Water Residuals to Reduce Soil Phosphorous (Awwa Research Foundation Reports)

The goal of the co-sponsoring utilities (Pennsylvania American Water Company, Tulsa Metropolitan Utility Authority, and Denver Water), , is to exploit the unique characteristics of WTR for beneficial use. Specifically, the targeted beneficial use is improved P management of agricultural lands by controlling the release of P. The mechanism for this approach is to use metal hydroxides present in WTR to bind P in agricultural soils that have high P levels. The differences in WTRs observed during this research support the recommendation that utilities characterize their WTRs on a seasonal basis due to changes in source water quality or the required level of pretreatment chemicals. Further, utilities that are considering modifying WTR management programs for greater capacity should include the enhanced ability of liquid WTR to bind P as a selection factor. Numerous suggestions for further research are provided.