One of the top concerns with residents in our communities is water quality. Surveys I have conducted with the public support this statement. One of the top concerns with water quality in the coastal areas is health advisories. These are issued when concentrations of selected fecal bacteria are too high.
In coastal areas, the selected bacteria are Enterococcus. It is important to note that Enterococcus bacteria are found in the digestive systems of birds and mammals. So, its presence does not automatically mean there is human waste in the water. However, there are pathogens associated with bird and mammal waste humans should be concerned about. And very high concentrations are most likely due to human waste. Science is working on additional methods to confirm high levels of Enterococcus are human. It is assumed that these will one day be used.
Enterococcus bacteria are used in coastal waters due to their ability to tolerate higher salinity. Some species, such as E. coli, that are used in freshwater systems die in saline ones. This suggests that the waste is not there, when in fact it is. It is also important to know that Enterococcus bacteria in themselves are not health concern for us. They are in our digestive tracts. But their presence in the water indicates that waste is present and there are pathogens in this waste that are of concern – hence the advisories issued.
In this series we will look at three methods we can use to help reduce human waste from entering our local waterways. Those are (1) maintaining your septic system, (2) converting your septic system to sewer, and (3) maintaining your sewer lines. We will begin with maintaining your septic system.
Septic systems have been used in rural and suburban communities where sewer systems have not been available for decades. Even today, the growth of new neighborhoods is outpacing the sewer infrastructure to support them. Many of these new communities are using septic systems. If properly placed and maintained, septic systems can work well. But many are not placed in good locations, and most are not maintained.
A conventional septic system is composed of a septic tank and a drainfield, where most of the wastewater treatment takes place. Image: US EPA
The system begins with the water leaving your home and entering a large tank made of concrete, fiberglass, or polyethylene buried in the yard. The average size of these tanks is 1000 gallons, but – depending on the number of bedrooms and bathrooms in the house, they could be larger. Here the sewage sits. Over time the solid waste will settle on the bottom (sludge) while the fats, oils, and grease float to the surface. The liquid layer in the middle (effluent) will flow from the tank into a series of smaller perforated drainpipes that slowly discharge into a drain field. A properly designed drain field will have a layer of sand that will allow draining of the effluent to occur.
Let’s talk about how to maintain this system.
Do not overload the system with too much water. The tank is designed for a specific number of bedrooms/bathrooms. Overusing water can fill the tank and initiate leaking before the sewage has had time to settle. Watch your water use.
Watch what you are flushing down the drain. Fats, oils, grease, and even milk will solidify and clog the lines. There are many products that describe themselves as “flushable”. They are, but they are not biodegradable. These two will cause clogs and backups in the system. Some harsh cleaning products can harm the bacteria within the tank who are breaking down the waste – these should be avoided. Also avoid using the garbage disposal. Septic systems were designed for water and sewage, not garbage and food. Compost your food waste instead.
Periodically have your tank pumped and inspected. This is a step that many do not follow and can lead to leaking of untreated sewage into local waterways. It is recommended that you have your septic tank pumped and inspected once every 3-5 years. There are several businesses in your area who do this type of work. They can also provide advice on how to better maintain your specific system.
Protect your drain field. Do not drive over this area of your lawn. Vehicles can compact the porous soil needed for efficient percolation and possible crack pipes. Planting trees and shrubs in this area can introduce roots into the lines, plant shallow root plants only. Design your landscape so that rainwater does not flow over the drain field during storms. The draining of your system is designed to be a slow process, allowing both physical and biological treatment of the waste to occur before reaching any water source. Rain and flooding conditions impede this from happening.
Developing a septic maintenance plan for your property can help reduce the number of health advisories your community will see. For more information contact your county health department or extension office.
Flooding after a storm can damage septic systems, causing them to fail. Image: B White, NASA Public Domain
After floods or heavy rains, the soil in your septic system drainfield can become waterlogged. But, for your septic system to treat wastewater, water needs to drain freely in the drainfield. Special care needs to be taken with your septic system after a storm in order to ensure its proper function.
What should you do if flooding occurs?
