Combined sewer systems are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same conduit. Combined sewer systems send wastewater to a wastewater treatment plant (WWTP), where it is treated and then discharged to a water body. During rainfall periods, however, the wastewater in a combined sewer system can exceed the capacity of the conduits and of the treatment plant. For this reason, combined sewer systems are designed to overflow occasionally and discharge excess wastewater to nearby channels, rivers, or other water bodies. These overflows, called combined sewer overflows (CSOs), although diluted contain stormwater and also untreated human and industrial waste, toxic materials and debris. In the last years new sewer systems are designed separated and with the introduction of LID (Low Impact Development) strategies (Gambi et al., 2011), but we have also to cope with old combined sewer systems and it is important define strategies for their best management. The environmental impact of CSOs are considered, although indirectly, in several EU Directives and the wastewater Utilities must face the challenge to contribute to the Good Ecological Status of the water bodies that are influenced by their infrastructure. Historic data sets of registered pollutants discharged by CSOs proved the relevance of CSOs spills (Marinelli et al., 1997). Although conclusions depend on the pollutant under consideration, in general CSOs impact cannot be ignored (Dirckx et al. 2011). The first evidence of CSOs impacts on the receiving water bodies came to light in the 1960s but it was not until the 1990s that reducing the CSOs became a concern, because the most visible dry-weather pollution had been reduced by a systematic construction of WWTPs. Among the major effects caused by the CSOs is the acute short-term impact due to dissolved contaminants, bacteria and viruses, causing fish death, health risks and making water body unsuitable for the intended use (drinking water, bathing, etc.).
Casadio Andrea, Cipolla Sara Simona, Maglionico Marco, Martinini Pierpaolo (2013). NUMERICAL MODELING OF THE SEWER SYSTEM OF RIMINI (ITALY) AND STRATEGIES FOR THE CSOs REDUCTION ON THE ADRIATIC SEA. ENVIRONMENTAL ENGINEERING AND MANAGEMENT JOURNAL, 12 S11, 121-124.
NUMERICAL MODELING OF THE SEWER SYSTEM OF RIMINI (ITALY) AND STRATEGIES FOR THE CSOs REDUCTION ON THE ADRIATIC SEA
CIPOLLA, SARA SIMONA;MAGLIONICO, MARCO;
2013
Abstract
Combined sewer systems are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same conduit. Combined sewer systems send wastewater to a wastewater treatment plant (WWTP), where it is treated and then discharged to a water body. During rainfall periods, however, the wastewater in a combined sewer system can exceed the capacity of the conduits and of the treatment plant. For this reason, combined sewer systems are designed to overflow occasionally and discharge excess wastewater to nearby channels, rivers, or other water bodies. These overflows, called combined sewer overflows (CSOs), although diluted contain stormwater and also untreated human and industrial waste, toxic materials and debris. In the last years new sewer systems are designed separated and with the introduction of LID (Low Impact Development) strategies (Gambi et al., 2011), but we have also to cope with old combined sewer systems and it is important define strategies for their best management. The environmental impact of CSOs are considered, although indirectly, in several EU Directives and the wastewater Utilities must face the challenge to contribute to the Good Ecological Status of the water bodies that are influenced by their infrastructure. Historic data sets of registered pollutants discharged by CSOs proved the relevance of CSOs spills (Marinelli et al., 1997). Although conclusions depend on the pollutant under consideration, in general CSOs impact cannot be ignored (Dirckx et al. 2011). The first evidence of CSOs impacts on the receiving water bodies came to light in the 1960s but it was not until the 1990s that reducing the CSOs became a concern, because the most visible dry-weather pollution had been reduced by a systematic construction of WWTPs. Among the major effects caused by the CSOs is the acute short-term impact due to dissolved contaminants, bacteria and viruses, causing fish death, health risks and making water body unsuitable for the intended use (drinking water, bathing, etc.).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
