Adele Houghton's presentation at the inaugural SXSW Eco conference this week, "John Snow’s Legacy: the Next Generation of Sustainable Water Solutions," proposed a new model for water management that capitalizes on collaboration between public health regulators, climate change policy makers, and green building practitioners.
The talk, which reviewed the link between water and public health and the impact that climate change is likely to have on global water resources, concentrated on innovative approaches to managing water supplies sustainably while continuing to protect the public from exposure to the waterborne pathogens that were major killers as recently as 1900.
This blog post offers a brief synopsis of the talk as well as links to reference information and useful resources.
The origins of modern day public health lie in sanitation, most famously exemplified by Dr. John Snow’s observation that Cholera outbreaks in mid-nineteenth century London appeared to be associated with contaminated water sources. Since that time, many innovations in building and infrastructure technology have been driven by health concerns. Today, however, public health regulations are often regarded as impediments to innovation rather than as useful safeguards of the public’s health. Building on public health’s evidence-based approach to managing water resources, this presentation will introduce a new, collaborative model for developing innovative solutions to one of sustainability’s most pressing challenges.
Water and Public Health
From 1900 to 2000, the leading causes of death in the US changed from infectious diseases to chronic, non-communicable diseases. In 1900, the top three causes of death were infectious disease, two of which include water as a pathway. By 1998, the first infectious disease on the list, pneumonia, has dropped to number 6. Regulations improving water quality and sanitation practices greatly contributed to the reduction in mortality associated with infectious disease.
CDC, Leading Causes of Death, 1900-1998.
CDC, Top 5 Causes of Drinking Water Outbreaks in the US from 1971-2006.
Water and Climate Change
Climate predictions indicate that we are headed towards a world where both energy and water will become more scarce and where natural disasters that threaten the ability of our sanitary systems to function will become more frequent and more severe.
Bernstein et al. (2007). Climate Change 2007: Synthesis Report, An Assessment of the Intergovernmental Panel on Climate Change.
Global Climate Change Impacts in the United States: A State of Knowledge Report from the U.S. Global Change Research Program (2009).
Greer, et. al. (2008). Climate change and infectious diseases in North America: the road ahead. CMAJ. 178(6):715-22.
Robert Wilkinson, Analysis of the Energy Intensity of Water Supplies for West Basin Municipal Water District (2007).
Sandia National Laboratories, Energy-Water Nexus Web Page.
A New Approach to Sustainable Water Solutions
COMMUNITY SCALE: North Texas Municipal Water District East Fork Wetland Project
The North Texas Municipal Water District East Fork Wetland Project demonstrates how in direct potable water reuse technologies can be instituted successfully. The project diverts 91 million gallons per day of water from the east fork of the Trinity River to flow through a 1,840 acre constructed wetland, using aquatic plants to remove harmful contaminants. The purified water is then pumped 43 miles to Lake Lavon, where it is treated to potable water standards along with other raw water sources and delivered to customers in the Dallas-Fort Worth metro area.
This kind of project, which integrates environmental and climate change benefits into the existing water purification infrastructure, is a perfect candidate for collaboration with local public health officials. Psychologists have found that scientific evidence is not sufficient to convince people that something that triggers revulsion (such as drinking purified human sewage, or, as opponents like to call it, toilet to tap) is actually safe. However, introducing a few intermediate steps that separate the source of perceived contamination (the toilet) from the end product (the tap), can drastically increase acceptance of a technology or practice that previously had be viewed as unacceptable. (Dingfelder, 2004)
The role of public health in this setting is, first, to test and monitor the system to ensure that the wetlands are purifying the water to the intended level. Second, they should be incorporated into the facility’s communications and education strategy. A wetland that purifies effluent can be used as the basis for educating the public about where their water comes from, what types of tests are performed to verify its safety, and the complex relationship between the city’s drinking water system and the region’s overall hydrological cycle. These kinds of messages reinforce the priorities of all three groups: the need to maintain a high level of water quality, the need to reduce carbon emissions, and the need to act as stewards of the environment.
Case Study of North Texas Municipal Water District East Fork Wetland Project on North Texas Municipal Water District website.
Case Study of North Texas Municipal Water District East Fork Wetland Project on the John Bunker Sands Wetland Center website.
Sadie F. Dingfelder, From toilet to tap: Psychologists lend their expertise to overcoming the public's aversion to reclaimed water. (2004) APA Monitor. 35(8):26.
Lorie Woodward Cantu, John Bunker Sands Wetland Center, Texas Wildlife, August 2011: 46-50.
