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Nutrients Glossary
What is the Problem? | What is EPA's National Nutrient Policy? | What are EPA and the States Doing? | Glossary
"Terms of Environment" defines in non-technical language the more commonly used environmental terms appearing in EPA publications, news releases, and other Agency documents available to the general public, students, the media, and Agency employees. The definitions do not constitute the Agency's official use of terms and phrases for regulatory purposes, and nothing in this document should be construed to alter or supplant any other federal document. Official terminology may be found in the laws and related regulations as published in such sources as the Congressional Record, Federal Register, and elsewhere.
Some definitions specific to the Nutrients program are listed below. EPA's master list of definitions can be found at Terms of Environment.
- Algal bloom
- Sudden spurts of algal growth, which can affect water quality adversely and indicate potentially hazardous changes in local water chemistry.
- Chlorophyll
- A green photosynthetic pigment found in most plants, algae and cnyobacteria
- Eutrophication
- The slow aging process during which a lake, estuary, or bay evolves into a bog or marsh and eventually disappears. During the later stages of eutrophication the water body is choked by abundant plant life due to higher levels of nutritive compounds such as nitrogen and phosphorus. Human activities can accelerate the process.
- Hypoxia/Hypoxic Waters
- Waters with dissolved oxygen concentrations of less than 2 ppm, the level generally accepted as the minimum required for most marine life to survive and reproduce.
- Microbe
- Microorganisms such as bacteria, algae, diatoms, plankton, and fungi.
- Nitrate
- A compound containing nitrogen that can exist in the atmosphere or as a dissolved gas in water and which can have harmful effects on humans and animals. Nitrates in water can cause severe illness in infants and domestic animals. A plant nutrient and inorganic fertilizer, nitrate is found in septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps.
- Nutrient
- Any substance assimilated by living things that promotes growth. The term is generally applied to nitrogen and phosphorus in wastewater, but is also applied to other essential and trace elements.
- Other definitions for nitrogren can be found at the Terms of Environment.
- Phosphorus
- An essential chemical food element that can contribute to the eutrophication of lakes and other water bodies. Increased phosphorus levels result from discharge of phosphorus-containing materials into surface waters.
- Other definitions for phosphorus can be found at the Terms of Environment.
- Phytoplankton
- That portion of the plankton community comprised of tiny plants; e.g. algae, diatoms.
- Wastewater
- The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter.Water Pollution: The presence in water of enough harmful or objectionable material to damage the water's quality.
- Sewage
- The waste and wastewater produced by residential and commercial sources and discharged into sewers.