In January 2010, the American Society of Civil Engineers conducted a series of
workshops to address problems with infrastructure deficiencies in the United States. The
outcomes associated with these workshops were discussed in Civil Engineering Magazine
(April 2010). Based upon these outcomes, a consensus was reached that the water and
wastewater infrastructure in the United States is in a state of crisis and that the following
recommendations may provide a roadmap to ease that crisis and a vision for
improvement:
• Increase Federal Leadership in Infrastructure;
• Promote Sustainability and Resilience;
• Develop Federal, Regional and State Infrastructure Plans;
• Address Life-Cycle Costs and Ongoing Maintenance; and
• Increase and Improve Investment from all Stakeholders.
The above information and the predicted infrastructure rehabilitation and replacement
needs expected in the next decade prompted the USEPA to commit to promoting
sustainable infrastructure practices. If successfully implemented, these practices would
help reduce the predicted gap between infrastructure needs and infrastructure spending
(USEPA, 2006). Disinfection is one of the key unit processes for the protection of public
health. In order to fully implement the four pillars of the USEPA sustainable
infrastructure model, approaches must be taken to incorporate sustainability into
engineering design and operation of disinfection unit processes for water and wastewater
infrastructure systems.
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Posted: May 20th, 2011 | Filed under: Stormwater, Waste Water Treatment, Water Treatment | Tags: Environmental Impact, Green Infrastructure, Improved Disinfection, Improved Infrastructure, Increased Federal Leadership, Plant Improvement, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
City of Sunnyvale Water Pollution Control Plant
Sunnyvale, California
At wastewater treatment pond facilities where removal of algae suspended solids is
required, the harvested biomass is often returned to the ponds for disposal. This biomass
is potentially valuable as a biofuel feedstock, and in the context of wastewater treatment
plants, biogas is currently the most practical biofuel to produce. While future algal high
rate pond treatment facilities, which maximize algae production for nutrient removal,
would integrate algae digesters, existing pond facilities may benefit in the immediate
future from algae digestion or co-digestion to increase production of renewable energy.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Algae Digestion, Cost Savings, Energy Savings, Environmental Impact, Green Infrastructure, Increased Renewable Energy Recovery, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Woodward Avenue WWTP
Hamilton, Ontario (Canada)
The City of Hamilton, Ontario is faced with increasing pressure from growth and
development, greater wet weather treatment needs, and stringent effluent targets. In
order to address these challenges, the City of Hamilton initiated an ambitious program
to identify alternative upgrade options for the Woodward Avenue WWTP. Two
alternative treatment strategies were short-listed for further study. The first option,
termed Parallel MBR / MF, included a more conventional style membrane facility with
a MBR facility treating approximately half of the primary effluent in parallel with a
membrane filtration facility filtering nitrified secondary effluent from the existing
secondary treatment plant. The second option, termed Tertiary Nitrifying MBR or TMBR,
involves installing a membrane bioreactor using feed consisting of non-nitrified
secondary effluent from existing high rate secondary treatment plants. A detailed triple
bottom line (Economic, Social, and Environmental) evaluation was carried out on the
two alternatives. The evaluation revealed that the two options are very similar in most
respects, with the exception of energy efficiency. More specifically, the T-MBR option
was found to require significantly lower energy, primarily due to reduced oxygen
demand and more efficient oxygen transfer characteristics within the MBR processes.
Annual savings with T-MBR are expected to be $500K. In addition, the additional
biogas production with T-MBR is expected to result in additional revenues approaching
$600K annually. These factors drove the selection of the T-MBR strategy as the
preferred alternative for the expansion of the Woodward Ave. WWTP.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Increased Biogas Production, Increased Energy Efficiency, Plant Enhancements, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Green Bay Metropolitan Sewerage District (GBMSD)
Green Bay, Wisconsin
The Green Bay Metropolitan Sewerage District (GBMSD) used the principles presented in
Effective Utility Management, a Primer for Water and Wastewater Utilities in development of its
Strategic Plan and Solids Management Plan. The self-assessment and attributes of a Highly
Effective Utility were crucial to the successful development and implementation of these plans.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Effective Utility Management, Environmental Impact, Improved Strategic Planning, Optimized Self-Assessment, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Solids Management Planning | No Comments »
Due to increasing public interest in water purity, and projected sharp increases in energy costs in
the near future, Wastewater Treatment Plants (WWTP) are becoming interested in optimizing
their activated sludge process to reduce operating costs, and stabilize process operation. This
paper presents an activated sludge process evaluation that describes how aeration energy savings
of 23 to 45% and process stability can be obtained by controlling the Solids Retention Time
(SRT) and Dissolved Oxygen (DO).
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Posted: May 20th, 2011 | Filed under: Waste Water Treatment | Tags: Aeration Control, Controlled Nitrification, Controlled Solids Retention Time, Cost Savings, Energy Savings, Environmental Impact, Minimized Dissolved Oxygen Fluctuation, Plant Optimization, Plant Sustainability, Process Optimization, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
City of Mishawaka WWTP
Mishawaka, Indiana
Combined Heat and Power (CHP) systems are superior to other digester gas utilization systems
in their ability to reduce utility costs and carbon emissions. Economic viability of digester gasfired
CHP is a function of many plant specific variables, foremost of which are electric and gas
utility rates, building and process heating (and cooling) loads, digester gas impurities, and
digester gas production. These and other utility, system, and plant specific data impacts on
digester gas energy recovery system economics are presented, discussed, and evaluated using
both simple and sophisticated energy modeling techniques.
