The disclosure relates to a method of treating waste water containing suspended organic material, the method including the steps of: (a) mixing agriculturally beneficial acids selected from phosphoric acid, sulphuric acid or nitric acid with the waste water, wherein the acid reduces the pH of the waste water to 1 to 4 (b) holding the waste water and acid mixture for a period of time between 12 and 48 hours to allow particulate matter to precipitate out of the mixture (c) flocculating the mixture with an alkali containing material, wherein the alkali containing material includes calcium and/or magnesium containing material selected from lime, hydrated lime, agricultural lime, calcium hydroxide, magnesium oxide, dolomite, serpentine or calcium bentonite, and wherein the alkali containing material increases the pH to between 10 and 12 and (d) collecting the resulting flocculent of step (c) and applying it to pasture or soil as a fertiliser and/or soil modifier.
