According to the “Conclusions of the State Sanitary and Epidemiological Service” No. 05.03.02-04/59006 dd 24.09.2014 domestic wastewater after deep biological treatment on the BIOTAL plant must be disinfected. The microbial composition of the wastewater must be brought to the CGB index <1000 and the index of coliphages <1000, which will guarantee the absence of pathogenic intestinal microorganisms in the water. Between the garden and vegetable plots, which are irrigated with biologically cleaned and disinfected wastewater, and sources of decentralized water supply (wells), appropriate sanitary protection zones should be observed in accordance with the current sanitary standards.
Irrigation of garden plots should be carried out by the method of internal soil irrigation. The method of sprinkling is not allowed. For not fructifying trees and shrubs, you can apply a drip surface watering method (dripping from tubes located in a few centimeters from the ground surface above the root system of plants).
In areas where household wastewater is expected to be disposed of, and their sediments after treatment on the BIOTAL plant, it is allowed to grow grapes, fruit and non-fruit trees and shrubs, flowers, ornamental plants, grains, technical and fodder crops.
It is necessary to ensure constant monitoring of the quality of treated and disinfected domestic wastewater and their effect on soil and plants, to provide measures to prevent flooding of the garden area by surface rain and meltwater from overlying areas.
If it is not possible to use wastewater for irrigation (for example, in winter), it is necessary to provide the discharge of biologically treated sewage into storm drainage, filtering trench, filtering well or bioplato. In the case of discharge of treated sewage into the water body, it is necessary to disinfect with chemical or other effective methods.
With a deep groundwater table, sufficient filtration capacity of rocks, lack of flooding and sources of water supply (wells, capturing sources), it is possible to discharge biologically treated sewage water after BIOTAL plants through filtering wells and trenches into the ground flow, and after their post-treatment on sandy-gravel filters and obligatory disinfection – on the relief (ditches, cuvettes, beams, natural rain gutters, etc.). But in both cases, coordination with local regulators is required.
In the absence of natural gradients of relief, it is possible to discharge purified and treated wastewater into existing drainage and reclamation systems in coordination with local regulatory authorities.
After post-treatment on the bioplato, water is suitable for discharge into water bodies of the category of fishery water use provided that SanPiN 4630-88 requirements are met. After additional treatment of biologically treated sewage water on sand and gravel filters, the filtrate, after disinfection, can be discharged into open water bodies, including marine waters.