What is a possible outcome of not removing phosphorus from wastewater?

Phosphorus removal from wastewater is crucial to prevent a phenomenon known as eutrophication. When phosphorus is not adequately removed, it can lead to its discharge into nearby water bodies. In these aquatic environments, phosphorus serves as a nutrient that promotes excessive algae growth. This overgrowth of algae can deplete oxygen in the water as it decomposes, leading to "dead zones" where aquatic life cannot survive. Such conditions harm fish populations and disrupt entire ecosystems. Therefore, the consequence of not removing phosphorus from wastewater directly relates to the health of receiving waters, making eutrophication a significant environmental concern.

While increased operational costs, sludge management issues, and impacts on drinking water quality are important considerations in wastewater treatment, the most direct and pressing biological consequence of phosphorus discharge is the eutrophication of water bodies, which poses severe threats to aquatic ecosystems.