Proceedings

Contents
1. Drivers for microbiological reduction
2. How microbiological reduction is achieved in wastewater treatment
• Dilution
• Disinfection
• Reduction through wastewater treatment processes
3. Benefits of understanding site specific reduction

Shellfish Waters
• Shellfish water protected areas are areas designated for the protection of shellfish growth and production.
• Filter-feeding shellfish concentrate and retain human pathogens.
• Shellfish are classified based on E. coli concentrations in their flesh, e.g. Classification of Bivalve Mollusc Areas:
For Class B status 90% of sample results must be less than or equal to 4,600 E. coli/100g and no sample result may exceed
46,000 E. coli /100g.
• Operation of sewage overflows or overwhelming of sewerage systems have been linked to outbreaks of shellfish-associated
illness.
• Shellfish-associated illnesses are mainly virus related – Norwalk and Norovirus have been isolated as a common cause.
• 19th July EA issued PR19 Driver Guidance for discharges to Shellfish Waters