Corrosive water can be simplistically defined as a condition of the water's quality which will dissolve metals from a home's metallic plumbing at an excessive rate. Unfortunately, most surface waters and many groundwaters in New Hampshire are highly corrosive. If you have copper plumbing and notice a bluish-green stain on sinks and showers or below a leaky faucet, your water likely is highly corrosive.
Blue green is the color of copper oxide, as orange brown is the color of iron oxide.
These three concerns are discussed below. If your water is leaching metal from the plumbing of your home, you should expect that eventual plumbing repair or replacement will be necessary. While all plumbing will be effected over time by the water its carries, corrosive water will damage plumbing much more rapidly than water with low corrosivity. Pre-flushing the plumbing before taking water for consumption will not lessen this structural damage but will reduce the risk to health. At higher levels of copper, water will have a metallic taste.