This practice applies where phosphorus presents a resource concern to surface water bodies and is mobilized and transported as a dissolved constituent.  Critical source areas of dissolved phosphorus in agricultural areas include subsurface (tile) drains, soils with phosphorus levels greater than the phosphorus sorption capacity, livestock heavy use areas, manure storage and handling areas, and other areas with high impervious surface area and converging flows.  The NRCS conservation practice standard for phosphorus removal systems is not intended to address resource concerns related to particulate phosphorus.  Excess particulate matter and sediment may foul the phosphorus sorption media and reduce the performance and lifespan of the dissolved phosphorus removal system.