What are some common indicators of water quality?

Biological oxygen demand (BOD), total dissolved solids (TDS), and coliform bacteria levels are all important indicators of water quality that provide insight into the health of a water body.

BOD is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water, indicating the level of organic pollution. High BOD values often signify pollution that can deplete oxygen levels in the water, adversely affecting aquatic life.

Total dissolved solids (TDS) represent the total concentration of dissolved substances in water, including minerals, salts, and organic matter. High TDS levels can impact water quality by influencing water chemistry and affecting the organisms that rely on the water for habitat and nutrients.

Coliform bacteria levels serve as indicators of fecal contamination and the potential presence of pathogens in the water. High levels of coliform bacteria suggest a risk of waterborne diseases, making this indicator crucial for assessing water safety for human and ecological use.

The other choices include various combinations of indicators that also play a role in assessing water quality but do not include the same set of relevant indicators as the correct option.