In Colombia, with the new SDG agenda, utilities are starting to understand the importance to become more efficient in their operation, not only because of the costs, but also due to the impact that their systems have in the environment. The example of Aguas de Cartagena showcased the effort of a water utility to increase its efficiency, with the optimization of the pumping system it was possible to reduce the energy consumption (and energy costs) in the water supply system, and consequently a reduce the GHG emissions.
The removal or degradation of pharmaceutical compounds present in the urine or other real wastewater matrices mixed or contaminated with urine is a foremost necessity due to the frequent notifications of various multi-drug resistance based disease outbreaks in whole biosphere. Thus, these compounds are subsequently required to be removed from the urine matrix before their dissolution into the bulk or sewage wastewater streams. Therefore, urine collection at source followed by in-situ or separate ex-situ treatment has been proposed to effectively treat a limited volume of concentrated pharmaceutical compounds present in a small batch. The additional benefit of this source separated urine treatment is the possibility of efficiently recovering nitrogen, phosphorus, and potassium based nutrients.
The treatment and disposal of sludge sediments come from sewer cleaning process is the key for carbon neutrality of the whole system. This means that the sludge sediments should be recycled and beneficial reused rather than directly incineration, landfill or even laissez-faire. nevertheless, besides the environmental impacts of carbon footprint mitigation, relevant co-conflicting issues may include engineering cost, public perception, socio-economic, rules/regulations, and managerial aspects of cleaning process. They all receive excessive consideration from government authorities and stakeholders.
Use of supervisory, control, and data acquisition (SCADA) system for monitoring, supervision and controlling of pumping systems can help minimize energy consumption of GHG emissions. It includes measurements in real time of water levels, pressures, flows, energy consumption and other operational parameters. It also helps to adjust and control the pump station operation, contributing to fight water losses or infiltration, reduce pumping during energy peak hours and adjust pumping volumes to the needs of the system. The SCADA systems provide utility managers with access to real-time operating data and can help offset the higher operating costs by minimizing unplanned downtime and improving maintenance plans. The SCADA system can also be used to optimize pumping in real-time through advanced pump optimization software and control, or through either a model-based or knowledge-based optimization that is implemented via a rule-based system programmed into the SCADA system. This type of optimization entails the use of algorithms to determine the best pumping scheme for a given situation. This can incorporate the peak energy times previously referenced, but also a prioritization of which pumps or pumping stations are used to maximize efficiency whenever possible. For example, if only a certain volume is demanded, then the SCADA system will first operate the most efficient pumps or pumping stations to meet the demand until greater capacity or more pumps are needed.
Based upon the system head conditions, pumps may be able to pump at higher rates than needed when operating at 100% motor speed. This flow rate can be controlled by one of two ways, throttling the pump with a valve if the pump is a constant speed pump, or changing the motor speed with a variable speed drive. The former is only energy efficient if the higher flow operating point of the pump without throttling is to the right of the best efficiency point on the pump performance curve, and the throttling results in reducing the flow to a point closer to the best efficiency point on the pump curve. Otherwise, throttling the pump can result in using more energy than at the higher flow, as well as wasting energy because you end up using more energy than is needed. When the demand on the system fluctuates significantly, the pumping rate can be controlled automatically by varying the speed of the motor with a variable frequency drive (VFD), such that the pump output matches only what is needed to meet demands or the intended pumping conditions. The pump’s flow rate then increases or decreases based upon the affinity laws and the controlled speed of the motor. This way lower pumping rates can be achieved, which may result in lower efficiency than those at full motor speed; however, the energy consumption is still lower because the energy requirements to pump lower flows at lower heads are lower.
