Why shouldn't oil be drained into the sewer?

Oils used at home include animal and plant oils such as tempura oil used in cooking and mineral oils such as kerosene. Animal and plant oils can be decomposed by microorganisms, but their degradation speed is very slow, and if they flow into rivers and the sea, the oil that cannot be decomposed is oxidized over time, consume oxygen in the water, living organisms, etc. Can be affected. In addition, it becomes a floating object such as an oil ball and can rot and generate odors.

Mineral oils such as kerosene are generally difficult to decompose by microorganisms, and depending on the components contained in mineral oils directly affect organisms and make it difficult to inhabit.

If household wastewater is drained into the sewer, animal and plant oil can be treated at the water reclamation center, but if it flows in large quantities, it cools and hardens, block the sewer pipe, or affects the treatment. Mineral oil is difficult to treat at the water reclamation center, so do not allow even small amounts to flow into the sewer.