Several parameters are measured by water quality testing, and in many cases, these values are used to determine a lake's or pond's health. Dissolved oxygen, for example, is a good indicator of the health of a lake or pond, but it can also be affected by temperature and the amount of organic matter in the water. Additionally, the pH level of a water body can affect the effectiveness of algaecides and herbicides.

Many state health departments in the United States have labs for water testing. While this can be time-consuming and costly, it is a practical option for many areas. Water testing can also be done on private wells, which can be helpful in regions that have outdated municipal plumbing systems. Furthermore, mining and livestock farming can affect a water table and aquifer.

The WHO has guidelines for drinking water quality, published in three volumes. The policies cover guideline values for more than 60 parameters and address the needs of small rural communities. Despite the widespread use of WHO guidelines, these standards are often not used uniformly worldwide. This means that water quality testing will differ from country to country.

Bacteria are found in all water, so even though water is contaminated, this doesn't make it unsafe to drink. The presence of bacteria is essential, but only the ones that cause disease can be dangerous. Total coliform bacteria are a good indicator of bacterial contamination in water. Total coliform bacteria are commonly found in vegetation, surface water, and the digestive tracts of warm-blooded animals. The water is safe for human consumption if the coliform bacteria test shows a low count.

The Drinking Water Inspectorate regulates public water supply companies in England and Wales. Testing can be done at the environmental health office of your local authority. In the United States, water quality testing is conducted by the Department of Homeland Security, a cabinet department of the federal government. Created in response to the 9/11 attacks, this department protects the country from terrorist attacks, responds to natural disasters, and promotes environmental quality.

Peer-reviewed test methods are used to determine the quality of drinking water. These methods are developed by government agencies, private research organizations, and international standards organizations. To ensure compliance with regulatory standards, peer-review panels must approve test methods. In addition, water quality tests must be done following the local health department's guidelines for sampling. These guidelines also help ensure that water is safe for human consumption.

The parameters used to measure water quality are total solids, bacteria, and chemicals. When these values exceed the limit, they put human health at risk. They can cause digestive problems, illness, and death.