Some noteworthy findings are the greatly superior return on investment, compared to CHP
alternatives, of heating-only systems in plants with significant facility heating loads, and the
general need for monetary incentives, both capital and operating, to lower economic hurdles to
cogeneration implementation.
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Posted: May 20th, 2011 | Filed under: 50k-100k, Waste Water Treatment, Water Treatment | Tags: Combined Heat and Power, Cost Savings, Energy Savings, Environmental Impact, Improved Digester Gas Energy Recovery, Plant Optimization, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Water & Sewer Authority of Cabarrus County (WSACC)
Concord, North Carolina
The Water & Sewer Authority of Cabarrus County (WSACC) teamed with CH2M HILL to
explore beneficial use of waste heat produced by their biosolids incinerator in the face of rising
energy costs and an increased emphasis on sustainability. Studies showed the resulting heat at full
utilization could generate up to 2MW – equivalent to powering 1400 homes.
The project team worked with specialty legal counsel to obtain a first-of-its-kind ruling that
classified WSACC biosolids as a ‘renewable fuel’, with the intent of selling the electricity rather
than using it at their plant. The ruling allowed this energy to be sold at a premium…nearly double
their retail rate. This revenue stream could produce $1M-$1.3M annually.
Project findings are relevant to facilities that incinerate biosolids as well as utilities considering
projects involving ‘green’ power generation. Rethinking traditional payback models and
capitalizing on emerging renewable energy markets could give utilities millions of reasons to “Go
Green”.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Green Infrastrucute, Heat Recovery, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
New Hampshire Department of Environmental Services
Concord, New Hampshire
Electrical-grid powered aeration is used to mix and oxygenate wastewater in most treatment
plants. However, much more mixing than oxygenation typically is needed. This imbalance
creates an operational inefficiency that increases costs and greenhouse gas emissions. The New
Hampshire Department of Environmental Services directed a 3-site study to assess the ability of
solar powered circulation (SPC) to reduce or eliminate the need for aeration. Water quality, odor
event, sludge buildup and power consumption data were collected 1-year pre-SPC and 1.25-years
during-SPC. The results generally indicated no differences between study periods in effluent
flow rates, total suspended solids, biochemical oxygen demand, dissolved oxygen, pH, ammonia
or nitrate levels. No discharge violations or odor events, and little or no sludge buildup, occurred
during SPC. Power consumption declined by 43-91%, and payback periods were 1.5-3.9 years.
These data and a 25-year, low maintenance, SPC-unit life expectancy indicated a long-term
improvement in operational efficiency.
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Posted: May 20th, 2011 | Filed under: 100K-500K, 50k-100k, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Green Infrastructure, Improved Effluent Quality, Improved Oxygenation Efficiency, Improved Wastewater Mixing, Innovative Mixing Design, Operational Costs Declined, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Solar Power | No Comments »
Upper Occoquan Service Authority
Centreville, Virginia
The cost of energy has become an increasing concern to water and wastewater utilities.
Economic drivers, combined with general industry concerns about energy supply reliability,
climate change, and sustainability have encouraged many utilities to consider alternative project
delivery methods to finance desired energy efficiency and renewable energy projects. One such
alternative delivery method is the Energy Performance Contract.
Energy performance contracting has been applied most actively by Energy Service Companies
(ESCOs) to implement building efficiency improvements at institutional facilities: universities,
schools, hospitals, and government buildings. It has been only within the past five years that
municipal water and wastewater utilities began using this alternative delivery method to
implement energy efficiency improvements at their treatment plants.
This paper provides an overview of energy performance contracting and the ESCO market. It
also presents a case study from a municipal wastewater utility in Virginia that is utilizing energy
performance contracting to implement energy efficiency projects: the Upper Occoquan Service
Authority in Centreville, VA.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Efficiency, Energy Savings, Heat Drying, Plant Optimization, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Renewable Energy | No Comments »
City of Newark Ohio’s Division of Water and Wastewater
Newark, Ohio
The City of Newark Ohio’s Division of Water and Wastewater tried something new to recover
the energy and generate revenue from biogas produced by their anaerobic digesters. The City’s 8
mgd WWTP is equipped with three anaerobic digesters, which collectively produce an average
of 100 mcfd of biogas. This gas is used for facility heat and process heat, with the balance of
approximately 50%, flared. This waste of energy and the environmental consequences of
burning fossil fuels has long been an issue with the Division, so they began exploring
alternatives to flaring. Generating electricity with the gas was investigated, but the high capital
and maintenance costs for the generation equipment and the gas cleanup costs made it financially
unattractive. They were looking for an economically viable alternative.
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Posted: May 20th, 2011 | Filed under: 100K-500K, 50k-100k, Stormwater, Waste Water Treatment, Water Treatment | Tags: Energy Savings, Environmental Impact, Green Infrastructure, Improved Energy Production, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »