On the worst days, when the backyard would flood and the toilet would gurgle and the smell of sewage hung thick in the air, Monica Arenas would flee to her mother-in-law’s home to use the bathroom or wash laundry.
“It was a nightmare,” Arenas, 41, recalled one evening in the modest house she shares with her husband and teenage daughter several miles north of downtown Miami.
She worried about what pathogens might lurk in the tainted waters, what it might cost to fix the persistent problems and whether the ever-present anxiety would ever subside.
Residents in neighborhoods around Arenas’s have similar tales to share — of out-of-commission toilets, of groundwater rising through cracks in their garage floors, of worries about their own waste running through the streets and ultimately polluting nearby Biscayne Bay.
SEPTICTANKS: Little River to Biscayne Bay
0:26
For all the obvious challenges facing South Florida as sea levels surge, one serious threat to public health and the environment remains largely out of sight, but everywhere:
Septic tanks.
Millions of them dot the American South, a region grappling with some of the planet’s fastest-rising seas, according to a Washington Post analysis. At more than a dozen tide gauges from Texas to North Carolina, sea levels have risen at least 6 inches since 2010 — a change similar to what occurred over the previous five decades.
This image is a key for the following image which is a map. The map is titled "One village’s risk" with a description: "Officials worry about the threat of rising groundwater along the Little River in and around El Portal, where many homes rely on septic systems"
Officials worry about the threat of rising groundwater along the Little River in and around El Portal, where many homes rely on septic systems
A map showing septic systems along the Little River in an area of Miami-Dade county that includes El Portal and portions of Miami and Miami Shores.
King tide shown is the highest observed tide at Virginia Key on Oct. 28, 2023 (1.96 ft.)
Along those coastlines, swelling seas are driving water tables higher and creating worries in places where septic systems abound, but where officials often lack reliable data about their location or how many might already be compromised.
“These are ticking time bombs under the ground that, when they fail, will pollute,” said Andrew Wunderley, executive director of the nonprofit Charleston Waterkeeper, which monitors water quality in the Lowcountry of South Carolina.
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To work properly, septic systems need to sit above an adequate amount of dry soil that can filter contaminants from wastewater before it reaches local waterways and underground drinking water sources. But in many communities, that buffer is vanishing.
A diagram titled "How rising waters threaten septic systems" The most common type of septic systems rely on gravity to move sewage through a tank where solids settle and liquid waste is slowly released into the soil through a series of perforated pipes called a drain field. The soil acts as a natural filter, neutralizing germs and pollutants before they can contaminate groundwater. Sea level rise and extreme rainfall are raising groundwater levels, resulting in more shallow buffers of soil that help protect local waterways and underground aquifers. If a conventional septic system becomes submerged, wastewater will not be properly treated. Toilets can stop working and sewage can flood yards.
How rising waters threaten septic systems
The most common type of septic systems rely on gravity to move sewage through a tank where solids settle and liquid waste is slowly released into the soil through a series of perforated pipes called a drain field.
The soil acts as a natural filter, neutralizing germs and pollutants before they can contaminate groundwater.
Sea level rise and extreme rainfall are raising groundwater levels, resulting in more shallow buffers of soil that help protect local waterways and underground aquifers.
If a conventional septic system becomes submerged, wastewater will not be properly treated. Toilets can stop working and sewage can flood yards.
An estimated 120,000 septic systems remain in Miami-Dade County, their subterranean concrete boxes and drain fields a relic of the area’s feverish growth generations ago. Of those, the county estimated in 2018, about half are at risk of being “periodically compromised” during severe storms or particularly wet years.
Miami, where seas have risen six inches since 2010, offers a high-profile example of a predicament that parts of the southeast Atlantic and Gulf coasts are confronting — and one scientists say will become only more pervasive — as waters continue to rise.
A chart showing annual average sea levels at Virginia Key, Biscayne Bay, Florida where according to Post analysis, seas have risen 6.0 inches since 2010. The chart shows linear trends for two periods: 1932-2009 where the trend is 0.1 inches per year and 2010 to 2023 where the trend is 0.4 inches per year.
here, expensive repairs afflict homeowners as septic systems falter. Fetid water increases the risk of gastrointestinal diseases and other health hazards as floodwaters fill yards and streets. Profound worries persist about the environmental toll — which, researchers in Miami say, means submerged septic tanks are leaking nutrients into the porous limestone, potentially fueling algae blooms that kill fish.
“It’s really pretty gross,” said Michael Sukop, a hydrogeologist at Florida International University.
Rising seas will only exacerbate the problem, he added. “As the water table gets higher, all bets are off.”
Miami-Dade County is racing to replace as many septic tanks as possible, as quickly as possible. But it is a tedious, expensive and daunting task, one that officials say will ultimately cost billions of dollars they don’t yet have.
