to the garden ponds and waterfalls in the western gardens, since disappeared, sending it to a reservoir once located on the lawn. Part of this reservoir still exists near the racecourse, but it no longer contains water. Some of this hydrologic work was used to feed factories in the valley. The gardens that remain were watered by a completely different system based on an aqueduct coming from the area around Senlis. In the 18th century a mineral water source was discovered in the valley and a garden pavilion was built between 1725 and 1728 to allow the public to come drink from it. This was a separate source from the source of ferruginous water, called Chantilly water, discovered at La Chausée in Gouvieux, and bottled and carbonated there from 1882 into the 20th century. Also in the 18th century, a supply of drinking water was created by diverting water from the reservoir. In 1823, the last prince of Condé had eighteen fountains installed for the use of residents. In 1895 these were replaced with a supply from a water treatment plant in the neighboring village of Lamorlaye. This brought in water from Chantilly, Lamorlaye and Boran-sur-Oise then distributed the treated water through two water towers on the Mont de Pô in Gouvieux. This water supply has been managed by the private company Lyonnaise des eaux since 1928. In 1999 the average price of a cubic meter of water was 3.25 euros. The sewer system was installed in 1878 meanwhile, but initially limited to the area around rue d'Aumale, the Condé Hospice and the rue de Paris, now known as the avenue du Maréchal Joffre. It was extended to the entire town in 1910 through a state subsidy financed by a tax on racetrack bets. A sewage treatment plant was built in 1969 at La Canardière, then moved to Gouvieux in 2006. This 22 km network is administered by a regional agency, the syndicat intercommunal pour le traitement des eaux de la vallée de la Nonette (SICTEUV), which covers Apremont, Avilly-Saint-Léonard, Chantilly, Gouvieux et Vineuil-Saint-Firmin. History Before the city No traces of habitation from the prehistoric or Iron Age eras have ever been found in Chantilly. A Roman-era grave site was however found on the banks of the Nonette, and Gallo-Roman roads have been discovered in Chantilly Forest. Merovingian tombs from the seventh century were found in the 17th and 19th