Disinfection of wells and wells
Measures to eliminate the deterioration of water quality include cleaning, rinsing and preventive disinfection.
Disinfection of wells that have fallen into the flood zone includes:
– preliminary disinfection of the well;
– cleaning of the well;
– re-disinfection of the well.
Pre-disinfection of the mine well
Before disinfection of the well, the volume of water in it (in cubic meters) is calculated, which is equal to the cross-sectional area of the well (in square meters) to the height of the water column (in m). Irrigation is carried out from the hydraulic console of the outer and inner parts of the mine shaft with a 5% solution of bleach at the rate of 0.5 l per 1 sq. m of surface.
A 5% solution of bleach is prepared at the rate of 50 gr. bleach per 1 liter of water (that is, for 1 well, about 1 kg of bleach is needed by irrigation).
When using another disinfectant, you must follow the instructions for use of the drug.
Perform disinfection as follows: prepare a 5% solution of chlorinated water. To do this, 500 grams of bleach is poured with cold water, rubbed until a liquid slurry is obtained and poured into 10 liters of water. Mix thoroughly, defend, drain clear water. For 1 cu. m of water consume 1 bucket of transparent composition. The walls of the well are poured with a sprayer, the water is left open and the well is left for a day. The water is thoroughly mixed, the well is covered with a lid and left for 1.5 – 2 hours, preventing water from being drawn from it.
Cleaning is carried out 1.5 – 2 hours after the preliminary disinfection of the well. The well is completely freed from water, cleaned of foreign objects that have fallen into it and accumulated sludge. The walls of the mine are cleaned mechanically from fouling and contamination. Dirt and sludge selected from the well are taken to a landfill or immersed in a pit 0.5 m deep dug in advance at a distance of at least 20 m from the well and buried, after filling the contents of the pit with a 10% bleach solution (100 g of bleach per 1 liter water).
The walls of the shaft of the cleaned well, if necessary, are repaired, then the outer and inner parts of the shaft are irrigated from a hydro-panel with a 5% solution of bleach (or another agent prepared according to the instructions for the preparation) at the rate of 0.5 l / cu. m mine.
Re-disinfection of the well
After cleaning, repairing and disinfecting the walls of the shaft, they begin to re-disinfect the well.
Withstand the time during which the well is refilled with water, re-determine the volume of water in it (in cubic meters) and add the required amount of bleach solution or other disinfectant according to the instructions for use. For example, when using chlorine-containing tablets “Aquatabs” – 8.67, 5 tablets per 1 cu. m (1000 l). Based on 1 well with a volume of 7 cubic meters. m (7000 l) – 35 tablets.
After adding the disinfectant solution, the water in the well is mixed for 10 minutes, the well is closed with a lid and left for 6 hours, preventing water from being drawn from it.
After the specified period, the presence of residual chlorine in water is determined qualitatively – by smell or using the iodometric method. In the absence of residual chlorine, 0.25 – 0.3 of the initial amount of the disinfectant is added to the water and kept for another 3 – 4 hours.
After re-checking for the presence of residual chlorine and positive results of such a check, the water is pumped out until the strong smell of chlorine disappears.
Control over the effectiveness of disinfection of the well is carried out in the laboratory. And only after that the water can be used for drinking and household purposes.
If measures to eliminate the deterioration of water quality have not led to a stable improvement in its quality in terms of microbiological indicators, the water in the well must be constantly disinfected with chlorine-containing preparations or other means and methods approved for use and aimed at destroying bacterial and viral contamination.
Disinfection of water in a well is carried out after disinfection of the well itself using various techniques and methods, but most often with the help of a dosing cartridge filled, as a rule, with chlorine-containing preparations. The cartridge can be made independently, using a 0.5-liter plastic drinking water bottle (or another container, based on the amount of disinfectant), pre-perforated, a load (stones) is placed on the bottom.
According to the amount of the drug, a cartridge (or several cartridges of a smaller capacity) is selected, filled with the drug, water is added with stirring until a uniform slurry is formed, closed with a cork and immersed in the water of the well at a distance of 20 to 50 cm from the bottom, depending on the height of the water well. pillar, and the free end of the rope (twine) is fixed on the head of the mine.
With a decrease in the amount of residual chlorine or its disappearance (after about 30 days), the cartridge is removed from the well, freed from the contents, washed and refilled with a disinfectant.
In case of detection of persistent chemical contamination caused by the impact of potentially hazardous objects during flooding, a decision should be made to eliminate the water intake device.