Nutrients can be a resource or an issue. Discharges from typical human activities contain nitrogen and phosphorus, which can degrade surface water and groundwater. Nutrients entering surface waters, such as lakes, can cause algal blooms, which deplete oxygen. Oxygen depletion is detrimental to fish and other aquatic life. Nitrogen entering groundwater can contaminate potable water supplies and have negative health effects.
Nutrients are a resource if recovered and reused. As an example, plant species need nutrients to sustain healthy growth. Many of our systems reduce nutrients to safe levels or provide nutrients and water for shallow subsurface irrigation. In the near future, many treatment systems will recover phosphorus, which is a finite supply.