SPA - From the sixteenth to the nineteenth century
Protective measures to ensure the purity of the springs were started in the sixteenth century.

In 1624, an ordinance compelled the citizens of Spa to repair the water conduits to avoid any mixing of the waters they carried with the Spa Waters coming out of the fountain.

..About a century later, in 1772, the Prince-Bishop Charles Velbruck, issued a preventive decree :  “No building works could be done in places where the mineral water springs of Spa flow, without it having been determined beforehand that there could not result there from any effect prejudicial to the said springs and having taken the most precise precautions in this respect”
To these judicial aspects of protection of the waters must be added an improvement in the conditions for piping them.
Other measures were taken to supervise the quality of the waters that were taken away and sold.  Thus specific decrees ordered that the Spa Waters should be drawn in an absolutely limpid condition and at the best times with fine weather, calm and favourable wind.
 
In the eighteenth century, all these ordinances relating to hygiene were repeatedly re-enacted with increasing severity, and their observance was strictly enjoined in the certificates that went with water despatches.

In 1889, in the Moniteur Belge appeared an extremely important royal decree providing for the protection of the Spa Waters : a protective perimeter around the Peter-the-Great Pouhon was proclaimed, having an area of 34.6 hectares and a length of 3Km500, which comprised Spa, with two branches extending towards the North and towards the West.  This was the first European protective perimeter !