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 »
Pittsburgh, Pennsylvania
Many older cities have antiquated sewer systems that are unable to accommodate increasing
amounts of impervious surface runoff from urban expansion. Excess stormwater runoff often
causes systems to become overwhelmed resulting in untreated raw sewage spills into lakes,
streams, and rivers.
Installation of green roofs addresses this problem by using plants to cover the roofs of buildings;
providing runoff control as well as lowering the amount of radiant heat absorbed by the roof.
Green layered roofing systems absorb water that otherwise would have become runoff and
entered the sewer system, reduce runoff flow rates, delay peak flows and, possibly, improve the
water quality of runoff. Quantitative information is presented on the long term performance of
two different green roof technologies in terms of initial runoff retardation, maximum peak flow
retardation, and quantity of flow as compared to companion control roofs located in the
Pittsburgh, Pennsylvania area.
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Posted: May 20th, 2011 | Filed under: >1M, <50K, 100K-500K, 500K-1M, 50k-100k, Stormwater, Waste Water Treatment, Water Treatment | Tags: Best Practices, Environmental Impact, Green Infrastructure, Improved Water Quality, Lowered Absorbed Radiant Heat, Reduced Carbon Footprint, Reduced Flooding, Reduced Raw Spillage Leaks, Reduced Runoff, Sewer Overflow Control | No Comments »
Manteca Wastewater Quality Control Facility
City of Manteca, California
The Manteca Wastewater Quality Control Facility (WQCF) is a 6.5-million gallons per day (mgd) rated
activated sludge plant. The WQCF treats typical municipal wastewater generated in the City of Manteca,
California and the neighboring City of Lathrop. The plant also receives seasonal discharges from a local
food processor. Over the last few years, the Manteca WQCF underwent a $60-million expansion to increase
its capacity from 6.5 to 9.87 mgd. Part of this expansion included the construction of a new influent pump
station with two mechanical screens, and a new dewatering building with two centrifugal dewatering
systems. Because housing developments within the City of Manteca are encroaching upon the plant, and a
new regional softball complex was constructed nearby, an odor control system needed to be designed and
built during the plant expansion to ensure that potential odor complaints from neighbors would be
minimized. Foul air from the influent pump station and the dewatering building is conveyed through large
ducts into a new open bed lava rock-based biofilter near the influent pump station. The biofilter is
composed of five beds, including one used as standby. The four duty beds were designed to treat 33,000
cubic feet per minute of foul air. Approximately 2,100 cubic yards of lava rock were needed for the
biofilter. To the authors’ knowledge, this open bed lava rock biofilter is the first and largest full scale
biofilter of this type in the nation.
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Posted: May 3rd, 2011 | Filed under: 50k-100k, Waste Water Treatment | Tags: Biofiltration, Reduced Odor Complaints, Reduced Odors, Signifcantly Reduced Maintenance Requirements | No Comments »
Wakarusa WRF
Lawrence, Kansas
Wastewater and biosolids treatment processes are designed to support regulatory requirements
for effluent quality and solids final use. However, it is common that future changes in the
regulatory environment or solids management area can require subsequent modifications to the
plant’s processes. While the objective of the original design is to provide for anticipated future
requirements, it can be difficult to predict when, or if, more stringent requirements will be
imposed. Since higher levels of treatment correspond to greater capital and operating costs,
treatment that exceeds anticipated needs is typically not desirable. Consequently, the goal is to
design flexible systems that meet current needs but minimize future facility obsolescence or
abandonment.
The design for the Wakarusa WRF in Lawrence, KS incorporates features that support initial
liquid stream and biosolids treatment requirements, but allows relatively easy conversions and
upgrades to meet potential tightening of effluent treatment criteria as well as changes in biosolids
final use within the lifespan of the plant. These design features avoid abandoning or replacing
equipment or facilities. This paper discusses design approaches incorporated in the Wakarusa
treatment processes that can maximize system flexibility, which, in turn, will minimize costs
associated with removal or abandonment of existing treatment processes.
