Community groundwater supply source protection

Report: TR 2000/10

Author: John Hadfield

The objectives of this report are to detail community groundwater supplies in the region and discuss a strategy for their protection.

Community groundwater supply source protection makes good public health, economic and environmental sense. Groundwater resources are vulnerable to contamination. Cleaning up contaminated groundwater is complicated, costly, and sometimes may be practically impossible. By comparison source water protection costs very little. It is in the interests of the community, Waikato Regional Council, health and other local government authorities, to work together for more effective groundwater supply source protection.

There are many potential sources of groundwater contamination including human and animal effluent, industrial wastewater, landfill leachate, fertilisers and pesticides, leakage from pipelines and underground storage tanks. Contamination of groundwater usually happens gradually and can go unnoticed for some time. Shallow, water table aquifers with thin soil cover are most vulnerable to contamination, which generally enters from the ground surface. This highlights the need for proper well-head completion by sealing around the top of well casing with concrete to avoid direct access of contaminants e.g. micro-organisms.