High Density Polyethylene (HDPE) hydromechanical grease interceptors have become much more popular in the commercial plumbing engineering community. Why has this segment grown so quickly in the last 10 years? Here are seven reasons to consider.
Engineers are being given less and less area to place grease interceptors (or any of their systems for that matter). Utilizing a hydromechanical unit, in most cases, gives the designer a unit half the size and with more capacity. Hydromechanical units are flow-based separation (gpm) whereas gravity units are time-based separation. In many cases, a 100 gpm hydromechanical unit can hold much more grease than a 1,000 gallon gravity unit under the 25% rule.
2. Code approvals
PDI-G101 is the most stringent hydromechanical grease interceptor code in the plumbing industry. Most jurisdictions are requiring this or the slightly less stringent version from ASME.
3. Design flexibility
With the lighter HDPE material, engineers have the ability to set these HDPE tanks above ground, below ground or even suspend them. Most manufacturers make these less than 36 inches, so they can fit through doorways in retrofit situations. You do not have all of these options with traditional tanks.
The dominant material for decades on specified grease interceptors traditionally has been concrete or steel. It is not a matter of if these tanks will fail, it is a matter of when they will fail. Industry studies have concluded that concrete tanks will typically fail within 10 to 12 years, and steel tanks will typically fail within five to seven years. This becomes a continual cycle of replacement. HDPE tanks are a lifetime solution. The EPA states that the acidic level of fats, oils and grease (FOG) in grease interceptors is so high, it should be neutralized. Industry standard neutralization tanks are made from HDPE, not concrete or steel.
The Authorities Holding Jurisdiction (county municipalities) are becoming much more proactive and environmentally conscious. When these inferior interceptor material types fail, they leech into the ground. If these older interceptors are not being inspected on a regular basis, the food establishment owner may forget to have the interceptor pumped and the FOG material is being passed into the sewer system. This can cause a myriad of issues. You do not want manholes floating in the street, lift stations getting locked up or your local wastewater treatment plant having issues with fatbergs. The AHJs are starting to rewrite very old grease program guidelines to include the use of HDPE units and beef up their inspection teams.
6. Contractorsontractor deals with many issues that we don’t ever hear about during construction. One of the issues with concrete tanks is you cannot set these somewhere while you are prepping your hole and then easily place the tank in the pit. You need a crane, and the schedule has to be down to the hour for delivery from the tank manufacturer. A 1,000-gallon concrete tank weighs around 10,000 pounds. A 1,000-gallon HDPE tanks weighs around 1,000 pounds. This makes jobsite coordination of the HDPE tank very easy. The contractor can keep it at the shop or on the jobsite until he needs it and can use a readily available piece of equipment to move it.
7. GI manufacturers
Grease Interceptor manufacturers have stepped up their marketing and sales efforts for HDPE hydromechanical units. Even though in many cases, HDPE unit sales are cannibalizing their steel units, they are committed to making the plumbing industry more environmentally aware and are shouldering more responsibility to that effect.
MIFAB has been in the interceptor business for 40 years and the HDPE interceptor business for the last 10. For more information, visit www.mifab.com.