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Accurately Modeling the Effect of Dissolved Oxygen on Nitrification

justin — Tue, 06 Jul 2010 18:42:38 +0000

The prime objective of the work described in this paper was to determine the correct half saturation dissolved oxygen coefficients, KDO,AOB and KDO,NOB for the ammonia oxidizing and nitrite oxidizing bacteria, respectively for accurately simulating the Greeley WPCF, using the Biowin 3™ software. These parameters are often considered to be constants, whose values are generally accepted to be the default values embedded in the Biowin 3™ software. However, they are in fact not constants, and unless care is taken in the assignment of the proper values, errors in predicted air quantities or the required DO concentrations to achieve the necessary effluent ammonia concentrations will result. Determining the specific KDO value for a given application is important because it impacts the rate of nitrification achieved for a given oxygen concentration, the SRT, the consequent size of the aeration reactors, and the energy required to maintain required DO levels. Our other experiences subsequent to the work described in this paper showed that simulation results achieved by using the half saturation coefficients determined in this paper provide a much better goodness of fit than the current Biowin 3™ default values. For future plant simulations, the same type of stress tests carried out for this work are recommended as part of the wastewater characterization and calibration exercises. However, if this is not possible, adjusting the default values in Biowin 3™ to the values presented in this paper is recommended. The work presented in this paper can only be accomplished using a properly calibrated dynamic model. A steady state modeling approach would not produce the required results and would not be suitable to confirm nitrifier growth rates with plant scale measurements. Source: WEFTEC 2009 Proceedings

Strategic Planning: Key to Effectively Managing Your Utility

justin — Tue, 06 Jul 2010 18:23:13 +0000

Strategic planning is a key to being an effective utility, as described in the Effective Utility Attributes (U.S. EPA, 2007). When the City of Kissimmee divested its water department to form the Toho Water Authority, it was recognized that a strategic plan was needed to guide and align the organization to address its challenges and realize its opportunities. Five carefully and collaboratively selected key strategies were developed in the areas of customer service, water supply, workforce, infrastructure, and financial health. These strategies are also helping Toho to address the Attributes of an Effective Utility developed by the water sector in 2007 and 2008. Employing the Scan, Plan, Do approach has resulted in a viable Strategic Plan for Toho that is designed to accommodate continuous improvement. Toho used a proven process to develop a strong Strategic Plan that will serve to realize its vision for the future, consistent with the Ten Attributes of Effective Utilities. This Strategic Plan is proving to be a key to their success, now and in the future. Source: WEFTEC 2009 Proceedings

Inside-Out Leadership: Transforming Public Water and Wastewater Utilities Through Authentic Relationships

justin — Tue, 06 Jul 2010 18:19:15 +0000

This paper provides an alternative approach to transactional change methods for public sector leaders seeking to transform organizations internally. Described is a summary of an ongoing, four year study that began in June, 2005 with Montgomery County Water Services (MCWS) in Dayton, Ohio. The objective was to implement an innovative plan called “The Iceberg Concept” to build authentic relationships and overcome internal barriers including, low trust, limited respect, poor accountability, teamwork and communication. This was done by developing teams, the leader’s vision, clear expectations, shared core values, a decision-making path, coaching and a strategic plan. Outcomes have shown a reduction in grievances, workers compensation claims, water service disruptions and customer complaints. Continuous improvements were observed in communication, teamwork, accountability, hiring, selection and management development. Based on evidence thus far, this approach will provide long-term benefits and cost savings to Montgomery County and others seeking to improve efficiency and effectiveness. Source: WEFTEC 2009 Proceedings

Basin Size Optimization Forecasts Savings of $190 Million for PRASA

justin — Tue, 06 Jul 2010 18:13:21 +0000

The Puerto Rico Aqueduct and Sewer Authority (PRASA) faces large construction costs in order to improve its sewer systems to comply with the Clean Water Act. Using databases of flow, rainfall and GIS data, and a graduated flow monitoring basin optimization process helped to minimize estimated costs of subsequent SSES, rehabilitation and construction work. The process allowed PRASA to choose the lowest apparent overall cost approach for characterizing and improving 52 collection systems Island-Wide. Central components of the analysis were: 1) graduated basin size monitor placement and optimization, 2) basin size versus RDII isolation estimates and 3) a cost-effectiveness database. Using the three tools in combination as described herein, PRASA was able to reduce the estimated projected costs of follow-on work by an estimated $190 million while simultaneously focusing rehab on basins with excessive rainfall dependent infiltration and inflow (RDII) and on areas with capacity limitations. Presented herein is a process to optimize flow monitor site selection, tie the monitoring more tightly to capital improvement programs, boost quality of dynamic model results, increase the probability of highly effective rehabilitation and minimize follow-on SSES and construction scopes and costs. Graduated Basin Size selection can create multiple benefits that not only increase quality but also decrease costs. Benefits include:
• Increased model quality
• Lower short-term SSES costs
• Improved effectiveness of sewer rehabilitation
• Reduced long term CIP costs. Source: WEFTEC 2009 Proceedings

