Because the drainage system is over loaded by to many fixture units
Salt and water do make hydrochloric acid... Highly corrosive.
it is found in sewer pipes in the USA
the toilet overflows if either the building sewer, branch line in your sewer system or trap in your toilet gets clogged.
Not normally even the connection to the public sewer is not covered
3" - 6"
With a wire brush.
You could install your own sewer cam and get a look however doing so would likely involve getting in to your sewer pipes which is best left to a professional. Call a plumber to look in to your pipes if he can't find anything install the cam while he's got the pipes open.
Probably not, but where does the water from the sink and shower go and what sewer problems are you having?
Pipes. It is used for alot of underground storm, sewer or freshwater pipes by cities.
yes
Moisture from rain can push sewer gases back up through drains or vents into your house, especially if there is a blockage in the plumbing system. The pressure changes in the atmosphere on cloudy, rainy days can exacerbate this issue by affecting the way gases move through the pipes. It's important to have a plumber inspect and address any plumbing problems to prevent this unpleasant smell.
a person who jabs poo or likes sewer pipes. It is a persons name.