NEIGHBORHOOD/DEVELOPMENT SCALE: Central Texas Climate Change Environmental Public Health Indicators Project
This pilot project, located in Austin, Texas, demonstrates how public health participation in climate change and green building policies can reduce community vulnerability. The Central Texas Climate Change Environmental Public Health Indicators Project uses a GIS portal to provide the community and local policymakers with a source of visual analysis for how vulnerable populations and the environment could be impacted by proposed climate action policies. Its goal is to raise awareness among the general public about the links between climate change and public health.
Based on an historical evaluation of which natural hazards had resulted in the highest mortality rates in Travis County from 1970-2004, the project team developed two climate change indicators for the pilot phase: extreme heat events and flash flooding events.
This type of tool provides neighborhood-specific information about the environmental and health hazards associated with climate change. When a downscaled climate model is added, policymakers and planners could use the tool to perform a health impact assessment of future land use planning schemes (such as the comprehensive plan) – identifying which areas of town are likely to become more or less vulnerable to the effects of climate change over time.
It could also act as an educational tool for outreach to neighborhood associations, explaining the links between climate change and human health and the reasons a particular neighborhood has been identified as vulnerable to flooding. By providing background information and information about things the neighborhood could do to reduce their vulnerability, it could galvanize neighborhood associations to work together to reduce their vulnerability through activities such as: clearing out gullies, increasing low-impact stormwater strategies, and instituting a buddy program to check up on particularly vulnerable neighbors during flash flood events.
Borden, K. A., & Cutter, S. L. (2008). Spatial patterns of natural hazards mortality in the United States. International Journal of Health Geographics. 7(64). doi: 10.1186/1476-072X-7-64.
CIDRAP, ASTHO, Using Vulnerability Maps to Inform Local Public Health Policies and Climate Change Adaptation Efforts (TX).
GEMSS (Geospatial Emergency Management Support System), a project of TNRIS (Texas Natural Resources Information System).
Houghton, A.; Prudent, N.; Scott III, J. E.; Wade, R.; Luber, G. (2011). Climate change-related vulnerabilities and local environmental public health tracking through GEMSS: A web-based visualization tool. Applied Geography (in press). doi:10.1016/j.apgeog.2011.07.014.
SITE SCALE: On-Site Rainwater Capture, Treatment, and Reuse
The energy intensity associated with the municipal water system (from treatment to pumping), coupled with the increasing threat of being overwhelmed by natural disasters such as hurricanes and tornadoes, makes the concept of flipping our current water system from a centralized, uni-directional system to a distributed, multi-directional system more economically and politically feasible than in the past.
The concept of net zero water is similar to net zero energy: using a combination of water efficiency strategies and onsite water collection, treatment, storage, and reuse strategies to generate a development's water supply.
The 2011 Texas legislature passed two bills that expand the sources of potable water available to developments connected to the public water supply. HB 3391 allows developments to be designed to use harvested rainwater as their sole source of water supply. HB 3372 allows rainwater to be used as an indoor potable water source for structures connected to a public water system. Currently, no federal or state standards exist for harvested rainwater quality. These two bills therefore offer an ideal opportunity for local and state public health agencies to collaborate with TCEQ and the climate change community to develop reasonable guidelines for regulation that will safeguard the public's health without imposing requirements that are overly onerous -- either economically or technologically.
Texas HB 3391
Texas HB 3372
Texas A&M AgriLife Extension Website, Rainwater Harvesting Web Page.
Texas Water Development Board Website, Rainwater Harvesting Web Page.
Toward Net Zero Water: Best Management Practices for Decentralized Sourcing and Treatment. (2011) Cascadia Green Building Council.
The American culture has been so thoroughly convinced that modern sanitation practices protect them from the threat of waterborne diseases such as cholera, that the concept that they might once again rise to the level of major killers is largely rejected by mainstream society. However, climate change, population growth, land use parctices, and overconsumption have placed our centralized public water systems in peril. A new approach is needed to maintain access to high quality water in the future.
Each of the examples in this talk take an integrated approach to water management:
Identify and control the potential source of contamination (the primary goal of public health)
Reduce the carbon footprint associated with the water source (which will help communities meet their climate change objectives)
Design the human intervention to expand native habitat, enhance biodiversity, and restore the natural hydrological cycle (a fundamental goal of green building projects)
Examples such as these offer a model for the future of sustainable water management in the era of climate change.
Copyright: © Biositu, LLC, and Building Public Health, 2011.