The global consequences of sea level rise — flooding, destruction of wetlands habitat, increased storm surges — are devastating. But the personal consequences are both terrifying and disgusting. Millions of people in coastal communities could find raw sewage oozing into their homes.
People living in coastal areas often have personal septic tanks designed to treat wastewater. If this is news to you, here’s a little septic tank 101.
“The septic tank digests organic matter and separates floatable matter (e.g., oils and grease) and solids from the wastewater,” explained the the EPA. “In conventional, or soil-based systems, the liquid (known as effluent) is discharged from the septic tank into a series of perforated pipes buried in a leach field, chambers or other special units designed to slowly release the effluent into the soil. This area is known as the drain field.”
But as sea levels rise, the drain field becomes too saturated to do its job of absorbing treated waste. The National Oceanic and Atmospheric Administration (NOAA) has projected that sea levels will rise along the U.S. coastline up to a foot over the next 30 years. By 2100, NOAA predicts a rise of three-and-a-half to seven feet!
“This could indeed lead to the flooding of septic tanks,” said Marc F. P. Bierkens, a professor of hydrology at Utrecht University in the Netherlands, reported by Newsweek. “Not only will the septic tank stop working, but if groundwater levels rise to the surface, groundwater that has been in contact with septic tank sewage could end up in people’s homes, backyards or on the street.”
Not only is this totally gross, but it can ruin the drinking water supply. When exposed to this mess, people will likely get diarrhea, which will wind up in the same place and exacerbate the contamination. Worst case, backed up septic systems might lead to cholera and dysentery, according to Bierkens. Other raw sewage nastiness includes human pathogens that can lead to hideous and sometimes barely pronounceable afflictions like leptospirosis, campylobacteriosis and cryptosporidiosis. Plus hepatitis A, E. coli, stomach flu and even typhoid.
What can coastal communities do to stay safe? Invest in their sewage systems to make sure they don’t leak. (inhabitat via Newsweek)