Pet owners should always pick up pet waste and throw it in the trash. Pet waste is full of bacteria that is a health risk to pets and people, especially children. If washed into storm drains and surface water, the bacteria can harm aquatic life and contaminate drinking water supplies. Pet waste can increase the biological oxygen demand of surface water, which reduces water oxygen content and puts a strain on aquatic life. In some jurisdictions, picking up after a pet is legally required.