This study proposes an emergency remedial measure aimed at reducing the eutrophic load of the supernatant of pig manure when discharge in the aquatic environment is unavoidable. Phosphate removal appears to be a temporary solution to the reduction of manure fertility for the aquatic environment. The efficiency of three phosphate precipitants, namely, alum (Al2(SO4)3), lime (Ca(OH)2), and zirconium tetrachloride (ZrCl4) was evaluated in 60 litre experimental tanks. Alum yielded the best efficiency, both for the chemical precipitation of P and for algal growth potential reduction determined with the green alga Selenastrum capricornutum. Zirconium tetrachloride was also very active, but for a shorter period of time. Finally, lime was relatively less efficient.