In Parts I and II of this series I covered the history and impact of the construction of infrastructure in the United States, as well as the dynamics behind its slide into its current state of decay. In the near future we will need to get serious about making repairs and improvements, but before we do so it is certainly worth some time and effort to consider what infrastructure we need to have in place for a prosperous and healthy 21st century. This analysis can help us to determine if we should fix the infrastructure that we have or replace it with something else.
As we discussed in Part I, the installation of sewer systems in cities drastically reduced the spread of disease. However, while they may have been a public health miracle, sewers are an engineering design failure. If you are trying to manage a waste stream as an engineer, the two things you absolutely want to avoid are increasing the volume of the waste or transporting the waste over long distances. Both of these factors dramatically decrease the efficiency and increase the cost of treating the waste. Flush toilets and sewer systems include both of these shortcomings. Even low-flow toilets dramatically add to the volume of waste and expensive sewer systems must be installed to transport the waste stream over long distances to reach treatment facilities.
The best engineering approach to managing human waste is the composting toilet. In this case, little or no water is added. Decomposition occurs at high enough temperatures to sterilize the waste, which can then be used to fertilize your rose bushes. Also, contrary to what you may be thinking, modern composting toilets do not smell. Given that one of the defining characteristics of the 21st century will be a limitation of fresh water supply, there is almost certainly going to be a movement towards composting toilets. Therefore, we should carefully evaluate large investments in sewer system expansions. Keep an eye out for high-end housing developments in California offering only composting toilets as the leading edge of this wave.
During the 20th century we built our world to accommodate personal automobile use with highways, suburbs, and distant shopping malls and food stores. From an engineering standpoint, transportation efficiency should be judged by energy expended per person-mile of travel. It would be rather difficult to come up with a less efficient way of shuttling ourselves around between this distanct points in single-occupant automobiles. I suppose that a fleet of personal helicopters would be worse.
In the coming decades I anticipate a reduction in personal automobile use. As this trend develops, you can expect rural roads to return to cheaper-to-maintain gravel rather than pavement (this is already happening in Texas) as well as projects to convert car lanes on highways to light rail. We can’t keep building highways to the near exclusion of other transit systems. If you are skeptical look to China. As I write this column, a traffic jam on a Chinese highway has entered its 10th day. Seriously, people have been stuck on the road moving slowly for 10 days. Food vendors have lined the highways to cater to them while they wait.
With ample justification, I am often accused of being a bit pessimistic in these columns. So let me highlight that, although the commentary above is a criticism, I think much of our infrastructure investment over the last 200 years was well spent. Here are some examples.
- Our freight train network is a great national asset and should be repaired and expanded. Of particular benefit is raising bridges to allow trains to carry two levels of containers to ocean ports where they can be loaded on to ships.
- Our investment in an extensive national electricity grid was money well spent. This system should be repaired as well as upgraded with smart grid technology, which reduces line losses and facilitates the incorporation of locally generated wind and solar panels.
- The U.S. is also well served by our networks of hospitals, schools, and universities.
As we consider our local infrastructure, we need maintain and repair our storm water system capacity and our aging schools. Looking toward the future I’d like to see us get serious about bike and pedestrian facilities, and continue to invest in systems to support a more localized food network. With these and other investment, irrespective of what decisions our federal government makes, the Chapelboro area will be better able to face the challenges of this century.
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