Hint: Sewage consists of food substances that consist of phosphate and additionally agriculture fertilizers incorporate phosphate which is added in excess in cornfields. Common sources of excess nitrate reaching lakes and streams encompass septic systems, animal feedlots, agricultural fertilizers, manure, industrial wastewaters, sanitary landfills, and garbage dumps.
Complete explanation: Phosphate is a necessary compound of fertilizer which is added to crop fields and then is passed down to water bodies throughout rains via runoff. It is additionally existing in sewage that is dumped into the water body. This nutrient brings about dense growth of water plant life especially the algae and causes algal bloom. This algal bloom leads to oxygen depletion in water bodies and causes loss of life of aquatic life. As a result, the underlying aquatic animals and plants suffocate and then they die. When this algal bloom dies, it similarly enhances the eutrophication process, greatly decreasing the dissolved oxygen in the water. Nitrates in water can cause extreme illness in infants and domestic animals. Sewage in vast water can be dangerous to the environment. When untreated sewage is directly discharged into water bodies, it is referred to as organic loading. Organic loading is one source for expanded nutrient (especially nitrogen and phosphorous) concentration in the water in our bodies (or eutrophication). Eutrophication additionally affects surface runoff from agricultural fields in which huge amounts of nitrogen and phosphorus fertilizers have been used.
'Sewage and agricultural fertilizers' are the correct answer to this question.
Note: Phosphate pollution in the water is directly related to the release of untreated sewage and agricultural fertilizers into the water body. Agricultural fertilizers such as phosphate inspire algae growth which blocks sunlight and influences the quality of the water. Sewage and agricultural fertilizers produce phosphate that is high quality which is very unsafe to the distinctive species that live in the water.