Study of the storm runoff mechanism (for discussion)

Summary

For the hydraulic calculation of surface runoff disposal networks in SP 32.13330.2018 «Sewerage. External Networks and Structures», a technique is applied that implements the method of «limiting intensities». Despite its notability and widespread use in practice, a number of authors point to a limited area of its use. However, there are no results of a quantitative assessment of the errors of this method in the technical literature. For this reason, the analysis of the degree of influence of the accepted assumptions on the results of hydraulic calculations was carried out. It has been established that with certain ratios of other factors, the use of the «limiting intensities» method can result in an underestimation (from 1.2 to 1.7 times) of the calculated wastewater flow rates. Taking into account the results obtained, two directions of work are formulated to eliminate the consequences of flooding in sewer basins. The first direction provides for the introduction of engineering measures aimed at increasing the reliability and efficiency of the sewer system operation, the second – the improvement of the construction regulations that exclude the creation of problem situations in the future.

Key words

drainage area , method of limiting intensities , climatic parameters , force of rain , rainfall duration , surface runoff disposal systems , travel time

UDC 347.265.6:504.064
DOI 10.35776/VST.2023.12.08

Iantsen O. V., Gogina Elena, Kolosova Kamilla, Spasibo Elena

Исследование характеристик поверхностных сточных вод

Summary

The results of studies of surface runoff (rainfall and snow-melt waters) are presented. The qualitative composition of surface runoff from various catchment areas in the urban environment was determined for the subsequent estimation of their possible splitting, local treatment and reuse. The problems of battery limits associated with the discharge of polluted surface runoff are considered, and possible ways to solve the identified problems are proposed. The results of the studies prove the possibility of rational use of surface runoff by legal customers to split the flows and draw up discharge reduction plans. It is advisable to reuse rainfall and snow-melt waters collected from the roof of a building, including as process water for a number of facilities using a minimum amount of the treatment equipment.

Key words

surface runoff , rain and melt waters , drainage area , flow splitting

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UDC 628.312:628.336.3

Variushina G. P., Primin Oleg

The experience of operating surface runoff treatment facilities
and the guidelines for the improvement of sludge treatment technology

Swimmer

The data on the mechanical and physical properties of surface runoff sludge generated on the lands allotted for settlement and highways is presented. The observations of the processes of natural sludge drying on the sand sludge dewatering beds at the treatment facilities show that the sludge is characterized by low dewatering properties (more than 89–94%), and this fact stipulates the demand for the improvement of the sludge treatment technology. As a result of the chemical and analytical studies of the surface runoff sludge composition it was stated that the sludge from industrial sites located in the residential districts and industrial areas, from residential constructions on the lands allocated for settlement with parklands as well as from the recreation areas with nature-sanctuaries could be attributed to class IV of hazard (low-hazard). Sludge from the territory of the Moscow Ring Road, gasoline stations, and parking lots at the shopping malls could be attributed to class III of hazard (moderately hazardous). The results of the laboratory studies showed that the use of high molecular polyelectrolytes provided for sludge thickening and efficient dewatering by centrifuging to 74–82% moisture content. The design data on the sludge specific volume (98–99% moisture content) generated in storage tanks is presented as well as the data on the specific volume of dewatered sludge (89–94 % moisture content) generated annually on 1 ha catchment area for different types of catchment areas. It is recommended during the design process not to remove water charged sludge with a moisture content of 98–99% by trucks (sludge pumps) as an expensive and ineffective method, but to dewater sludge directly at the treatment facilities with the use of stationary or mobile mechanical equipment (vacuum-filters, filter-presses, centrifuges, geotubes).

