A significant portion of the population uses drinking water from wells. Requirements for well equipment, maintenance, and water quality are especially relevant after floods, when the quality of water in wells may deteriorate.
The State Service for Food and Consumer Protection informs that sanitary and hygienic requirements for well equipment, their maintenance, and the quality of water from wells are regulated by the State Sanitary Norms and Rules «Hygienic Requirements for Drinking Water Intended for Human Consumption» DSanPiN 2.2.4-171-10.
When installing mine wells, the following requirements must be met:
- isolate the well from the penetration of surface runoff (rain and melt water);
- the walls of the well should be constructed mainly with monolithic reinforced concrete, concrete or reinforced concrete rings, and in their absence - with ceramics, brick, stone or wood. The walls of the well should be dense, without gaps;
- The stones for constructing the walls of the well must be made of strong, stable rocks and laid on cement mortar;
- in the case of using wooden log cabins, logs should be used with a thickness of at least 0.25 m, straight, without deep cracks and wormholes, not affected by fungus, aged (harvested at least 5-6 months before their use). In this case, preference should be given to such tree species as larch, alder, elm or birch, but oak and pine can also be used (oak and pine can give the water a taste and smell from the beginning of operation). The crowns of the above-water part of the log cabin can be made of logs or beams of pine or spruce;
- the underwater part of the well walls should be deepened into the aquifer by no more than one meter to better open it and increase the water layer. With a weak aquifer flow, it is necessary to expand the well casing in the lower part;
- in the case of installing a well in sandy soils, a reverse sand-gravel filter is arranged at its bottom (from several layers of thoroughly washed sand and gravel with small fractions of 0.1-1.0 mm laid in the lower part of the filter, and large fractions of 2-10 mm in the upper part, with the thickness of each layer being 0.1-0.15 m, the total thickness being 0.4-0.5 m) or a foam concrete filter, and foam concrete filters are also arranged in the walls of the water intake part of the well;
- in the case of installing a well in open pits, gravel filters are installed at the bottom of the well;
- to lower a person into a well for the purpose of cleaning and repairing it, it is necessary to insert metal brackets into the walls of the well, placed in a checkerboard pattern at a distance of 0.3 m from each other;
- The above-ground part of the well (head), designed to protect the mine from pollution and monitor water intake, is arranged at least 0.8 m above the ground surface. In order to protect against clogging, the head must be tightly closed with a metal or wooden lid or have a reinforced concrete ceiling with a hatch, which is also closed with a lid. A canopy is arranged on top of the head, a canopy or the head is placed in a booth;
- Pumps (preferably submersible pumps) should be used to lift water from the well. The pump discharge pipe should have a hook for hanging a bucket. If it is impossible to use a pump, it is allowed to equip the well with a rotary pump or a firmly attached "crane" with a bucket for general use;
- a stand for buckets should be arranged near the well, and there should be a fence (with a radius of at least 2 m) with a gate (gate) and a paved path (from the gate to the well) around the structure;
- To protect the well from contamination by surface runoff, intercepting ditches should be arranged to divert runoff from the well. A "castle" of well-mixed and layer-by-layer compacted clay or heavy loam (2 m deep and 1 m wide) should be made around the well, or a site with a radius of at least 2 m should be concreted (asphalted) on a base of crushed stone 15-20 cm thick and sloping away from the well should be constructed;
- Around a well located in permeable soils (sand, sand-gravel, sand-pebble) with a small (2 m) cover of sandy loam or loam, it is necessary to cement a site with a radius of at least 2 m and with a slope away from the well.
Requirements for the installation of tubular wells (wells):
- By its structure, a tubular well is a well equipped with a water filter, a water-lifting pipe and a pump. If the soil in which the well is built is very weak or the depth of the well is great, the well must be reinforced with casing pipes. Tubular wells are shallow and deep. Water is lifted from a tubular well using a manual or electric pump;
- The head of the tubular well should be 0.8-1.0 m above the ground and hermetically sealed, have a casing and a drain pipe with a hook for a bucket. Blind areas, drainage and a clay "castle" are arranged around the head of the well, as well as a stand for buckets, as for a mine well;
- Shallow tubular wells (Abyssinian) can be for individual and public use. They should be installed in areas where the groundwater level is not very deep - up to 7-9 m. Such a well is more protected than a mine well;
- Deep tube wells should generally be used if the depth of the aquifer exceeds 9 m.
After floods, it is necessary to rehabilitate wells in early spring.
Remediation of mine wells is allowed both by specialized organizations and by well owners themselves, provided that safety precautions are observed and personal protective equipment is used.
After remediation (cleaning, repair of the log house, disinfection of the above-water and underwater parts) of the well, it is necessary to conduct laboratory control of the quality of drinking water according to sanitary-chemical and microbiological indicators.
The indicators are regulated by Appendices No. 1, No. 2 of the State Sanitary Norms and Rules "Hygienic Requirements for Drinking Water Intended for Human Consumption" (DSanPiN 2.2.4-171-10), as well as Section V Periodic Control of the Safety and Quality of Drinking Water from Pump Rooms, Wells and Source Captations (Non-centralized Drinking Water Supply of the Population) of these Rules.
In cases where the rehabilitation of a mine well and the disinfection of the water in it have not led to an improvement in its quality or there are no dosing cartridges for water disinfection, it is PROHIBITED to use such water for drinking purposes, a sign should be posted on the well. «"The water is not suitable for drinking!"».