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 The neighborhoods are densely populated with old or outdated infrastructure, and how we manage these systems can cause problems as well.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.
Are you a Florida homeowner connected to a private well and/or septic system? Do you know want to learn more about your water and wastewater management systems at home?
If so, please join the UF/IFAS Central and Northwest Florida water resources regional specialized agents Yilin Zhuang and Andrea Albertin, in our four free private well and septic system webinars in February and March:
Thursday, February 9 at 2:00 p.m.: Private Wells 101
Thursday, February 16 at 2:00 p.m.: Septic System 101
Thursday, February 23 at 2:00 p.m.: Private Well Care Before and After Storms
Thursday, March 2 at 2:00 p.m.: Septic System Care Before and After Storms
After completing the webinars, attendees will also receive free mail-in well water screening for total coliform bacteria and E. coli.
To register, please visit our Eventbrite page: https://2023FWON.eventbrite.com. These webinars are free, but we ask all attendees to register.
For more information, please contact Dr. Yilin Zhuang at yilinz@ufl.edu, or Dr. Andrea Albertin at albertin@ufl.edu or via telephone: (850) 875-7111.
A conventional septic system is composed of a septic tank and a drainfield, where most of the wastewater treatment takes place. Image: US EPA
Why do you need to maintain a septic system?
Conventional septic systems are made up of a septic tank (a watertight container buried in the ground) and a drain field, or leach field. In the septic tank, solids settle on the bottom (the sludge layer), and oils and grease float to the top and form a scum layer. The liquid wastewater, which is in the middle layer of the tank, flows out through perforated pipes into the drainfield, where it percolates down through the ground. Most wastewater treatment takes place in the drainfield.
Solids settle to the bottom of a septic tank (sludge), oils and greases float to the top (scum) and wastewater (effluent) flows out of the tank into the drainfield for further treatment. Image: Soil and Water Science Lab, UF GREC.
Although bacteria continually work on breaking down the organic matter in your septic tank, sludge and scum will build up, which is why a system needs to be cleaned out periodically. If not, sludge and scum can flow into the drainfield clogging the pipes and sewage can back up into your house. Overloading the system with water also reduces its ability to work properly by not leaving enough time for material to separate out in the tank, and by flooding the system.
Should you use additives in your septic system?
Septic systems do not need any additives to function properly and treat wastewater. Although there are many commercial microbiological and enzyme additives sold on the market that claim to enhance bacterial populations and reduce the time between septic system pumping, there really isn’t any peer-reviewed scientific literature that shows that these additives are effective in doing what they claim.
In Florida, the Department of Health (DOH) reviews commercially sold additives to ensure that they are safe to use in septic systems. DOH clearly states that although products are approved, it does not mean that this is an endorsement or a product recommendation. Approval simply means that as required by Florida law, the additive doesn’t interfere with septic system function and that when an additive is used, the effluent (wastewater) leaving the septic system meets Florida’s water quality standards. Only products in compliance with this law can be sold or used in septic systems in Florida. You can find a list of approved products and more information regarding additives on the Florida Department of Environmental Protection (FDEP) septic system website. Access the list of products directly here (updated 10/18/2021).
How can you properly care for your septic system?
The best way to keep your system functioning properly is to follow some common-sense practices.
Only flush human waste and toilet paper down the toilet. Wet wipes do not break down in the septic system even though the packaging labels them as septic-safe!
Be mindful of what you put down sinks and flush down toilets. All drains in your home lead to the septic tank. Image: A. Albertin
Think at the sink. Avoid pouring oil and fat down the kitchen drain. Avoid excessive use of harsh cleaning products and detergents which can affect the microbes in your septic tank (regular weekly cleaning is fine). Prescription drugs and antibiotics should never be flushed down the toilet.
Limit your use of the garbage disposal. Disposals add organic matter and additional water to your septic system, which results in the need for more frequent pumping.
Take care at the surface of your tank and drainfield. Don’t drive vehicles or heavy equipment over the system. Avoid planting trees or shrubs with deep roots that could disrupt the system or plug pipes.
