Superstorm Sandy’s Sewage Legacy

Aging infrastructure that combines stormwater and sewage, built to handle historic rainfall and smaller populations, is not effective at handling the water flow from increasingly intense storms. Outfall pipes are also often located at historically low water levels where they are now vulnerable to storm surge and sea level rise.

With Halloween upon us, I can’t help but binge-watch zombie flicks in between marathons of The Walking Dead. One recurring theme I’ve noticed is how incredibly efficient a zombie virus is at spreading. By the time we meet our protagonists, there is already an undead hoard waiting to chase them through streets and shopping malls. I imagine that once a major waterway is infected, it means game over for an unsuspecting city.

Now why am I bringing this up on a wildlife blog? Well we may not be up against a zombie virus, but our aging infrastructure, climate change, and increasingly urbanized population is presenting us with a serious public health issue: sewage. A year ago, Hurricane Sandy sent a wake-up call to the east coast and revealed just how vulnerable our built environment is, and how this spells bad news for our health, fish and wildlife, and our economy.

A Deluge of Sewage

Like a mad scientist releasing a plague upon the world, Hurricane Sandy knocked out sewage infrastructure from D.C. to Connecticut, resulting in the overflow of over 11 billion gallons of untreated and partially treated sewage. That’s about 50 BP Gulf oil spills worth of sewage spilling into waterways millions of people rely on for food and recreation. Worse yet, field studies have discovered drug-resistant bacteria in impacted waterways. While not exactly ‘zombie-viruses,’ these bacteria can cause swimmer’s ear, skin rashes, pneumonia, blood infections, urinary infections, or food poisoning.

Untreated sewage also brings large amounts of nitrogen into rivers, bays, and other coastal areas. This high dosage of nutrients causes algae and bacteria to thrive, causing eutrophication. The resulting bloom and death of these microorganisms devours dissolved oxygen, creating hypoxic (low-levels of oxygen) environments. Combined with warmer-than-average temperatures, bodies of water can become anoxic (lacking oxygen) ‘dead zones’ where almost nothing can survive. National Wildlife Federation released a report detailing just how severe the consequences of eutrophication are in the Great Lakes, and in Long Island Sound, this is at least partially to blame for the decline in lobsters over the last 15 years.

Nature to the Rescue

Just like how wildlife can battle, and defeat, the undead, nature can provide a solution to this health risk. New York City’s sustainability plan, PlaNYC, and Philadelphia’s Greenworks Plan, are just two of countless city initiatives working to use nature to prevent combined sewer overflows (CSOs) in the future. In Staten Island, protecting green space that absorbs stormwater has saved New Yorkers $80 million in infrastructure costs while raising property values and providing habitat for wildlife. Increasing the amount of green space throughout the city allows water to naturally penetrate the earth, while urban trees can absorb and retain stormwater, removing strain on sewer systems. NYC plans to invest $1.5 billion on green infrastructure over the next 20 years, ultimately saving New Yorkers more than $2 billion compared to an all-grey approach.

Cut the Carbon

If harmful bacteria and nitrogen in sewage is the zombie virus of our time, climate change is the villain that makes it all worse. Climate change can’t be blamed for any one storm, but it will increase their frequency and intensity. More water in shorter periods of time will put a strain on already vulnerable infrastructure and natural resources. Nature-based approaches can help communities prepare for some of these impacts, but investments in carbon reduction, such as offshore wind, can help reduce the severity of climate change. We need to hold our elected officials accountable to address climate change, protect public health, and ensure we continue to have access to clean water.