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Posted: May 3rd, 2011 | Filed under: 50k-100k, Waste Water Treatment, Water Treatment | Tags: Biosolids Management, Cost Minimization, Planning for Future Compliance, Plant Optimization, Plant Sustainability, Reduced Plant Disruption | No Comments »
City of Tallahassee’s Underground Utilities
Tallahassee, Florida
Implementing an Environmental Management System program and achieving ISO 14001:2004 certification is a significant goal. Once achieved it becomes a milestone in the ongoing continual improvement management structure. This case study focuses on the EMS program in the City of Tallahassee’s Wastewater Treatment before and after certification, and how it provides the basic structure for future improvement programs. EMS program provides the basis for Utility Management. It does not end with achieving ISO 14001:2004 certification. It takes effort to maintain the program, but the benefits achieved far out weigh the efforts required. As a management system, it can help provide the structure needed to support management through reorganizations and maintain effectiveness during other major changes, such as the AWT project described herein. EMS is also the basis for integrating other Utility Management programs and makes them easier to implement. Past, Present and Future EMS provides the basis for continual improvement. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Waste Water Treatment | Tags: Cost Savings, Environmental Impact, Maximize Sustainability | No Comments »
United Utilities
United Kingdom
This paper will describe the results achieved by applying a Model Predictive Control (MPC) system to an Activated Sludge Plant (ASP) in the UK, with the objective of reducing energy consumption, whilst maintaining compliance within permitted environmental standards. Installation of the MPC system was initially an R&D project to assess if the suppliers performance expectations were valid. The successful outcome of the trial allowed the project to move to a permanent installation assessing the benefits over a longer period. During the R&D Phase the system demonstrated a high availability with an average of 20% energy reduction and peaks of 40% energy reduction when compared to conventional control. To date the system has reliably demonstrated energy savings and offers the potential to contribute significantly to United Utilities objective to reduce its Carbon emissions by 8% by 2012 if the benefits are replicated across the companies asset base of large ASP’s. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Electric, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Reduced Carbon Footprint | No Comments »
Hanover Park WRP
Hanover Park, Illinois
There is considerable interest by utilities to establish carbon footprints of wastewater treatment plants (WWTPs) with respect to greenhouse gas emissions, energy usage, energy production, and carbon credits for wastewater treatment. The methodologies and methods are at an early stage and have a great deal of uncertainty and variability. In this paper, a systematic and summary methodology to determine the carbon footprint of a WWTP including at operating, construction, process sinks and emitters’ levels has been presented. The paper also presents a case study based on this systematic summary methodology to illustrate the tools used. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Waste Water Treatment | Tags: Environmental Impact, Plant Sustainability, Reduce Carbon Footprint, Reduce Greenhouse Gas Emissions | No Comments »
Parkway WWTP and Henrico County WRF
Laurel, Maryland and Richmond, Virginia
Nitrogen removal to increasingly strict discharge standards requires, in many cases, the use of supplemental carbon (methanol, glycerol, acetate, sugar water, etc). The supplemental carbon provides the driving force for further biological denitrification and is typically applied as a polishing treatment such as to a post anoxic zone or a tertiary denitrification filter. The practical use of supplemental carbons has attracted substantial attention from both process optimization and cost minimization perspectives. This paper presents the operational experiences gained with the secondary and indirect impacts of supplemental carbon addition to BNR/ENR treatment facilities at the Parkway WWTP, located in Laurel, Maryland, and at the Henrico County WRF, located in Richmond, Virginia. The focus of the paper deals with the sometimes unexpected beneficial secondary effects of supplemental carbon addition to post anoxic zones in the BNR/ENR treatment processes. This paper has demonstrated secondary impacts from supplemental carbon addition for nitrogen removal. The benefits demonstrated included improved biological phosphorus removal, improved anoxic zone performance, increased biosynthesis for P and N removal, lower residual DO in the internal recycle, and improved utilization of influent rbCOD. Additionally various ways of calculating by the CODadded/Nremoved ratio was developed using effluent TN with and without supplemental carbon. The impact of lower NOx-N load in the RAS when the pre-anoxic zone is not fully utilized was shown to be a significant factor in the resulting CODadded/Nremoved ratio. These impacts illustrate the importance of considering the whole system response rather than an isolated portion of a reactor when evaluating supplemental carbon. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Waste Water Treatment | Tags: Environmental Impact, Improved Anoxic Zone Performance, Lower Residual DO, Nitrogen Removal, Phosphorus Removal | 1 Comment »
City of Appleton
Appleton, Wisconsin
The Conkey Pond and Northland Creek channel naturalization and floodplain lowering projects consist of a wet stormwater detention pond and naturalization of 286.5 meters (940 feet) of navigable stream in an industrial area in the City of Appleton, WI. Sustainable features include extensive use of natural materials and vegetation that reduce maintenance costs, improves water quality, add biodiversity and enhances habitat and aesthetics. These two facilities reduce downstream flood stages by about 0.82 meters (2.7 feet), and reduce TSS loadings within the city by 27 tonnes/year (30 tons/yr), which is about 11 percent of the remaining citywide TSS removal goal. Additional benefits include naturalization of a concrete lined channel, and the creation of wetlands in shallow depressional areas within the newly created floodplain. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Sanitary Sewer, Stormwater | Tags: Environmental Impact, Improved Water Quality, Reduced Downstream Flood Stages, Reduced Maintenance Costs, Reduced TSS Loading, Stormwater Sustainability | No Comments »
City of Quincy
Quincy, Massachusetts
Facing a $4 million combined account deficit in its water and sewer departments, the City of Quincy, Massachusetts performed an end-to-end audit of all systems, procedures, and personnel assignments from financial, managerial, organizational, and technical standpoints. The audits started with the review of the master water meters receiving water from the Massachusetts Water Resources Authority and ended with a revised abatement policy. Quincy executed a programmatic approach to modifying the manner in which it conducted business as sewer and water service providers, and increased the level of service to their customers; streamlined formerly cumbersome meter reading, data entry, and billing processes; and reduced its unaccounted-for water percentage and peak I/I flows. As a result, Quincy erased the projected deficit in one fiscal year, anticipating a surplus of $1 million. This situation is very common in municipalities across the country. Time constraints and budgetary concerns rarely allow for an overhaul of systems and processes. In this way, issues that may seem small when they first appear are allowed to snowball and become systemic problems across many of the utilities functions. The results achieved by Quincy in performing this audit and implementing changes based on the findings demonstrate the power of investing in comprehensive review of these processes and using a proactive and programmatic approach to bringing success to the municipally run utility. Source: WEFTEC 2009 Proceedings
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Posted: July 6th, 2010 | Filed under: 50k-100k, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Optimizing Organization | No Comments »