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A major problem in sustainability of animal production is excess of manure phosphorus (P) exceeding land assimilative capacity. Land application of manure results in P buildup in soil and increased potential for P losses through runoff and subsequent eutrophication of surface waters. A wastewater treatment process was developed for removal of P from livestock wastewater. Phosphorus is selectively precipitated using an alkaline earth metal after carbon and ammonia buffers are reduced with a nitrification pretreatment. The method was tested with wastewater collected from nine hog lagoons in North Carolina. In all cases, the soluble P was effectively recovered as P precipitate. When used as a lagoon retrofit, the technology enables precision control of the N:P ratio of the treated effluent to desired levels to match specific crop needs or to solve problems of P accumulation in soil or remediation of contaminated spray fields. The final product is calcium phosphate that can be exported from the farm and reused as fertilizer.