EPA Report to Congress 2000(latest available on web)
Provided to Dr.G. Powell by Dr. D. Monreau, NCSU for this website
Uses for which assessments were made
• Aquatic life support • Fish consumption • Primary contact recreation (swimming)• Secondary contact recreation • Drinking water supply• Agricultural
Rivers and Streams
Rivers and Streams
Lakes, Ponds, and Reservoirs
Estuarine Waters
Estuarine Waters
Oxygen Balance in Streams
Balance between
Supply and Demand
Oxygen Supply
Sauration Concentrations for Dissolved Oxygen
0
2
4
6
8
10
12
14
0 5 10 15 20 25 30
Temperature, degrees C
Sat
urat
ion
Con
cent
ratio
n, m
g/l
867768595041
Temperature, degrees F
Oxygen Resources of Streams
Atmosphere
WaterOxygen
O2
Conc. Saturation(equilibrium)
Temperature of Tar River at Tarboro,NC 1974-1994Selected Sampling Times
0
5
10
15
20
25
30
0 1 2 3 4 5 6 7 8 9 10 11 12
Month of Year
Tem
pera
ture
, deg
C
from USGS NASQAN data
86
77
68
59
50
41
32
oF
Saturation Concentration for Dissolved Oxygen in Tar River at Tarboro
0123456789
101112131415
0 1 2 3 4 5 6 7 8 9 10 11 12
Month
Sat
urat
ion
Con
cent
ratio
n, m
g/l
Water Quality Standard = 5 mg/l
Oxygen Demand
Atmospheric Oxygen
Dissolved Oxygen
Bacteria Organic matter CO2
BIOCHEMICAL OXIDATION OF ORGANIC MATTER
IN STREAMS
Water
Biological Oxidation of Organic Matter
• Carbohydrate Oxidation: CxHyOz + O2 bacteria CO2 + H2O
• Algal cell oxidation: (CH2O)106(NH3)16 H3PO4 + 1.2 O2 bacteria
CO2 + H2O
Algae = 34.3% C; 7.1% H; 51.8% O; 6.0% N; 0.8% P (15 lb algae/lb N)
Nitrogen CycleAnimal protein
Organic N
Plant protein
Organic N
Ammonia
NH3 and NH4+
Nitrites NO2-
Nitrates NO3-
Atmospheric
N2
Waste material, death & decay
decay
O2
O2Anaerobic (O2 absent) Aerobic (O2 present)
lightning
nitrogen-fixing bacteria
bacteriabacteria
bacteriabacteria
Hydrolysis is a chemical decomposition process that uses water to split chemical bonds of substances.
hydrolysis
The Oxygen Sag-Net Effect of Supply and Demand
Decay of Organic Matter
Dissolved Oxygen
Degradation Recovery Zone Zone (dearation > (reaeration > dearation) reaeration)
0 xc , tc
O2 O2 O2 O2 O2 O2 O2
Saturation Concentration
Dissolved Oxygen Profile of Neuse River under 1995 Loading Conditions
0
1
2
3
4
5
6
7
8
0 10 20 30 40 50 60 70 80 90 100 110 120
Distance from Falls Lake, miles
Dis
so
lved
Oxyg
en
, m
g/l
Raleigh Johnston Co. Goldsboro WWTP WWTP WWTP
Nutrients
Dead algae
N
PC
N
P
DissolvedOxygen
Sunlightt
Creation of Dead Zones in Estuaries
Algae
Low DO Zone
1 lb N
16.7 lb algae
1.2 lb O2/lb algae
20 lb O2/lb N
Approximate chemical formula for algal cells: (CH2O)106(NH3)16H3PO4
C= 34.3% H = 7.1% O = 51.8% N = 6.0% P = 0.8%
respiration
synthesis At 0.0015 lb NH3/day/person (0.00124 lb N/day/person),oxygen demand associated with algal growth =0.025 lb/day/person
Generally exerted in lakes or estuaries where reaeration is low.
