Abstract
Groundwater abstracted from the Middle Devonian aquifer system is the main source of drinking water in South Estonia. High iron and manganese concentrations in groundwater are the greatest problems in this region. The total iron concentrations up to 16 mg L -1 are mainly caused by a high Fe 2+ content in water, pointing to the dominance of reducing conditions in the aquifer system. A pilot study was carried out to estimate the effectiveness of 20 groundwater purification plants with eight different water treatment systems (aeration combined with Manganese Greensand, Birm, Nevtraco, Hydrolit-Mn, Magno-Dol and quartz sand filters) in Voru County. The results demonstrate that in most cases the systems with pre-aeration effectively purify groundwater from iron, but only 13 out of 20 water treatment plants achieved a reduction of iron concentration to the level fixed in drinking water requirements (0.2 mg L -1 ). Manganese content decreased below the maximum allowed concentration in only 25% of systems and in cases where the filter media was Birm or quartz sand and pre-oxidation was applied. The study showed that the high level of iron purification does not guarantee effective removal of manganese.
Highlights
Most of the Estonian population (87% in 2010) uses drinking water from public water supply systems; the rest is consuming water from shallow private wells
In Estonia iron concentration is above the limit value in 39.4% of water supply facilities (Birk 2010), which means that approximately 20% of inhabitants consume Fe-rich drinking water
Water supply of Võru County is based on the Middle Devonian (D2) aquifer system
Summary
Most of the Estonian population (87% in 2010) uses drinking water from public water supply systems; the rest is consuming water from shallow private wells. Due to the geological conditions, groundwater chemistry does not meet the quality standards set for drinking water. The deficiency or redundancy of some substance in drinking water may disturb physiological processes and cause illnesses. In Estonia iron concentration is above the limit value in 39.4% of water supply facilities (Birk 2010), which means that approximately 20% of inhabitants consume Fe-rich drinking water. According to the EU directive 98/83/EC (EC 1998) and Estonian requirements for drinking water quality (MSA 2001), the limit value set for iron in tap water is 0.2 mg L–1 and for manganese 0.05 mg L–1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
