Behaviour of Fecal Contamination Indicators (Fecal Coliforms, Somatic Phages and Helminth Eggs) in Biosolid-Soil Mixtures for Ryegrass Sward Farming

Colombia presently treats only 8% of wastewater flows. However, the increase in the construction of treatment plants has led to the production of biosolids and it is necessary to consider management alternatives. The Plant El Salitre in Bogotá produces close to 145 dry tons/day of biosolid classified as class B according to USEPA. Close to Bogotá, there are several dairy cattle farms that require high quality grass. Because of this a research was done with the objective of evaluating the behavior of pathogens present in the biosolid product once it is applied to the soil and the grass used to feed the cattle. The results show the rate of decrease in microorganism populations and relative persistence in the soil. Approximately 26 months are required for reduction to the equivalent of Class A biosolids pathogen densities.