Orange County Sanitation District (OCSD)
Orange County, California
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.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment | Tags: Cost Savings, Improved Plant Efficiency, Project Management | No Comments »
San Jose/Santa Clara Water Pollution Control Plant (SJ/SC WPCP)
San Jose, California
In this study, Nocardia foam control using a combination of polymer addition and solids
retention time (SRT) reduction was investigated at the San Jose/Santa Clara Water Pollution
Control Plant (SJ/SC WPCP). A three-week continuous polymer addition at increased dosing
rates of 0.35 mg/l, 0.5 mg/l and 0.75 mg/l reduced Nocardia foam coverage from 100% to less
than 5%. But, foam accumulation returned to 95% coverage when polymer dosing was stopped
for a week. It only took a week to eliminate Nocardia foam from the aeration tanks when 0.5
mg/l polymer addition was accompanied by SRT reduction from eleven days to four days. A
potential effluent ammonia permit violation associated with SRT reduction was avoided by
aerating the anoxic compartment of the aeration tanks and converting the step-feed biological
process to plug flow mode. Except an increase in secondary effluent solids concentrations during
plug flow operations, polymer addition to the return activated sludge (RAS) and Nocardia
wasting to the digesters via dissolved air floatation did not cause foaming in the digesters nor
was it detrimental to effluent filtration.
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Posted: May 20th, 2011 | Filed under: >1M, Waste Water Treatment | Tags: Improved Plant Effluent, Improved Plant Operations, Nocardia Foam Control, Reduced Solids Retention Time | No Comments »
Point Loma WWTP
San Diego, California
San Diego’s Point Loma WWTP is a 160 MGD (240 MGD permitted), 100% advanced primary
treatment plant that has historically used iron salts for collection system sulfide control and
chemically enhanced primary treatment. Beginning in 2006, a PRI-SC® (Peroxide Regenerated
Iron – Sulfide Control) program was implemented by adding H2O2 at the intermediate pump
station PS2 (in place of the FeCl3), and again to the plant influent (ahead of FeCl3 addition for
CEPT). The application of PRI-SC® in the Point Loma system was designed to provide at least
$685/day in cost savings, to be achieved through reduced ferric chloride use at PS2 and Point
Loma, while improving sulfide control and CEPT performance. Since integrating the PRI-SC®
program full-time in 2008, SDMWD is realizing savings of approximately $4,700 per day
(~$1.72 million/yr) compared to the 2007 baseline iron salts program. At the same time, both
sulfide control and CEPT performance has improved. The cost savings were helped by the
hedging aspect of the PRI-SC® program – iron salt price volatility in 2008 and 2009 was
upwards of 45%. The PRI program has reduced the total iron salt use from the 2007 baseline rate
of 32.5 dry tons per day to approximately 19.3 dry tons per day in 2009, with the core savings
coming from an overall reduction in ferric chloride use at PS2 and the treatment plant (Table 1).
Significantly, ferric chloride use at PS2 was eliminated and, for CEPT, reduced from 24 mg/L to
10 mg/L (16.6 to 6.8 dry tons per day) with no loss in performance. In addition, total sulfide
removal has improved over baseline levels, and average CEPT performance exceeds the permit
levels at 89% for TSS and 65% for BOD, and effluent water quality has improved (with 60% less
spent iron (as FeS) present in the ocean discharge). For the most part, digester biogas H2S levels
were maintained below the permit requirement of < 40 ppm, but required approximately twice
the baseline FeCl2 feed rate. Even so, the overall program has maintained the stated savings
benefit.
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Posted: May 20th, 2011 | Filed under: >1M, Waste Water Treatment | Tags: Chemically Enhanced Primary Treatment, Cost Savings, Improved Operational Efficiency, Improved Plant Effluent, Improved Plant Performance, Sulfide Control | No Comments »
Miami-Dade Water and Sewer Department
Miami, Florida
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
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Effective Communication, Improved Customer Relations, Improved Plant Efficiency, Improved Work Morale | No Comments »
Werribee Treatment Plant
Melbourne, Australia
Waste Stabilization Ponds are used extensively for sewage treatment in moderate and
tropical climates, and represent one of the most cost-effective, reliable and easily
operated processes for the treating domestic and industrial wastes. One of the biggest
problems associated with pond treatment, however, is the high algae concentrations in the
effluent. In many cases algae are not a desirable by-product and are themselves a source
of secondary pollution, rich in carbonaceous and nitrogenous algae matter. This puts an
environmental strain on the receiving waters. One of the recently improved ways to
control algae is to use trickling filters with a heterotrophic biofilm created by augmenting
readily available sustenance to the filter media. This paper examines some of the hybrid
facilities being used that combine existing stabilization ponds with trickling filters or
activated sludge for enhanced biological degradation and polishing of the final effluent.
