Applications of Life-Cycle Cost Analysis in Water and Wastewater Projects: Lessons from European Experience - Governing the Nexus: Water, Soil and Waste Resources Considering Global Change - page 129

should be made clear that the smaller the spatial scale of analysis, the more

intensely the dynamic development must be differentiated.
Further challenges arise in the context of climate change, which possibly leads to
quantitatively increased and intensi

ed events of extreme weather (heavy rainfall,
droughts) with considerable implications for the managed amounts of water. The
dimensioning of the pipes and the entire network must consider these extreme
conditions.

2.3 Resource-Ef ciency and Water-Energy Nexus

In water management, there are certain potentials for implementation of more
resource-ef ciency and even a nexus between water and energy.

In water and wastewater networks, there are currently many activities to improve
resource-ef ciency. Yoshida et al. ( 2013 ) for example analysed current studies on

life-cycle assessment of sewage sludge management. In their list, the majority of
studies had been driven by either phosphorus recovery or energy recovery (p.
1085).
In light of ever-increasing energy prices, water and wastewater management is
interested in higher energy efficiency as well. Hence, there are numerous research
activities targeting this direction such as using renewable energy to power the water
and wastewater facilities.
Moreover, a nexus can be achieved between water and energy as well (e.g.
Novotny 2013 ). Wastewater for example provides several potentials in this context.
The biogenic substances (sewage sludge) contained in wastewater could be utilized
by drying and incineration, which is currently done in Dresden, Germany, where
the sewage sludge from wastewater treatment

is energetically utilized (Urban

Drainage Dresden 2014 ).
Further options include the direct use of thermal energy of wastewater through
the installation of heat exchangers, as well as the utilization of gravitational and
kinetic energy of running water.

3 Life-Cycle Costing: Concept and Regulations

The approach to integrate life cycle costs into cost and investment decisions follows
the perception that costs do not only occur during the construction of an asset, but
also during all phases of the life cycle starting with the extraction of raw materials
to production and operation up to the

final disposal (see Fig. 3 ). Basis for the
current debate on life-cycle costing (LCC) is the standard work by Fabrycky and
Blanchard published in 1991. The scienti c debate ranges from theoretical aspects

such as the relationship between LCC and Life-Cycle Analysis (LCA) (Rebnitzer
and Hunkeler 2003 ) to more practical questions of how LCC can support decision