In a surprising coincidence the book I've just been reading is The Great Stink of London: Sir Joseph Bazalgette and the Cleansing of the Victorian Metropolis by Stephen Halliday. Bazalgette did an amazingly good job in designing and building the sewers, planning enough capacity that they're still in use today. He was also responsible for the Embankments, and several London bridges that are still standing. I feel slightly embarrassed that I knew nothing about him before, and on my recent trip to London did actually take the time to find the memorial to him on the Embankment.
The preface to the book points out that before the sewers nearly half of the babies born in British towns didn't reach their fifth birthday. The blurb on the Wateraid site gives a figure of 1.8 million children dying each year before their fifth birthday from diarrhoea. Pumps, bogs, drains and sewers may not be the most glamourous of items, but what a difference they can make to life.