Final answer:
Scientists analyze sewage to monitor drug usage in communities and to manage chemical pollution, which assists in the effective wastewater treatment process.
Step-by-step explanation:
One reason scientists analyze chemical compounds in sewage is because drugs and parts of drug compounds are eliminated in urine. Analyzing wastewater can reveal what types of drugs are being used by a community, and in what quantities.
This data helps in understanding the impact of chemical pollution from waste, including pharmaceuticals, on the environment and public health. Moreover, wastewater analysis is a critical process in wastewater treatment plants for removing contaminants and ensuring the treated water is suitable for discharge or reuse.