Hello and nice to meet you,
I wanted to create a guide, designed to aid and inform homeowners, on the basic care and maintenance required, for a few of the most common on-site sewage facilities, or as they are more commonly called, septic systems. I have been in the septic industry since 1995, and during that time, have acquired an Installer II license, Site Evaluator’s License, Class C Wastewater License, Maintenance Provider’s License, and on my way to becoming a soil scientist. I am still learning something new, nearly every day, however, the one problem I run into almost every day, is the lack of time spent with homeowners to give them a better understanding of how there system operates. I intend to help remedy this, and by the end of this article, I hope homeowners are able to make a more informed decision when installing a new system, buying a home with a new system, or just caring for the one they already own.
A few of the systems I will be touching on are as follows:
1. Conventional Septic with standard subsurface lateral line disposal.
2. Low Pressure Dose (LPD) with pumped, subsurface disposal.
3. Aerobic System with surface spray application.
4. Drip Emitter System (Aerobic System with subsurface drip irrigation distribution)
These 4 system types are by no means the only systems out there, but are however the most commonly installed today.
NOTE: This guide is not intended to replace the normal maintenance provided by a state licensed installer or maintenance provider. This guide is designed to help inform homeowners, on the do’s and dont's, of specific septic systems, and why your system may be performing in a certain way. Be sure to call your preferred septic repairman if you feel your system is not performing properly, or if you just need more info. A professional septic company should never charge for their time on the phone. We are here to help diagnose your problem as well as answer any of your questions.
(Conventional Septic System)
The first system I would like to talk about is the conventional septic system. This system type is quickly becoming the least commonly used system on new constructions, but still by far, outnumbers all the other system types in the ground today. The first thing you need to know about any system is that they ALL have some type of treatment happening in the tanks. With conventional septic systems there are typically 1-2 tanks, normally round, concrete, and 500 gallons in capacity each. These specs can very but the purpose is the same. These tanks rely on retention time and settling, to do a major part of the waste breakdown, at this step of the process. As waste travels down your inlet pipe from the home, it soon enters the first tank. Inside this tank the waste loses velocity due to the large capacity of liquid in the tank. This provides the retention time, the waste needs, in order for as much of the waste as possible to settle out of the liquid, and to fall to the bottom of the tank. At this point the second form of treatment begins to take place. This is called anaerobic bacteria breakdown. Not to be confused with aerobic bacteria, anaerobic bacteria need no free oxygen in the water to live and breakdown waste. They are however very slow to breakdown waste and also give off methane gas during this process. This is the reason for the strong odors that are commonly associated with conventional septic systems, and the poor quality of the water even after settling and breakdown. This same process happens in each tank installed on the system. The more tanks you have the cleaner the discharge will be to the disposal field. The inlet into the tanks as well as the outlet leaving the tanks are near the top of the tanks, at approximately 10" from the bottom of the inlet and outlet pipe, to the bottom of the tank lid. This means that if your septic system is working properly, the waste level in the tanks should stay approximately 10" below the tank's lids at all times. Heavy solids sitting up on top of the inlet pipe, inside the tank, as well as waste surfacing above the tank lid, are two of the first signs of failing lateral lines or possibly a broken outlet line. All septic systems are designed to treat and dispose of a certain amount of waste per day. This is your system's gallon per day or GPD. This number was decided on by the engineer that designed your system, and is based on bathrooms in the home, square footage, and occupancy. Using a few formulas, this GPD translates directly to a certain amount of square footage of application in your lateral field. That means the lateral field on your system is designed, in size, to properly handle the waste expected to be used in the home under normal operation. Heavy rains