Sustainability Archive » Stormwater

Improving Utility O&M and Capital Decisions by Incorporating the Concepts of Asset Condition, Criticality and Risk

justin — Fri, 20 May 2011 16:47:36 +0000

Toho Water Authority (TWA) provides water, wastewater and reclaimed water service to
approximately 85,000 customers in Kissimmee Florida. For the past three years the Utility has
been implementing an asset management program for their over $700 million dollars worth of
water, wastewater, and reclaimed water assets. During this program TWA has made significant
investments in asset management information systems including INFOR EAM Computer
Maintenance Management System (CMMS) and an ESRI Geographic Information System (GIS)
database. These two systems now contain the comprehensive asset inventory for the utility. A
built-in interface between the programs allows the CMMS and GIS to integrate and share
information.
Once the software implementation and inventory was complete, TWA wanted to obtain
additional physical, financial, and asset management attributes for their assets to support the
overall asset management program, which includes evaluating asset risk, measuring utility
performance and effectively planning for future renewal and replacement needs. The CMMS
software was configured to store the attribute data in January of 2008 after conducting interactive
workshops with staff to define the attributes. In August of 2008 a pilot project was implemented
to define the process to consistently collect and calculate the asset data including condition,
consequence of failure, risk, and replacement cost for all vertical assets in the utility. The pilot
area contained one water plant, one wastewater plant and 47 lift stations that fed the wastewater
plant. This paper will describe the methodology that was established to obtain and calculate the
data, the results of the data analysis, and uses for the data to further their asset management
program and overall decision making.

Project Management – Overcoming Resistance to Change

justin — Fri, 20 May 2011 16:47:35 +0000

The purpose of this paper is to help project managers in public agencies understand the reasons
for resistance to change and provide steps to overcome or minimize the resistance. These are
challenging times for all public agencies so there is a need to be wise stewards of public
resources. An increase in efficiency may require reorganizing departments, reallocating
resources and realigning staff roles and responsibilities and managing projects differently. These
all require change and growth from all levels of employees in an organization. Reducing the
resistance to change requires strong leadership qualities combined with proper project
management skills. If these combined skills are incorporated into projects that implement
change, they will be successful and can result in significant cost savings. The Orange County
Sanitation District (OCSD) has undergone many of the aforementioned changes in the past
couple of years and continues its austerity through efficiency while completing all tasks.

Converting Residuals To Reuse: Taking Aeration Out Of Oxidation

justin — Fri, 20 May 2011 16:47:35 +0000

Aeration accounts for up to 60% of the total energy required for a typical activated sludge wastewater plant. A new process was developed that decreases aeration demand during secondary wastewater treatment. This process, called BIOBROx, blends oxidant-laden residuals with screened municipal wastewater followed by treatment in a fixed-bed (FXB) bioreactor. Pilot testing showed that the BIOBROx process was effective at removing perchlorate and nitrate from membrane residuals. Considerable biochemical oxygen demand (BOD) and suspended solids were also removed across the process. A 3.8-mgd BIOBROx demonstration facility is now operating at the Magna Water District. The BIOBROx train treats 1/3 to 1/2 of Magna’s total wastewater flow, uses no aeration, has an empty-bed contact time of 10 minutes, and has a footprint that is one-twentieth the size of the conventional secondary processes. Preliminary data show effluent that even under these conditions, BOD5 and TSS levels in the effluent from the BIOBROx process are similar to those in Magna’s conventional secondary treatment effluent.

CSO Control, Treatment and Disinfection at Saco Wastewater Treatment Plant using Advanced Vortex Technologies

justin — Fri, 20 May 2011 16:47:34 +0000

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.

Selection of a Solids Management Plan to Meet a Sewerage District’s Vision of Becoming a Leader in Sustainability

justin — Fri, 20 May 2011 16:47:34 +0000

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.

Integrated Approach to Biosolids Management for a Utility with Multiple Small Facilities

justin — Fri, 20 May 2011 16:47:06 +0000

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.

EPA’s Response to the Current Status of CSO Control Efforts Development of New Tools and Guidance

justin — Fri, 20 May 2011 16:47:06 +0000

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.

An Economic Approach to Off-Line Storage: A Means of Mitigating SSOs

justin — Fri, 20 May 2011 16:47:05 +0000

This paper reports on the use of a two cell 30-million-gallon (MG) equalization basin and diesel
engine-driven pump station as a means of mitigating sanitary sewer overflows (SSOs). The
ultimate capacity of the pump station, which utilizes vertical turbine solids handling pumps
(VTSH) arranged in a self-cleaning trench-style wet well, is 68 million gallons per day (MGD).
Configuring the pump station with diesel engine-driven pumps provided a 20-year, $1 million
present worth savings in comparison to a conventional electrical motor driven pump station
arrangement. The use of diesel engine-driven pumps eliminated the peak electrical usage of 450-
horsepower (HP) electrical motors, as well as the need for variable frequency drives and
redundant power generation needs during electrical outage time periods. A supplemental 150-
kilowatt (kW) generator was installed to provide emergency power needs for SCADA, seal water
systems, influent screen, and a 50-HP maintenance pump for wetwell cleaning.

“Say it Loud, Say it Clear”: Effective Communication Under Duress

justin — Fri, 20 May 2011 16:47:05 +0000

Difficult times require an extra effort when it comes to communication. With all of the talk
about layoffs, budget cuts and salary reductions, utilities face an uphill battle against the internal
“rumor mill”, declining morale during the current economic downturn, and external pressures to
do more with less. A well-developed communication strategy is one key to sustaining
performance in the face of these challenges.
The Water Distribution and Transmission Division of the Miami-Dade Water and Sewer
Department is meeting these challenges “head-on” with an aggressive communication program
that has been developed and refined over a number of years. This presentation will highlight that
program from the perspectives of the Division Chief, managers and supervisors, and employees.
Extensive interviews at various levels of the organization identified key communication
strategies and tactics that are helping this agency maintain a high level of performance through
the most significant economic crisis the US has faced since the Great Depression. These
strategies and tactics will be discussed in detail and results will be presented as a “business case”
for optimizing communication during challenging times.
Focus of Study and Results:
This presentation will include discussion in communication topic areas including:
1. General overview of communication strategies and tactics
2. Types, frequencies, and styles for effective communication
3. Directional communication – up, down, and across the organization
4. Formal and informal communication methods and tools
5. Strengths and weaknesses of various communication approaches
6. Value and results from effective communication programs

Recycled Water Corrosivity Control: The Additional Advantage of Disinfection with Sodium Hypochlorite

justin — Fri, 20 May 2011 16:47:05 +0000

Recycled water corrosivity control is an important consideration in the design and operation of
wastewater treatment plants and recycled water distribution systems. Even mild corrosivity can
have significant long-term impacts on equipment and pipelines. Corrosivity control involves
adjustments to water chemistry (pH, alkalinity, hardness, etc.), but how adjustments are
implemented can vary based on existing treatment processes. For the Michelson Water
Recycling Plant, corrosivity control was achieved by modifying an existing process rather than
adding a new one. This paper discusses the investigation and evaluation of several treatment
alternatives for corrosivity control. The study resulted in replacing chlorine gas disinfection with
sodium hypochlorite disinfection, which offered the additional advantage of addressing
operational, regulatory, and safety concerns associated with the use and storage of gaseous
chlorine. The study highlights the connection between disinfection and corrosivity, an important
consideration for other agencies starting water recycling programs to meet increasing water
demand.