Systems Analysis of Zaragoza Urban Water - SWITCH - Managing ...
Systems Analysis of Zaragoza Urban Water - SWITCH - Managing ...
Systems Analysis of Zaragoza Urban Water - SWITCH - Managing ...
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<strong>Systems</strong> <strong>Analysis</strong> <strong>of</strong> <strong>Zaragoza</strong> UWS<br />
Guillermo Penagos<br />
consumption and atmospheric emissions derived from sludge disposal are suggested to<br />
be included within system boundaries.<br />
Another important question concerning system boundaries is water infrastructure. The<br />
usual time perspective to plan and construct a UWS is <strong>of</strong> several decades. But<br />
sustainability is a long term concept, therefore a time horizon projection <strong>of</strong> about 100<br />
years is suggested. The construction <strong>of</strong> the water supply also may have significant<br />
environmental impacts which can be quantified such impact on the basis <strong>of</strong> the mass <strong>of</strong><br />
material needed to construct the pipes, considering lengths, diameters and comparing<br />
different materials. Environmental Impact <strong>of</strong> putting pipes into the ground may also be<br />
considered (Lundin & Morrison, 2002)<br />
Lassaux et al. (2005) found infrastructure construction as having a significant<br />
contribution to the overall environmental impacts <strong>of</strong> the UWS. This is very important<br />
since improving WWT systems will increase environmental impacts in one way, because<br />
materials are used for construction, and then chemicals and energy are consumed. The<br />
authors also found that construction phase is responsible for important environmental<br />
impacts before tap (withdrawal pipeline, drinking water treatment, and distribution<br />
network) have less impact than stages after tap (sewer system and WWTP). In fact<br />
sewer network construction was the factor that contributed the most to the global<br />
environmental load <strong>of</strong> the anthropogenic water cycle from the Wallon region in Belgium.<br />
In contrast, Lundie et al. (2004) found infrastructure construction to contribute with less<br />
than 4% <strong>of</strong> all different categories <strong>of</strong> burdens to the environment, for both present<br />
conditions and alternative future scenarios <strong>of</strong> Sydney’s UWS.<br />
Lundie et al. (2004) used an LCA approach for assessing alternative future scenarios for<br />
strategic planning <strong>of</strong> Sydney’s UWS with a high degree <strong>of</strong> segmentation within the<br />
system. In order to select the best environmental performance different alternatives were<br />
classified after LCA in two categories: (1) options that improve the overall environmental<br />
performance and (2) options that improve one area <strong>of</strong> the system but worsen other<br />
areas. Sustainability is about management options that improve the system as a whole.<br />
This is one <strong>of</strong> few LCA studies covering the whole UWS. Main focus regarding<br />
environmental performance was given to water withdrawal and energy consumption.<br />
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