The U.S. Environmental Protection Agency (EPA) offers these guidelines:
Relieve pressure on the septic system by using it less or not at all until floodwaters recede and the soil has drained. Under flooded conditions, wastewater can’t drain in the drainfield and can back up in your septic system and household drains. Clean up floodwater in the house without dumping it into the sinks or toilet. This adds additional water that an already saturated drainfield won’t be able to process. Remember that in most homes all water sent down the pipes goes into the septic system.
If sewage from the septic tank has backed up into your house, clean up the affected area and disinfect the floor using a chlorine solution of a half cup of chlorine bleach to each gallon of water for thorough disinfection.
Avoid digging around the septic tank and drainfield while the soil is waterlogged. Don’t drive vehicles or equipment over the drainfield. Saturated soil is very susceptible to compaction. By working on your septic system while the soil is still wet, you can compact the soil in your drainfield, and water won’t be able to drain properly.This reduces the drainfield’s ability to treat wastewater and leads to system failure.
If you suspect your system has been damaged, have the tank inspected and serviced by a professional. How can you tell if your system is damaged? Signs include: settling, wastewater backs up into household drains, the soil in the drainfield remains soggy and never fully drains, a foul odor persists around the tank and drainfield. The tank shouldn’t be opened or pumped if the soil is waterlogged. Silt and mud can get into the tank if it is opened and can end up in the drainfield, reducing its drainage capability. Pumping under these conditions can cause a tank to float or ‘pop out’ of the ground and can damage inlet and outlet pipes. Only a licensed professional should clean or repair the septic tank.
For septic systems with electrical components, make sure to check all the electrical connections for damage before restoring electricity (to pumps, for example).
Have your private well water tested if your septic system or private well were flooded or damaged in any way. Your well water may not be safe to drink or to use for household purposes (making ice, cooking, brushing teeth or bathing). You need to have it tested for total coliform bacteria and E. coli to ensure it is safe to use.
Many county health departments provide testing for bacterial contamination. If they do not offer testing, they can help point you to commercial labs in the area for testing.
The Florida Department of Environmental Protection (FDEP) also maintains a site where you can search for certified water testing labs by county: Certified Water Testing Laboratories
Health advisories are issued by state and local health departments when levels of fecal bacteria become too high for the public to safely enter the water. Sewage can be a source of these fecal bacteria. They can harbor pathogenic organisms that can cause of a variety of health problems. State and local health departments routinely monitor local waterways, particularly where people recreate, to assure the level of fecal bacteria is not unsafe. It is understood that the presence of fecal bacteria in waterways is normal, animals do go the bathroom, but excessive levels can be unsafe.
Closed due to bacteria.
Photo: Rick O’Connor
In the Pensacola Bay area, most of the human recreation areas near the barrier islands rarely have health advisories issued. Once every few years there is an issue at the sewage treatment facility on Pensacola Beach and an advisory is issued, or a sewage line is broken either near Santa Rosa Sound or Big Lagoon with the same results. But is very rare.
However, our local bayous are different. The neighborhoods are densely populated with old or outdated infrastructure, and how we manage these systems can cause problems as well. We are going to do a three-part series on what property owners can do to help reduce the number of health advisories issued in waterways where they are more common. In Part 1 we will look at how to maintain your septic system.
Septic systems were commonly used decades ago when city limits, and treatment facilities, were smaller. Many communities within our counties are on a septic system, and it falls on the property owner to properly maintain them.
Most understand how the system works, but for those who are not familiar – here are the basics.
When you flush your commode, take a shower, or wash your clothes, the wastewater leaves your house through a series of pipes and empties into a septic tank buried in your yard. These tanks are usually made of concrete and there are different sizes. A typical tank will be about 8 feet long x 4 feet wide x 6 feet deep and hold around 1000 gallons (again, sizes vary). The solid material settles to the bottom where it is broken down by living microbes. The oils and fats float to the surface forming a scum layer. The remaining wastewater settles in the middle of the tank and drains into a drain field through a series of perforated pipes.
