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Stream Conditions: Biochemical Oxygen Demand (BOD)

The excerpts below are from Deas, M.L. and G.T. Orlob. 1999. Klamath River Modeling Project. Project #96-HP-01. Assessment of Alternatives for Flow and Water Quality Control in the Klamath River below Iron Gate Dam. University of California Davis Center for Environmental and Water Resources Engineering. Report No. 99-04. Report 236 pp. Inset boxes not from Deas and Orlab (1999).
 

Although not identified in the causative factor matrix, biochemical oxygen demand (BOD) is an important water quality variable that should be included in water quality studies/monitoring. Most organic materials are biodegradable to various degrees. The amount of oxygen used in the metabolism of carbonaceous biodegradable soluble and non-soluble organic matter is termed biochemical oxygen demand (BOD) or carbonaceous biochemical oxygen demand (CBOD). Nearly all biodegradable material will be converted via biochemical oxidation (bacterially mediated) to CO₂, NH₃ and H₂O given enough time.

Because of complications measuring this ultimate BOD (BOD_u), BOD_u is usually extrapolated from laboratory 5-day BOD bottle tests  .  BOD should be determined using nitrification inhibited samples to avoid double counting nitrogenous BOD (NBOD) (Tchobanoglous and Schroeder 1986).

Sources of BOD, in addition to direct loading, include decaying algae and macrophytes and other biota. Typically, a fraction of this matter contributes to BOD, while the remainder is assumed to oxidize immediately for energy. Background levels in natural systems range from 0.5 mg/l to 3.0 mg/l. Municipal and industrial wastes can exceed 30 mg/l (EPA 1997). Although BOD is rarely related to biota health, high BOD loads can severely depress DO. Further, it is a required parameter in most water quality simulation models.

References

Colt, J., S. Mitchell, G. Tchobanoglous, and A. Knight. 1979. The use and potential for aquatic species for wastewater treatment: Appendix B, the environmental requirements of fish. Publication No. 65, California State Water Resources Control Board, Sacramento, CA.

Davis, J.C. 1975. Minimal dissolved oxygen requirements of aquatic life with emphasis on Canadian species: a review. Journal of Fisheries Research Board Canada. 32(12), 2295-2332.

Deas, M.L. and G.T. Orlob. 1999. Klamath River Modeling Project. Project #96-HP-01. Assessment of Alternatives for Flow and Water Quality Control in the Klamath River below Iron Gate Dam. University of California Davis Center for Environmental and Water Resources Engineering. Report No. 99-04. Report 236 pp.

Krenkel, P.A. and V. Novotney. 1980. Water Quality Management. Academic Press, New York.

North Coast Regional Water Quality Control Board. 2001. Water Quality Control Plan for the North Coast Region. Staff report adopted by the North Coast Regional Water Quality Control Board on June 28, 2001. Santa Rosa, CA. 124 p. Appendix.

United States Environmental Protection Agency (EPA). 1973. Development of Dissolved Oxygen Criteria for Freshwater Fish. Ecological Research Series EPA-R3-73-019. February.

Water Quality Assessments. 1996. Water Quality assessments: A guide to the use of biota, sediments and water in environmental modeling. Ed. D. Chapman. Published on behalf of UNESCO United Nations Education, Scientific, and Cultural Organization; WHO World Health Organization; UNEP United Nations Environmental Programme. Chapman & Hall, London.