What does a higher BOD value in the water sample indicates regarding its pollution level?

High pollution

The correct answer is Option (1) -High pollution

The BOD test determines the amount of oxygen consumed by microbes in water bodies. A higher BOD value of a sample water indicates that it is highly polluted.

In the BOD test, microbes in the water consume organic matter as a food source, which requires oxygen. When the water sample has a high BOD value, it indicates that there is a substantial amount of organic matter present in the water. This organic matter can come from various sources, such as sewage, industrial waste, or agricultural runoff, and is often associated with pollution.

The presence of a high BOD value suggests that the water body has a significant input of organic pollutants. These pollutants can deplete the dissolved oxygen in the water as microbes consume them, leading to reduced oxygen levels. This can have detrimental effects on aquatic life, as oxygen-depleted water can harm fish, plants, and other organisms.

Therefore, a higher BOD value in a water sample is an indication that the water is highly polluted with organic pollutants and requires proper management and treatment to reduce its environmental impact and protect aquatic ecosystems.