Second in a 3-month series
By Rich Pollack
When it comes to sewage treatment in Florida, septic systems get no respect.
One of the most basic forms of treating sewage, septic systems have long been used in Florida, with estimates of close to 2.8 million systems statewide and more than 50,000 in Palm Beach County alone.
In the coastal areas of South Palm Beach County, septic systems are common and used by the majority of single-family homes in Ocean Ridge, Manalapan and Gulf Stream.
As populations, especially in urban areas, continue to grow, conventional septic systems are coming under fire from environmental advocates and others who say that nutrients found in water coming from septic tanks and going into the ground are creating ecological issues at an increasing rate.
“Septic systems leach into the ground water and surface water,” says state Rep. Mike Caruso of Delray Beach, whose district includes much of the barrier island in South Palm Beach County. “We’re creating the perfect environment for blue green algae growth.”
Caruso, a Republican, is so concerned that he teamed with Rep. Will Robinson, R-Bradenton, to introduce legislation last session that would have required routine inspections of septic tanks. The legislation died in committee.
“We can’t continue the way we are,” Caruso said.
In fact, science and technology have helped make septic systems more environmentally friendly for decades.
“Septic systems get a bad rap because what we think about are conventional systems,” said Roxanne Groover, executive director of the Florida Onsite Wastewater Association. “We have gotten a lot better because people are working together to reach higher standards.”
Advanced systems have been developed to help reduce nutrients — including nitrogen and phosphorus — in the effluent coming out of septic systems. “We’re smarter now,” Groover said. “As we get smarter, we get more responsible.”
Impact on coastal waters
Still, older conventional systems are likely to be the most common in South Florida, and the often nutrient-rich effluent coming from those systems is having an impact on the marine environment, said Dr. Brian Lapointe, a research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute.
“We’re increasingly seeing problems in coastal waters that are the result of nutrient enrichment from human activity,” he said. “Sewage can be a major contributor to nutrient pollution.”
Both leaky municipal sewage systems and septic systems contribute to algae growth.
In the case of septic systems, effluent percolates through the soil and makes its way into groundwater, which then goes into canals. Water that is rich in nutrients, especially nitrogen, can feed the growth of blue green algae in waterways. It can also reach the ocean and feed the growth of red tides and brown seaweed, Lapointe said.
There was a small blue green algae bloom in the Lake Worth Lagoon in 2016, and a brief flare-up of red tide occurred along much of the South Florida coast in 2018.
In a 2008 study reported in a paper produced by University of Florida IFAS Extension, researchers found that almost 40 percent of the state’s septic systems were located in coastal areas. Sandy soil in those areas allows for “rapid transport of contaminants into the groundwater,” especially during the rainy season when the water table is high.
“Everybody has been led to believe that all the nutrients are coming from farms,” Lapointe said. “There is more than 21/2 times more nitrogen from sewage than from fertilizer going in the groundwater and feeding algae blooms.”
Although the scientific community agrees that nitrogen feeds algae blooms, skeptics question whether sewage is the primary source.
In addition to nutrients, conventional septic systems could be a source of fecal coliform bacteria getting into groundwater and estuaries, said Lapointe, who was the lead scientist on a fecal bacteria study in the mid-1990s at Jupiter Creek. The study, funded by the Loxahatchee River District, led to the conversion from septic to sewer in that area.
Another study in an area near Florida’s Suwannee River, conducted for the Florida Department of Health and the National Oceanic and Atmospheric Administration several years ago, found a significant reduction in fecal coliform bacteria in canals leading to the river once a regional treatment plant, which replaced onsite treatment systems, was built and operated. In the river, however, no significant reduction of fecal coliform was found.
Lapointe said there is evidence that fecal coliform bacteria is reaching coastal waters and the ocean, especially during periods of heavy rain when salinity — which the bacteria don’t like — is reduced.
Still, a spokesman for the Florida Department of Health in Palm Beach County said there is no link between beach closings and bacteria from septic systems that the department is aware of.
One of the challenges for people hoping to gauge the impact of nutrients and fecal bacteria from septic systems is that there is really no routine testing of effluent coming from conventional systems. Advanced systems, however, do often require additional oversight, including annual inspections.
“Testing for nitrogen, fecal coliform and other components is only done during special research projects, such as research projects performed by department staff, contractors for the department, or other researchers,” a spokesman from the Florida Department of Health wrote in an email.
