A “QUICK & ECONOMICAL” MODELING APPROACH TO HELP EVALUATE COMMUNITY ODOR ISSUES AND FACILITATE ODOR CONTROL SYSTEM DESIGN – CASE STUDY

Odor control at sewer/wastewater treatment plants (WWTPs) is becoming an increasingly important design parameter as well as a public relations issue for virtually every sewer district located in the major metropolises in the United States. Population growth has extended to areas in close proximity to WWTPs. The selection and design of an effective odor control technology requires: (1) a thorough understanding of odor releases around the plant (sources); and (2) the transport of odorous gases by atmospheric dispersion to the surrounding residential communities (receptor sites). Odors are perceptive in nature, subject to the threshold levels of “human noses” in the neighboring communities inhaling them. Therefore, effective community involvement was integral to understanding odor releases to the environment, as perceived by the community residents (Melarkode, et al. 2000). The data gathered from odor survey and the subsequent odor sampling phase provided qualitative ranking of the odor problems. The atmospheric dispersion mechanism of the odorous gases from the WWTP sources to the surrounding receptor locations was evaluated to obtain a quantitative measure of the odor releases from the plant. The seasonal pattern and frequency of odors noted in the odor complaint logs and surveys was analyzed further using this modeling approach. The computer simulations enabled a quick and economical means to perform several “what-if” scenarios related to odor transport. Meteorological data and geographical terrain information of the region were taken into account to perform the simulations. Another important consideration for the design of an odor control system for the WWTP was to review whether any minor modifications to the stack design, such as, the diameter or height of the stack favored the dilution process by atmospheric dispersion.