The drain field should be made of less compacted soils to allow percolation into the surrounding environment. There is some physical, chemical, and biological treatment of the wastewater as it percolates, but only if the drain field is properly designed and located. For obvious reasons you should not (and most communities will not allow) have your drain field next to an open or public water system. In Florida it is required that the loose uncompacted soils must be no less than 24 inches above the wet/water table.
A conventional septic system is composed of a septic tank and a drainfield, where most of the wastewater treatment takes place. Image: US EPA
It has been found that if the septic system is placed in the correct location and maintained properly, it does a good job of removing pathogens from the wastewater. However, it was not designed to remove nutrients, which can still leach into waterways and cause algal blooms. And the presence of pharmaceuticals and household chemicals are not always removed, which can cause problems for aquatic wildlife. But to reduce health advisories they can work.
So…
How do we maintain our septic system so that it functions properly?
Watch what you pour down your drain. As mentioned above, many household chemicals and pharmaceuticals are not removed and become environmental problems when they leach from the drain fields into the local environment. Fats, oils, and grease (and even milk) can solidify and form the scum layer at the top of the septic tank. These solids can clog the lines running to the septic tank, or the drain field lines themselves. They can create back flows and could cause untreated sewage to back flow into your home. Our local utility offers the FOGProgram. In this program you can visit a local dispensing site (these can be found at ECUA’s website and there is one at the Escambia County Extension Office) to obtain as free 1-gallon plastic jug. Pour your bacon grease, oils, etc. into these containers. When full, return them to the dispensing location and swap out for a clean empty one. The service is free.
Watch how much water you use. As mentioned, septic tanks come in different sizes and are designed for a certain amount of water. “Flooding” of the system can occur if you are using more water than your system is designed for and this could include flooding of semi, or untreated, sewage.
The scum and solid layers of the tank need to be pumped out. It is recommended the septic systems are pumped once every 3-5 years, depending on the size of the tank. A pump out may cost you several hundreds of dollars, but a tank replacement is going to be in thousands – it is a good investment and will help reduce health advisories in local waterways.
Do not drive over your septic system, or drain field, with heavy vehicles. This could crack the tank and/or compact the soils within the drain field.
The FOG gallon containers are found in these metal cabinets placed around the county.
Photo: Rick O’Connor 1-gallon container provided free to dispose of your oil and grease.
Photo: Rick O’Connor
Studies have shown that a properly designed, properly placed, and properly maintained septic system will work well in reducing the presence of pathogenic fecal bacteria in our local waterways for up to 50 years. Note: like all things, even a good septic tank does have a live span. If you do not know the history of your septic system, we recommend you contact a certified professional to come do an assessment.
As always, if you have additional questions, do not hesitate to contact your county extension office.
For many in the Pensacola Bay area, water quality is a top concern. Excessive nutrients, heavy metals, and fecal bacteria from run-off have all been problems. In recent years fecal bacteria has become a major concern, forcing both health advisories at public swimming areas, and shellfish harvesting closures. In a report from the Florida Department of Environmental Protection last modified in 2021, 43 sites in the Pensacola Bay area were verified as impaired and 11 of those (22%) were due to high levels of fecal bacteria1.
Closed due to bacteria. Photo: Rick O’Connor
As the name implies, these are bacteria associated with the digestive tract and find their way into waterbodies via animal waste. Animal waste can harbor pathogenic organisms and contribute to algal blooms which leads to hypoxia (low dissolved oxygen in the water), and potential fish kills. As bad as hypoxia and fish kills can be, it is the health issue from the pathogens that are often the larger concern.
The spherical cells of the “coccus” bacteria Enterococcus. Photo: National Institute of Health
In saline waters, the fecal bacterium Enterococcus is the species used for indication of animal waste. This bacterium is more tolerant of salt water than E. coli, or other fecal bacteria, and a better choice as an indicator for this reason. Enterococcus is found in the intestines for birds and mammals and enters waterways through their feces. Waterfowl, pets, and livestock can all be sources, but it is human waste that many point to when the bacteria counts are over the environmental thresholds set. Human waste enters the waterways either by septic or sewer overflows. It is the septic systems we will look at in this article.
A conventional septic system is made up of a septic tank (a watertight container buried in the ground) and a drain field. Image: Soil and Water Science Lab UF/IFAS GREC.
