Scientific substantiation of simplified eco-hygienic requirements for the location and size of the first belt of sanitary protection zones for groundwater wells of water pump complexes in populated areas

Abstract

Purpose. To provide a comparative hygienic assessment of the quality and safety of groundwater from pump room and water supply wells fed from the same aquifers, under the conditions of their different purposes and operating conditions, in order to substantiate simplified ecological and hygienic requirements for the design and construction of pump room complexes in settlements. Materials and methods. The current regulatory documents and construction projects for groundwater wells of pump rooms complexes were analyzed. A comparative hygienic assessment of retrospective and modern data on the chemical analysis of the composition (12 indicators) of groundwater from pump rooms and water supply wells fed by the same aquifers (Cenomanian and Jurassic) in the Kyiv was conducted. The research covered 22 pump rooms at specific addresses located in different districts of the city, and water supply wells from five city water intakes. The current situation regarding the placement of pump rooms and the size of their water protection zone (first belt) in the settlement (Kyiv) was analyzed. The work used sanitary-chemical, bibliometric, analytical and mathematical methods. Results. Analysis of regulatory documents in the field of water supply has shown that there are still no standards in the country for the design and construction of groundwater wells for pump rooms, which are identified with water supply wells, being different from them in purpose and operating mode. Monitoring of groundwater quality from pump rooms showed that the chemical composition of pump room water, as well as from centralized water supply wells, generally meets sanitary requirements for drinking water and only in some samples are abnormally recorded levels for odor, turbidity, total iron, manganese. These individual non-toxic indicators do not pose a direct threat to the health of water consumers. It is also shown that the quality of pump room water does not change significantly during long-term operation of wells (over 25 years) and does not depend on the size of the first belt of the water protection zone (30 m, 15 m, 7-10 m). For pump room wells, this belt of the water protection zone is nominal (formal) in nature, in which the legal regime of its proper maintenance is not maintained. For pump room wells, this factor is not a key factor in influencing the quality of groundwater extracted from deep-water horizons. Conclusion. The established differences between groundwater wells of pump room complexes and water supply wells became the basis for the development of simplified ecological and hygienic requirements for the design and construction of groundwater wells of pump room complexes. They require regulatory regulation by amending the current DBN V.2.5-74:2013 «Water Supply. External networks and facilities. Main provisions» and DSanPiN 2.2.4-171-10 «Hygiene Requirements for Drinking Water Intended for Human Consumption».