Every time Northern California is inundated with water from the sky, which happens on a fairly predictable and in fact easily projectable basis, the news fills about a day later with warnings about beach closures. We are advised to avoid scores of public beaches because they’ve been contaminated with raw sewage and then a few days later they usually open again and we go about our business as though nothing has happened.
In the storms in December where Southern California got hammered with an unusually high amount of rainfall, the problem was particularly severe. Covering it at the Los Angeles Times, Tony Barboza described the problem pretty neatly:
As dirty storm runoff rushed seaward during the rains, it overwhelmed some of the region’s sewage systems, rupturing sewer mains, disabling pump stations and surging above manhole covers in a series of spills that swept hundreds of thousands of gallons of waste into the ocean.
Sewage on the beaches is a problem for a number of reasons. There’s the issue that most people want to be able to use beaches, and tend to get upset when they are closed, of course. There’s also the fact that large amounts of sewage can cause environmental problems. Nitrogen-rich materials like those found in wastewater tend to attract algae and can create algal blooms, in turn leading to fish kills as the water clouds. This can harm the local ecosystem as well as the economy, because when fish are dying, fisheries aren’t able to operate. There’s a cascading series of problems that happens when eutrophication occurs in waterways and they can become very serious.
The sewage/stormwater problem is a direct consequence of the way storm drains and sewers are set up. These two systems are intended to run separately and do, in many areas. Runoff is directed to beaches, rivers, lakes, and other waterways for disposal. Sewage goes to a treatment plant so it can be processed. The processed sewage can be used in a variety of ways; there’s a trend in some areas of California, for example, to employ it in municipal landscaping, to avoid using freshwater that might be directed to other purposes, like drinking.
However, when the stormwater system gets overloaded, problems can start to develop, and you get crossover, because all those cracked and leaking pipes and illegal sewer connections start to rear their ugly heads, sending untreated sewage dumping into the stormwater drainage system. The sewage/stormater issue is a particularly large problem in cities with what are called ‘combined’ systems, which is a large percentage of them, since this system was dominant well through the 1930s. In such systems, sewage and runoff from streets is transplanted in the same piping, which gets overloaded in storms. Emergency releases go into operation, releasing, yes, raw sewage directly into waterways to dump the system out as quickly as possible, with the goal of avoiding problems like sewage backups.
Some cities have recognised that this solution is far from ideal and they’ve implemented holding ponds. When the weather gets rough, the sewage gets shunted to those ponds for collection, where it hangs out until it can be processed, after the system is no longer overloaded. Another alternative is to retrofit the existing system, leaving it in place but creating a separate internal system for handling stormwater. This is expensive and disruptive, but still cheaper than redoing the whole system.
Cities justified the original installations by claiming it was cost effective and it would work, for their needs. This was undoubtedly true. Now, many cities are faced with sewage treatment plants that are not meeting their needs and they lack the funding and the infrastructure to take care of the problem. It’s not just that it would be very expensive to redo an entire sewage system, or substantial chunks of it. Cities would basically have to set up a separate sewage system while maintaining the old one, transitioning people to it as they replace the old one, because you can’t have wastewater treatment offline. This is a costly and challenging task and a lot of cities aren’t up to it —talk about job creation, retrofitting basic municipal services in the United States would have been a solid way to use stimulus funds.
The problem goes round and round, endlessly, and people are reminded of it during storms when they read about yet another beach contamination and closure. And then the beach opens and they go back to what they were doing, while the underlying problem is still present. Overloaded runoff systems during storms are a warning of other problems with a water management system. As cities go, much of their infrastructure remains the same. Water usage is going up, methods for handling that water when it’s used are not increasing correspondingly. And people can generate a lot of wastewater for collection in gutters and streets; gardening, washing cars, working on various other projects. Every little bit adds to the system, and bit by bit, the systems fall apart.
In Southern California, authorities were heavily criticised for not anticipating the problem and taking some steps to address it. It’s entirely possible, in their defense, that they did see the problem, and they may have even developed proposals for taking care of it and increasing water safety. However, they might not have been provided with enough money to implement needed changes, to fix broken and inadequate systems. And then they opened up their copies of the Times to be reminded yet again of their failed efforts; can people really be blamed when they see a problem, outline a plan for dealing with it, and are denied the funding and resources they need to address the issue?
And how many other cities have ticking time bombs in their sewer and storm runoff systems? One consequence of climate change is increasing rainfall in some areas, which means these systems are going to be tested more than ever before, by swelling populations as well as increased amounts of rainwater to handle. How many will be up to the task?