INTEGRAL CONTROL REQUIREMENTS FOR SEWERAGE SYSTEMS

Sewerage systems and sewage treatment plants are often planned, designed and operated as totally separate entities. As a result, sewage treatment efficiency is subject to considerable variability, depending both on general hydrologic conditions in the urban watershed (wet versus dry periods), and on specific ''instantaneous'' operating conditions. It has been postulated that the integration of design and operation in urban drainage and wastewater treatment could allow minimization of the harmful effects of discharge from treatment plants, combined sewer overflows and surface runoff. This ''ideal condition'' can be achieved through the introduction of so-called ''Real-Time Control'' technology in sewerage collection and treatment operations. This paper examines the requirements of a hypothetical integrated sewer flow and sewage treatment model, the mathematical tools used to design and operate Real-Time Control systems, and the issues emerging from an integration of the conveyance and disposal aspects of the sewerage cycle.