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Posted: May 20th, 2011 | Filed under: >1M, Waste Water Treatment | Tags: Algae Removal, Improved Plant Effluent, Improved Water Quality, Plant Sustainability, Reduced Carbon Footprint, Reduced Nitrogen Load, Reduced Nutrients, Reduced Solids | No Comments »
Milwaukee Metropolitan Sewerage District (MMSD)
Milwaukee, Wisconsin
Significant opportunities exist to increase renewable energy production using existing municipal
anaerobic digesters. Many wastes can be added to co-digest more carbon and produce more
methane. The objectives of this study were to identify and compare potential co-digestates,
determine synergistic, antagonistic and neutral co-digestion outcomes, quantify performance of
co-digestion for selected wastes and estimate economic benefits. Over 80 wastes were identified
from 54 facilities within 160 km of an existing municipal digester. The most promising wastes
(26 wastes) were characterized by biochemical methane potential (BMP) and other testing. A
simple economic comparison identified the greatest benefits for seven co-digestates.
Performance was investigated using bench-scale digesters receiving synthetic primary sludge
with and without co-digestates. Methane production rates in co-digesters were as much as 180%
greater than anticipated from the additional chemical oxygen demand (COD). Therefore,
significant synergism was observed. The VS destruction efficiencies were 49 and 33% higher
when co-digestates were present. Co-digestion is one method to increase renewable energy
production via anaerobic digestion.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment | Tags: Cost Savings, Environmental Impact, Improved Plant Performance, Improved Plant Sustainability, Increased Biogas Production, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Sacramento Area Sewer District
Sacramento, California
The Sacramento Area Sewer District (District) is in the final stages of implementing a new
Supervisory Control and Data Acquisition (SCADA) system for their 103 pump stations. While
implementing this new SCADA system, the District faced many challenges and obstacles, such
as developing the SCADA system requirements, designing the networking system, testing station
communication, and cutover to the new SCADA system. Implementing a new SCADA system
has provided the District with valuable experience that can be shared with other sewer agencies
that may also be in the process of replacing their SCADA system.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater | Tags: Improved Plant Efficiency, Improved Plant Performance, Improved Plant Reliability, Reduced Communication Failure | No Comments »
Miami-Dade Water and Sewer Department (MDWASD)
Miami, Florida
The Miami-Dade Water and Sewer Department (MDWASD) is implementing a major upgrade
program at the South District WWTP in response to capacity upgrade requirements, regulatory
mandates and commitments to optimize water resources. In the recent past, MDWASD initiated
implementation of one of the largest High Level Disinfection Programs in the country (285-mgd
peak hour). In general, wastewater treatment facilities deal with a large number of operating and
maintenance concerns, not the least of which is Figuring Out Good solutions to Fats, Oils and
Grease (FOG) problems. The MDWASD SDWWTP has unique FOG problems including typical
clogging and aesthetics concerns as well as the presence of very fine and dispersed FOG in its
secondary effluent. The chemical composition and characteristics of FOG result in an inherent
difficulty with its treatment and its impacts to WWTP’s, especially for effluent polishing (filtration
and chlorination) and advanced treatment with membranes. Based upon significant concerns
for impacts of Fats, Oils and Grease levels on the existing secondary WWTP and concerns for
clogging of 30 planned, large deep bed filters with a capacity rating of 285 mgd, an intensive
field sampling, testing and evaluation program for FOG sources and treatment options was completed.
Results of this evaluation were presented at WEFTEC 2005, and are hereinafter referred
to as “FOG Part 1”. Under FOG Part 1, FOG clogging of main WWTP pipelines, and existing
continuous backwash filters for effluent reuse onsite resulted in a detailed sampling and analytical
program that reviewed and characterized FOG sources. FOG characterization in the septage,
leachate and influent sources to the WWTP were addressed. Based upon this characterization,
influent sources and clarifier scum removal were identified as key areas of focus in the WWTP.
Related improvements to these key areas including the addition of a Septage Receiving and
Treatment System at the front end of the WWTP, improvements to FOG removal at the secondary
clarifiers, direct removal or vacuum removal of FOG from the wastewater flow stream, additional
separation and concentration of FOG that is removed from the wastewater flow, and the
addition of a select residuals management system for mixing, handling and disposal of FOG
along with other residuals (grit, screenings, etc) were recommended at this secondary plant in
preparation for the addition of an HLD system. These improvements are currently under construction
with a planned completion of around fall of 2011.
