At an early age, we learn that the color of the water in our lakes, rivers and ponds is blue, but we expect the water in our drinking glass to be clear. When homeowners discover their home drinking water has a slight blue tint, it’s a cause for concern.
Blue or blue-green water likely means it contains copper. When water stands in copper pipes, the copper sometimes dissolves, which causes a blue tint when it reacts with the water. This can also give your water a metallic taste or leave blue-green stains on porcelain bath fixtures.
Copper absorbing into your water can happen when the pipe is less than one-year-old and can go away with time. What is more likely, however, is that your home has corrosive water. The cause of corrosivity is low water pH. This gets worse when the water is hotter and can cause physical damage to piping and hasten the need to replace your plumbing. Flushing the pipes before each use will lessen the metallic taste, but it won’t prevent damage to your pipes.
Excessive consumption of copper can have adverse health effects, but what is more troublesome is that copper sometimes indicates there is lead in the water as well. When corrosive water interacts with the lead used to seal pipe joints, it dissolves into the home’s water supply. Lead is colorless, odorless and tasteless in water and is known to cause neurological damage, which is why lead seal joints were not used in home plumbing after 1986.
What water tests should I do?
If there are copper pipes or pipe fittings, tests should be done to measure levels of copper, lead and other metals in your water. If there is more than one type of pipe, find which pipes serve the faucets most used for drinking. If both hot and cold water flows through PVC plastic pipes, there is little to no health risk other than lead from faucets or well pumps.
When testing for corrosivity, samples must be taken after the water has been left stagnant in your pipes for at least the previous six hours, such as first thing in the morning. The sample should be taken at the faucet most used for drinking.
A key test for determining corrosivity is pH. If the pH is 6 or below, that is highly corrosive, and treatment will likely be needed. If the pH is 6 through 6.9, the water is somewhat corrosive, and more testing may be needed. Higher pH values mean the water is likely not corrosive, but further testing may be warranted, depending on the case.
How can I fix corrosive water?
Addressing corrosive water is a matter of adjusting the pH level of the water entering your home. There are some methods, from basic to expensive.
• Calcite Chips: Adding calcite chips to the bottom of an existing well can reduce corrosivity at a low cost, but can also cause hardness and alter the water’s taste.
• Chemical feed pump: This approach works by pumping a solution of soda ash or baking soda into the water. This does not increase hardness, and the solution can be altered depending on the pH of the water. It could, however, cause damage to some mechanical devices and requires routine inspections and filling of the chemical solution every few weeks.
• Neutralizing Filters: This filter has a pressurized tank containing a filter bed of calcium carbonate or calcite. As the acidic water passes through the filter, the calcium carbonate neutralizes the acidity. This method will increase the hardness of the water.
• Phosphate feeder: A phosphate feeder installed before the copper piping will pump phosphate into the water system and coat the piping to reduce or slow down the corrosion effects.