QMRA AFFCO Horotiu WWTP discharge

AFFCO Horotiu NZ was granted a 25-year consent in 2015 with a requirement to conduct a Quantitative microbial risk assessment (QMRA) as a consent condition for the discharge of treated wastewater into the Waikato River. The wastewater stream from the AFFCO Horotiu consists of meat works wastewater from the AFFCO plant, as well as wastewater from a newly built Open Country dairy factory. This combined wastewater stream is treated at the AFFCO Horotiu WWTP before the treated wastewater discharge (herein referred to as the AFFCO Horotiu discharge) is released into the Waikato River through an existing outfall.

To support the fulfilment of the discharge consent condition, AFFCO contracted QMRA Data Experts through ArgoEnvironmental Ltd to assess the potential effects of the AFFCO Horotiu discharges on the receiving environment. Increasingly, where discharges may contain a significant concentration of microorganisms that could impact upon public health, regional councils are requiring assessments that go beyond the traditional method of conformity to faecal indicator bacteria (FIB) guidelines. This study provided a scientifically robust assessment of whether the AFFCO Horotiu discharges have a ‘more than minor’ effect on the state of the receiving environment for recreational uses and shellfish harvesting.