Environmental Engineering Reference
In-Depth Information
The textbook includes comprehensive coverage of all aspects of USEM in detail.
This chapter, because of space limitations, includes only brief discussion of the
most salient points.
Situation in ICs
Sewerage technology evolved essentially from the experiences of the Western
European countries, then the United States, and this evolution developed in three
stages:
1. Construction of sewers in the community to collect excreta and to export
the collected wastewater for discharge into a nearby river or stream or
drainage channel. This removes the excreta from the immediate community
environment where, if unmanaged, it poses great hazards for transmission
of enteric diseases. Although disposal of the untreated wastewater into the
waterways involves some disease hazard, this is small compared to the
hazard from the presence of unmanaged excreta in the community.
2. Treatment of the collected wastewater, primarily to protect stream ecology
but also for public health protection purposes. The target is achievement
of complete treatment (primary plus secondary) of the collected waste-
water.
3. Use of advanced waste treatment methods for removal of nutrients, together
with effective control of point sources for control of toxics.
The resulting situation is that the typical IC city does have an effective
wastewater management system, including sewers, interceptors, transmission
liens, pumping stations, and treatment facilities, together with point source
control and effective use of on-site septic tank/leaching units for buildings
not connected to the sewers, including effective periodic monitoring of overall
system performance.
BOX 4.2 PREFACE OF TEXTBOOK OF APPROPRIATE
SEWERAGE TECHNOLOGY FOR DEVELOPING COUNTRIES
H. Ludwig, B. Fennerty, S. K. Leng, and K. Mohit
“Practically all existing textbooks on planning/design of municipal sewerage
systems (MSSs) are written by Westerners and tend to emulate the
environmental standards and matching design criteria utilized in the affluent
industrialized countries (ICs), and because these same standards and design
criteria have been used for planning/design of MSSs in the developing
countries (DCs), most of the MSSs built in the DCs have been dysfunctional
and have not achieved their intended objectives. The new textbook is
believed to be the first that is written to be appropriate for DC use, featuring