Concurrent with the HLD and FOG upgrades, MDWASD is implementing one of the country’s
largest water reclamation facilities – 21-mgd treatment, delivery of 18.6 mgd of finished product
water, used for augmentation of Miami-Dade County’s drinking water supply through groundwater
recharge. Thus, potential impacts of FOG on advanced treatment membrane processes- microfiltration
(MF) and reverse osmosis (RO) needed to be investigated due to potentially significant
impacts to capital costs, operation and maintenance and downtime that could limit capability
for reliably providing the necessary quantities of water to augment drinking water supplies in this
region.
An advanced treatment pilot system was constructed and tested using secondary effluent at the
SDWWTP. The pilot system consisted of deep bed filters and high level disinfection (HLD) with
chlorine solution, plus advanced wastewater treatment processes including MF, RO, ion exchange
(IX) and ultraviolet disinfection with advanced oxidation (UV-A). The pilot was utilized
to demonstrate treatment capability of the proposed process units, define design criteria, and better
understand operational and maintenance issues and potential concerns such as FOG.
At the time of the pilot testing, the majority of the upgrades for improved FOG removal from the
secondary process were still under construction, and therefore, the reclamation pilot was tested
under “worst-case” conditions from a FOG perspective. FOG influent and effluent data were collected
and analyzed. The pilot deep bed filter system removed FOG from the secondary process -
FOG levels of roughly 1 to 11 mg/l were reduced to roughly 1 to 3 mg/l. Also, visual observations
indicate that this removal of FOG at the filters did not impact the filter media. However,
due to the nature of the fine FOG particles at SDWWTP, FOG downstream of the filters still
needed to be addressed from the perspective of potential accumulation on the membranes. Regarding
potential impacts of FOG on the membranes, specific flux plotted versus run time for the
RO membranes shows relatively stable specific flux values, with gradual decline over a duration
of about 3 months. A cleaning cycle then was implemented for collection of “cleanability” data.
Subsequent to cleaning, the data generally show an increase in specific flux to roughly the initial
specific flux rate of the membranes which supports that FOG did not accumulate on the membranes.
Similarly, Permeate Conductivity Versus Run Time and showing Differential Pressure
Versus Run Time indicate relatively stable data over roughly 3 months. In general, pilot testing
supports that FOG, which has been a concern for the South District Secondary WWTP, is not
anticipated to impact the advanced treatment processes for production of reclaimed water that
will supplement the Miami-Dade County drinking water supply through groundwater recharging.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Advanced Wastewater, Cost Effective Alternative, Fats, Oils and Grease (FOG) Control, Optimize Water Resources, Reduced O&M Problems, Reduced Pipe Clogging | 1 Comment »
Metro Wastewater Reclamation District
Denver, Colorado
Ongoing construction at the Robert W. Hite Treatment Facility in Denver, CO, requires taking up to 25
percent of the secondary treatment capacity off-line for extended periods of time. Weekly average effluent
limits for nitrate require diligent management of day-to-day performance to prevent excursions and
maintain consistent denitrification. Process modeling indicated intermittent carbon limitations for
denitrification during the construction period, leading to design and installation of a temporary carbon
addition system. Acetic acid was selected as a supplemental carbon source due to intermittent demands.
Performance testing of the acetic acid addition system at the RWHTF gave treatment personnel
confidence in its operation and performance. The carbon addition system assisted in maintaining
compliance with weekly nitrate effluent limits during construction and remains in occasional use. This
paper reviews the potential limiting factors for denitrification, solutions for compliance during
construction, and general criteria for supplemental carbon addition chemical selection.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Construction Compliance, Decreased Effluent Nitrate Concentrations, Enhanced Denitrification Process, Improved Plant Confidence, Permit Compliance, Plant Optimization, Reduced Effluent Contaminants | 1 Comment »
Bureau of Sanitation, City of Los Angeles
Los Angeles, California
The goal of this research study is to enhance the efficiency and economy of carbon scrubbers in
controlling odors and VOCs at the wastewater collection and treatment facilities of Bureau of
Sanitation, City of Los Angeles. The objectives are: 1) to use carbon life expectancy and
breakthrough methods for monitoring carbon towers; 2) to reduce harmful impacts of pollutants
on public health and the environment; 3) and to recommend efficient active carbon application.
The butane activity and hydrogen sulfide breakthrough capacity of activated carbon were
assessed. Air streams were measured for odorous gases and VOCs. Single-stage wet scrubbers at
some wastewater treatment processes, while removing moderate levels of reduced sulfur
compounds, showed low to negative removal of VOCs when compared to carbon towers alone or
in series. Regular monitoring of activated carbon has resulted in useful information on carbon
change-out frequency and packing recommendations to enhance odor- and VOC-removal
capacity.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Effective Odor Monitoring, Cost Effective VOC Monitoring, Cost Savings, Efficient Active Carbon Application, Environmental Impact, Increased Public Health, Odor Control, VOC Reduction | No Comments »