What is the recommended slope ratio for soil water pipes?

_______ is used below sinks to prevent entry of foul gases.

Water is recycled into the atmosphere by vegetation through the process called __

What are the masonry chambers constructed at suitable intervals along sewer lines called?

Cast iron pipes should confirm to IS 1729.

________ should not be placed near water body.

What is the percentage of purification of septic tank effluent?

Which of these is a single event?