Mt. Gilead WWTP
Mt. Gilead, Ohio
The Mt. Gilead WWTP, an activated sludge facility, expanded capacity to include revisions to both primary and secondary treatment processes as well as the biosolids handling for the proposed .82 MGD facility. The Poggemeyer Design Group was asked to evaluate various design alternatives for mixing and aeration of the (2) 62’ and (1) 45’ diameter aerobic digester/sludge holding tanks included in the expansion and upgrade. The Engineer compared complete aeration systems with aeration / hydraulic mixing systems with various combinations of hydraulics and aeration rates. After reaching a decision on his final design, the mixing system manufacturer completed a final design layout after analyzing placement of the diffuser grids in relation to the hydraulic flows required. The final design is now in operation with lower than anticipated operating costs which have resulted in substantial yearly savings along with other significant advantages that will be discussed in this paper. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment | Tags: Energy Savings, Increased Digester Loading Capability, Operation Savings, Reduced Greenhouse Gas Emissions | No Comments »
City of Taft POTW
Taft, California
One solution to address overloaded collection and treatment systems is to develop satellite units for wastewater treatment. The challenge is to implement a treatment system of such efficacy that these satellite units can exist throughout an area without a large footprint. Membrane bioreactors are one option; electrocoagulation is another. Ecolotech systems are designed to meet effluent criteria that allow the non-potable reuse of the effluent, while solids are transmitted to the centralized wastewater treatment plant. The system can create an unobtrusive water recovery facility by replacing tradition treatment equipment. A small footprint can be used to effect a 95% reduction in wastewater effluent to the collection system, an odor-free system, rapid implementation, and a source of emergency non-potable water. This paper describes the electrocoagulation process, Ecolotech system components, and case study results providing proof of concept for use in small wastewater treatment and water recovery facilities. Pilot testing of the Ecolotech system has demonstrated that that electrocoagulation is a viable technology and that each unit can treat up to 250 gallons per minute (gpm) of wastewater. The Water Recovery Treatment Center is a viable option for communities that want to offer wastewater treatment to new development without having to invest heavily in new or upgraded infrastructure. Reusing treated wastewater will reduce the use of potable water for non-human consumption uses, therefore conserving a valuable resource for the community. Small-scale (<2 mgd) MBR systems typically cost about $10 million per mgd capacity. The Ecolotech system is estimated to be approximately 40% to 60% of the MBR cost, depending upon site conditions and other factors. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: <50K, Waste Water Treatment | Tags: Achieving Greater Throughput, Cost Savings, Energy Savings, Improved Treatment, Increased Treatment Capacity | No Comments »
Metropolitan Water Reclamation District of Greater Chicago's Calumet Water Reclamation Plant
Chicago, Illinois
As part of an ongoing capital improvement plan, the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) plans to construct twelve 47.2 m (155-ft) diameter circular primary settling tanks (PST) at its Calumet Water Reclamation Plant (CWRP). The new PSTs are intended to receive flows up to 75,700 m3/h (480 mgd). Due to the magnitude of the proposed facilities, the MWRDGC partnered with the design consultant and researchers at the University of Illinois to use computational fluid dynamic (CFD) modeling of the PSTs in order to optimize the design of the tanks. A three dimensional, multi-phase, turbulent flow model was developed. The model was used to optimize the arrangement of the inlet pipe and feedwell to maximize removal efficiency. In addition, the model allowed the design team to select a tank sidewater depth and tank diameter that are estimated to save the MWRDGC $2 million in construction cost without adversely affecting performance. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment | Tags: Cost Savings, Increased TSS Removal Efficiency, Optimize Inlet and Feedwell Dimensions, Plant Optimization | No Comments »
Population growth and improving standards of living, coupled with dramatically increased urbanization, are placing increased pressures on available water resources, necessitating new approaches to urban water management. The tradition linear “take, make, waste” approach to managing water is increasingly proving to be unsustainable as it is leading to water stress (insufficient water supplies), unsustainable resource (energy and chemicals) consumption, the dispersion of nutrients into the aquatic environment (especially phosphorus), and financially unstable utilities. Different approaches are needed to achieve economic, environmental, and social sustainability. Fortunately a toolkit consisting of stormwater management/rainwater harvesting, water conservation, water reclamation and reuse, energy management, nutrient recovery, and source separation is available to allow more closed loop urban water and resource management systems to be developed and implemented. Water conservations along with water reclamation and reuse (multiple uses) are becoming commonplace in numerous water-short locations. Decentralization, enabled by new, high performance treatment technologies and distributed stormwater management/rainwater harvesting, is