How the septic system works…
The process of course begins when you flush. The wastewater leaves the commode and enters a pipe which leads to the septic tank outside. Here the wastewater separates. The solid waste will settle to the bottom forming a layer called sludge. Fats, oils, and grease float on water and form a top layer called scum. The untreated wastewater settles in the middle. This wastewater will drain from the septic tank into a series of smaller pipes and leach into a drain field. The drain field should be made of large grain material, like sand or gravel, that allows the filtration of the water as it dissipates into the environment. On paper this system should work well, and often does, but you can see where problems can occur.
Was the septic system placed in the correct area? Often as a homeowner you have no control over where the tank is placed but there are regulations on this, and they should have been followed.
Is there sufficient drain material for the effluent to effectively drain and filter (plenty of sand/gravel)?
Is the site too close to the water table? Saturated ground will not allow for proper filtration and can create layers of untreated water to settle near the surface creating foul odors and leach into local waterways. Over the last decade the Pensacola area has seen an increase in the annual amount of rain. This increase can turn what was a suitable location into one that is no longer.
Again, many homeowners have no control over the placement of the septic but doing your due diligence when purchasing a home, you can do. Checking the situation of the septic can save you a lot of problems down the road.
1-gallon container provided free to dispose of your oil and grease. Photo: Rick O’Connor
The FOG gallon containers are found in these metal cabinets placed around the county. Photo: Rick O’Connor
What are you flushing down the commode? Here you DO have control.
Excessive amounts of fats, oils, and grease will increase the scum layer, and this can enter the pipes leading to the drain field causing clogging of those. Clogs can cause backups into the tank and leaks near the top as well as backups into your home. Not only can these overflows create problems in the home, but they can also end in our waterways creating water quality problems. So, what do you do with the oil and grease left over from cooking? In Escambia County, the Emerald Coast Utility authority provides what they call the FOG program2. This program provides free 1-gallon plastic jugs to place your oil and grease in. You can find these in metal cages at locations around the county, there is one at the extension office. You take it home, fill it up, and return it for a new one.
Disposable wipes can be flushed, but they do not degrade. Excessive amounts of disposal products flushed into your septic system will certainly create clogs in the drainpipes and backups into the lawn, waterways, and your home. Do not flush these! Toss them into the trash can.
Interestingly we are learning that milk will solidify after pouring down the drain. It forms solid chunks resembling concrete and can also create backups and overflows. This is relatively newly discovered problem. One suggestion is to pour unwanted milk on your garden, but you do not want to flush it down the drain to your septic tank.
There has been discussion on chemical products marketed to clean your septic. Many of our experts believe that these can alter the good microbes within the tank that breakdown the solid waste layer, the sludge. This is not something you want.
The last one is water itself. Not that you cannot flush water down the drain, but excessive amounts can create situations where either the scum or the sludge layers reach the drainpipes and form clogs. Do not use excessive amounts of water from different sources in your home at the same time. Do not overload the system.
Driving over the septic tank or drain field.
Most understand that this can cause problems. It can compact the soil being used for the drain field, thus making it less effective at draining and filtering. It can also cause cracks in both the tank and the drainpipes, which can create leaks that allow untreated wastewater to travel away from the drain field. Be careful where you use heavy vehicle traffic on your lawn.
Pumping out your septic system.
This is something few people do. The untreated wastewater should flow into the drain field and percolate through the sand/gravel bed. However, the scum and sludge do not drain and need to be pumped periodically. The recommended cycle for pump outs is once every 3-5 years. Again, this is something most homeowners do not do until backup problems occur. We do recommend having your system pumped on that cycle.
Convert to a sewer system.
This is not an option for everyone, and we know for some in which it is, they are not eager to do so. But converting to a sewer takes the maintenance issue off the homeowner and onto the local utility. The conversion can be expensive but, in some communities, there are cost share programs to help with this. Check with your local utility for more information.
If placed, used, and maintained properly septic systems can last 25-30 years and not be a major problem for local waterways. Converting to a sewer system can help, but there are also problems here. We will address those in our next post.
