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United States Department of Agriculture

Agricultural Research Service

Title: Phosphorus Sources in An Ozark Catchment, Usa: Have We Forgotten Phosphorus from Discrete Sources?

Authors
item Haggard, Brian
item White, Kati - BAEG - UNIV OF ARKANSAS
item Chaubey, Indrajeet - BAEG - UNIV OF ARKANSAS
item Matlock, Marty - BAEG - UNIV OF ARKANSAS
item Green, W - BAEG - UNIV OF ARKANSAS
item Delaune, Paul - BAEG - UNIV OF ARKANSAS
item Moore, Philip

Submitted to: International Conference on Diffuse Pollution
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2003
Publication Date: July 18, 2003
Citation: Haggard, B.E., White, K.L., Chaubey, I., Matlock, M.D., Green, W.R., Delaune, P.B., Moore Jr, P.A. 2003. Phosphorus sources in an ozark catchment, usa: have we forgotten phosphorus from discrete sources?. International Conference on Diffuse Pollution. CD-ROM. Dublin, Ireland. International Water Association.

Interpretive Summary: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treatment plants (WWTPs). We sampled the water column at 30 sites in the Illinois River Basin [Ozark Plateaus, USA]; this catchment receives effluent from four municipal WWTPs. The average annual P load was approximately 208,000 kg from 1997 through 2001, and municipal WWTPs represented almost 45% of the average annual load. Water column P concentrations were significantly greater during surface runoff conditions compared to base flow conditions. Phosphorus concentrations and stream flow displayed distinct relations during base flow and surface runoff conditions. Water column P concentrations were increased by WWTP effluents during base flow conditions and the increase in P concentrations may be traced upstream to one WWTP. The sediments at these systems may represent a transient storage pool of P, lengthening the time required to see improvements in water-quality after WWTP inputs are reduced. Thus, watershed managers in the Ozark Plateaus must address discrete sources of P and sediment-bound P to facilitate a reduction in stream P concentrations.

Technical Abstract: In the Ozark Plateaus, the focus of watershed mangers is often on diffuse sources of phosphorus (P), especially agricultural runoff and land application of animal manure. However, it has become apparent in the Ozarks that this shift in focus may be premature and neglect P from discrete sources, e.g. wastewater treatment plants (WWTPs). We sampled the water column at 30 sites in the Illinois River Basin [Ozark Plateaus, USA]; this catchment receives effluent from four municipal WWTPs. The average annual P load was approximately 208,000 kg from 1997 through 2001, and municipal WWTPs represented almost 45% of the average annual load. Water column P concentrations were significantly greater during surface runoff conditions compared to base flow conditions. Phosphorus concentrations and stream flow displayed distinct relations during base flow and surface runoff conditions. Water column P concentrations were increased by WWTP effluents during base flow conditions and the increase in P concentrations may be traced upstream to one WWTP. The sediments at these systems may represent a transient storage pool of P, lengthening the time required to see improvements in water-quality after WWTP inputs are reduced. Thus, watershed managers in the Ozark Plateaus must address discrete sources of P and sediment-bound P to facilitate a reduction in stream P concentrations.

Last Modified: 12/18/2014
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