Conserve water. Reduce the amount of water pumped into your septic tank through water conservation practices like (1) repairing leaky faucets, toilets, and pipes, (2) installing, low-flush toilets, low-flow showerheads and faucet aerators, and (3) only running the washing machine and dishwasher when full.
Have your septic system pumped by a certified professional. The general rule of thumb is every 3-5 years, but it will depend on household size, the size of your septic tank, how much wastewater you produce and what you flush down your toilet.
Even when conventional septic systems are well maintained, they are still a source of nutrients, particularly nitrogen, to groundwater. They were designed from a public health perspective to remove pathogens, not nutrients.
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.
Senate Bill 712 ‘The Clean Waterways Act’ was signed into Florida law on June 30, 2020. The purpose of the bill is to better protect Florida’s water resources and focuses on minimizing the impact of known sources of nutrient pollution. These sources include septic systems, wastewater treatment plants, stormwater runoff as well as fertilizer used in agricultural production.
Senate Bill 712 focuses on protecting Florida’s water resources such as Jackson Blue Springs/Merritt’s Mill Pond, pictured here. Credit: Doug Mayo, UF/IFAS.
What major provisions are included in SB 712?
Primary actions required by SB712 were listed in a news release by Governor Desantis’ staff in June 2020 as:
Regulation of septic systems as a source of nutrients and transfer of oversight from the Florida Department of Health (DOH) to the Florida Department of Environmental Protection (DEP).
Contingency plans for power outages to minimize discharges of untreated wastewater for all sewage disposal facilities.
Provision of financial records from all sanitary sewage disposal facilities so that DEP can ensure funds are being allocated to infrastructure upgrades, repairs, and maintenance that prevent systems from falling into states of disrepair.
Detailed documentation of fertilizer use by agricultural operations to ensure compliance with Best Management Practices (BMPs) and aid in evaluation of their effectiveness.
Updated stormwater rules and design criteria to improve the performance of stormwater systems statewide to specifically address nutrients.
How does the bill impact septic system regulation?
The transfer of the Onsite Sewage Program (OSP) (commonly known as the septic system program) from DOH to DEP becomes effective on July 1, 2021. So far, DOH and DEP submitted a report to the Governor and Legislature at the end of 2020 with recommendations on how this transfer should take place. They recommend that county DOH employees working in the OSP continue implementing the program as DOH-employees, but that the onsite sewage program office in the State Health Office transfer to DEP and continue working from there. DOH created an OSP Transfer web page where updates and documents related to the transfer are posted.
How does the bill impact agricultural operations?
SB 712 affects all landowners and producers enrolled in the Florida Department of Agriculture and Consumer Services (FDACS) BMP Program. Under this bill:
Every two years FDACS will make an onsite implementation verification (IV) visit to land enrolled in the BMP program to ensure that BMPs are properly implemented. These visits will be coordinated between the producer and field staff from FDACS Office of Agriculture and Water Policy (OAWP).
During these visits (and as they have done in the past), field staff will review records that producers are required to keep under the BMP program.
Field staff will also collect information on nitrogen and phosphorus application. FDACS has created a specific form, the Nutrient Application Record Keeping Form or NARF where producers will record quantities of N and P applied. FDACS field staff will retain a copy of the NARF during the IV visit.
FDACS-OAWP prepared a thorough document with responses to SB 712 Frequently Asked Questions (FAQ’s). It includes responses to questions about site visits, the NARF and record keeping, why FDACS is collecting nutrient records and what will be done with this information. The fertilizer records collected are not public information, and are protected under the public records exemption (Section 403.067 Florida Statutes). For areas that fall under a Basin Management Action Plan (like the Jackson Blue and Wakulla Springs Basins in the Florida Panhandle), FDACS will combine the nitrogen and phosphorus application data from all enrolled properties (total pounds of N and P applied within the BMAP). It will then send the aggregated nutrient application information to FDEP.
Details of how all aspects of SB 712 will be implemented are still being worked out and we should continue to hear more in the coming months.
