WATER QUALITY PARAMETERS
Total Suspended Solids | Nitrate-Nitrogen | Total Phosphorus | Ortho Phosphorus | E. coli Bacteria

ORTHO PHOSPHORUS (OP)

The form of phosphorus that is readily available for use by algae and other aquatic plants for growth.

What is Ortho-phosphorus?
Under natural conditions, phosphorus is typically scarce in the aquatic environment. Human activities, however, have resulted in excessive loading of phosphorus into many freshwater systems. A portion of the total phosphorus concentration in surface waters is available to plants to support their growth. Phosphorus exists in the water in either a dissolved phase or a particulate phase. Dissolved inorganic phosphate (orthophosphate) is the form required by plants for growth.
OP is of particular concern for lakes and streams because ortho-phosphates are immediately available in the aquatic environment for algal uptake. OP is a soluble form of phosphorus that is readily available to algae (bio-available) and under certain conditions it can stimulate excess algae growth leading to subsequent depletion of dissolved oxygen.

Ortho-phosphorus Sources
Natural processes produce ortho-phosphates, but major human-influenced sources include: partially treated and untreated sewage; runoff from agricultural sites; and application of some lawn fertilizers. Ortho-phosphate concentrations in a water body vary widely over short periods of time as plants take it up and release it.