In the hunt for “Big Data” that will underpin smarter cities, the next new discoveries may be found in an unexpected place – our sewers.

The emergence of smart cities and big data

Urban planning practitioners have recently gotten very excited over the possibilities that evolving communication, remote sensing and data management technologies offer in an urban context. Under the banner of ‘smart cities’, new pieces of whiz-bang kit ranging from home energy meters to drones are offering more data than you can analyse to better understand cities and their populations.

While the potential to measure and monitor the performance of our transport systems, energy systems and general lifestyle have gained a lot of attention – the majority of the focus has been on gathering data from buildings and visible infrastructure. It is now becoming evident that some real data gems could be mined from the murky cesspits of the city – the sewage system and the waste it carries.

The dirty truth

Recently, research into drug use in cities has taken an unconventional approach, snubbing surveys and anecdotal evidence to go straight to the hard evidence of drug traces in sewerage. Testing of Adelaide's wastewater by the University of Adelaide has revealed a 25 per cent spike in methamphetamine use over the past year, and a tripling of consumption over the past five years. The monitoring also revealed seasonal and weekly trends in drug usage, with differing patterns of use on weekends, and a 90 per cent increase in MDMA in the December silly season. The same study showed that cocaine was most prevalent in the more affluent areas of Adelaide.

From a data point of view, the possibilities for capturing information about a population’s health and behaviour from human faeces are vast. As demonstrated by the example of drug use monitoring, a key advantage is that the results are available almost in real-time, and can be captured and compared for different cities or even suburbs, making this the kind of data that can be readily used to inform decisions both by the public and by city planners.

A Fitbit for our suburbs

The monitoring of drug usage is just the beginning in terms of the potential data offered by sewage monitoring. Analysis techniques could also become valuable for monitoring a population’s general health and rates of disease. Researchers at University of Queensland are looking for compounds in wastewater that could indicate the prevalence of various diseases, as well as how good we are being at eating fruit and vegetables. Soon, we could have a suburb-specific picture in real time of the health of the population.

How can we use dirty data help create smart cities?

You could say datasets are only as good as their user. Largely an ‘untapped’ data source to date, collection and use of data will require collaboration between water utilities (who could most effectively gather the data), health authorities and city planners. Used well, the data could be used to inform the structure and operation of our cities – informing health infrastructure planning and support programs as well as targeting areas of low health for liveability initiatives such increased urban greening to encourage active lifestyles and targeted improvements to access to healthier food.