Septic Safety Considerations
What Do You Want in Your Yard?
As discussed on the Types of Septic Systems page, different types of systems send different qualities of treated sewage to your yard. You have a choice of fully treated wastewater or wastewater that needs further treatment by the soil. Relying on the soil for treatment can create safety risks.
Even if designed to today’s standards, a sewage treatment system can result in untreated sewage on your lawn if it is not maintained, underperforming, or undersized. Unsafe discharges can be caused by something as simple as heavy household water use like a big laundry day or multiple showers. These can overwhelm and push untreated sewage into your yard. If there’s a lot of water, it will come to the surface. This can also happen if there’s a period of heavy rainfall. This untreated wastewater contains high levels of harmful pathogens and is unsafe for human or pet contact.
Sewage overflows from the house ultimately plug dispersal fields and lead to a lawn wet with sewage that is not fully treated. This condition is a reason that many conventional septic systems fail mandatory public health inspections when an owner is selling a property.
- Across the U.S., millions of conventional septic systems fail to meet safe discharge standards.
Remember, the wastewater from your septic system eventually finds its way through the soil and into the water table or into local streams and rivers.
As the homeowner, you are responsible if your system pollutes by discharging wastewater that does not meet standards. This is particularly an issue if you have an EPA permit that allows effluent to be discharged off your property into roadside ditches or other water bodies.
Many states do not allow a house to be sold if the sewage treatment is not up to code. This can require a buyer or seller to find a new area of land for a leach field. Replacement costs can range from $10,000 to $30,000, plus the loss of the associated usable land.
Compare the Safety of Septic Systems
The chart below shows the expected level of bacteria and solids in wastewater released into your soil from a properly operating system. The best full treatment systems always produce an effluent with both TSS and BOD less than 10 mg/l and fecal coliform less than 20 cfu/100 ml sample. For reference, a public beach closes if E. coli bacteria is around 200 cfu/100 ml. E. coli is just one type of harmful fecal bacteria. Some health departments also have standards for total fecal coliform bacteria.
|Fully Treated Wastewater:
|Partially Treated Wastewater:
(NSF 40 Standard for Aerated Systems)
|Fecal Bacteria (including E.coli)||Not Detectable||< 10,000 cfu/100 ml||< 1,000,000 cfu/100 ml|
|Organic Matter cBOD
(Biological Oxygen Demand)
|< 5 mg/l||< 25 mg/l||< 250 mg/l|
|Total Suspended Solids (TSS)||< 1 mg/l||< 30 mg/l||< 100 mg/l|
cfu/100 ml = Colony Forming Units (counted bacteria) per 100 ml of sample
BOD is the amount of dissolved organic contaminants in wastewater
TSS is the suspended/non-dissolved contaminants in water
TSS and BOD interfere with UV disinfection and can hurt wildlife
Be sure to ask your septic system designer or installer about the actual performance history of the system you are installing. Some health departments also have this data from installed systems in their area. It is important to know what levels of bacteria and contaminants you should expect to be discharged into your yard and whether they meet health and environmental standards.
The safety of your family and your surrounding environment should be your main concern when choosing a septic system. Choose your system wisely!
A Safer, Cleaner Alternative to Septic
The LandSaver® MBR protects property owners, neighbors, and the environment by assuring full treatment before wastewater effluent is discharged into the soil. Its state-of-the-art treatment technology uses aeration to help microorganisms break down organic matter and is paired with an ultrafiltration barrier to remove sub-micron particles. The LandSaver MBR system comes equipped with UV light to kill bacteria and deactivate viruses. The LandSaver MBR’s full treatment system removes TSS, BOD, and E. coli to near non-detectable levels, making water much safer to discharge anywhere on or off of your property.