Littleton/Englewood Wastewater Treatment Plant Case Study

I. Introduction
There are many threats to a publicly owned treatment work (POTW) and one of those is fats, oil, and grease (FOG) which is one of the most common and regulated conventional pollutant. FOG build-up in the collection system and WWTP causes significant damage which can include replacement or repair of equipment (i.e. pump and valves) as well as sanitary sewer overflows which requires extensive cleanup. The FOG program has been established in many POTWs to reduce the amount of FOG entering the collection system and this is commonly done by public outreach and inspections. For this research paper the intent is to calculate the amount of FOG produced by industrial users (IUs) that would enter the sanitary sewer without the aid of a gravity grease interceptor (GGI) and/or best management practices (BMPs) within the City of Littleton and the City of Englewood districts of the Littleton/Englewood Wastewater Treatment Plant (LEWWTP) service area.
II. History
The Littleton/Englewood Wastewater Treatment Plant (L/E WWTP) has been operating since April of 1977; the third largest publicly owned treatment works (POTW) in Colorado. In 1972 the City of Englewood and the City of Littleton had two separate, smaller facilities that were in need of improvement to meet the new minimum of 85% treatment efficiency removal

This can be seen with the use of waste grease bins (WGB) containers for grease waste from fryers, grills, woks, etc. also known as yellow grease. Kitchen staff and their roles also fall under BMPs as well as maintenance procedures and management practices. When this is no longer a feasible option, or was never an option, because some businesses are not capable of reducing their FOG discharge then they are required to install a gravity grease interceptor