THE NEED FOR DEVELOPING BOREHOLE WATER SUPPLY SYSTEMS IN SMALL TOWNS AND SETTLEMENTS OF POLTAVA REGION

Poltava Region is geographically located above the center of the Dnipro-Donets Artesian Basin (DDAB), which lies within the sedimentary cover of the Dnipro-Donets Depression. Four aquifers are used for water supply: the Poltava, Kharkiv, Buchac-Kaniv, and Cenomanian–Lower Cretaceous aquifers. Several small towns and settlements in Poltava Region use groundwater from the Kharkiv and Buchac-Kaniv aquifers for centralized water supply. The Kharkiv aquifer has a limited yield, but the water is of high quality. The Buchac-Kaniv aquifer, while sufficiently productive, contains elevated levels of fluoride — up to 4 mg/dm³, exceeding the maximum permissible concentration of 1.5 mg/dm³. Consumption of such water leads to fluorosis among the population. To address the issue of providing the population with high-quality drinking water, three options were considered (using the town of Myrhorod as a case study). The first option was physicochemical water treatment to remove excess fluoride. However, the proposed methods were deemed unacceptable due to the potential toxic effects of residual aluminum in the treated water. The second option involved blending additional high-quality water from the Kharkiv aquifer in clean water reservoirs with fluoride-rich water from the Buchac-Kaniv aquifer. Calculations showed that fluoride concentration could only be reduced to 1.85–2.06 mg/dm³. Additionally, this would require drilling 14 new wells and decommissioning 8 existing ones. This option was rejected as both ineffective and economically unviable. The third option proposed the development of a decentralized borehole water supply system based on the high-quality groundwater from the Kharkiv aquifer. This borehole system is designed to supplement the centralized supply. The advantages of this approach include: elimination of fluorosis in the population; free access to safe drinking water for residents; provision of additional drinking water sources during martial law or emergencies; 24/7 availability of drinking water; improved reliability of water supply to the population. The main drawbacks are the need for substantial capital investment, maintenance and repair costs, and somewhat reduced convenience compared to in-home centralized supply. A representative example of such a system is Kyiv’s borehole water supply network, where more than 200 public boreholes have been constructed. Residents have free access to potable water at any time and use it extensively for both drinking and cooking. The borehole water supply system based on the Kharkiv aquifer is a radical solution for combating fluorosis in small towns and settlements across the central part of Poltava Region. This system is not intended as a replacement for centralized water supply, but rather as a valuable complement to it.