Paulding County
Georgia
Before the recession, Metro Atlanta and its surrounding counties were one of the fastest growing
regions in the United States. In order to reduce the impact of treatment plant discharges on its
limited water supply and to offset water demands on potable water systems, they were
increasingly looking at water conservation and water reuse. Paulding County was one of those
fast-growing counties, consistently ranked between the 12th and 15th fastest growing counties in
the United States. Wastewater treatment facilities are among the most critical to support the
County’s rapid population increase. With tighter effluent limits on the way and a halt on surface
water discharge permits, the County had to look at alternative uses for the treated wastewater.
Several technologies were evaluated, and based on this evaluation, MBR technology became the
apparent leader. This paper provides an overview of the selection process, the procurement
process, and the performance of four MBR systems currently operating in Paulding County.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Improved Plant Efficiency, Plant Sustainability, Reduced Carbon Footprint, Water Reuse | No Comments »
District of Columbia Water and Sewer Authority (DC Water)
Washington, DC
Due to potential risks associated with transportation and handling of liquid chlorine, the District
of Columbia Water and Sewer Authority (DC Water), switched to the use of liquid sodium
hypochlorite as the disinfecting agent at the Blue Plains Advanced Wastewater Treatment Plant
(AWTP). The escalating cost of bulk purchased sodium hypochlorite prompted DC Water to
commission a study to evaluate disinfection alternatives that: 1) are compatible with existing
treatment processes; 2) meet all plant effluent disinfection requirements; and 3) reduce life cycle
costs of disinfection.
The study involved a detailed technical, economic and non-economic evaluation of the feasibility
of constructing and operating an onsite sodium hypochlorite generation facility in lieu of bulk
purchase. Economic analyses included capital and O&M costs, life cycle costs over a 30-year
time horizon, and sensitivity of price of bulk sodium hypochlorite and salt, electric power cost,
debt service on life cycle costs.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Capital Savings, Improved Plant Reliability, O&M Cost Savings | No Comments »
Saco Wastewater Treatment Plant
Saco, Maine
The use of novel CSO control, treatment and disinfection systems based on advanced vortex technologies
including Vortex Flow Controls (VFC) and Hydrodynamic Vortex Separator (HDVS) that enable,
Screening, Grit Removal, Sedimentation and Disinfection to be accomplished in one vessel is described.
The application of the technologies at the Saco Wastewater Treatment Plant involves a new generation of
HDVS and vortex flow controls that regulate wet-weather flows to control maximum flows to the existing
wastewater treatment plant to avoid hydraulic overloading and the diversion of excess combined sewage
flows to the new CSO treatment facility.
The wet-weather treatment facility utilizes an advanced HDVS that incorporates a non-powered, selfactivating
and self-cleansing CSO floatables screening system; with the captured pollutants comprising
sewer debris and solids including sediments, settleable organic solids and floatables, being returned to the
headworks at the treatment plant and the clarified, screened and disinfected overflow being discharged to
the receiving environment (Saco River), after de-chlorination.
The ability to perform several essential unit processes (i.e. Screening, Grit Removal, Sedimentation and
Disinfection) all in one vessel resulted in significant savings in the overall project scheme costs on
account of the more compact design of the advanced HDVS system coupled with the elimination of
additional tanks and vessels that would have been required with the conventional approach. Analytical
results from post-construction compliance monitoring have confirmed the efficacy of the advanced vortex
technologies.
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Posted: May 20th, 2011 | Filed under: <50K, Stormwater, Waste Water Treatment | Tags: Cost Savings, Improved Disinfection, Improved Plant Efficiency, Improved Solids Removal, Optimal CSO Control | No Comments »
Green Bay Metropolitan Sewerage District (GBMSD)
Green Bay, Wisconsin
The Green Bay Metropolitan Sewerage District (GBMSD) is a public utility, established in 1931,
that reclaims 38 million gallons of wastewater per day at two treatment facilities in Green Bay
and De Pere, WI. Its service area covers 285 square miles and serves more than 219,000 people.
