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 »
Annacis Island Wastewater Treatment Plant
Vancouver, British Columbia (Canada)
Annacis Island Wastewater Treatment Plant which is operated by Metro Vancouver, is leading
the way in working within a carbon based regulatory environment. British Columbia has
instituted carbon reduction legislation province wide, a leader in North America. As a result
public entities, such as Metro Vancouver, must be carbon neutral by 2012. In response the utility
is holistically investigating different approaches to achieve the required GHG reductions. One
approach now being actively pursued is the implementation of co-digestion at Annacis Island.
Having developed a the scope for a full co-digestion program at the plant, a pilot facility was
constructed to provide further process controls as well as a start at reducing emissions by codigesting
material at the plant. This project also provided Metro Vancouver a basis of handling
its own sludges from other wastewater treatment plants on an emergency or planned basis by
dual tasking the receiving facility to receive both sludges and co-digestion substrates.
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Posted: May 20th, 2011 | Filed under: 500K-1M, Waste Water Treatment | Tags: Cost Savings, Energy Production, Environmental Impact, Improved Plant Performance, Improved Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | 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 »
Pump stations are an integral part of wastewater collection and treatment systems. Their
applications can be quite varied: lift stations in the collection network pump raw sewage up to a
level where gravity can take over; pumping systems within the treatment plant move effluent
through various treatment stages or deliver it from the plant to agricultural users and others.
While wastewater pumps have a common function––moving fluid where gravity can’t––the
design of any individual pump station can depend on many factors.
Choosing the right pump station design for the application is a matter of balancing personal
preference with the requirements of the job, the necessity for energy efficiency and the need for
pump station reliability. This presentation examines three very different pumping system
designs, and weighs the advantages and disadvantages of each in the context of real-world
applications.
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Posted: May 20th, 2011 | Filed under: Stormwater, Waste Water Treatment | Tags: Efficient Lift Station Design, Energy Efficiency, Improved Plant Performance, Improved Plant Reliability, Improved Wastewater Pumping | No Comments »
Philadelphia Water Department (PWD)
Philadelphia, Pennsylvania
Because of issues with plant efficiency and the inconsistency of year round performance, the
Philadelphia Water Department (PWD) identified areas where they would like to see the
performance of their DAFT systems improve. The objective was to investigate factors that
would improve the DAFT’s performance, particularly by increasing float solids concentrations
and reducing the suspended solids loads returned to the treatment plants via the underflow. An
evaluation of existing plant operational data showed that in most cases the parameter that most
influences float solids concentration was the SVI and the parameter that most influences the
underflow concentration was the air/solids ratio.
Because of the importance of the air/solids ratio in maintaining low underflow solids
concentrations, an on site evaluation of the efficiency of the air saturation systems was
performed. Representative tanks were tested using a saturator monitoring unit which isolates a
small portion of the pressurized flow from the saturation tank and measures the mass of air
precipitated from the volume of flow. The mass of the precipitated air volume was compared to
the theoretical mass of air dissolved under the same ambient conditions to compute efficiency. A
well designed saturation system should provide an efficiency of approximately 88-percent. The
measured efficiencies ranged from approximately 48 to 78 percent. There are a number of
actions that could be taken to improve efficiencies including nitrogen purging from the saturator
headspace, verification that impingement plates are adequately designed and fully intact, and
adequately sized nozzles within the saturators. Improving the A/S ratios would reduce underflow
solids thereby reducing the return solids loads and overall operating costs at the plants.
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Posted: May 20th, 2011 | Filed under: >1M, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Improved Plant Efficiency, Improved Plant Performance, Increased Float Solids Concentration, Operating Savings, Optimized Air/Solids Ratio, Reduced Suspended Solids | No Comments »
City of Durham WWTF
Durham, North Carolina
The objective of this study was to utilize process modeling to predict effluent quality at design
flow for two biological nutrient removal (BNR) facilities, and determine what additional
improvements would be needed at each facility to meet limit of technology (LOT) nitrogen and
phosphorus standards. Then, optimization, pilot-testing, and bench-testing were conducted to
support this approach.
Process modeling using calibrated BioWin models determined that side stream treatment and
equalization, supplemental carbon addition, and increased nitrified recycle (NRCY) rates would
optimize nitrogen and phosphorus removal at both plants. Zone dissolved oxygen (DO) control
will also enhance denitrification and the effectiveness of the supplemental carbon. Both plants
are also considering the Ostara process to improve BPR.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Biological Nutrient Removal, Enhanced Denitrification, Improved Plant Performance, Optimized Nitrogen Removal, Optimized Phosphorus Removal, Plant Optimization | No Comments »
Metro Wastewater Reclamation District (MWRD)
Denver, Colorado
In 2007, the Metro Wastewater Reclamation District teamed with Black and Veatch and Brown
and Caldwell to implement a Capital Project Management Program to manage expenditures
approaching $100M annually. As the Program began it was successful in managing many
elements across multiple areas, but over time delays began to occur in business process
improvement work and products. In order to address these problems, a best practices-based
strategic planning process was implemented to align the Program team around the Program
vision, reprioritize improvement efforts, and improve work process interaction among the team.
The ultimate goal was to establish a repeatable continuous improvement-based planning and
execution methodology to develop the annual Program Plan. Throughout 2009 the Program team
focused on implementing high priority initiatives and continuously measured performance on
objectives. The 2010 planning effort was much more efficient as the Program team embraced
this approach and adapted the lessons learned throughout 2009.
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Posted: May 20th, 2011 | Filed under: >1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Improved Communication, Improved Plant Efficiency, Improved Plant Performance, Improved Strategic Planning, Improved Team Work, Plant Optimization | No Comments »
Most water utilities recognize the correlation between performance measurement and
effective utility management (EUM). Strong performance measurement, and management of
that data, establishes greater transparency that supports continuous improvement and
strengthens utilities. The Effective Utility Management primer, produced by the
Environmental Protection Agency and six national water/wastewater associations, have listed
Ten Attributes of Effectively Managed Water Sector Utilities (Ten Attributes) to help
utilities more effectively manage their utilities and have provided sample measures that serve
as a guide to utilities seeking to improve their performance measurement practices.
In turn, utilities are using performance indicators, such as those found in the QualServe
continuous improvement program, within their strategic planning process – aligning their
strategic plan with the Ten Attributes and integrated measures.
This paper/presentation illustrates how utilities have linked performance indicators that
incorporate the Ten Attributes into their strategic planning and performance management
practices, which has led to more effective utility management.
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Posted: May 20th, 2011 | Filed under: Stormwater, Waste Water Treatment, Water Treatment | Tags: Chemically Enhanced Primary Treatment, Cost Savings, Effective Utility Management, Emergency Response Readiness, Energy Savings, Improved Customer Relations, Improved Plant Performance, Improved Water Quality, Optimized Plant Improvement, Plant Sustainability | No Comments »