Table 1 shows the methodology used in this work related to
physic-chemical, bacteriological, parasite and protozoa analysis. E.
coli CFU count was performed at each dilution and the media
concentration was expressed as CFU.100 ml1 in the case of water
samples and CFU g1 (dry weight, related toTotal Solids) in the case
of coarse solids, grit and sludge. In the case of C. perfringens,
Salmonella spp. and pathogenic protozoa the results were
expressed as presence (P) or absence (A). In order to identify
the presence of parasites, helminths and protozoa in vivo, an
aliquot of sampleswas concentrated by centrifugation and other by
formalin-ethylacetate method. Smears from all concentrated
samples were examined by means of microscopy and stained by
modified Zielh–Neelsen stain to detect coccidian oocysts (Henriksen
and Pohlenz, 1981).