or over usage can cause these lines to fail and cause back up towards the home. Failure due to rain should subside after the ground has had time to dry. However failure due to over usage may be more difficult to deal with. As this is usually a house holds way of life. This may be temporary or could be from additional family members moving into the home which may be a more permanent increase in usage. Remember as children grow up, so does their water usage. Large parties or family functions, may also cause a temporary failure in the field, as this greatly increases usage rates. Failures occur due to the ground around the lateral field not accepting water as fast as you are adding it. If the ground is already saturated due to rains, then understandably, the field will start to fail when you add more to it. This is the same in an over usage situation, as the ground becomes saturated, and will not take any more waste. Now with all this in mind, remember the ground around the lateral field is in a constant state of degradation. Over the years, the dirt around the lateral lines, becomes coated with a material known as bio mat. This material is the natural build-up of waste that the tanks were unable to remove from the discharge leaving the tanks. The build-up rate of bio mat is dependent on water usage rate, amount of tanks installed, how well they have been maintained, as well as the amount of years the system has been in service. At the point where the layer of bio mat increases to a certain amount, it starts to restrict the flow of liquids from the lateral line into the ground. This will start to cause slowdowns and even back-ups in the home. Weather situations, and over usage, only amplify the effects of bio mat. Unfortunately there is not a fix for bio mat. Once the bio mat becomes a problem...lateral line replacement or system replacement becomes the ONLY viable option. This is what a septic company will call, a failed system. A failed system may also start to surface waste above the ground, as well as cause back-ups. These areas should be avoided at all cost, until repairs are made, as this is potentially harmful untreated waste. Lateral lines installed in improper ground, can also cause system failure. Some types of soil do not take water as well as others. Obviously sand will take water very well, as clay does not. This is why it is very important to have your system designed by a licensed professional, who knows the difference between ground types. A lateral field installed in clay (type IV soil), is doomed to fail, and may do so very soon after installation. If you are having any of the above problems, be sure to call your preferred septic company for advice, on the proper repairs necessary, to get the system back in full operation. That being said, with a good working conventional septic system, there is very little maintenance needed, to keep the system operating. The most important thing that you can do is to have the tanks pumped on a routine basis. Do NOT wait till you have a problem, as at that point it is probably too late. Pumping the tanks regularly, will greatly decrease the build-up of bio mat, and improve the lifespan of your lateral field. Pumping the tank yearly, if you have only one, is highly recommended and, every two to three years, on two or more tank systems. Obviously, the more often you pump them the better. As for additives, if you are routinely pumping them as I mentioned above, there is absolutely no need for additives of any kind, in my opinion. You will be de-sludging the system way before a harmful amount of sludge is ever allowed to build-up. These are ball park numbers and should be adjusted if you have heavy usage in your household. Also do not get sucked into pumping a failing system at a frequent interval. Get to the root of the problem ASAP. Pumping is expensive, and will quickly become very expensive, doing them just to keep a failing system operational. A flooded and backed-up septic system may only provide 2-3 days of relief after pumping, before causing the exact same problems again. Pumping your system will cost you somewhere around $250 to $350 for a typical two tank system. Make sure to speak to a septic repairman, if you find yourself having to pump your system more often than usual, just to keep the system in operation. A septic pumping company will likely not elaborate on your problems, as they would love to keep returning and re-pumping, your failed system. As far as proper toilet papers, soaps etc., as long as you are doing your routine pumping schedule, and are staying under your rated gallons per day for the system, you should feel free to use the system however you feel comfortable inside the home.
