Since the earliest civilization, gaining easy access to water has been a priority. The strides that were made in 6500 BC were a precursor to what we use today. Different civilizations and people throughout the millennia have helped to make modern plumbing what is it today. The amenities that we get to have in our homes are something that is only recent in our history. The history of how clean water enters the home and how dirty water exits is rather interesting. By understanding the history of water sanitation, a person can begin too truly appreciate the luxuries they live with today.
Traditionally, water was not sanitized when it entered or left the home. In early civilizations, people didn't understand the importance of this (especially waste water that left the home). The Indus Valley Civilization had two methods of disposing of wastewater: a cesspit and bodies of water. The cesspits were cleaned, but due to the difficulty most waste was put back into bodies of water. Even the Ancient Greeks and Romans, who had flushable toilets, put wastewater back into water supplies.
During the Middle Ages, cesspits became increasingly popular, but this was done so that waste could be used as fertilizer. These practices were most prevalent in England, Japan, and China. The city outhouses in London were cleaned and emptied each night by specially designed wagons. The waste would either be used for fertilizers, saltpeter, potassium nitrate, or black powder.
It wasn't until the mid-1700s that water treatment became a main focus. The very first attempt of purifying water was to desalinate seawater. This was done with a sand filter, but it did not work. Even though the sand filter didn't help to clean salt water, it was still able to help purify fresh water. Two more decades passed before James Simpson was able to treat public water supplies. These discover sparked a lot or research and development, and throughout the next centuries more and more developments were made.
The developments made throughout history have allowed major cities to build up and grow. New York City, which has over 10 million inhabitants, would never be able to function without the plumbing systems we have today. Plumbers in NYC can handle any plumbing problem that arises in such a big city. This allows water to come into the home clean and leave the house in a proper way. It is truly incredible what we have accomplished, in terms of indoor plumbing, throughout the centuries.