A few nice Water Filtration images I found:
The Water of Hot Springs National Park, Arkansas
Image by Ken Lund
The water of Hot Springs National Park all comes from the same deep source, but surface appearance of the springs differed. What was called Mud Spring had a tepid ooze where there was no danger of being scalded. Springs acquired names such as Magnesia, Big Iron, and Arsenic. Big Iron’s water, with significant iron oxide, would precipitate ocherous crusts and stains. Arsenic Spring, on the other hand, contains no detectable traces of that substance. The water from many springs is now combined in one supply, with the total amount of water varying from 750,000 to 950,000 gallons a day. The temperature averages about 143°F (61°C). Maximum temperatures have declined about 5°F (3°C) since records have been kept.
In 1905 curative characteristics were being ascribed to radium and Professor Bertram Boltwood of Yale examined these waters. There is a measurable level of radioactivity primarily due to dissolved radon gas, with some radium. At the time collection and distribution equipment was designed to retain the radon gas, while now it is designed to allow it to escape. The level of exposure to radiation that results from bathing appears to be similar to the level that would result from sitting in the sun for the same period of time. The park water is considered well within safe limits and similar to other natural waters throughout the world.
Drinking water is dispensed from several hot water jug fountains. The hot water is naturally potable. Two cold water springs (Happy Hollow and Whittington Springs) are treated using ozone filtration. Regulations prohibit private individuals from selling the park’s waters.
Image by Wyrmworld
The Italian Fountains at the north end of the Long Water in Hyde Park. Originally these were filtration beds for water flowing from the Westbourne River into the Long Water. Now days they’re purely ornamental.
RC Harris Filtration Plant – Toronto
Image by bksutherland
Map of water treatment facilities and other infrastructure.