User Guide
Frequently Asked Questions
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How does a compact HGI replace the function of a 1000
gallon concrete tank?
A Gravity Grease Interceptor (your typical concrete tank) will be sized on capacity and therefore typically a number between
750gallons and 1500gallons is commonly seen. This number can however be substantially higher based on local requirement
or application. In most jurisdictions, a method called the 25% rule is employed as the means to indicate or mandate the
cleaning frequency. The 25% is the percentage of the total working volume of the interceptor which can be occupied by a
combination of Fats , Oil and Grease and Food Solids.
For example: A GGI tank with a capacity of 1000 gallons can only function to a point where 250gallons (1000 X .25) of its
volume is occupied by solids and grease. That equates to approximately 1090 lbs of grease. If we assumed that 100 gallons
of this is the solid material, that leaves 150 gallons of grease capacity before cleaning is “required”. On average this translates
to approximately 8-10 weeks on average. Now compare this to an XL100 HGI. Based on the independent third party testing
to determine qualied performance & eciency, the Endura® XL100 has a signicantly smaller 257gallon total capacity, but
a qualied eciency exceeding 95%. This translates to essentially the same grease capacity as the GGI, exceeding 1000lbs of
functional grease capacity.
Can I install more than one Endura® XL unit if my jurisdiction
needs a minimum capacity by code?
In principal, yes you can. It will be necessary for you to contact your plan check or review team at the authority having
jurisdiction and have your engineer submit a proposal based on the information provided on Page 10 of this document. This
page and the other specication drawings are available as downloads from our website – www.EnduraXL.com
I heard that plastic tanks can oat in high water table
areas, particularly when pumped down for cleaning.
Is this true?
Yes it is, however Endura® XL is specically designed to address this challenge. If you look at XL tanks from the end you
will see that the top is narrower than the bottom and that there are along the sides corrugations that are closed toward
the bottom of their prole. This prole is the reverse of an ice cube sitting in a freezer tray. Typically some upward force is
applied around or beneath the ice cube and out it pops! Now reverse that principle to the form of the tanks – the broad
base not only provides stability but also has substantial resistance to being forced upward by water or freeze-thaw action.
This in conjunction with the closed corrugations positively captures the tank in the excavation once backlled. For areas of
particular concern in addition an 8” concrete slab can be poured around the base to introduce further resistance. Provision is
also made for the use of ground anchors or alternates that will need to be specied locally by an engineer respective of local
ground conditions.