ASABE Technical Library - Abstract
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FOOD SERVICE ESTABLISHMENTS WASTEWATER CHARACTERIZATION
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Paper number 701P0104, . (doi: 10.13031/2013.15797)Authors: B.J. Lesikar, O.A. Garza, R.A. Persyn, M.T. Anderson, A.L. Kenimer
Keywords: Restaurants, Wastewater, BOD5, FOG, TSS, Flow
Food service establishments that use onsite wastewater treatment systems have experienced
pretreatment system and/or drain field failure. Design guidelines for these systems are typically
provided in State regulations, are in table format, and are based on residential hydraulic
applications. Because of this, design of restaurant treatment systems using these guidelines has
led to failures. Other factors that contribute to the difference between residential and restaurant
applications include the extensive use of certain items in restaurants such as meats, fats, lard,
baking goods, cooking oil, butter, and dairy products and the use of cleaning agents such as
disinfectants, cleaners, floor strippers, and soaps.
This study included characterization of four wastewater parameters from 28 restaurants located
in Texas during June, July, and August 2002. The establishments selected for the study
represent a variety of types of restaurants that include single and full service restaurants, buffettype
restaurants, restaurants with different cuisine types, etc. The field sampling methodology
included taking a grab sample of wastewater from each restaurant for six consecutive days at
approximately the same time each day (noon to 3 p.m.), followed by a two-week break, and then
sampled again for another 6 consecutive days, for a total of 12 samples per restaurant and 336
total observations. The laboratory analyses of the samples included five-day biochemical
oxygen demand (BOD5), total fats, oils and greases (FOG), and total suspended solids (TSS).
The fourth parameter evaluated in this study is flow. Water meter readings were taken each day
at the time samples were collected. Daily flow values were obtained by taking the difference
between daily meter readings. In instances where meter readings from consecutive days were
not available, the average of other days was used. Other data used includes the number of seats
reported for each establishment by restaurant personnel.
Data exploration and statistical analyses of the data from the 28 restaurants was performed with
the standard gamma probability distribution model in ExcelTM and used to determine inferences
of the data. The analysis indicates higher organic and hydraulic values for restaurants than those
typically used by industry designers.