(Low Pressure Dose)
The second system I would like to talk about is the low pressure dose, or LPD. This system uses the same setup as above, typically 3 tanks, but instead of gravity feeding into a lateral field, a sewage pump, installed in the final tank, automatically injects the liquid into a designed field of lines. The field will usually consist of one and one half inch PVC, up to two inch PVC. The engineer that designs this system, will specify hole spacing and size, based on your gallon per day rating from the home. The more GPD you have, the more lines, holes, and square footage of application you will have. This system type is allowed in soils that a standard lateral line system will not function in. This is due partly to the waste being forced into the ground by the pump, and by the slow, low pressure, application of the waste to the entire field, evenly. This system, at first, may seems like the best option of all four of the units I am describing, due to its balance of maintenance, life span, and moving parts. With only one pump that will typically need replacement every 5-7 years, and a typical pumping schedule as mentioned on the system above, it is definitely a viable option. However I want to take some time to go over a few of this system’s downfalls, so that you can have a full understanding of your options. This systems biggest weakness is in its’ distribution lines. The price of installing this system will be approximately the same price as installing an aerobic system. The problem here is that you are potentially installing a system with a life span. The same as the system above, this system relies on the ground to accept the waste at whatever interval the pump feeds it. If this water acceptance rate slows down for any reason, system failure may occur. Bio mat in the ground, and heavy rains, are a few reasons for LPD failure. LPD failures can in ways be worse than the conventional system failure described above. Since this system type does use a pump to force water out, if the field begins to fail, waste may begin to surface at an alarming rate. This system also tends to create a marshland in the area of the disposal field, especially when installed into soil types that do not accept water well. This may make the disposal area unable to be mowed, or in extreme cases completely unusable. Odor may occur as well, as this system type uses the same treatment process as the standard conventional above, thus the waste being pumped into the ground is partially untreated, and will have odor, and maybe even potentially harmful microorganisms. Surfacing from this system type, should be avoided at all cost, until repairs to the system can be made. Unfortunately, once again with this system type, if LPD lines fail, the only viable repair is the installation of a new field and lines. This requires re permitting, and possibly, redesigning the entire system. This is a very costly repair, and may cost nearly as much as installing an entirely new system. This is where having all the information, will aid you, in deciding if this system is a good option for your future septic needs. Where this system shines is in its’ required maintenance. A normal pumping schedule, as outlined above, coupled with a sewage pump replacement every 5-7 years, is nearly all the maintenance this system requires. Since the discharge is subsurface, you are not required to add chlorine, as well as there are no ongoing maintenance contracts required. These bonuses may out way the possibility of future failures for some customers. With this information in hand, you will have to decide if this system type is right for you.
(Aerobic Septic System)
The third system I would like to talk to you about is the aerobic septic system. This system has quickly become the most installed system in many areas. It has also received the most criticism from installers and homeowners alike. This system has received a blemished name, over the last 15 years, and this is partially, if not mostly, due to septic installers, builders, and maintenance companies. As with the two systems above, I want to outline the downfalls, bonuses, basic operation, and care of these systems. The key to a long low-maintenance life span, on your aerobic system, actually goes straight back to the installation. If you go cheap, you will get cheap, and with this type of system you will pay for it in the years to come. Most homeowners understand this, however, one of the largest problems facing this system, is that they are almost exclusively the go to system for new contructions and renovations. The problem here, is that the vast majority of builders go with the most inexpensive installer they can find. This is mostly because they do not have to deal with the system, or the homeowners, after the construction is complete. Another bad situation is mobile home and land combo deals. These have the absolute worst systems installed, in most cases. In both of these instances, I've seen people staring to have issues in as little as 6 months. That is absolutely appalling. In both of these scenarios, the homeowners are the ones that get stuck with the repair costs. In my opinion this is one of the largest reasons aerobic systems have received such a bad reputation. With all that being said, I want to take a little time, to show you how this system is not nearly as bad as it may seem at first. Aerobic systems can be installed in nearly any soil type, and when properly installed, have low to no problems dealing with adverse weather conditions like heavy rains. They also rarely fail, due to overloading, as long as all the moving parts are working. For me however, the next reason is the absolute number one reason I feel so comfortable with aerobic septic systems. Aerobic systems are a mechanical based unit, and yes I know this comes at a cost. However with a mechanical system, you will always have the peace of mind knowing, that if the mechanical parts are working, the system will work, regardless of any other conditions put on it. All the other systems above, leave a lot of possibilities of failure in overuse, heavy rains, and poor ground absorption. Unlike the other systems above...an aerobic system can possibly be the absolute last system you would need to install, at the said property. All the other systems above have an expiration date, whether it be 5 years, or 40 years. Aerobics do not. With aerobics there will be parts that have to be replaced over the years but you will never have to reinstall, redesign, or start completely back over. Another problem with one of the above systems failing, is there is no telling what kind of rule changes will be in place, at the time of your system failing. If you then have to reinstall a new system, you will be at the mercy of these new rules, and whatever type of new, possibly way more expensive system, that you are forced to install at that time. You can't just go back with your same system type, if you regulatory body says they want you to install something different. For me it's like having a '75 Chevy in my garage. They are fairly easy to work on, with no need for special equipment or tractors. The components