“It was a nightmare,” Arenas, 41, recalled one evening in the modest house she shares with her husband and teenage daughter several miles north of downtown Miami.
She worried about what pathogens might lurk in the tainted waters, what it might cost to fix the persistent problems and whether the ever-present anxiety would ever subside.
Residents in neighborhoods around Arenas’s have similar tales to share — of out-of-commission toilets, of groundwater rising through cracks in their garage floors, of worries about their own waste running through the streets and ultimately polluting nearby Biscayne Bay.
SEPTICTANKS: Little River to Biscayne Bay
0:26
For all the obvious challenges facing South Florida as sea levels surge, one serious threat to public health and the environment remains largely out of sight, but everywhere:
Septic tanks.
Millions of them dot the American South, a region grappling with some of the planet’s fastest-rising seas, according to a Washington Post analysis. At more than a dozen tide gauges from Texas to North Carolina, sea levels have risen at least 6 inches since 2010 — a change similar to what occurred over the previous five decades.
This image is a key for the following image which is a map. The map is titled "One village’s risk" with a description: "Officials worry about the threat of rising groundwater along the Little River in and around El Portal, where many homes rely on septic systems"
Officials worry about the threat of rising groundwater along the Little River in and around El Portal, where many homes rely on septic systems
A map showing septic systems along the Little River in an area of Miami-Dade county that includes El Portal and portions of Miami and Miami Shores.
King tide shown is the highest observed tide at Virginia Key on Oct. 28, 2023 (1.96 ft.)
Along those coastlines, swelling seas are driving water tables higher and creating worries in places where septic systems abound, but where officials often lack reliable data about their location or how many might already be compromised.
“These are ticking time bombs under the ground that, when they fail, will pollute,” said Andrew Wunderley, executive director of the nonprofit Charleston Waterkeeper, which monitors water quality in the Lowcountry of South Carolina.
Story continues below advertisement
To work properly, septic systems need to sit above an adequate amount of dry soil that can filter contaminants from wastewater before it reaches local waterways and underground drinking water sources. But in many communities, that buffer is vanishing.
A diagram titled "How rising waters threaten septic systems" The most common type of septic systems rely on gravity to move sewage through a tank where solids settle and liquid waste is slowly released into the soil through a series of perforated pipes called a drain field. The soil acts as a natural filter, neutralizing germs and pollutants before they can contaminate groundwater. Sea level rise and extreme rainfall are raising groundwater levels, resulting in more shallow buffers of soil that help protect local waterways and underground aquifers. If a conventional septic system becomes submerged, wastewater will not be properly treated. Toilets can stop working and sewage can flood yards.
How rising waters threaten septic systems
The most common type of septic systems rely on gravity to move sewage through a tank where solids settle and liquid waste is slowly released into the soil through a series of perforated pipes called a drain field.
The soil acts as a natural filter, neutralizing germs and pollutants before they can contaminate groundwater.
Sea level rise and extreme rainfall are raising groundwater levels, resulting in more shallow buffers of soil that help protect local waterways and underground aquifers.
If a conventional septic system becomes submerged, wastewater will not be properly treated. Toilets can stop working and sewage can flood yards.
An estimated 120,000 septic systems remain in Miami-Dade County, their subterranean concrete boxes and drain fields a relic of the area’s feverish growth generations ago. Of those, the county estimated in 2018, about half are at risk of being “periodically compromised” during severe storms or particularly wet years.
Miami, where seas have risen six inches since 2010, offers a high-profile example of a predicament that parts of the southeast Atlantic and Gulf coasts are confronting — and one scientists say will become only more pervasive — as waters continue to rise.
A chart showing annual average sea levels at Virginia Key, Biscayne Bay, Florida where according to Post analysis, seas have risen 6.0 inches since 2010. The chart shows linear trends for two periods: 1932-2009 where the trend is 0.1 inches per year and 2010 to 2023 where the trend is 0.4 inches per year.
here, expensive repairs afflict homeowners as septic systems falter. Fetid water increases the risk of gastrointestinal diseases and other health hazards as floodwaters fill yards and streets. Profound worries persist about the environmental toll — which, researchers in Miami say, means submerged septic tanks are leaking nutrients into the porous limestone, potentially fueling algae blooms that kill fish.
“It’s really pretty gross,” said Michael Sukop, a hydrogeologist at Florida International University.
Rising seas will only exacerbate the problem, he added. “As the water table gets higher, all bets are off.”
Miami-Dade County is racing to replace as many septic tanks as possible, as quickly as possible. But it is a tedious, expensive and daunting task, one that officials say will ultimately cost billions of dollars they don’t yet have.
