Land use and activities within drinking water catchments and storage reservoirs can contaminate source water, adversely impacting water quality (Watercorporation, 2017). The three main types of contamination are:
- Microbiological (protozoa, bacteria, viruses)—often related to faecal material from humans (e.g. septic tanks), wild animals (e.g. wild birds) or domestic animals (such as cattle).
- Chemical—often related to pesticides, fertilisers or fuel spills.
- Physical—such as turbidity and salinity. This may be caused by erosion and runoff associated with weather events, fires, pigs wallowing, and vehicles on source water reservoir banks.
Producing safe drinking water requires the management of the whole process of water supply from source, through to capturing and final consumption at meat chicken sheds. Drinking water source protection involves protecting surface water and groundwater sources from microbial, chemical and physical contamination caused by land use and activities. Water source protection includes basic measures and management, such as installing a fence around the source, keeping grazing animals out of the surrounding areas or controlling nutrient and pesticide application rates in the surrounding areas (Watercorporation, 2017). Examples of source control measures to protect the quality of drinking water are illustrated in Table 11 (below).
Meat chicken farms that use on-site dams and bores can manage the water quality of these water sources by enacting drinking water, source protection measures. It is not feasible for meat chicken farms using mains or major rivers as a source of water to manage them with protection measures. They must, therefore, assess and manage risks in their catchment which they do have control over (e.g. managing runoff from grazing land during heavy rainfall into dams using diversion ditches). Elements of this ‘source to consumption’ approach to managing microbiological risk are illustrated in Figure 2 (below).
In certain instances, drinking water source protection can improve the overall quality of source water, which consequently lowers the treatment and disinfection doses needed in the pre-treatment and disinfection stages of water treatment.
Table 11. Examples of control measures to protect the quality of drinking water
| Part of system | Control measure |
|---|---|
| Water source | Fence area to exclude livestock Surface water diversion ditches Wastewater drainage |
| Water capture | Use safe roofing materials to capture rainwater Install first flush diverters to lower risk of contamination |
| Land use | Protection zones (designated and limited uses, protective requirements) Control nutrient and pesticide application rates Control human activities within the drinking water catchment Set-back distances Minimum safe distance (latrine-source) Animal access control Maintain grass cover in the immediate area |