Enhancing EMS Via Integrated Data Management at the Moccasin Bend WWTP, Chattanooga,TN

justin — Tue, 06 Jul 2010 18:04:48 +0000

The Moccasin Bend Wastewater Treatment Plant in the City of Chattanooga (Chattanooga) recognized the need for electronically-assisted data management to support their biosolids generation, analysis, land application, and National Biosolids Partnership (NBP) Environmental Management System (EMS) programs. Chattanooga observed that data management is integral to support: 1) their developing EMS program, 2) mandated regulatory reporting, and 3) increased public and private scrutiny of their biosolids production and management. In addition, the lack of current, complete, and accurate data in a centralized location made it difficult to properly address day-to-day operational needs. This paper describes the successful implementation of a customized version of the Material Manager™ database (Material Matters, Inc, 2009), a centralized biosolids land application management tool that provides multiple functions: recordkeeping, management support, quality assurance and quality control (QA/QC), contractor oversight, and reporting. The idea of implementing new contractor oversight programs can induce friction. Most often, there is a real effort to preserve the status quo. Development and implementation of an EMS program was instrumental in moving both Chattanooga and their land application contractor toward a streamlined, accurate, and reliable data management system. The system also allowed Chattanooga to more easily share critical information with farmers and the public, providing needed confidence in records. Both Chattanooga and the land-application contractor wanted to have accurate hauling records to ensure the integrity of invoicing and payment. Properly managed, the efforts of implementing a more detailed biosolids data management and oversight program were judged as highly valuable and worthwhile. The efforts required are far outweighed by having an efficient data management system in place as well as the recognition of being part of a biosolids program that responsibly handles material, efficiently does business, and submits accurate regulatory reports. Source: WEFTEC 2009 Proceedings

Merging Environmental Management Systems at the Alexandria Sanitation Authority AWTF

justin — Tue, 06 Jul 2010 18:01:01 +0000

The Alexandria Sanitation Authority (ASA) operates a 54 mgd Advanced Wastewater Treatment Facility (AWTF) in Alexandria, Virginia. ASA has been awarded Tier 4 Platinum Certification under the National Biosolids Partnership (NBP) for its Biosolids EMS and under the Virginia Environmental Excellence Program (VEEP) has been awarded E3 (Exemplary Environmental Enterprise) status. This paper provides a case study for merging separate EMS systems including a summary of the process and lessons learned that will be of interest to facilities that currently have or are considering an EMS. It was learned that the following steps are part of a successful merging of management systems at ASA: 1) develop boundary conditions for the merger, such as maintaining certification from external auditors and organizations, and identifying organizational goals, such as streamlining staff efforts and documentation; 2) perform a baseline review of requirements for the MSs to identify similarities and differences; 3) develop alternatives for merging the MS which could range from a full merger into one EMS program, or where that is not practical, to streamlining terminology and documentation; and 4) develop an implementation plan that includes communication and training for all staff and awareness of timing of external audits. Source: WEFTEC 2009 Proceedings

Encina Wastewater Authority’s Innovative Management Plan for Class A Biosolids Pellets

justin — Tue, 06 Jul 2010 18:00:04 +0000

The Encina Wastewater Authority (EWA) recently upgraded the biosolids and energy management facilities at the Encina Water Pollution Control Facility (EWPCF) in Carlsbad, California. Biosolids processing improvements included replacement of existing dewatering equipment with centrifuges and the installation of a triple-pass, rotary drum heat dryer system to produce Class A biosolids pellets for beneficial reuse. As an integral part of its expansion project, EWA prepared a Biosolids Management Plan (BMP) through a multifaceted process that included formulation of evaluation factors for the decision framework, surveys of potential endusers, evaluation of various reuse/disposal (R/D) options using economic and qualitative analyses, generation of a Financial Model, preparation of a Business Plan, and other related elements. This paper presents an overview of the BMP, focusing on the major planning elements, development process, and several unique features that make the approach used in the BMP a valuable tool for development of EWA’s biosolids distribution and marketing program. Source: WEFTEC 2009 Proceedings

Case Study – Fargo, North Dakota: Hydrogen Peroxide for Regeneration of Ferrous Chloride, an Innovative Approach to Hydrogen Sulfide Control

justin — Tue, 06 Jul 2010 17:56:42 +0000

Historically, ferrous chloride (FeCl2) injection has been utilized to successfully control odors and corrosion within the sanitary sewer collection system of Fargo, North Dakota. However, increased odor complaints prompted an evaluation of the odor conditions present in the sanitary sewer system. Study results indicated that the current FeCl2 dosing rate was insufficient to control odors. In response, a number of liquid phase odor control treatment alternatives were evaluated. Due to the existing FeCl2 injection program, iron regeneration and improved odor control were realized through the innovative use of hydrogen peroxide. A program was initiated to demonstrate the efficacy of the proposed treatment strategy on a full-scale level. In response to improved sulfide treatment, reduced FeCl2 injection rates, and economic benefits realized during the demonstration program, the City of Fargo elected to incorporate PRI-SC as part of their upcoming collection system improvements. Variable dosing strategies for FeCl2 and H2O2 were incorporated for efficient odor control. The injection rates will fluctuate based on diurnal and seasonal sulfide loadings to prevent overdosing and reduce overall chemical costs. Hydrogen peroxide injection will be utilized to regenerate spent FeCl2 at a new 151,410 m3/d (40 mgd) sanitary lift station located in north Fargo. The PRI-SC technology will serve to reduce odors and corrosion in the 750 mm (30 inch) diameter forcemain from the new lift station and at the forcemain discharge at the WWTF headworks. While PRI-SC was found to be beneficial for the City of Fargo, any liquid phase technology should be evaluated for effectiveness based on site specific conditions. Source: WEFTEC 2009 Proceedings

Biosolids Irrigation for Tree Propagation

Killian Tobin — Sat, 19 Dec 2009 00:44:20 +0000

The Wastewater Division manages 600 acres of hybrid poplar trees, planted for nutrient uptake from biosolids which are irrigated on the tree plantation. The site can accept up to 2000 dry tons of biosolids on an indefinite basis under agronomic loading rates.

Here is where we would expand on the details of the plan, link to other resources, etc…