GBMSD’s mission is to promote public health and welfare through the collection, treatment, and
reclamation of wastewater, while assessing stable, competitive rates. In conjunction with others,
the organization will encourage pollution prevention and support programs to help ensure that
water contaminated by human activity is returned clean to the environment. GBMSD conducts
its business using a sustainable approach within the social, environmental, and economical
values of our customers and stakeholders.
GBMSD initiated the development of a Solids Management Plan in 2008 to address aging solids
handling facilities and the solids loadings from recently acquired De Pere Facility. The existing
solids processing system consists of belt press dewatering followed by multiple hearth
incineration. The solids system is located at the Green Bay Facility. Solids from the De Pere
Facility are transferred by pipeline to the Green Bay Facility for processing. The solids system
was constructed in the 1970s and is reaching the end of its useful life. The multiple hearth
incineration process is now considered an outdated technology. Current incineration technology
uses fluidized beds, which consume less fuel and lower air emissions.
The solids management planning effort was undertaken to develop a long-term plan for handling,
processing, and disposing of solids. The plan included a comprehensive evaluation of numerous
solids management technologies and approaches. This paper describes the process used to
develop the plan, the alternatives that were considered, the alternatives evaluation process, and
the preferred solids management alternative.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment | Tags: Environmental Impact, Minimized Life-Cycle Cost, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
DC Water and Sewer Authority (DC Water)
Washington, DC
The DC Water and Sewer Authority (DC Water) is implementing new sludge and biosolids
processing facilites at the 1.4 million cubic meters/day (370 million gallons per day [mgd]) Blue
Plains Advanced Wastewater Treatment Plant (AWTP) in Washington D.C. The program
involves thermal hydrolysis (TH) followed by anaerobic digsetion and includes a major
cogeneration facility to provide electric power for the treatment plant and steam for the TH
process.
Decision and development criteria for DC Water’s biosolids program have evolved over recent
years and now include a broad range of factors with strong emphasis on sustainability criteria. A
major link between high-performance digestion and renewable energy production has been
forged. Key criteria for decision-making now include renewable power and energy production,
climate change issues, biosolids product quality, digestion performance, and site efficiency, as
well as capital constraints and economics.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Biosolids Minimization, Economic Benefits, Energy Management, Improved Digestion Performance, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Pine Creek WWTP
City of Calgary, Alberta (Canada)
The 100 ML/d Pine Creek WWTP is a state-of-the-art BNR facility that serves the City of
Calgary, Alberta. A delay in the construction of the primary sludge fermenters allowed a
comparison of the performance of the BNR process with and without fermentation for
extended periods of time, and facilitated a life-cycle cost analysis in which the cost of
primary sludge fermentation was compared with alternative forms of primary sludge
thickening and meeting the effluent total P limit by chemical addition. Data from the first 20
months of plant operation indicated that, with primary sludge fermentation, the plant is
capable of reliably meeting its stringent effluent total P target of <0.3 mg/L. Without
fermentation, the plant required the in-plant addition for approximately 50 mg/L of alum to
meet this same effluent quality standard. The life-cycle cost comparison between primary
sludge fermentation and enhanced biological phosphorus removal (EBPR), and two
alternative forms of primary sludge thickening and chemical P removal, indicated that
primary sludge fermentation is a cost-effective method of reliably meeting a stringent
effluent total P standard. Using a 20-year net present value (NPV) analysis, primary sludge
fermentation was found to be approximately 8 percent cheaper than mechanical primary
sludge thickening and chemical P removal, and 22 percent cheaper than gravity thickening of
primary sludge and chemical P removal.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Biological Nutrient Removal, Phosphorus Removal, Sludge Handling | No Comments »
Humber Treatment Plant (HTP)
Toronto, Ontario (Canada)
The Humber Treatment Plant (HTP) was experiencing severe settling problems. An opportunity
to improve the performance of the HTP was seized by the plant’s Senior Engineer by developing
and implementing a program of repair, continuous assessment, analysis, and tuning to ensure
optimal operation of the aging infrastructure. Through the strategic utilization of existing inhouse
expertise and resources, a new benchmark of excellence, serving the community through
improved and consistent effluent quality with accompanying odour reductions, was established.
