature Rise Costs you~ 1,000 lbs/day of BOD5 or 5 mg/L of effluent BOD5
y = 830009x-1.238R² = 0.9985
1000020
BO
D5
LO
AD
ING
(lbs
/day
)
TEMPERATURE (°C)
BOD5 LOADING VS TEMPERATURE
'@ 7Q10 OF 900 CFS Power ('@ 7Q10 OF 900 CFS)
@ 32°C, 11,315 lbs/day effluent limit for BOD51. For 25 mgd Qeffl, BOD5 = 54 mg/L2. For 40 mgd Qeffl, BOD5 = 34 mg/L3. For each 2°C temperature rise, ~5 mg/L less BOD5
Michael R. Corn, P.E.AquAeTer, Inc., Brentwood, TN(615) 373-8532
For a copy of today’s presentation
Go to www.aquaeter.com/downloads.htm
