Urbanization modifies underlying groundwater systems. This often leads
to adverse hydrological, water quality, geotechnical, and socio-economic
effects which jeopardize sustainability. Indeed, for many urban aquifers
world-wide, we do not know whether there even exist socially-acceptable
sustainable hydrological systems. Given that around 50% of the world's
population live in cities, and that urban populations are expanding
rapidly, the issues are important and becoming increasingly urgent. To
reduce the effects of such impacts, management is required irrespective
of whether the groundwater is to be used or not. This management must be
based on a sound technical understanding of the interacting processes
involved. The forty papers in the present volume explore the state of
this understanding in the context of a wide range of countries (and
therefore cultures), climates, and geologies. They are divided into
topic areas covering flow, chemical water quality, biological water
quality, remediation, engineering, and socio-economics. An initial
section sets the scene with a range of integrated regional-scale
studies. The volume will be of interest to practicing groundwater
specialists in industry and research. We hope that it will also provide
an insight into groundwater issues for other urban specialists,
including planners: without communication between the disciplines
involved, progress towards acceptable urban sustainability will be slow.