ABSTRACT
Concrete sewers are subjected to the same external conditions as any other buried structure. Under certain conditions the sewers may also be subjected to internal corrosion above the waterline from sulphuric acid (H
of hydrogen sulphide (H 2 S) that is generated below
the waterline and is released into the sewer atmosphere, or acid attack below the waterline due to acidic effluent. The manifestation of these conditions and their causes are different.
