I've just done an initial test of my bore water here in the Largs Bay area and I found the pH was quite alkaline at around 8 with some ammonia and about 5ppm nitrates. What does that mean? Well, the high pH might come from the parent rock beneath the surface leaching into the water. Thanks http://soilquality.org.au/factsheets/soil-ph-south-austral for this diagram.
Some ammonia in the water is natural, as there may be decaying matter beneath the surface. The nitrates can be an issue apparently, but according to some up to 10ppm is considered safe for drinking water (but that doesn't mean go ahead and drink it folks). You may have heard that some add nitrates to bacon as a preservative and bacon hasn't had the greatest health wrap of late. Tastes bloody good though.