Advanced Ecotechnology for Decentralized Wastewater Treatment and Reuse - Restorative Redevelopment of Devastated Ecocultural Landscapes - page 385

Irrigation to Fit Local Needs & Culture
Interceptor
tank
Small Bore Sewer
Treatment
Compatible with locality
FIGURE 19.1 Decentralized collection, treatment, and reuse schematic. The rising and fall-
ing slope of the small-bore sewer depicts the inflective sewer grading possible with STEG
collection systems. The local treatment facility is depicted as a constructed wetland, but could
be other technologies as well.
advantages of variable-grade piping. The additional mechanical complexity of pres-
sure or vacuum sewers requires periodic maintenance supported by local manufac-
turing and service industries or they will fail.
A decentralized collection system delivers wastewater to treatment systems
near the sources of wastewater, including homes, schools, business, and others.
Decentralized treatment must be a good neighbor to that community. Careful atten-
tion to odor control in design and operation is therefore crucial. Passing exhaust
gases from wastewater treatment through earth or compost filters is one simple and
effective way of controlling odor. Mechanical-chemical odor-scrubbing systems are
too expensive to consider for most decentralized treatment applications.
To be visually acceptable, decentralized treatment systems should be hidden,
either out of sight or in plain view. The former category is represented by underground
treatment systems (Figure 19.2) and systems hidden in buildings or behind landscap-
ing. The latter category is represented by wetland treatment systems (Figure 19.3).
Certain wastewater treatment systems (e.g., package plants) present greater chal-
lenges for visual integration into the local community (Figure 19.4).
PUBLIC HEALTH AND ENVIRONMENTAL CONCERNS
Wastewater reuse must protect human and environmental health. Both of these topics
are vast and can only be discussed briefly here because of limitations of space. Reuse
water must not put people at risk of becoming ill from pathogens. Environmental health
takes into consideration the impact of reuse water on surface water, groundwater,