This achievement was accomplished paradoxically using less energy and chemicals, thus,
significantly reducing the Humber’s environmental footprint. The direct delivery of these
services by City staff, while further enhancing in-house knowledge, skill, and stewardship,
eliminated the delays associated with project delivery using external contractors and made it
possible to reap the immediate rewards. The monetary benefits to the City are savings in
operating costs of $550,000 per year and capital savings of $6,000,000.
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Posted: May 20th, 2011 | Filed under: 500K-1M, Waste Water Treatment | Tags: Capital Savings, Decreased Energy Consumption, Improved Plant Sustainability, Operating Cost Savings, Reduced Carbon Footprint, Reduced Odor Problems | No Comments »
Massaponax WWTP
Spotsylvania, Virginia
Spotsylvania County embarked up an aerated static pile composting program in 2002 to manage
undigested dewatered wastewater treatment plant (WWTP) residuals cake from their
Massaponax WWTP in conjunction with brush collected through a convenience center and at the
Livingston Landfill. The initial compost facility included a covered aerated static pile process
that provided intermittent positive aeration only. The quantity of dewatered residuals being
composted has increased from approximately 8,800 tons per year in 2003 to in excess of 12,600
tons per year in 2009. Even with this rapid increase in quantities, all regulatory process criteria
have been met and offsite odor impacts have been non-existent. Howeverer, residuals cake
continued to be landfilled from a second WWTP, the FMC plant, in the amount of 5,000 – 6,000
tons per year. The County embarked upon a compost facility expansion program in 2006 with
three main goals.
1. To manage the ever increasing quantities of residuals cake generated from both County
WWTP’s over the next 20 years.
2. To enhance and automate the compost process performance.
3. To accomplish this expansion with no offsite odor impacts.
Construction of the new facilities was completed in March, 2010. This paper presents data on the
process flow, process controls, and the odor management system of this successfully expanded
aerated static pile composting operation.
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Posted: May 20th, 2011 | Filed under: Waste Water Treatment | Tags: Cost Savings, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint, Reduced Odor | No Comments »
Polk County Utilities (PCU)
Polk County, Florida
To assure that Polk County Utilities (PCU) is ready for coming changes in regulations and ever
increasing solids production from ten treatment facilities geographically dispersed throughout the
County, the County wanted to develop a proactive long term biosolids management plan that
integrated residuals management approaches among the various treatment plants. Geographical
dispersion and capacity diversity combined with a desire for an integrated long-term
management plan gave rise to a number of possible alternatives to be included in the evaluation.
The landfill disposal alternative investigated met PCU’s objectives which were to identify a cost
effective method for managing current and future biosolids generated at PCU’s facilities that
would represent a viable plan for the next twenty years. An agreement developed between PCU
and Polk County’s Solid Waste Division to mutually address disposal of leachate and biosolids
resulted in significant cost savings for both these County agencies.
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Posted: May 20th, 2011 | Filed under: Stormwater, Waste Water Treatment | Tags: Biosolids Management, Cost Savings, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint | No Comments »
EPA’s combined sewer overflow (CSO) program has reached a mature stage. Some communities
have completed their CSO controls, while others are in the process of constructing controls or
evaluating potential alternatives. With the recent emphasis on green infrastructure, some
communities are evaluating the role of natural systems and ecological processes in Long Term
Control Plans (LTCPs) for controlling CSOs. The convergence of these critical milestones and
issues for the national CSO program highlights the need for updated tools and guidance to
facilitate future CSO control efforts. In response, EPA is developing guidance on post
construction compliance monitoring for CSOs, as well as the Green LTCP-EZ, a tool that allows
small CSO communities to incorporate green infrastructure as part of their LTCP efforts. This
paper discusses these initiatives serves as outreach to CSO communities on these efforts.
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Posted: May 20th, 2011 | Filed under: Sanitary Sewer, Stormwater | Tags: CSO Control, Environmental Impact, Green Infrastructure, Meeting Compliance | No Comments »