EVALUATION OF ALTERNATIVES FOR A GREENFIELD WATER RECLAMATION FACILITY, INCORPORATING CARBON-FOOTPRINT AND SUSTAINABILITY PERSPECTIVES

City of Columbus Utilities
Columbus, Indiana

In recent years there has been an exponential rise in concern and interest regarding global
warming trends, with the evidence becoming increasingly stronger that climate change is a
result of greenhouse gases (GHGs) emitted largely by human activity. The GHGs of most
concern are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3),
chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorinated carbons (PFCs), and
sulfur hexaflouride (SF6). By far the most common of the GHGs is CO2, but several of the
other GHGs have considerably stronger effects on global warming potential relative to their
total mass, and at least two of them (CH4 and N2O) are common to wastewater treatment.
Wastewater treatment facilities are not considered to be among the top producers of GHGs
from human activity; however, a more holistic view of wastewater management indicates that
its impacts on GHG emissions spread into other sectors of GHG production. Because of their
engineered nature, wastewater treatment facilities represent significant opportunities to reduce
GHG emissions. It follows that when a municipality is planning new wastewater treatment
facilities, the evaluation of treatment alternatives needs to consider the relative impacts of
those alternatives on GHG emissions. Sustainability principles also need to be incorporated
into the evaluation methodology.
This paper presents a case study evaluation of wastewater management alternatives including
GHG-emissions and overall “carbon-footprint.” This case study is for a future, greenfield-type
wastewater treatment facility in Columbus, Indiana. The evaluation demonstrates how
different wastewater management options present differing impacts on GHG emissions and
carbon sequestration. Consequently, the impacts of GHG emissions and carbon management
need to be part of the wastewater facility planning process.
Using a decision science approach, the evaluation compares potential impacts of wastewater
management alternatives for new wastewater treatment facilities (19-mgd design capacity).
Five different treatment alternatives were evaluated, with three of those alternatives involving
sub-options, for a total of eight treatment scenarios investigated:
This paper summarizes the results of the evaluation and demonstrates how traditional and
non-traditional wastewater management options are affected by their impacts on carbon
management and their potential for reductions in GHG emissions. It is concluded that the
evaluation of the GHG-emission impacts and “carbon footprints” of wastewater treatment can
and should be considered when evaluating alternatives for the design and implementation of
water reclamation facilities.

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Posted: July 29th, 2010 | Filed under: Sanitary Sewer, Stormwater, Waste Water Treatment | Tags: Biosolids Management, Decreased Energy Consumption, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint | No Comments »

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