Frequently Asked Questions
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How does the septic design process work?
The septic design process can seem intimidating. To help make it a smooth process, we have broken it down into 5 phases.
- Planning: Once you book an appointment with us we use multiple county websites and some offline sources to familiarize us with with your property and it’s history. We typically know quite a bit about you property before we set foot on it. We will also obtain as much information from you about your future plans for the property as well. That can include a site visit or or a conversation on the phone. Lastly, if we have any questions, we will communicate those to you as soon as they come up to keep the septic design process and your project moving forward.
- Soils Evaluation: Most of the designs we do start with a soils evaluation. We will arrange for an excavator to be on site to dig approximately 4 soils logs on your property to determine soil type and depth to a restrictive layer.
- On-site septic system design: Once we have dug test pits, we will use highly accurate field data collection equipment such as a total station or base/rover gps systems to record site features such as existing structures, soil logs, topography, existing wells, proposed well site, shoreline, cut banks, etc. We use this information along with the soils information to design your new septic system. We typically will have a preliminary design from your review within a few days from our site visit. Once you approve the design, we will complete the final design. The final design may have many pages of calculations as well as specifications of septic tanks, drainfield lines as well as cross section drawings of components. It will also include a detailed, scaled site plan depicting your property and placement of the septic system. Certain counties have requirements for critical areas, we will address that with you if it is required.
- Health jurisdiction review: Once your septic design is submitted to the local health department and the application fee paid, they typically take around 20-30 days for approval. Designs can sometimes be returned sooner based on urgency (failed system), site complexity and how busy the health department is at the time. As soon as the design is approved, we will email you an approved copy so that you may get bids for installation costs. We can recommend installers that have a proven track record and have worked with us successfully in the past.
- Installation / inspection: After the septic system has been installed, we will return to perform a pre-cover inspection. During this inspection we will make sure the system was installed per the design. At this time we will use our field data collection equipment to collect the location of all the installed septic components. We use this information to create the record of construction or ‘as-built’ drawing. The as-built shows the location of the septic system components as well as specific information about system size and dosing (if needed). This drawing gets submitted to the health Department for their records. If you are building a home on the property, final occupancy will not be granted without an approved as-built.
How do I know what type of septic system I will get?
There are many factors that go into determining septic system type. The septic system will be customized to your site based on soil type, soil depth and planned usage are the main factors. Your septic system must be installed in native, undisturbed soil. The depth of this soil to a restrictive layer is what determines what type of septic system can be designed, such as gravity, pressure, pre-treatment or above ground / mound systems. The deeper the soil, the cheaper the system is a good rule of thumb. The next factor is designing your septic system is planned usage. How Many bedrooms are you planning? Do you entertain frequently? Large extended family? The next factor is the soil type. Soil type or texture is what determines the loading rate of the soil. The soil type along with your planned usage is how we determine the size of your drainfield, sometimes referred to as a leachfield. We will design you the simplest and most cost-effective septic system that meets all state and local regulations and of course, your specific needs.
What is a 'Perk Test?'
A ‘Perk Test’ or ‘Preliminary Soils Assesment’ is a service that we provide to help you understand what type of septic system is allowable by code on your property. Traditionally a perk test was conducted by monitoring how fast water would absorb, or percolate into the soil. The Department of Health has since determined that effluent is heavier than water and therefore has a different percolation rate. Because of this they defined different soil types with differing loading rates. We use this information in determining the septic system type. Today, we dig a test pit approximately 3 feet wide and 6 feet long. We enter the test pit and observe the different soil horizons, depth to a restrictive layer and texture of the soil. We use all of this information to determine the type and size of your new septic system.
Typically you would have a perk test done before you purchase a piece of bare land to ensure that you are not buying an expensive camp site. Some lenders also require a perk test before they will approve the loan, again to ensure the property is buildable. Frequently we will also do a perk test if you are looking to expand your existing system or build an ADU or accessory structure with its own septic system.
What are the main type of septic systems?
There are many differing types of septic systems available. We use many factors in determining the type that nest suits your septic project. Below are the main types and required soil depths.
- Gravity: Conventional gravity systems consist of a 2 compartment septic tank and drainfield. Minimum of 36 inches of vertical separation is required for a gravity system.
- Pressure: A pressure system consists of a 2 compartment septic tank, a pump tank, effluent pump, pump timer control panel and drainfield. This is a pressurized system that uses the entire drainfield like a sprinkler. A minimum of 24 inches of vertical separation is required for a pressure system. This type of system is very common today and they work very well.
- Pre-treatment: A pretreatment system is very similar to a standard pressure system except we need to add an ATU or Aerobic Treatment Unit in between the septic tank and pump tank. This ATU aerates the sewage with a air motor and promotes the growth of aerobic bacteria which is more effective at breaking down sewage than the bacteria in a traditional septic tank. A minimum of 12 inches of vertical separation is required for a pre-treatment type system.
- Above ground / mound systems: There are a few different types of above ground systems including the traditional mound, the GlenDon Biofilter and the Oscar family of low mounds. A mound system, or above ground system require a minimum of 12 inches of useable soil. Without at least 12 inches, a septic system is not possible.
What is a 'Restrictive Layer?'
A restrictive layer is soil that prevents the flow of sewage into the ground. Typically referred to as the bottom of the trench. A restrict layer can be clay, hard pan, till, evidence of a water table or water itself.
How long does the septic design process take?
Generally speaking, from the time the soil logs are dug on your property, our goal is to have your septic design ready for submittal within 7-10 business days. Once submitted to the health Department, they can take up to 30 days for review. Of course there can be requirements for wetlands, landslide or shoreline to be mitigated before we can submit your septic design to the health Department.
What is this 'Vertical Separation' you speak of?
Vertical separation is the amount of soil below the drainfield trench and above a restrictive layer. Your typical trench can be installed a minimum of 6 inches into native, undisturbed soil. We use vertical separation to determine the type of septic system that can be designed for your project.
What if I can't afford to pay for a replacement septic system?
When a septic system fails it’s often costly to replace or repair it. For homeowners, the situation can be urgent. Public health agencies require prompt repair to ensure the safety of your family and your neighbors. A failing septic system can make your home unlivable and if you can’t afford to repair or replace your system, you may even be forced out of your home. Fortunately there is Craft3.
Clean Water Loans to finance septic repairs
Craft3, a nonprofit lender, offers Clean Water Loans to allow homeowners to borrow the entire cost of eligible design, permitting and installation. Lower interest rates may be available for qualified lower-income borrowers, and there are no up-front loan fees or pre-payment penalties. Please visit Craft3’s website using this link for rates and terms, to check eligibility, and begin your application.
How do I know which installers to hire?
Local health jurisdictions maintain a list of certified installers that you can choose from. We can help narrow down recommendations based on your project location. We can refer you to a specific contractors that have a proven track record and that have worked with us successfully on previous projects.
If I don't have enough vertical separation, can I add soil?
The short answer is no. Septic systems must be installed in native, undisturbed soil.
