How much does a new septic system cost?
The cost to install a new residential septic system widely varies, depending on the type and size of system required. Typically, construction costs are between $8,000 and $15,000 but can be more or less depending on the details of the project. Commercial systems have an even wider range, with many bigger systems costing several hundred thousand dollars or more.
↑ Go to Top of Page Can I choose what type of septic system goes on my property? Not really. The soil on your property dictates the “treatment standard” which will be required. Depending on what “treatment standard” is required, there may be multiple technologies which meet the requirements (this mostly applies to “alternative”, higher end systems). You can always elect to install a higher treatment level or over-sized system, but most owners choose to have us design the least expensive system that meets the state and county requirements. See our page on septic system types for more information.
↑ Go to Top of Page Why can’t all systems be standard gravity type? Different soil and site conditions dictate what type of system is required. Alternative type systems are sometimes required in order to help increase the life of the system and to help protect public health. See our page on septic system types for more information.
↑ Go to Top of Page How long does a septic system last? With normal maintenance and no abuse of the system, a typical system life expectancy is about 30-40 years. Some systems will fail sooner and others have lasted much longer.
↑ Go to Top of Page What causes a septic system to fail? There are many ways a system can “fail”. It can be as simple as a clogged pipe or burnt-out pump (which is easy to fix), or as major as a plugged sand-filter or a decreasing absorption rate of the soil, both of which typically lead to a system replacement. As you can imagine, the liquid entering your system is full of organic matter. Over time, this organic matter can plug the pores in the soil (or pre-treatment filter) causing it to no longer absorb water. A residence which generates a larger than normal volume of waste or a waste which is stronger than typical for a residence will likely have a pre-mature system failure. There are many other factors which can play a role in system failure.
↑ Go to Top of Page Can I install my own septic system? Typically the answer is “no”. However- some Counties allow resident homeowners to installer their own gravity system (assuming your property has been approved for a gravity system). Contact your local health department for more information.
↑ Go to Top of Page Can I inspect my own septic system? Sometimes. It depends on the County you reside in and the type of system you have. Generally speaking, it's best to hire a professional.
↑ Go to Top of Page Why don’t you design systems with drainrock anymore? Due to the cost and availability of clean drainrock, the labor required to shovel drainrock into the trenches and the size reduction available when using graveless technology, most drainfields today are made with “graveless panels”. They are injection molded half-dome panels that create a void area above the trench bottom to allow the water to enter the soil.
↑ Go to Top of Page Do I need my tank pumped every four years? Not necessarily. You should have your system inspected by a licensed septic inspector and if needed, the inspector will recommend having your septic tank pumped. We recommend yearly inspections for all systems, but most jurisdictions allow them between one and three years depending on the system type.
↑ Go to Top of Page Are garbage disposals ok? Even if your system is designed for a garbage disposal, they are not a good idea. They can add lots of extra organic matter to the system which can plug system components and the soil in the drainfield. A system failure can result from over-usage of a garbage disposal.
↑ Go to Top of Page Should I use additives in my septic tank? It’s normally not necessary. Some additives are nothing more than filler. Some can actually harm your system. To learn more, check out this publication from the State of Washington Department of Health: http://www.doh.wa.gov/Portals/1/Documents/Pubs/337-025.pdf
↑ Go to Top of Page Should I get a “perc” before purchasing vacant land? YES! For some reason, not all real-estate agents require the seller to get a perc. As a buyer, you should be very wary if there isn’t a current perc approval. If the site can’t obtain a perc approval, it will be unbuildable. Even if it can obtain a perc, the only location approved may be where you plan to build a house, or it may be a system type which is more costly than your budget can afford. Some properties do not meet the minimum requirements for septic approval. These are not very common, but they do exist.
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↑ Go to Top of Page Can I choose what type of septic system goes on my property? Not really. The soil on your property dictates the “treatment standard” which will be required. Depending on what “treatment standard” is required, there may be multiple technologies which meet the requirements (this mostly applies to “alternative”, higher end systems). You can always elect to install a higher treatment level or over-sized system, but most owners choose to have us design the least expensive system that meets the state and county requirements. See our page on septic system types for more information.
↑ Go to Top of Page Why can’t all systems be standard gravity type? Different soil and site conditions dictate what type of system is required. Alternative type systems are sometimes required in order to help increase the life of the system and to help protect public health. See our page on septic system types for more information.
↑ Go to Top of Page How long does a septic system last? With normal maintenance and no abuse of the system, a typical system life expectancy is about 30-40 years. Some systems will fail sooner and others have lasted much longer.
↑ Go to Top of Page What causes a septic system to fail? There are many ways a system can “fail”. It can be as simple as a clogged pipe or burnt-out pump (which is easy to fix), or as major as a plugged sand-filter or a decreasing absorption rate of the soil, both of which typically lead to a system replacement. As you can imagine, the liquid entering your system is full of organic matter. Over time, this organic matter can plug the pores in the soil (or pre-treatment filter) causing it to no longer absorb water. A residence which generates a larger than normal volume of waste or a waste which is stronger than typical for a residence will likely have a pre-mature system failure. There are many other factors which can play a role in system failure.
↑ Go to Top of Page Can I install my own septic system? Typically the answer is “no”. However- some Counties allow resident homeowners to installer their own gravity system (assuming your property has been approved for a gravity system). Contact your local health department for more information.
↑ Go to Top of Page Can I inspect my own septic system? Sometimes. It depends on the County you reside in and the type of system you have. Generally speaking, it's best to hire a professional.
↑ Go to Top of Page Why don’t you design systems with drainrock anymore? Due to the cost and availability of clean drainrock, the labor required to shovel drainrock into the trenches and the size reduction available when using graveless technology, most drainfields today are made with “graveless panels”. They are injection molded half-dome panels that create a void area above the trench bottom to allow the water to enter the soil.
↑ Go to Top of Page Do I need my tank pumped every four years? Not necessarily. You should have your system inspected by a licensed septic inspector and if needed, the inspector will recommend having your septic tank pumped. We recommend yearly inspections for all systems, but most jurisdictions allow them between one and three years depending on the system type.
↑ Go to Top of Page Are garbage disposals ok? Even if your system is designed for a garbage disposal, they are not a good idea. They can add lots of extra organic matter to the system which can plug system components and the soil in the drainfield. A system failure can result from over-usage of a garbage disposal.
↑ Go to Top of Page Should I use additives in my septic tank? It’s normally not necessary. Some additives are nothing more than filler. Some can actually harm your system. To learn more, check out this publication from the State of Washington Department of Health: http://www.doh.wa.gov/Portals/1/Documents/Pubs/337-025.pdf
↑ Go to Top of Page Should I get a “perc” before purchasing vacant land? YES! For some reason, not all real-estate agents require the seller to get a perc. As a buyer, you should be very wary if there isn’t a current perc approval. If the site can’t obtain a perc approval, it will be unbuildable. Even if it can obtain a perc, the only location approved may be where you plan to build a house, or it may be a system type which is more costly than your budget can afford. Some properties do not meet the minimum requirements for septic approval. These are not very common, but they do exist.
↑ Go to Top of Page
Very knowledgeable engineers. I saved a ton of money and got a better system than what was previously recommended. Courteous folks to work with from the first phone call until completion. True professionals. Very highly recommended.
Geary Ferguson