By Matt Ries
Managing Director of Technical and Educational Services at the Water Environment Federation
I recently attended the First National Expert and Stakeholder Workshop on Water Infrastructure Sustainability and Adaptation to Climate Change, joining over 130 other EPA and other federal agency water and climate experts; academics; NGO and association representatives; and consultants. The two-day workshop was sponsored by the US EPA Office of Water and Office of Research and Development, and results and input from participants will be used to help direct EPA’s water-related climate research and other initiatives. I took away three main points from the plenary presentations and subsequent concurrent sessions:
1. The impacts of climate change are already occurring. Jim Hanlon, Director of the EPA Office of Wastewater Management stated that “we are beyond the question of whether climate change is occurring and moving toward looking at how utilities can adapt” while other speakers outlined climate change impacts to water utilities. Sea level rise is impacting water intakes, outfalls, sea walls, and other infrastructure near oceans while saltwater intrusion becomes more prevalent. Storms of increased intensity result in flooding and can overwhelm infrastructure. Droughts decrease water supplies while at the same time increasing the demand for water. Changing patterns of snowfall and snowmelt deviate from historical hydrological patterns and challenge infrastructure designed for different conditions. Increasing water temperatures impacts water quality - what does this mean if your NPDES permit is a function of the assimilative capacity of the receiving waters?
2. There is a need for climate models to provide sound, reliable data that can support specific planning efforts. As one modeler with over 4 decades of modeling experience stated, climate change models are the most complex – and the uncertainties greater – than any other type of environmental model he’s worked with. That said, climate models and computing power continue to improve. Down-scaling climate models to useful resolutions remains a challenge even with great strides over the past few years. While most models shown predict increases in temperatures, resulting precipitation patterns and, for example, CSO frequencies range from slightly lower percentages to much higher percentages depending on the model. But, as EPA Deputy Assistant Administrator for Water Michal Shapiro concluded, “we can’t wait for the perfect answer” to address climate change.
3. Stationarity is dead. A February 2008 Science article, “Stationarity is Dead: Whither Water Management” (see www.sciencemag.org, vol. 319, page 573) described the need for a new approach to predict hydrologic patterns for water resource planning. Yogi Berra’s quote in the title of this blog reflects how planners used to be able to use past patterns to predict the future using the concept of stationarity, “the idea that natural systems fluctuate within an unchanging envelope of variability.” However, the article authors and many at the workshop assert that recent changes in the earth’s climate are producing uncertainties that go beyond human impacts and natural variability in the hydrologic cycle that could be accounted for in previous planning approaches. So is that pump station you just built with the elevation of the designated 100-year floodplain at risk if future precipitation patterns don’t correspond to historical norms and we’re seeing 100-year storms roll though every couple of years?
So what’s a utility to do? For a start, thinking about incorporating flexibility in both operations and design into your system’s infrastructure. The workshop discussions outlined a need to provide methods and models to adequately assess infrastructure risk, including vulnerability assessments, something the EPA Office of Water will be working on. These tools will be needed to help utilities properly evaluate alternatives in light of relative risks. Also, consider dual-benefit solutions and approaches - Dr. Steven Buchberger of the University of Cincinnati noted that aging infrastructure and climate change are “complimentary, concurrent challenges.” What about incorporation of multi-benefit green infrastructure into stormwater mitigation plans? Drinking water, wastewater, and stormwater infrastructure can last half a century or longer, meaning changes in climate that may not be evident for decades will impact the infrastructure you’re planning, designing, and building today. And a visit to WEF’s Knowledge Center on Sustainability & Climate Change could also help in your planning.
There is clearly a dichotomy to addressing this issue. Most of the utilities presenting at the workshop were from large, metropolitan areas and in the breakout discussions, it was noted that small to medium utilities are having trouble “keeping their heads above water” (no pun intended by the participant, I’m sure), much less worrying about climate change. Also, it is clear that some utilities in some states, such as California, are moving forward with plans for adaptation and working on mitigation efforts while in other parts of the country, climate change is not on the radar screen yet. What are you doing, if anything, to incorporate CC into your planning, designs, and operations and how do you think water utilities can meet yet another challenge to providing a quality, consistent product and continue protecting the public’s health?