The acidity of drinking water, characterized by a low pH, is a common concern for homeowners regarding potential risks to both personal health and home infrastructure. Water acidity can arise naturally, such as when water passes through soil rich in carbon dioxide, or it can be a result of industrial or other human activities. While water is generally regarded as a universal solvent, a low pH significantly enhances its corrosive properties, which is the source of the problems associated with acidic water.
Understanding pH and Safe Ranges
The potential for hydrogen, or pH, is a measure that indicates how acidic or basic water is, using a scale that runs from 0 to 14. A pH value of 7.0 represents a neutral state. Water is classified as acidic when its pH falls below 7.0.
The U.S. Environmental Protection Agency (EPA) recommends that the pH of public drinking water systems should ideally fall within the range of 6.5 to 8.5. Water with a pH below this recommended range is considered corrosive and may produce a metallic or bitter taste.
Health Consequences of Acidic Drinking Water
Consuming water with a low pH can have minor effects on the body. Highly acidic water may cause irritation to the lining of the stomach and esophagus. The acidic nature of the water can gradually weaken tooth enamel over time, potentially increasing the risk of cavities and tooth decay.
The most significant health danger, however, is an indirect consequence of the water’s corrosive nature. Acidic water actively dissolves the metal components it passes through in the plumbing system, causing heavy metals to leach into the drinking supply. This process can introduce toxic contaminants such as lead and copper into the tap water, even if the water leaving the treatment plant is clean.
Lead exposure is particularly harmful, especially to children, where it is linked to learning difficulties and developmental issues. High levels of copper, often detected by a metallic taste, can cause gastrointestinal distress, including vomiting and diarrhea.
Impact on Home Infrastructure and Appliances
Acidic water aggressively attacks the metal pipes and fixtures within a home’s plumbing system. This corrosive action is often first noticed as blue-green stains left behind in sinks, tubs, and shower stalls. These stains are the residue of dissolved copper leached from copper pipes.
Over time, continuous corrosion weakens the structural integrity of the pipes, particularly copper and galvanized steel. This deterioration can lead to a reduction in water pressure and, more seriously, result in pinhole leaks. Such leaks can cause significant property damage and necessitate expensive plumbing replacements.
Appliances that rely on water, such as dishwashers, washing machines, and water heaters, also experience a reduced lifespan. The corrosive qualities of the water cause internal components to break down more quickly, resulting in premature failure and decreased efficiency.
Steps for Testing and Treating Acidic Water
The first step in addressing water acidity is accurate testing, which can be done through a simple home pH kit or, more reliably, through a professional laboratory analysis. Professional testing is highly recommended because it provides an exact pH value and, crucially, can detect any heavy metals that have leached from the plumbing. If the pH is below 6.5, or if heavy metals are detected, treatment is necessary.
The most common treatment method for mildly acidic water is a point-of-entry neutralizing filter installed where the water enters the home. These filters contain media, often calcium carbonate, or calcite, which slowly dissolves into the water to raise the pH back toward a neutral level. For water with a lower pH value, a blend of calcite and magnesium oxide may be used for a more effective neutralization.
For more severely acidic water, or for systems that require precise pH control, a chemical injection system is often employed. This system uses a chemical feed pump to inject a solution of soda ash (sodium carbonate) or sodium hydroxide directly into the water supply. Unlike neutralizing filters, which can increase water hardness, injection systems raise the pH without adding hardness minerals to the water.