Which pollutant category includes nitrogen, phosphorus, radioactive substances, and heat as examples?

• A. Conventional pollutants
• B. Nonconventional pollutants
• C. Toxic pollutants
• D. Disinfectant byproducts

Answer: (B)

The main idea is understanding how pollutant categories are defined for regulation. Conventional pollutants are the classic list (BOD5, total suspended solids, pH, fecal coliform, oil and grease). Nitrogen and phosphorus are nutrients that drive eutrophication, heat is thermal pollution, and radioactive substances are radionuclides—none of these fit the traditional conventional list. Together they fall under nonconventional pollutants, a broader category that covers nutrients, temperature, radionuclides, pesticides, and many other substances not included in the conventional group. Toxic pollutants are a separate category for hazardous substances, and disinfectant byproducts are a specific subset of toxic pollutants formed during disinfection. So these examples are best described as nonconventional pollutants.