furthering this transition. Likewise, traditional approaches to residuals management are evolving as higher levels of energy recovery are desired and nutrient recovery and reuse is to be enhanced. A variety of factors affect selection of the optimum approach for a particular urban area, including local hydrology, available water supplies, water demands, local energy and nutrient management situations, existing infrastructure, and utility governance structure. A proper approach to economic analysis is critical to determine the most sustainable solutions. Stove piping within the urban water and resource management profession must be eliminated. Adoption of these new approaches to urban water and resource management can lead to more sustainable solutions, defined as financially stable, using locally sustainable water supplies, energy neutral, providing responsible nutrient management, and with access to clean water and appropriate sanitation for all. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment, Water Treatment | Tags: Energy Management, Nutrient Recovery, Rainwater Harvesting, Source Separation, Stormwater Management, Sustainability, Water Reclamation and Reuse | No Comments »
CUPSS (“Check-Up Program for Small Systems”) is an asset management software tool for very small drinking water and wastewater systems. It allows system managers to evaluate their system to determine the most efficient, lowest cost approach to maintaining the desired level of service over the long term. This stand-alone, user-friendly software helps systems meet their public health goals and maintain compliance with environmental regulations. Specifically, CUPSS can help small water and wastewater systems to realize the following benefits: (i) better communication between utility staff and decision makers; (ii) migration from crisis management to informed decision making; (iii) more efficient and focused utility operations to achieve an optimal level of service; and, (iv) improved financial management and strategic planning to make the most use of limited resources. The software program is designed to help a utility answer five core questions: “what is the current state of my assets,” “what service level do my customers require,” “which assets are critical to sustained performance,” “what are my best capital improvement and operations and maintenance strategies,” and “what is my best long-term funding strategy.” No other free or commercially available product duplicates these features or is tailored to the unique needs of this audience. The CUPSS project was jointly undertaken by U.S. EPA/OW/OGWDW and U.S. EPA/OW/OWM, with input from a 50-member steering group, including representatives of the Rural Community Assistance Partnership, the National Rural Water Association, various environmental finance centers, state agencies, and local utilities. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment, Water Treatment | Tags: Improved Financial Managemen and Strategic Planning, Migration from Crisis Management to Informed Decision Making, Optimize Level of Service, Possible Benefits: Increased Communication | No Comments »
Water Works and Sewer Board of the City of Prichard
Prichard, Alabama
To comply with a State issued Consent Decree, the Water Works and Sewer Board of the City of Prichard, AL had to replace or repair 1,000 private sanitary sewer laterals to reduce inflow and infiltration that was leading to sanitary sewer overflows (SSOs). The anticipated cost of this effort was expected to be between $800,000 and $1 million, a significant amount for a community with a median household income of less than $20,000. Early struggles with excessive paperwork, inadequate equipment, and inexperienced personnel led to concerns by the State about the lack of progress. A revised strategy that simplified analysis and streamlined work was developed. The results were a 30 percent reduction in inflow and infiltration at a cost of $550,000. Overall SSO volumes were reduced by 95% and the number of recurring SSOs dropped from eight to one. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Sanitary Sewer, Water Treatment | Tags: Cost Savings, Reduced Inflow and Infiltration, Reduced Sanitary Sewer Overflows | No Comments »
Digester foaming is poorly understood. An increasing number of wastewater utilities are experiencing significant disruption of both liquid stream treatment and solids processing operations as a result of foaming episodes and, in some cases, costly structural damage to their digesters. A review of the literature indicates that we should anticipate increased foaming problems in the future as the use of biological nutrient removal (BNR) and membrane (MBR) processes become more prevalent, and as utilities operate at lower DO concentrations to contain operating costs and reduce their carbon footprint. This paper reviews research findings and actual operating experience related to digester foaming and describes foam formation and its behavior inside the digester. Measures to reduce the impacts of digester foaming such as changes in digester operational practices and facility and equipment modifications that can make a digestion complex more “foam tolerant” are reviewed, along with the prospects for their success based on observations at operating plants. Merely optimizing operational practices may not be sufficient in all cases, and some wastewater utilities have opted to make major process changes in an effort to reduce digester foaming. Early operating experience with two phase digestion, in particular, has shown considerable promise at several treatment plants with long histories of foaming in conventional digestion systems. Short of undertaking major capital improvements to effect process changes, there are more modest steps that can be taken to reduce the potential for facility damage and disruption from digester foaming. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment | Tags: Optimizing Operational Practices, Reduced Digester Foaming | No Comments »
