Understanding water’s pH provides valuable insights into water quality. The term pH measures how acidic or alkaline a water-based solution is, reflecting the concentration of hydrogen ions. Water naturally exhibits a range of pH levels, and deviations from a neutral state can have implications for both human interaction and environmental health.
Understanding Alkaline Water
The pH scale ranges from 0 to 14. A pH value of 7 indicates neutrality, while values below 7 signify increasing acidity, and values above 7 denote increasing alkalinity. Water with a high pH, typically above 7 (e.g., 8.0 or higher), is referred to as alkaline water.
Alkalinity in water often results from the presence of dissolved minerals. These minerals include carbonates, bicarbonates, and hydroxides, which originate from the surrounding environment. These substances neutralize acids, contributing to the water’s buffering ability and elevated pH.
Common Causes of High pH in Water
Several factors contribute to elevated pH levels in water, stemming from both natural processes and human activities. Water naturally becomes more alkaline by interacting with geological formations. For instance, water flowing through areas rich in alkaline rocks and soils, such as limestone or chalk, dissolves minerals like calcium and magnesium carbonates, increasing its pH. Photosynthesis by aquatic plants and algae can also raise pH by consuming carbon dioxide, which otherwise forms carbonic acid in water.
Human activities also influence water’s pH. Agricultural runoff, containing substances like lime applied to fields, can introduce alkaline compounds into water sources. Industrial discharges may also contribute to increased alkalinity. Certain water treatment processes, involving chemicals like lime or soda ash for disinfection or corrosion prevention, can elevate the water’s pH.
Effects of High pH Water
High pH water presents various practical implications for human use, aquatic ecosystems, and agriculture. For human consumption, water with a pH above 8.5 can develop a bitter or “soapy” taste. When used for personal hygiene, alkaline water can strip natural oils from the skin, potentially leading to dryness, itching, or irritation.
High pH water also affects plumbing systems. It can cause scale buildup of mineral deposits like calcium and magnesium carbonates inside pipes, fixtures, and appliances. This scaling reduces pipe diameter, decreases water pressure, and can impair the efficiency of water heaters and other water-using appliances. For aquatic life, high pH levels are detrimental, as most aquatic organisms thrive within a narrower pH range of 6.5 to 8.0. Levels outside this range can affect their physiological processes and survival.
In agriculture, using high pH water for irrigation can impact plant growth. High alkalinity can reduce the availability of essential nutrients in the soil, potentially leading to deficiencies. It can also contribute to the formation of alkaline scale buildup in irrigation pipes, which can hinder water delivery and system efficiency.
Managing High pH Levels
Addressing high pH levels in water begins with accurate testing. Simple pH test strips can provide a quick indication, while digital pH meters offer more precise readings. For a comprehensive analysis, professional water testing services can identify pH.
Once high pH is confirmed, several methods can manage the levels. For household systems, acid injection systems are commonly used. These systems introduce a mild acidic solution, such as acetic acid (vinegar) or citric acid, into the water line to lower its pH. Sulfuric acid is sometimes used for industrial or agricultural applications with very high alkalinity.
Another approach involves carbon dioxide (CO2) injection, where CO2 gas is dissolved into the water, forming carbonic acid to reduce pH. Aeration, which exposes water to air, can also help adjust pH by facilitating the release of dissolved gases. These management strategies improve water usability and minimize potential issues.