There are special circumstances where water samples are required by the department of health and there are annual inspections required for commercial uses and in special cases. Routinely, however, the department inspects only the construction of new systems, existing system modifications and repairs and tank abandonment.
Two types of systems
While septic systems are often painted with the same broad brush, the Florida Onsite Wastewater Association’s Groover says that not all systems are the same and that many variables can determine the quality of effluent from those systems.
Essentially there are two types of septic systems, the conventional anaerobic system and the more advanced aerobic treatment system.
In the conventional system, wastewater from a home flows into a buried septic tank. In the tank, solids settle to the bottom. Bacteria that thrive without oxygen — anaerobic bacteria — inside the tank get to work on organic material in the liquid, breaking it down and producing the effluent.
The effluent then leaves the tank and is dispersed through pipes into a drain field. It then continues to percolate through a thin layer of bacteria that digest some of the excess nutrients as well as fecal coliform bacteria and viruses.
More advanced septic systems use oxygen to break down the organic matter in the tank. In these aerobic treatment units, wastewater from the home enters a tank where solids fall to the bottom. The remaining wastewater flows into a separate treatment unit where oxygen is added through an aerator. Strengthened by the oxygen, the aerobic bacteria break down the organic material faster and more effectively than in a conventional tank.
These systems are also more effective in removing nutrients, such as nitrogen, than are traditional systems because the effluent has less organic material. Different types of aerobic treatment systems are designed to meet even higher standards, with some using additional processes.
A homeowner who has an aerobic treatment system must get an operating permit from the state and have a maintenance contract with an approved company. In some cases, homeowners can be trained to do their own maintenance.
Aerobic treatment units are usually required of new-home builders who want to reduce the footprint of the system drain field, need a reduced setback, or want to build a larger home than the lot size would otherwise be allowed to support. Lab samples are required in these instances.
Aerobic treatment systems are more expensive than traditional systems. People in the business estimate the cost to be twice as much, somewhere around $10,000 for products and installation. Costs vary depending on the system.
How well a conventional septic system works depends on variables ranging from the size of the property to the size of the home and the number of people living in it. Rural areas, where homes are spread far apart, may be better-suited for traditional septic systems than urban areas, especially those near water, where it’s important to make sure that the system is working properly.
Age is also a factor, with older systems more likely to fail because of leaks in the septic tank or an aging drain field no longer allowing effluent to percolate through the soil.
“Just because you can flush, doesn’t mean your system is working and just because it’s working, doesn’t mean it’s treating properly,” Groover said.
Mandate from the state
There are no state mandates for communities in Palm Beach County to use advanced aerobic systems with every new septic installation or to convert to centralized sewage treatment systems.
The state Legislature did, however, impose a mandate on the Florida Keys in 1999 — when every part of the Keys was required to have advanced wastewater treatment or the best available technology installed within 11 years. Septic tanks and cesspits were no longer acceptable.
The result was a series of regional plants as well as some municipal plants at a cost of about $1 billion.
For the Keys, the mandate was as much about economics as the environment. With a tourist-based economy, improving near-shore water quality was essential.
To fund the project, the Keys looked to the federal government and the state, which both helped — though not as much as had been promised. Monroe County also used an infrastructure sales tax, in addition to assessments, to help cover the costs.
“It was absolutely the right thing to do,” said Kevin Wilson, an assistant Monroe County administrator. “It’s hard and expensive but it can be done. It just takes commitment and persistence.”
In a few other scattered areas of the state, homeowners are required to use advanced systems when replacing or installing new septic systems.
Groover says that she and her association are not averse to reasonable mandates, but says they need to be tailored to individual situations.
“One size doesn’t fit all,” she said. “You have to assess the needs of each community.”
Caruso, the state representative, says he believes there could be a statewide mandate within 10 years that could affect South Florida coastal communities. If so, he says, it would most likely have to be phased in over several years.
Standing in the way, however, could be a lack of political will, with legislators reluctant to pass bills that will financially burden their constituents and communities.
That reluctance, Caruso says, is why the septic tank inspection bill went nowhere. Still, he says, he plans to introduce the legislation again next session.
“We should no longer sit back and ignore science,” he said. “We as individuals can’t fix the sugar industry, we can’t fix the dairy industry and we can’t fix Lake Okeechobee. What we can fix is what’s in our own backyards.”