New York City Department of Environmental Protection
New York City, New York
Upcoming construction work related to facilities upgrades will require a shut down of the Gowanus Flushing Tunnel for approximately 26 months. During this time, DO levels in the Canal are expected to drop to unsatisfactory levels. To address this problem, an interim system was developed to maintain satisfactory DO levels throughout Gowanus Canal at all times during a typical year. This centralized oxygenation system would withdraw Canal water at a rate of approximately 0.43 m3/s, oxygenate it to between 16 mg/L and 40 mg/L (as necessary to maintain desired ambient oxygen levels), and then discharge it via a diffuser system featuring 51 nozzles: one at the head end to support DO levels there, and 50 spaced 12 to 15 m apart between Sackett Street and the 4th Street turning basin—a reach of the upper Canal with minimal boat traffic and water depths of at least 1.2 m at mean low tide. The diffuser system is expected to achieve mixing across the width of the Canal without disturbing bottom sediments as long as the discharge ports can be placed at least 0.6 m below the surface and 0.6 m above the bottom at MLW. In a typical year, the system would need to operate from April through November. With the system discharging about 1,500 kg/d of oxygen (discharge concentration about 40 mg/L), the results show that DO levels of 3.0 mg/L would be maintained throughout the length of the Canal continuously throughout a typical year. Reducing the discharge to 40 percent of that level (600 kg/d of oxygen, or a discharge concentration of 16 mg/L) is projected to maintain satisfactory DO levels throughout most of the year and minimum DO levels of at least 1 mg/L throughout the Canal at all times. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Uncategorized | Tags: Improved Water Quality, Maintaining Satisfactory DO Levels | No Comments »
City of Westlake
Westlake, Ohio
The City of Westlake, Ohio has a program to remove Inflow and Infiltration (I/I) from both their public and private property segments of the sewer system. Specifically, the private property program uses residential dye testing to identify houses that have downspouts that contributes water into the sanitary sewer system. Historically, houses that test positive are scheduled for rehabilitation using a lateral liner from the mainline sewer to the house. A liner is inserted into the sanitary lateral which prohibits any stormwater or groundwater from entering the lateral. During the installation of the liners, it was found that a more detailed testing of the house would have shown that the deficiencies could have been corrected with cheaper, spot repairs or other methods of rehabilitation may have been more effective. The more detailed testing included dye testing as many downspouts as possible on the home being tested, and using two Closed Circuit Television Camera for the inspection The sanitary pipe layout is also identified to provide a more detailed knowledge of how the sanitary and storm pipes cross over each other. The CCTV cameras were installed in both the storm and sanitary sewer and advanced to the lateral of the test house. Subsequent testing followed by using a push camera in the lateral and recreating the test, further isolating the deficiency on the property. From this information the City was able to isolate which downspouts could be spot repaired, eliminating lateral lining rehabilitation resulting in a cost savings to the City. The detailed testing methods of both Phase I and II eliminated 70% of the lateral linings. Estimated cost per house for lining was $8000.00. In an area with 100 homes, in which 40% were positive, reducing 70% of the lateral lining is significant in terms of cost and additionally, accurately solving the problem. At the conclusion of the program, the City accurately identified private properties with inflow, removed stormwater from the sanitary sewer, minimized lateral rehabilitation and construction disruption, and provided overall project cost savings. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Sanitary Sewer, Water Treatment | Tags: Cost Savings, Minimized Lateral Rehabilitation, Reduced Inflow and Infiltration | No Comments »
A project team from the Water Environment Federation’s (WEF) Collection Systems Committee (CSC) developed the Private Property Virtual Library (PPVL) to be a resource of private property program-related resource materials available through the internet. Following the development of the PPVL and its launch in May 2007, a second project phase was undertaken to update/expand the library and to provide public outreach opportunities by conducting a webcast, conference presentations and a WEFTEC workshop. Since private property continues to be at the forefront of issues that public utilities are facing, the development and maintenance of the PPVL will be an on-going effort for the CSC. This paper includes a summary of the PPVL collection built to date, including participating utilities and an overview of the type of private property programs that these utilities have established, and an outline of the CSC project team’s plan for sustaining these efforts in the future. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Sanitary Sewer, Water Treatment | Tags: Beneficial Database, Improving Knowledge, Innovative Idea | No Comments »