A common question when building a new home or upgrading a septic system is, what septic system is best? Although there isn't a straight forward answer we are going to share some helpful information in order to help you answer this question.
Loading Rates and Soil Types
The characteristic of the soil on your property is going to be a huge factor in determining what septic system is going to be best for you. Another factor we will consider is how much use this septic tank is going to see. The reason why soil type is important is because it impacts the percolation rates. A perc test can help us determine this. If percolation is low than we know the soil won't be able to handle large volumes of septic movement and can cause human health and environmental risk.
We also don't want the effluent to travel too quickly through the soil because we need the microbes in the soil to properly break down the pathogens and organic contaminants before it reaches ground water locations.
The size and type of septic system is going to be determined largely by the soil loading rate which is understood as the rate the effluent passes through the soil. This is typically measured by gallsons per day per square foot. Both the texture and the structure of your soil is going to have an influence on the results.
Restrictive Soil Layers
Another imprtant factor is the soil depth between the water table and the wastewater penetrating surface, or any ristrictive layer. Ristrictive layers can be restrictive soils, water bodies, bedrock, etc. This helps property process effluent before reaching freshwater.
If soil depth doesn't meet the required standards we can artificially increase this by using a sand filter or sand mound.
Concrete Septic Tanks vs. Poly Septic Tanks
Which type of tank is better for you? Concrete or plastic? Both have their pros and cons.
The advantages to a plastic tank:
- Light weight
- Corrosion Resistant
- Not prone to crack
- Easier to transport and manipulate on site
- Cheaper install
The disadvantages to a plastic tank:
- May float in a high water table because so light
- Sharp rocks can penetrate causing leaks
- Harder to have large volume tanks and might need multiple tanks due to this
- Maximum of 2-3 vurial depth which won't work if deeper depth is required for the system
Advantages to contrete tanks:
- More accessible to obtain larger tanks
- Very durable
- Heavy and will not float
- Can be burried deeper underground
Disadvantages to concrete tanks:
- Harder to install. Takes machinery. Higher cost.
- More prone to leaks and cracks
Other Septic System Options
A conventional septic system (Type 1)gets the primary job done with the septic tank, but then the soil's treatment finishes the job. What do we do in locations where the soil is up to the quality, the house is too close to a body of water, or there is simply not enough room for a full system?
Aerobic Treatment Units (ATUs) are used in these types of situations in order to increase quality of the disposable water exiting the tank. This high quality water is oygenated and allows your system to exist with a smaller footprint. ATUs are a Type 2 septic sytem.
There are other variant methods to install septic systems, like using chlorination or ultraviolet light (Type 3), or a pressure distribution system, and it is best to give us a call if you are unsure what your property needs.