also have a very predictable life span, when maintained properly. You simply fix these parts, and the system is back in full operation. Where the other systems above are more like a modern car. It's very difficult to locate the problem, when one of the systems above fail, and if it is in the distribution lines, you will not be allowed to repair this, and basically are forced to reinstall the entire field or system. Now that you know a few of the perks of the aerobic, let’s talk about a few of its’ cons. Firstly is that they absolutely need maintenance. The filter on your aerator needs to be cleaned or replaces twice per year. The filter on the effluent pump cleaned once per year. The system pumped out, and de-sludged, every 3-5 years. The aerator replaced, or rebuilt, every 3-6 years for linear and shaft style, and 8-15 years for rotary vane styles. The effluent pump will need to be replaced every 9-12 years, under good maintenance conditions. You will need to add chlorine as needed for surface spray systems, or underground distribution systems, near any water of body. Sprinkler heads will need replacing here and there as well. Other than small repairs like ant killer, re-leveling aerator platforms, and other small miscellaneous items, that is about it. Once again replacing these items as needed, will keep the system in operation indefinitely. I need to clarify however, by operation, I mean the toilets and facilities in the home are working as normal. Aerobics can be prone to having odor at times, emanating from either the tanks, or from the spray field. This is not necessarily a sign of the system causing a problem in the home. The majority of odors come from aerator failure, broken airline, or lack of oxygen to the digester for some reason. You can also receive odor from overloading, chemical infiltration, medications, high sludge readings, and any other bacteriological imbalance. Most odors are usually temporary, however, persisting odor should be looked at by your repair company. A quick explanation of how aerobic systems work is as follows. Most aerobics consist of three tanks, or a combo tank with three compartments. The first tank or compartment is basically a regular septic tank. It is there, to attempt to remove, as many of the settle able solids as possible. This consists mostly of toilet paper, heavy towelettes, feminine products, food waste, or any inorganic materials. After it leaves this tank, the next tank in line, is the digester. This is where the magic happens so to speak. A fiberglass digester is actually two tanks, one inside the other. Imagine a pointed sno-cone cup sitting inside of a regular cup. On concrete units, there are concrete baffles inside that separate these two inner compartments. The outer area is where the aeration is. Here the fresh oxygen is pumped into the waste water. This allows aerobic bacteria to grow. While alive, aerobic bacteria eat, and breakdown the waste, at a very rapid rate. The mixed up material then passes into the inner section of the digester, where there is no aeration. In here, the stillness allows the clear water to separate from the mixed materials. The clear water then passes thru the chlorine and into the final tank. The last tank or compartment has the effluent pump in it. Here the water is injected, by the pump, into the spray field. The pump is controlled by floats which monitor the water level. You may also have a timer, which allows the pump to only run between 12am and 5 am. This is typically on systems that have spray heads closer than 20 feet from the property lines. There is also an additional float in the final tank, which operates the audible and visible alarm systems. This is to warn you there is a high water situation in the final tank, and is in need of repair, before back up occurs. Some systems have an air pressure alarm as well. These are installed to warn you of air pressure loss to the digester. There will also be a control panel for the system, which houses the breakers for the different components, as well as alarm mute/test switches, and or pump test switches. There will also typically be an alarm light on the top, to signal system malfunction, even when the alarm switch is in the mute position. As far as the proper care is concerned. Pump them out at a routine interval.This is typically between 3 and 5 years but can vary on usage. Stay away from chemicals as much as possible. These include, but are not limited to, bleach, Ajax, Comet, Pine sol, anti- bacterial soaps, and Drano. Another big bacteria killer is food waste. This can be from garbage disposals, or rinsing heavy foods off plates, and into the drain. Food waste quickly depletes the oxygen levels in the digester, and thus causes bacteria loss and odors. Laundry water can also cause trouble. Some counties still allow for your laundry machine water to dump separate from your septic system, on its own line. This is preferable, however it isn't always an option. If your laundry water does go to the aerobic system, a few laundry tips can help to prevent system problems. The first is to do big loads. One big load is much less detrimental on the system than two smaller loads. Also spread your laundry out. Doing all your laundry on one day will cause peak loading, and remove all the retention time the system needs to breakdown your waste. Try to even your loads out over the entire week. Also limit your usage of detergents and bleach. Most people use way more detergent and bleach than they actually need to get the job done. I know this is the U.S.A. and if some is good, than more is even better, but this is one of the occasions where that is not true. Lastly there are medications. This is one problem with aerobic systems that may be out of your control. Many people take medications that either improve their way of life, or just plain keep them alive. This cannot be changed, but be aware that it may cause catastrophic effects on the system. Be sure to discuss your medications with your septic installer, before new installations, and with your maintenance company, on existing systems. There may be a few pointers that can help to minimize their effect on the system. The final topic I would like to discuss about aerobic systems is the continuing maintenance contracts. Many counties require a licensed, aerobic maintenance company, to maintain your system, by performing the mandatory 3 inspections per year. I highly recommend you keep this current as it will keep you from incurring fines from the county you reside in, as well as perform all the routine maintenance an aerobic system requires. These contracts nearly always pay for themselves in the cost of parts they will save you, due to lack of care and maintenance. That being said, make sure to do your research for a reputable company. Many companies do not actually come out to your property to perform these inspections which is NOT proper. These companies have made a bad name for maintenance contracts, and the companies providing them. They must perform their services on site. Whatever you do, get all the information you can on these systems, and then decide if you feel it is right for you.
