Ans.
Sludge can be defined as the semi-solid waste produced by sewage treatment of municipal and industrial wastewater as a byproduct. Sludge dumping involves discharge if sludge into the ocean.
It contains various contaminating agents, such as pathogens, heavy metals, chemicals, such as pesticides, and other hazardous substances. 'Sludge dumping is a threat to humans and marine life as it can cause various diseases, pollute beaches, and kill marine organisms.'