The removal of Mn is effective at those water treatment plants (Krabi 2, Antsla, Valio Voru, Kirsi-Veski, Lasva) where the increase in oxygen concentration is notable (Fig.
The same filter type, combined with open aeration (Krabi 2, Antsla and Lasva plants), reduces both Fe and Mn concentrations to the values that meet the drinking water requirements.
Water treatment plants in Voru County Plant Name Location Type Type number number 1 Krabi 1 Varstu Parish Manganese Greensand 2 Kraavi Antsla Parish 1 3 Vommorski Meremae Parish 4 Parksepa Voru Parish 5 Puiga Voru Parish 6 Misso Misso Parish 7 Vaimela Voru Parish 2 Birm 8 Lusti Antsla town 3 Nevtraco, Hydrolit-Mn, Magno-Dol 9 Krabi 2 Varstu Parish 4 Open aeration and 10 Antsla Antsla town Birm 11 Lasva Lasva Parish 5 Open aeration, 12 Passa Lasva Parish prefilter and Birm 13 Kaapa Lasva Parish 14 Rouge Rouge Parish 6 Closed aeration and 15 Nursi Rouge Parish Birm 16 Vastseliina Vastseliina 7 Closed aeration and Parish Manganese 17 Kose Voru Parish Greensand 18 Valio Voru Voru Parish 8 Closed aeration and 19 Vorusoo Voru town quartz sand 20 Kirsi-Veski Voru town Table 3.