What is the flow velocity condition required for the formation of hydrogen sulphide?

Which of these is a positive effect owing to the drier soil conditions?

At the last main hole of building sewerage, ______ is provided.

_______ is used to clean blockage in the line.

H2S gas is ___ to generate sulphuric acid.

When was SWMM developed?

How much is the water seal in intercepting trap?

What is the number of coats of paint required for manhole covers?