Raleigh
Durham
Approximately 160 river miles
Nutrient Loads in Neuse River Basin by Source
Estimated Distribution of Nitrogen Loads in the Neuse River Basin
Agriculture, 61%Point Sources, 13%
Urban, 5%
Forest, 13%
Load = point +export from land = 21.8 million tons/yr = 5.5 lb/ac/yr
Urban, 7%
Forest, 7%
Point Sources, 24%Agriculture, 57%
Estimated Distribution of Phosphorous Loads in the Neuse Basin
Load = point + export from land = 2.35 million lbs/yr = 0.59 lb/ac/yr
= 0.45 million lbs
Chesapeake Bay Watershed
Maryland
Delaware
New York
District of Columbia
Virginia
West Virginia
PennsylvaniaSusquehanna
James
Potomac
Appox. 160 mi.
Threats to the Bay and RiversNUTRIENTS
SEDIMENTS
TOXIC CHEMICALS
HABITAT LOSS
OVERFISHING
Estimated 1985 Base Nutrient Loads
Distribution of Nitrogen Load by Sources
Forest
Agriculture
Point Source
Atmospheric Deposition
Development
Total =303 million lbs/yrDHM
Distribution of Phosphorous Load by Sources
Point Source
Agriculture
DevelopmentForest
Atmospheric Deposition
Total =23.8 million lbs/yrDHM
Water Pollutant Loads
Unit Waste-loading factors for Municiapl WasteSource: Viessman and Hammer, 1998. Water Supply and Pollution Control.
Typical LoadsLoad, lb/capita/day per 100,000 Persons
Range Typical lbs/day 106 lbs/yr
Without ground kitchen waste:BOD5 0.13-0.24 0.180 18,000 6.570 Suspended solids 0.13-0.25 0.200 20,000 7.300 Ammonia 0.004-0.008 0.007 7,000 2.555 Organic Nitrogen 0.013-0.026 0.020 2,000 0.730 Total nitrogen 0.020-0.031 0.027 2,700 0.986 Organic phosphorous 0.002-0.004 0.003 300 0.110 Inorganic phosphorous 0.004-0.007 0.006 600 0.219 Total phosphorous 0.007-0.011 0.008 800 0.292
With ground kitchen waste: BOD5 0.18-0.26 0.220 22,000 8.030 Suspended solids 0.20-0.33 0.260 26,000 9.490
(Mass Loadings)
Nonpoint Source Loads of Nitrogen
in the United States
Input to fields
Export to streamsDeliveryto estuaries
Decay
INPUTS1 ton/ac = 3.125 lb/ac.
AppliedNitrogenLoadsFromCommercialFertilizer
Lbs/ac<3.13.1-6.36.3-12.512.5-21.9>21.9
AppliedNitrogenLoadsFromAnimalManure
INPUTS1 ton/sq.mi. = 3.125 lbs/ac
Lbs/ac<3.13.1-6.36.3-12.512.5-21.9>21.9
INPUTS1 ton/sq.mi. = 3.125 lb/ac
NitrogenLoadsFromAtmosphericDeposition
Lbs/ac<3.13.1-4.14.1-5.35.3-6.3>6.3
March, 2000
water.usgs.gov/nawqa/
Nitrogen Export by Region
Median Annual Export of Nitrogen from Watersheds to Streams
0
2
4
6
8
10
12
14
NE
Mid
AtG
lf
SE
At-
Glf
GLk
Ohi
o
Ten
n
Up
MS
Low
MS
Re
d-R
ny
Mo
Ark
-Re
d
TxG
lf
Rio
Grn
d
Up
CO
Low
CO
Grt
Bsn
NW CA
US
Tot
al E
xpor
t, k
g/h
a/yr
10
8
6
4
2
Lb/ac1 kg/ha = 0.89 lb/ac1 lb/ac = 1.12 kg/ha
Phosphorous Export by Region
Export of Phosphorous from Watersheds of the United States to Streams
0
0.2
0.4
0.6
0.8
1
1.2
NE
Mid
AtG
lf
SE
At-
Glf
GLk
Ohio
Tenn
UpM
S
Low
MS
Red-R
ny
Mo
Ark
-Red
TxG
lf
Rio
Grn
d
UpC
O
Low
CO
Grt
Bsn
NW CA
US
Hydrologic Unit
Exp
ort
, kg
/ha/y
r
0.9
0.7
0.5
0.3
0.1
lb/ac