Reference
1 Florida Department of Environmental Protection. 2021. Verified Lists for Group 4 Basins Cycle 2 – Pensacola Bay.
Many of Florida’s historic first magnitude springs are classified as nitrogen impaired. Image credit: UF/IFAS Communications
Septic systems are an effective means of treating wastewater when they are properly designed, constructed and maintained. Conventional systems are designed from a public health perspective and have been widely used since the 1940s to remove pathogens and protect human health. About 30% of Florida’s population relies on septic systems, which treat and dispose household wastewater drained from bathrooms, kitchens and laundry machines.
However, septic systems were not designed to remove nutrients. A conventional system removes only about 30 percent of the nitrogen that flows into it. Even a well-maintained system will become a source of nitrogen (particularly nitrate-nitrogen) to the surrounding soil in the drainfield, and may leach to groundwater. Excess nitrogen in Florida’s waterbodies can be a contributing factor to ecological community degradation and increases in algae.
What alternatives are there to conventional septic systems?
Many enhanced nitrogen removal technologies exist, but only those approved by the Florida Department of Health (FDOH) can be installed. Conventional septic systems are made up of a septic tank and a drainfield (or leachfield). Advanced treatment systems add steps to conventional system processes to improve contaminant removal. Types of advanced nitrogen removal technologies available include:
Aerobic Treatment Units ATUs are made of fiberglass, polyurethane or concrete. Unlike conventional systems, ATUs introduce air into the sewage in the tank using a pump. By aerating waste, the organic matter in the tank is broken down faster than in a conventional system. Effluent from an ATU is discharged into a drainfield for further treatment in the soil, just as with a conventional septic system. ATUs require higher energy input than conventional septic systems to power the aerator, and regular operation and maintenance to sustain performance ATU example from the US EPA
Performance Based Treatment Systems PBTS are specialized systems designed by professional engineers to meet specific levels of contaminant removal based on site and/or situation requirements. There are many proprietary commercial options available. Designs often include an ATU. Like ATUs, PBTS require higher energy input than conventional septic systems to power pumps, and regular maintenance is needed to sustain performance.
In-Ground Nitrogen Removing Biofilters INRB are also referred to as modified drainfields. These systems are passive, which means they require no electric aerators or pumps to treat wastewater, and maintenance requirements are lower than those for ATUs and PBTS. INRBs are nitrogen-reducing media layers placed underneath a conventional drainfield.
Ammonium-nitrogen in wastewater leaving the septic tank moves down through the Drainfield Area soil and an additional oxygen-rich zone (Unsaturated Nitrification Soil) to promote conversion into nitrate-nitrogen. Wastewater then passes through a low-oxygen, carbon-rich zone to promote denitrification (Woodchips/Soil Mix Denitrification Media). Denitrification is a process by which specialized bacteria convert nitrate into nitrogen gas that escapes into the atmosphere. This reduces the amount of nitrogen that can leach into groundwater.
The short answer is wherever a septic system remediation plan to protect Florida Springs has been put into place. The 2016 Florida Springs and Aquifer Protection Act was passed to protect 30 ‘Outstanding Florida Springs.’ The majority are historic first magnitude springs, springs with flows of more than 100 cubic ft/second. Twenty-four of these springs are identified as nitrogen impaired by the Florida Department of Environmental Protection.
If septic systems contribute more than 20% of the nitrogen load to the impaired spring, a remediation plan takes effect in specific areas (Priority Focus Areas) that are particularly susceptible to nitrogen pollution. Septic system remediation plans require new development to connect to central sewer where available. If this isn’t an option, new construction on lots of less than 1 acre must include advanced nitrogen-removal technology. In the Panhandle, areas around Wakulla Springs and Jackson Blue Springs have remediation plans.
The best source of information about specific remediation plans and whether or not you live in a Priority Focus Area is FDOH. Contact your local County Department of Health Office to find out if you live in a PFA or if you have questions about septic tank requirements, permitting and approved advanced nitrogen-treatment features for septic systems.
For more information and resources about conventional septic systems and advanced treatment system visit our UF/IFAS Septic Systems website.
