They work full-time in a variety of plants, hydraulic or sign contracts-orders for certain services.
Some plumbers also run his own business, under which perform minor plumbing services.
Nowadays, self-employed persons often assume hydraulic websites, which include information on the services rendered by them and their price list.
As recently as the late 19th century sewerage systems in some parts of the rapidly industrializing United Kingdom were so inadequate that water-borne diseases such as cholera and typhoid remained a risk. From as early as 1535 there were efforts to stop polluting the River Thames in London.
Beginning with an Act passed that year that was to prohibit the dumping of excrement into the river.Leading up to the Industrial Revolution the River Thames was identified as being thick and black due to sewage, and it was even said that the river ?smells like death.?24 As Britain was the first country to industrialize, it was also the first to experience the disastrous consequences of major urbanisation and was the first to construct a modern sewerage system to mitigate the resultant unsanitary conditions.citation needed During the early 19th century, the River Thames was effectively an open sewer, leading to frequent outbreaks of cholera epidemics.
Proposals to modernise the sewerage system had been made during 1856, but were neglected due to lack of funds.However, after the Great Stink of 1858, Parliament realised the urgency of the problem and resolved to create a modern sewerage system.Źródło: https://en.wikipedia.org/wiki/History_of_water_supply_and_sanitation.