Faecal coliform decline on pasture irrigated with primary treated meat-processing effluent

Abstract

Meat-processing effluent was applied to pasture every 14 days at a rate equivalent to 1000 kg N/ ha per year. Faecal colifonns on pasture, as indicator organisms, were enumerated by a Most Probable Number (MPN) method over a 12-month period. Regression of faecal colifonn counts against time demonstrated a decline in numbers, which followed first-order kinetics, over the 14-day period after an irrigation. Reduction in counts was not well correlated with environmental factors. A 99% reduction in numbers occurred after 14 days in all seasons of the year, with a 99 .9% reduction in winter and spring. Rates of decline were highest in spring and lowest in summer.

Keywords:

• faecal colifonns
• effluent
• meat plant
• land application
• indicator organism