I am worried, very worried about the degradation of water quality around the world and the impact this will have on our health. The global population has reached 7 billion, with more than 50 percent living within 150 km of a coastline, major lake or river system. Half of the world lacks any wastewater infrastructure, and other parts of the developed regions of the world (i.e. USA) are in desperate need of restoration. Beyond humans the numbers of cattle, sheep, pigs and chickens are estimated at 1.4, 1, 0.9 and 21 billion, respectively. On average, animals and humans generate 61.7 and 10.1 million metric tons of excreta per day, respectively (FAOSTAT).
All of this fecal waste is entering waterways and impacting the designated uses including for recreating and drinking. While what we do on the land is the source of these pathogens, climate is the driver of the pollution.
The severity of water quality problems are exacerbated by climate change both during scarcity and extreme events. Climate change will aggravate regional and global water scarcity by as much as 15 to 40 percent, which will mean that sewage dominated waterways and unplanned reuse will increase. And waterborne disease outbreaks tied to large precipitation events will continue to plague communities. This phenomenon has been found both in developing and developed regions of the world.
I am part of the Global Water Pathogens Project (GWPP) whose aim is to improve sustainable access to and uptake of sanitation by updating knowledge on water pathogens in a state-of-the-art reference on water-related disease risks and intervention measures. The GWPP has nine teams, and currently 110+ authors around the world committed to providing content on Sanitation Overview, Indicators and Microbial Source Tracking Markers, Pathogen Resources for Bacteria, Helminths, Protists, and Viruses, Persistence, Sanitation and Disinfection Technologies, and Global Case Studies for improving public health and decreasing the global disease burden associated with fecal contamination of water and the environment.
The data we are now generating are available for us to produce global and country specific maps on pathogen risks associated with fecal pollution. This information suggests that we need to address explicitly which sanitation technology is really effective for reduction of groups of pathogens important to public health whether it be viruses, bacteria, protists or helminths and at what scale can high coverage (or compliance) be achieved. Otherwise investments may not show the impact desired risking the bio-health of the planet and the ecosystem services that our aquatic resources provide.
In the US we are also looking at innovative technologies to move from conventional sewage treatment systems to resource recovery facilities where by water and nutrients will be recovered for reuse and energy will be produced. Yet most of these systems have yet to be evaluated in terms of the desirable water quality. This we must do.
The challenge for those involved in sanitation and wastewater treatment will be to build capacity and provide the data necessary to move the political will. Because it is this knowledge, informed by geospatial data that will feed directly into a risk framework and evidence-based decision making. Using quantitative microbial risk assessment (QMRA) will allow for science and policy integration to guide where, how and when to fund both innovative and general sanitation technologies to protect water quality and health investing the precious dollars wisely.
We now have the diagnostic tools and risk frameworks to utilize the data necessary to maximize the potential for the blue economy around the world, to enhance industrial activities and tourism, to improve the designated uses of waterways for water supply, recreation and agriculture and very importantly produce jobs where skilled human resources will be needed. The data around the world on pathogens in sewage and their removal are tremendous and once collated will be extremely useful.
I recommend that we utilize this knowledge and continue to invest in:
- Networks between public health institutions, universities, water providers and managers.
- Risk analysis frameworks to integrate science and policy and promote the translation of science into action around sewage sources.
- Global pollution maps for pathogen and country specific impacts.
- Advanced technology for water diagnostics to improve resolution of the evidence needed for decision making.
- A 21st century water curriculum for future water scientists, technicians, managers and engineers.
If we do, our energy and hard work can go toward the solutions to meet our aspirations and we will not need to worry as much about the Blue Planet that our grandchildren will live in.