What Are the Parameters of Water Quality Testing?
Regularly testing drinking water quality is crucial to avoiding potential harmful contaminants and ensuring water is safe for consumption. Multiple characteristics of water (known as parameters) are tested to have a more reliable and holistic understanding of water quality. The three main water quality parameter categories that are tested when investigating water quality are physical, chemical, and biological water parameters. Each parameter includes different characteristics of water, and all must be routinely evaluated to preserve optimal water quality.
Importance of Water Quality Testing
Drinking water contamination is a global phenomenon and a major public health issue, as many people use water that is contaminated with harmful levels of physical, chemical, or biological contaminants. The EPA has standards and regulations in place through the Safe Drinking Water Act for over 90 contaminants in public drinking water, and over 92 percent of the population supplied by public water systems receive drinking water that meets health-based standards. Even though the U.S. has some of the safest drinking water in the world, contamination still occurs and must be monitored regularly. Some of the negative health impacts of drinking contaminated water are exposure to diseases, gastrointestinal problems, reproductive issues, organ damage, and chronic illness. Testing all three water parameters helps avoid harmful levels of contaminants and mitigates health risks.
Physical Parameters
There are six main physical parameters tested to determine water quality: turbidity, temperature, color, taste and odor, solids, and electrical conductivity. Turbidity is measuring the amount of light able to pass through water and is also determined by the cloudiness of the water. Cloudy water is visually undesirable, can be a hiding place for harmful microbes, and has a greater chance of absorbing heavy metals. Water temperature is another important parameter, as temperature impacts palatability, odors, solubility, and chemical reactions. Color, taste, and odor are parameters that are typically noticeable when at extremely unsafe levels. Water that is pure is colorless, but water with a slight color doesn’t necessarily mean it is harmful to consume. Drinking water taste and odor can come from a variety of sources, including organic materials, industrial runoff, and dissolved gases. Solids in water can be identified based on the filter test, where dissolved solids pass through a testing filter, but suspended solids do not. Suspended solids are defined as particles larger than two microns, whereas dissolved solids are particles smaller than two microns. The electrical conductivity of water is measured by the ability of the water to carry an electrical current and is more important to measure when using water for irrigation or firefighting purposes.
Chemical Parameters
Chemical parameters are the water quality parameters typically referred to when discussing water quality, and testing includes measuring the presence of a variety of chemicals. This parameter also includes testing the hardness of water, which is testing for the level of dissolved minerals in the water. Typically, Calcium and Magnesium are naturally occurring minerals that can lead to hard water, and groundwater is usually harder than surface water. Water with up to 500 mg/L of hardness is viewed as safe, but water with more than 150 mg/L of hardness is usually noticed by consumers. Obtaining some Calcium and Magnesium nutrients through water is not considered harmful, and may indeed be beneficial for people with Calcium and Magnesium deficiencies.
Other water quality chemical parameters include testing pH, alkalinity, chloride, chlorine residual, acidity, sulfates, nitrogen, fluoride, iron, manganese, copper, zinc, dissolved oxygen, oxygen demand, toxic inorganic, and organic substances, and radioactive substances. Additional chemical parameters may be included in water testing depending on the chemical composition of water in specific geographical locations. Some of the most important chemical parameters to measure are pH, toxic organic and inorganic substances, and radioactive substances. pH is an indicator of how acidic or basic drinking water is, and typically the 6.5 to 8.5 pH level range is considered safe for drinking water. Toxic inorganic substances include metallic and nonmetallic compounds, and even slight exposure to these substances can lead to negative health impacts. A few of the inorganic metallic compounds tested are lead, mercury, and arsenic, and nonmetallic compounds include nitrates and cyanides. There are over 100 toxic organic substances that can be included in water quality testing. All these substances are man-made pollutants, and this category includes pesticides, disinfectants, detergents, and insecticides. Radioactive chemical substances include waste from industrial runoff and nuclear power plants, and naturally occurring radon gas from groundwater. Common radioactive chemicals tested include alpha and beta particles, photon emitters, radium, and uranium.
Biological Parameters
The four main biological parameters involved in water quality testing are bacteria, viruses, algae, and protozoa. While there are millions of microorganisms in the water we drink, the majority are harmless. One of the biggest challenges with biological parameters is when waste from people with infectious diseases enters the drinking water system, increasing the likelihood of others contracting the disease. Some of the more well-known bacteria include E. coli and Salmonella, and waterborne diseases resulting from high concentrations of bacteria are typhoid fever, leptospirosis, and cholera. Improving sanitary practices, like washing hands more frequently or longer, when possible may help reduce outbreaks of these diseases. Viruses are much smaller than bacteria, and viral pathogens found in water can lead to viral infections, such as hepatitis. Most, if not all, waterborne viruses and pathogens are destroyed by the disinfection processes at local water treatment plants, therefore transmission is no longer a major threat in the U.S. Algae is typically more of a nuisance, as it creates an unappealing taste and odor in drinking water. Certain types of algae do have associated health risks when consumed, including blue-green algae. Common pathogenic protozoa include Cryptosporidium and Giardia, both of which have the ability to survive water treatment plant disinfection processes and have been found in surface water and filtered drinking water. These protozoa are able to survive in water for extended periods of time and must be monitored regularly.
Conclusion
While the U.S. has enacted laws and regulations to protect residents from contaminated drinking water, it is important to understand the different water quality testing parameters in place at most (if not all) public water treatment plants. In addition to this, personal water filters are available for additional protection against the physical, chemical, and biological parameters discussed. Filtering water at home may help eliminate any contaminants that made it past the public treatment plant and further protect you from associated health impacts. Protect your drinking water with a new filter or water purification system today.
