Water source protection means:
- Prevention of pollution
- Control of non-point sources (e.g. stormwater, farm runoff of pesticides, fertilizers, etc).
Control of point sources of pollution such as sewage, industrial and agricultural effluents is essential. The risk of hazardous contamination in drinking water supplies is determined by source water quality and catchment conditions. Source protection provides the first barrier in protection of drinking water quality. Hazards and hazardous events that can have an impact on catchments and that should be taken into consideration as part of a hazard assessment include:
- Rapid variation in raw water quality
- Sewage and septic system discharges
- Industrial discharges
- Chemical use in catchment areas (e.g. use of fertilizers and agricultural pesticides)
- Major spills (both accidental and deliberate)
- Human access
- Active or closed waste disposal or mining sites/contaminated sites/hazardous wastes
- Geology (naturally occurring chemicals)
- Unconfined and shallow aquifers
- Climatic and seasonal variations (e.g. heavy rainfalls, droughts) and natural disasters.
Control measures to ensure effective resource and source protection includes the following elements:
- Developing and implementing a catchment management plan
- Ensuring that planning regulations include the protection of water resources from potentially polluting activities and enforcement thereof
- Promoting awareness in the community of the impact of human activity on water quality
To ensure continued improvement, an integrated approach involving multiple stakeholders is required (particularly with small point supplies). Shallow groundwater sources are particularly vulnerable and the construction of wellheads is often of poor quality. Efforts to train communities in the design and construction of wellheads, and the continuing operation and maintenance of these facilities are needed to ensure that water quality does not deteriorate. In small supplies, communities need to be active partners in water quality improvement to ensure continued provision of acceptable water quality. Examples of control measures for effective protection of source water and catchments include:
- Designated and limited uses
- Registration of chemicals used in catchments
- Specific protective requirements for chemical industry or refuelling stations
- pH adjustment of stored water
- Control of human activities within catchment boundaries
- Control of wastewater effluents
- Regular inspection of catchment areas
- Diversion of local stormwater flows
- Runoff interception
Where a number of water sources are available, there may be flexibility in the selection of water for treatment and supply.