Which of the following is a potential source of nutrient discharges to surface waters?

Nutrient discharges to surface waters can originate from a variety of sources, and the choice that encompasses all these sources is the most comprehensive. Agricultural runoff is well-known for contributing nutrients, particularly nitrogen and phosphorus, which can lead to eutrophication in water bodies. This occurs when excess nutrients stimulate algal blooms, which can deplete oxygen levels and harm aquatic life.

Household waste is another significant contributor, as it can include detergents, fertilizers used in lawns, and other household products that contain nitrogen and phosphorus. When these substances enter surface waters through improper disposal or runoff, they can similarly impact water quality.

Chemical manufacturing can also be a source of nutrient discharges. Facilities may release effluents that contain various chemicals, including nutrients used in the production of pesticides and fertilizers, which can find their way into surface waters.

Since all these sources contribute to nutrient loading in different ways, the correct choice reflects the broad range of potential contributors to nutrient discharges, making it clear that multiple sectors can impact surface water quality. Hence, the option that includes all sources recognizes the complexity of the issue and underscores the need for a comprehensive approach to managing and monitoring nutrient pollution.