Planificación local, impacto global – Como las Empresas de Agua y Saneamiento del Perú enfrentan el Cambio Climático
¿Cómo asegurar la prestación de los servicios de agua y saneamiento en un contexto de cambio climático? Los Planes de Mitigación y Adaptación al Cambio Climático (PMACC) son una herramienta para abordar este desafío. Permiten identificar las principales fuentes de emisiones de carbono y los mayores riesgos asociados al clima a lo largo del ciclo urbano del agua; así como las oportunidades de las empresas prestadoras de servicios de agua y saneamiento (EPS) para impulsar un cambio positivo hacia la neutralidad y adaptación climática. Siguiendo una metodología estandarizada y con la ayuda de herramientas virtuales, el proceso de planificación es más rápido y genera un reporte para informar a los tomadores de decisión. Gracias a esta buena planificación, algunas empresas del Perú han empezado a buscar soluciones prácticas para reducir sus emisiones de carbono, como es el caso de las empresas de agua de Cusco y Ayacucho. La iniciativa PMACC fue desarrollada e implementada en colaboración entre WaCCliM (responsable de la parte de mitigación) y PROAGUA II.
Planning locally, impacting globally – How Water and Wastewater Utilities in Peru are Facing Climate Change
How to ensure water and sanitation services delivery under a climate change context? The climate change mitigation and adaptation plans (PMACC; Planes de Mitigación y Adaptación al Cambio Climático) are tools to address this challenge. PMACC identify main carbon emissions sources and higher climate risks throughout the urban water cycle, along with water utilities’ opportunities to boost a positive change towards climate neutrality and adaptation. Following a standardised methodology and supported by web-based tools, the planning process becomes quicker and generates a report to informing decision-makers. This planning approach enabled some water utilities in Peru to start searching for practical carbon emissions reduction solutions, such as water utilities in Cusco and Ayacucho. The PMACC initiative was developed and implemented collaboratively between WaCCliM (responsible for mitigation) and PROAGUA II.
La Hoja de Ruta Hacia una Empresa de Agua y Saneamiento Urbano con Bajas Emisiones de Carbono ofrece a los gestores de empresas de agua y saneamiento un enfoque para dar respuesta a las dificultades más apremiantes a las que se enfrentan, al tiempo que reducen las emisiones de carbono con medidas que, o bien generan un rendimiento de la inversión mediante el ahorro de energía o agua, o bien se corresponden con inversiones previstas como parte del plan de gestión de activos destinado a mantener o mejorar sus servicios. Las empresas de agua y saneamiento que adoptan este enfoque contribuyen a un futuro neutro en carbono pues promueven un cambio de mentalidad, no solo en la gestión de los recursos hídricos urbanos, sino también inspirando a las demás empresas de las ciudades al compartir los riesgos y la urgencia de actuar para evitar que se agraven los efectos del cambio climático, de los que las empresas de agua y saneamiento son unas de las primeras víctimas: escasez, inundaciones y deterioro de la calidad del agua. (Roadmap in Spanish)
The National Reference Based on WaCCliM Roadmap for Water and Wastewater Utilities (WWUs) Towards Carbon Neutrality in Thailand presents utility managers with an approach to address their most pressing challenges, while reducing carbon emissions through measures that either have a return on investment through energy or water savings, or that correspond to planned investments as part of the asset management plan to maintain or improve their services.
A greenhouse gas (GHG) calculator tool (Biosolids Emissions Assessment Model, BEAM) was developed for the Canadian Council of Ministers of the Environment to allow municipalities to estimate GHG emissions from biosolids management. The tool was developed using data from peer-reviewed literature and municipalities. GHG emissions from biosolids processing through ﬁnal end use/disposal were modeled. Emissions from nine existing programs in Canada were estimated using the model. The program that involved dewatering followed by combustion resulted in the highest GHG emissions (Mg CO2e 100 Mg-1 biosolids (dry wt.). The programs that had digestion followed by land application resulted in the lowest emissions (-26 and -23 Mg CO2 e100 Mg-1 biosolids (drywt.). Transportation had relatively minor effects on overall emissions. The greatest areas of uncertainty in the model include N2O emissions from land application and biosolids processing. The model suggests that targeted use of biosolids and optimizing processes to avoid CH4 and N2O emissions can result in signiﬁcant GHG savings.