Mekorot (Israel)

Managed aquifer recharge (MAR) with treated municipal wastewater is a cost-effective, low-maintenance, and energy-efficient method for supplying water for irrigation and drinking purposes. The most expensive component of MAR is land use. Since the area of infiltration basins is inversely proportional to the infiltration rate (Ir), a higher infiltration rate allows for smaller basins, making it the most critical design factor. We examined the dependence of Ir on water levels by analyzing a decade of data from 50 recharge basins of an Israeli SAT as a case study. A positive dependence would imply that high water levels enhance infiltration, while a negative dependence would imply that shallower ponding is preferable. In 97% of over 45,000 flooding events, we observed a linear decline in the effluent level during the drainage phase. This water level-independent Ir was observed in all the studied basins, regardless of commissioning year, operating conditions, or season. Expressing Ir as a function of water level allows the operator to predict accurately the time needed to empty a basin. This also paves the road for developing site-specific predictive models of average Ir as a function of the current and historical operational and environmental conditions. A mechanistic two-resistance model explains the observed pattern, suggesting partial elasticity of the clogging film.

Every network of supply waterlines experiences thousands of yearly bursts, breaks, leakages, and other failures. These failures waste a great amount of resources, as not only the waterlines need to be repaired, but also water is wasted and the distribution service is interrupted. For that reason, many water facilities employ proactive maintenance strategies in their networks, where they replace likely-to-fail pipes in advance to prevent the failures. In this paper, we aim to establish a reliable prediction model that can accurately predict faults in waterlines prior to their occurrence. We propose a specific segmentation method for long transmission mains, as well as three data-driven models and one rule-based prediction model. We evaluate a real world waterline network used in Israel, operated by Mekorot company, using three common metrics. The results show that the data-driven algorithms outperform the rule-based model by at least 5% in each of the metrics. Additionally, their prediction becomes more accurate as they are trained with more data, but enhancing these data with geographically related features does not improve the accuracy further.

The COVID-19 pandemic has severely impacted public health and the worldwide economy. Converging evidence from the current pandemic, previous outbreaks and controlled experiments indicates that SARS-CoVs are present in wastewater for several days, leading to potential health risks via waterborne and aerosolized wastewater pathways. Conventional wastewater treatment provides only partial removal of SARS-CoVs, thus safe disposal or reuse will depend on the efficacy of final disinfection. This underscores the need for a risk assessment and management framework tailored to SARS-CoV-2 transmission via wastewater, including new tools for environmental surveillance, ensuring adequate disinfection as a component of overall COVID-19 pandemic containment. Converging evidence indicates that SARS-CoVs are present in wastewater for several days with potential health risks. This Review analyses knowledge about such risks as well as the potential spread of SARS-CoVs in waterborne, waterborne–aerosolized and waterborne–foodborne pathways during a pandemic.

Abstract Water is a resource that affects every aspect of life. Intentional or accidental contamination events in the water supply system could have a tremendous impact on public health. Quick detec...

Abstract The Shafdan wastewater treatment system treats the municipal wastewater of the Tel-Aviv metropolitan area, which contains 22 cities with a population of about two million. The conventional mechanical–biological treatment is followed by managed groundwater recharge. The effluent undergoes soil aquifer treatment (SAT) by controlled passage through the unsaturated zone and an average retention time of 960 days in the aquifer. The SAT provides effluent polishing treatment as well as seasonal and multiannual storage, which are much needed in the semiarid Mediterranean climate. The Shafdan SAT operates without disinfection prior to the land spreading of the secondary effluents or after the water is reclaimed from the aquifer. Despite that, since 1995 there has not been even a single positive test of fecal coliforms (FC) in any of the reclamation wells, and since 2001, all of the enterovirus tests in an observation well located midway between the infiltration basins and the reclamation wells were negativ...