Good practice guide to sanitary surveys and operational monitoring to support the assessment and management of drinking water catchments

Microbial pathogens are removed from source waters to make safe drinking water. Health-based targets (HBTs) refer to the quantities of pathogens that will NOT cause illness, and water treatment plants (WTPs) must ensure that the numbers of pathogens in potable water are the same or lower than the HBTs. WTP operators select the best pathogen removal treatment for a range of conditions such as season, rainfall and agricultural activity by referring to ‘sanitary surveys’. These are carried out approximately once a year by scientists driving and walking in the source water catchment, making observations, and collecting samples which are examined to look for indicators of harmful pathogens. Recent requirements to achieve HBTs, combined with technological advances, led to this project which aims to provide flexible sanitary survey guidance applicable to the broad range of Australian conditions and utilities. This Good Practice Guide reviews existing procedures, describes modern methods including aerial photography and the use of spatial databases, and describes the incorporation of sanitary surveys into ongoing source water operational monitoring in ways that support the establishment of log removal values and enable compliance with HBTs.