What amount of H2S causes increased eye problems?

Rain water from roofs can be allowed to flow through the house sewers.

What is the size of preferred taps for wash basins?

What is the minimum diameter of pipes used for drainage of waste water?

What is the depth of brick masonry required in inspection chambers?

House drainage should be laid by the side of the building.

How deep is the water seal in the water closet?

________ should not be placed near water body.