Method of evaluating the amount of emergency wastewater discharges into the environment

Summary

The method of evaluating the amounts of emergency discharges of wastewater into the environment caused by the overrun of wastewater inflow over the capacity of the sewage pumping stations resulted from the emergency shutdown of pumps or inflow of off-nominal wastewater flow is presented. The results of studying failure and restoration flows of the pumping equipment in the combined sewers are presented together with the algorithms of reliability assessment by analytical method and Monte-Carlo simulation method. The use of the developed method of evaluating the amounts of emergency discharges of wastewater into the environment provides for substantiating the solutions at the stage of project documentation development that meet the requirements of the legislative and regulatory documents in the field of water supply, wastewater disposal and environmental protection. The indicators of reliability and environmental safety (probability of flooding of the sewers transporting wastewater to the pumping stations when wastewater is discharged into the environment) variate not only depending on the failure-free performance and maintainability indicators but also depending on the state of the sewage pumping station during the initial period of operation. For this reason one of the ways of improving these indicators at sewage pumping stations is timely execution capital and regular repairs of pumps.

Key words

wastewater , sewerage pumping station , reliability indices , parameters of failure flows , analytical method of reliability assessment , simulation method , density function