Which of the following is not a source of groundwater pollution? a. landfills b. septic tanks c. smoke stacks d. fertilizer

The correct answer is c. smoke stacks.

Smoke stacks are chimneys or funnel shaped structures which emit smoke from a factory, vehicles and industrial set ups. Smoke stacks mostly discharge carbon dioxide and water vapor and oxides of nitrogen into the atmosphere. The exhaust released from smoke stacks cause air pollution. Air pollution can cause ailments like asthma and cancer. Thus, smoke stacks are not a source of water pollution.  

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