Hallo, it took some time, but here it is:
 
The Selters spring seems to used since the 8th century. It is situated at
Selters-Niederselters/Kr.Limburg-Weilburg/Hessen. In the late 19th century
they start to use another spring at Selters-Oberselters. The mineral water
from that springs was exported from the 18th century on (maybe earlier).
In the 19th century they exported up to 2 Million bottles mineral water,
as it seems - worldwide.
 
I only found one archaeological text on that problem and this Magister
thesios  isn't in
print yet. But You may wish to contact the author:
 
Michael Pecht M.A.
Bahnhofsplatz 1
97318 Kitzingen
Germany
 
He worked on the medieval castle 'Ehrenfels' near Ruedesheim on the rhine.
 
But I found some historical studies, most of them in german and regional,
so I don't know if they are reachable overseas:
 
 
- George Barnard, The Brunnens of Nassau and Scenery of the River Lahn
(London 1836-1841). (Engravings and a short touristic description of the
region)
- Die Mineralquelle zu Oberselters, ihre Geschichte, Bestandtheile und
Heilkraefte (Selters [um1880]). Edited by the Nassau-Selterser Mineral-
und Heilquellen AG (founded 4.9.1871). (A description of the newer spring
by the company running it)
- A.Kuhnigk/ F.Zimmermann, Niederselters und das Selterwasser in
historischen Darstellungen. Schriftenfolge Goldener Grund 14, 1972.
- Oberselters und seine Geschichte. Bad Camberger Archivschriften (Bad
Camberg 1993). (A regional history of the village)
- Reviewed by Eugen Caspary. Nassauische Annalen 105, 1994, 369f.
- U.Eisenbach, Mineralbrunnenindustrie. In: An Lahn und Kallenbach. Aus
Geschichte und Gegenwart von Löhnberg, Niedershausen, Obershausen und
Selters (Löhnberg 1993). (A regional history of the mineral water
industries there)
- Reviewed by Gerhard Buck. Nassauische Annalen 105, 1994, 349f.
- Geschichte von Niederselters (Selters 1994). (A regional history of the
other part of the Selters-village)
- Reviewed by Rolf Faber. Nassauische Annalen 107, 1996, 374f.
 
Sorry, I know there is some more literature on the stoneware bottles, but
I can't find it...
 
Good luck
 
Sven-Hinrich Siemers
Institut fuer Vor- und Fruehgeschichte
Johannes Gutenberg-Universitaet Mainz