Sediment reduces light penetration in stream, clogs gills of fish and aquatic invertebrates, cover fish spawning areas, create murky water, increases filling of impoundments.
Nutrients act as fertilizer for algae & aquatic plants which can cause highly varying dissolved oxygen levels. At low DO levels, the aquatic life has the potential to be harmed.
BOD (Biological oxygen demand) measures the amount of organic matter that is decomposed by microorganisms which deplete dissolved oxygen. Measure BOD for water quality
Toxics can impact life and contaminate drinking water supplies.
Bacteria/Pathogens are an indicator of possible diseases present in the system.