http://outsidethesink.rtu.lv/documents/Principles%20of%20Water%20Treatment.pdf
https://dec.alaska.gov/water/opcert/Docs/Chapter4.pdf http://www.lenntech.com/history-water-treatment.htm www. epa. gov/safewater
http://water.epa.gov/lawsregs/guidance/sdwa/upload/2009_08_28_sdwa_fs_30ann_treat
http://www.lenntech.com/history-water-treatment.htm#ixzz3luxsqf1S
https://en.wikipedia.org/wiki/Water_treatment
http://ec.europa.eu/environment/water/water-
drink/pdf/report2014/1_EN_ACT_part1_v3.pdf
http://ec.europa.eu/environment/water/water-drink/derogations_en.html
http://ec.europa.eu/environment/water/water-drink/index_en.html
http://ec.europa.eu/environment/water/water-drink/legislation_en.html