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Most current environmental laws focus of the designation of uses. In some countries these allow for some water contamination as long as the particular type of contamination is not harmful to the designated uses. Given the landscape changes in the watersheds of many freshwater bodies, returning to pristine conditions would be a significant challenge. In these cases, environmental scientists focus on achieving goals for maintaining healthy eco-systems and may concentrate of the protection of populations of endangered species and protecting human health. Measurement See also: water chemistry analysis The complexity of water quality as a subject is reflected in the many types of measurements of water quality indicators. Some of the simple measurements listed below can be made on-site temperature, pH, dissolved oxygen, conductivity, Oxygen Reduction potential (ORP) in direct contact with the water source in question.

More complex measurements that must be made in a lab setting require a water sample to be collected, preserved, and analyzed at another location. Making these complex measurements can be expensive. Because direct measurements of water quality can be expensive, ongoing monitoring programs are typically conducted by government agencies. However, there are local volunteer programs and resources available for some general assessment. Tools available to the general public are on-site test kits commonly used for home fish tanks and biological assessments. Testing in response to natural disasters and other emergencies Inevitably after events such as earthquakes and Tsunamis, there is an immediate response by the aid agencies as relief operations get underway to try and restore basic infrastructure and provide the basic fundamental items that are necessary for survival and subsequent recovery. Access to clean drinking water and adequate sanitation is a priority at times like this. The threat of disease increases hugely due to the large numbers of people living close together, often in squalid conditions, and without proper sanitation. After a natural disaster, as far as water quality testing is concerned there are widespread views on the best course of action to take and a variety of methods can be employed.

The key basic water quality parameters that need to be addressed in an emergency are bacteriological indicators of fecal contamination, Free Chlorine Residual, pH, turbidity and possibly Conductivity/TDS. There are a number of portable water test kits on the market widely used by aid and relief agencies for carrying out such testing. The following is a list of indicators often measured by situational category: Drinking water Alkalinity Color of water pH Taste and odor (geosmin, 2-methylisoborneol (MIB), etc) Dissolved metals and salts (sodium, chloride, potassium, calcium, manganese, magnesium) Microorganisms such as fecal coliform bacteria (Escherichia coli), Cryptosporidium, and Giardia lamblia Dissolved metals and metalloids (lead, mercury, arsenic, etc.) Dissolved organics: colored dissolved organic matter (CDOM), dissolved organic carbon (DOC) Radon Heavy metals Pharmaceuticals Hormone analogs Environmental Chemical assessment Conductivity (also see salinity) Dissolved Oxygen (DO) nitrate-N orthophosphates Chemical oxygen demand (COD) Biochemical oxygen demand (BOD) Pesticides Physical assessment pH Temperature Total suspended solids (TSS) Turbidity Biological assessment Biological monitoring metrics have been developed in many places, and one widely used measure is the presence and abundance of members of the insect orders Ephemeroptera, Plecoptera and Trichoptera. (Common names are, respectively, Mayfly, Stonefly and Caddisfly.) EPT indexes will naturally vary from region to region, but generally, within a region, the greater the number of taxa from these orders, the better the water quality.

EPA and other organizations in the United States offer guidance on developing a monitoring program and identifying members of these and other aquatic insect orders. Individuals interested in monitoring water quality who cannot afford or manage lab scale analysis can also use biological indicators to get a general reading of water quality. One example is the IOWATER volunteer water monitoring program, which includes a benthic macroinvertebrate indicator key. See also: Biological integrity and Index of biological integrity Standards and reports United States In the United States, Water Quality Standards are created by state agencies for different types of water bodies and water body locations per desired uses. The Clean Water Act (CWA) requires each governing jurisdiction (states, territories, and covered tribal entities) to submit a set of biennial reports on the quality of water in their area. These reports are known as the 303(d), 305(b) and 314 reports, named for their respective CWA provisions, and are submitted to, and approved by, EPA.