The last system is the drip emitter. This is basically identical in every way to the aerobic system above, except for the distribution system. They will have the same tanks, components, and maintenance requirements as the aerobic above. The difference in this system is that instead of distributing the effluent thru sprinkler heads, the pump forces the water into underground irrigation lines. Do not confuse these lines with the underground lines of an LPD system. Drip emitter lines are 5/8 inch vinyl tubing, with drip emitters, every 12" to 24" depending on style and GPD requirements. They are also installed much closer to the surface of the ground. Typically between 6"and 10". This is to allow the water to be used as lawn irrigation, instead of it going deep into the ground where lawns cannot readily utilize it. What the lawn does not absorb, goes up into the atmosphere via evaporation. Since this system allows for the lines to be much closer together, and has very low setbacks to property lines and lakes, it is very popular on small lots, or lots that are close to lakes. You can fit a very large area of application on a small lot with this system type. In some situations this system type may be your only option. That being said, this system does have its’ downfalls. In addition to the aerobic systems maintenance, you also have some maintenance specific to this system. The most important is servicing the micron filter. This is in the discharge line going to the field, and should be serviced at least twice per year. Secondly is back-flushing the field at least once per year, to help remove any waste build-up in the lines. Watching your water pressure in the field is also wise, as anything above 20 psi, can fatally damage the drip tubing and connections. Some systems have an automatic sand filter and back flushing mechanism installed. These types have even more maintenance required in this compartment. Like some of the systems I described above, the problem with this system, is the inherent flaw of disposal into underground lines. If these lines ever clog due to excessive dirt or waste infiltration, line replacement is the only option. Back flushing is designed to remove these materials, however if the system gets enough debris into the lines, back flushing becomes ineffective. Pop ups are also common. They are commonly called blow outs. This is where water finds an easy path to the surface, and begins to surface heavily in that one area. This may also occur from a puncture in the drip tubing, or separation at a connection. Like the LPD above drip lines can cause a swamp land effect, during heavy rains, or over use situations. This system is superior to the LPD, in this situation, as the water surfacing has been processed, and if the system is working properly, is completely safe. It will most likely be a nuisance for mowing and other outside events. The last note to keep in mind about the drip emitter system is its’ cost. You can figure the installation will cost you roughly $2,000 more than a typical aerobic. This difference can increase even more on larger or more intricate fields. Once again please get all your info on these intricate systems, before deciding they are right for you.
I hope you have found this article informative. The best thing you can do whether you are building a new home, replacing a system at an existing home, or buying a home with an existing system, is to call a septic professional to discuss your options. Find yourself a reputable company, and obtain as much info about your particular system, as you can. Do not forget to set up a regular maintenance routine as this can save you thousands of dollars over the years to come. Thanks again for your time and God Bless.
Author: William Ingram of Helton Ingram Septic Inc.
All comments reflect the opinions of the author and are not legally binding. All comments are copyright protected, and cannot be reused without the expressed written consent of the author. 2013
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