Key words

treatment facilities , sludge , surface runoff , drainage area , the dewatering apparatus

DOI 10.35776/VST.2021.04.05
UDC 628.221

Volkov Sergei, Zhitenev A. I., Rublevskaya O. N., Kurganov Iu. A., Kostenko I. G., IGNATCHIK V. S., Ignatchik S. Iu., Kuznetsova N. V., Seniukovich Mikhail

Evaluation of the effectiveness of mechanisms for eliminating flooding of urbanized areas with surface runoff

Summary

Flooding of urbanized areas happens quite often, while, during periods of heavy rains, water rises to the surface flooding streets and basements. Flooding occurs for different reasons or due to their combination. The list of measures to reduce the flooding rate has been worked out in the world practice. These include measures aimed at reducing the runoff coefficient of drainage areas, as well as increasing the spare regulating capacities of the networks and sewers, etc. However, evaluating their effectiveness in the Russian Federation is complicated by the fact that the standard method of hydraulic calculation provides for taking into account the values of the periods of one-time excess of the calculated rainfall rates p that indicates the overflow rate in the networks. However, this method does not determine the rate pp of area flooding that results from the water spills. Through the example of St. Petersburg, a calculation method is presented for determining the average annual number of floods, as well as the results of evaluating the effectiveness of measures aimed at reducing them.

Key words

drainage area , surface runoff disposal system , climatic parameters , force of rain , rainfall duration , travel time , flooding

DOI 10.35776/VST.2022.07.07
UDC 628.221

Volkov Sergei, Luk’ianchuk Maksim, Zhitenev A. I., Rublevskaya O. N., Erofeev Vasilii, IGNATCHIK V. S., Ignatchik S. Iu., Kuznetsova N. V.

Systems for the removal of surface runoff: problems and solutions (for discussion)

Summary

For the hydraulic calculation of storm sewer networks removing surface runoff in our country, the concept of immediate removal of runoff formed as a result of rainfall has been used for more than 60 years. With this aim, the method of «limiting intensities» has been used up nowadays, implemented with the help of the methods laid down in Norms and Technical Conditions for Design 141-56, SNiP II-G.6-62, SNiP II-32-74, SNiP 2.04.03-85, SP 32.13330. 2012, CP 32.13330.2018. If we continue to be guided by this concept, then in order to adapt the operated systems to the current conditions, in most cases relaying all the networks with larger pipe diameters would be required, which is practically impossible not only from the economic, but also from the technical and social point of view. In the current situation, introducing alternative solutions for adapting storm sewer networks is needed, which, in comparison with relaying all the networks, are more economically justifiable. Among them, noteworthy are the solutions that provide for the detention and retention of water in sewers, and for reducing runoff coefficients. The effectiveness of these solutions is estimated using numerical modeling and analytical calculations.

Key words

drainage area , method of limiting intensities , climatic parameters , force of rain , rainfall duration , surface runoff disposal systems , travel time

DOI 10.35776/VST.2022.11.05
UDC 628.221

Volkov Sergei, Luk’ianchuk Maksim, Zhukova Anastasiia, Zhitenev A. I., Rublevskaya O. N., Erofeev Vasilii, IGNATCHIK V. S., Ignatchik S. Iu., Kuznetsova N. V.

Economic efficiency of measures to provide for the surface runoff disposal systems adaptation to changing climate conditions

Summary

The process of economic justification of measures to provide for the surface runoff disposal systems adaptation to the new operating conditions comes down to solving an optimization problem where the maximum economic effect is assumed as the optimization criterion in the form of the difference between the cost of prevented damage from flooding of territories during the periods of heavy rains and the costs of investment and operating activity. The justification of this approach is obvious, since from a stochastic point of view it is impossible to completely eliminate flooding. Accordingly, the estimation of the effectiveness of adaptation measures should be based on the comparison of costs and benefits. The key elements of such an estimation, along with the justification of effective engineering solutions for adaptation, is the determination of the number of floods for the estimated period of time and the damage expected from them, i. e., the damage function that is the sum of the products of the probabilities of damage and its cost. In the Russian Federation the approach that takes into account the probability of flooding, is unrealizable at the regulatory level, since at the stage of hydraulic calculations, the probability of exceeding the calculated rain intensity is taken into account rather than water outcrop. In addition, in domestic practice, as an engineering measure for the adaptation of wastewater disposal systems, the method of network upgrade is mainly used which is the most expensive one compared to other alternative methods. Therefore, the effectiveness of applying the method of network upgrade in combination with the introduction of elements of a «green» infrastructure and regulation of wastewater flows is analyzed using the example of a pilot wastewater drainage area.

Key words

economic efficiency , drainage area , surface runoff disposal system , flooding , adaptation measures

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