2010 Monitoring Summary - Groundwater Quality
Groundwater is the main source of drinking water in Marlborough and it is important to monitor it's quality so that we know it is safe.
From 2010 onwards the Council will report annually on the standard of Marlborough's groundwater quality.
Key points
- 23 Wells are sampled each season by MDC
- Marlborough groundwater quality is generally of a very high standard
- Exceptions are caused by both natural and manmade processes
- The most common naturally occurring issue at 56% of sites was low pH
- Naturally elevated manganese levels occurred at 30% of sites, but only one was of health significance
- Iron concentrations exceeded the aesthetic guideline at 22% of sites
- Naturally occurring arsenic is a more widespread issue than first thought
- The main manmade contaminant is nitrate-nitrogen which exceeded the ecological guideline at 26% of sites monitored