ATL

Do septic systems freeze in extremely cold conditions?

Onsite Wastewater Systems (septic systems) have been installed in cold weather regions for quite some time.  If designed and installed properly per code then the systems typically have not froze.  Factors such as the temperature of the water exiting the home and proper burial depth of your septic system (septic tank(s) and drainfield) help to ensure adequate system performance.  For additional guidance, please contact a licensed septic contractor in your area.

Can the roof vent be used as the high vent?

The house roof vent functions as the high vent as long as there are no restrictions between the low vent and the house roof vent.  For more information, please review your area-specific design manual and regulatory code.

How should the ATL rows be connected for serial distribution applications?

In serial distribution applications the use of raised connections is recommended.

What is the difference between the system sand footprint and the basal area footprint?

• System Sand Footprint: area that is created by considering the amount of conduit and the system sand between and beside the individual ATL conduit rows.
• Basal Area Footprint: area at the bottom of the 6-inch system sand layer created in order to meet the minimum infiltrative surface area requirements

What is the minimum vertical distance from the bottom of the system sand to the seasonal high water table?

This distance varies by local code. Often the use of ATL allows for a reduced vertical separation distance to the seasonal high water table compared to conventional stone and pipe systems.