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

Oxygen Balance in Streams Balance between Supply and Demand

Oxygen Supply

Oxygen Resources of Streams Atmosphere Water Oxygen O 2 Conc. Saturation ( equilibrium)

oFoF

Water Quality Standard = 5 mg/l

Oxygen Demand

Water

Biological Oxidation of Organic Matter Carbohydrate Oxidation: C x H y O z + O 2 bacteria CO 2 + H 2 O Algal cell oxidation: (CH 2 O) 106 (NH 3 ) 16 H 3 PO O 2 bacteria CO 2 + H 2 O Algae = 34.3% C; 7.1% H; 51.8% O; 6.0% N; 0.8% P (15 lb algae/lb N)

Nitrogen Cycle Animal protein Organic N Plant protein Organic N Ammonia NH 3 and NH 4 + Nitrites NO 2 - Nitrates NO 3 - Atmospheric N 2 Waste material, death & decay decay O2O2 O2O2 Anaerobic (O 2 absent) Aerobic (O 2 present) lightning nitrogen-fixing bacteria 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

Saturation Concentration

Nutrients

1 lb N 16.7 lb algae 1.2 lb O 2 /lb algae 20 lb O 2 /lb N Approximate chemical formula for algal cells: (CH 2 O) 106 (NH 3 ) 16 H 3 PO 4 C= 34.3% H = 7.1% O = 51.8% N = 6.0% P = 0.8% respiration synthesis At lb NH 3 /day/person ( lb N/day/person), oxygen demand associated with algal growth = lb/day/person Generally exerted in lakes or estuaries where reaeration is low.

Approximately 160 river miles

Nutrient Loads in Neuse River Basin by Source

Load = point +export from land = 21.8 million tons/yr = 5.5 lb/ac/yr

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 Pennsylvania Susquehanna James Potomac Appox. 160 mi.

Threats to the Bay and Rivers N UTRIENTS S EDIMENTS T OXIC CHEMICALS H ABITAT LOSS O VERFISHING

Estimated 1985 Base Nutrient Loads

Total = 303 million lbs/yr DHM

Total = 23.8 million lbs/yr DHM

Water Pollutant Loads

(Mass Loadings)

Nonpoint Source Loads of Nitrogen in the United States

Input to fields Export to streams Delivery to estuaries Decay

INPUTS 1 ton/ac = lb/ac. Applied Nitrogen Loads From Commercial Fertilizer Lbs/ac < >21.9

Applied Nitrogen Loads From Animal Manure INPUTS 1 ton/sq.mi. = lbs/ac Lbs/ac < >21.9

INPUTS 1 ton/sq.mi. = lb/ac Nitrogen Loads From Atmospheric Deposition Lbs/ac < >6.3

March, 2000 water.usgs.gov/nawqa/

Nitrogen Export by Region

Lb/ac 1 kg/ha = 0.89 lb/ac 1 lb/ac = 1.12 kg/ha

Phosphorous Export by Region

lb/ac