Various WWTP's
Various States
A common problem encountered by traditional activated sludge systems involves failure
to develop biomass that separates efficiently from the liquid, leaving behind a clear
effluent that is low in BOD5 and suspended solids. Another problem is the bleed-through
of ammonia due to low detention time in the aeration tank. Oftentimes, failure may be
attributed to high return sludge flow rates (RSF) that affect not only clarifier hydraulics,
but also the growth of bacteria in the system. In order to promote efficient separation and
nitrification, system conditions should be maintained that favor the growth of flocforming
bacteria and nitrifiers over nuisance microorganisms that may include filaments.
Favorable conditions are encouraged by a regime of higher detention time and feast and
famine experienced by the bacteria in the system. By viewing system operation through
this lens, the following paper proposes that many activated sludge treatment systems can
achieve significant operational improvement through reduction in RSF. This paper
further provides a method for minimizing RSF and presents examples of successful
application of this method.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, 500K-1M, 50k-100k, Waste Water Treatment | Tags: Improved Effluent Quality, Improved Plant Efficiency, Maximized Feast/Famine Conditions, Maximized Nitrification, Reduced Return Sludge Flow Rates | No Comments »
Dallas Water Utilities (DWU)
Dallas, Texas
Dallas Water Utilities (DWU) has identified multiple projects within their wastewater treatment
plants (WWTPs) to support the Green Dallas Initiative for energy conservation and
sustainability. In 2010, a new co-generation facility at the Southside Wastewater Treatment Plant
(SWWTP) will be brought on-line. This facility will utilize digester gas for electricity
production. As part of the Green Dallas Initiative, and to optimize the co-generation facility, the
feasibility of adding high strength wastes to the anaerobic digesters at SWWTP to increase the
digester gas production was evaluated.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Electricity Production, Environmental Impact, Improved Plant Sustainability, Increased Digester Gas, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Montgomery County Water Services
Dayton, Ohio
Montgomery County Water Services (MCWS) is a regional water and sewer provider
with 11 water booster stations, 36 sewage lift stations, three equalization basins, and two
regional WWTPs (20 MGD and 13 MGD). MCWS provides an average 26 MGD
drinking water to 250,000 people. All drinking water is purchased from the City of
Dayton, OH. MCWS staff is comprised of 242 persons.
Responding to operational alarms and work requests at remote water and sanitary pump
stations often requires sending two people—one mechanic and one electrician. This often
creates unnecessary overtime as the corrective action usually requires either mechanical
or electrical repair—not both. In 2007, we began to study how to maintain core operation
and maintenance (O&M) responsibilities, save labor costs, provide improved mechanical
and electrical maintenance support using existing staff, and to develop better-skilled
maintenance employees. The ability to improve maintenance skills within the two
WWTPs was also examined.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Improved Employee Morale, Improved Maintenance, Improved Plant Reliability, Increased Equipment Service Life, Lobor Cost Savings, O&M Savings | No Comments »
Guelph Wastewater Treatment Plant
Guelph, Ontario (Canada)
Cost effective utility management strategies are fundamental to assimilate the multiplicity of
emerging challenges that municipalities must face, especially during downturns in the economy.
The paper demonstrates how organizational excellence, founded on authentic relationships and
applying effective management solutions, can result in significant performance improvement and
capacity benefits. The paper describes the significant human infrastructure changes necessary to
achieve and sustain the significant environmental and financial benefits.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Capital Cost Savings, Environmental Impact, Improved Management, Improved Plant Efficiency, Optimized Decision Making, Performance Improvement, Promote Employee Motivation | No Comments »
Portland Water Bureau
Portland, Oregon
A key challenge faced by utilities in managing their infrastructure is the need to confidently
determine short and long term asset investment requirements without getting buried in the detail
or waylaid by the poor quality of data, for thousands of individual assets. The paper will discuss
an approach using management strategies to simplify the management effort, appropriately
model short and long term future investment needs for all assets, result in improved confidence
in the quality and confidence of the analysis, – even in situations of limited data – and enhance
improved capital improvement program programming. It presents the benefits, implications, and
applicability of using management strategies as described by the implementation for the City of
Portland Water Bureau on the development of their future investment needs.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Improved Maintenance Operations, Improved Plant Reliability, Optimized Decision Making, Reduced Modeling Processing Time | No Comments »
Hill Canyon Wastewater Treatment Plant (HCTP)
Thousand Oaks, California
The City of Thousand Oaks’ Hill Canyon Wastewater Treatment Plant (HCTP) is seen by its
City Council and the citizens it serves as a unique community asset. The abstract title, $25.45, is
the City’s monthly sewer service charge for a single family residence, which reflects the City’s
pride in its environmental efforts and in this instance celebrating the creation of an
environmental and financially sustainable community asset at HCTP.
While the authors recognize that monthly sewer service charges can be affected by system age,
topography, varying regulatory requirements, and political priorities, they advocate a monthly
sewer service fee that meets outstanding debt requirements, allows for a proper Operations and
Maintenance budget, and saves money for the future.
The authors’ focus is on HCTP and how energy conservation, facility optimization, and
renewable energy generation has dramatically improved plant operations while keeping the
monthly sewer service charge stable for the foreseeable future.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment | Tags: Environmental Impact, Improved Customer Relations, Improved Plant Operations, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions, Renewable Energy Generation | No Comments »
Strass Wastewater Treatment Plant
Innsbruck, Austria (Europe)
With increasing operating costs and concerns regarding climate change, most wastewater
treatment facilities are under pressure to reduce the net energy used to treat a gallon of
wastewater. The ultimate goal would be to reduce the net energy use to the point that the
wastewater plant actually “breaks even” on energy use, by a combination of more efficient
operations and production of energy via digestion and power generation. This paper presents a
“roadmap” showing how a wastewater treatment plant can pursue the goal of energy self-sufficiency
via a combination of alternative philosophical approaches and innovations .
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, 50k-100k, Stormwater, Waste Water Treatment | Tags: Cost Savings, Energy Optimization, Energy Savings, Environmental Impact, Improved Plant Reliability, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Victoria, BC WWTP
Victoria, British Columbia (Canada)
A part of the planning effort for two green field secondary treatment plants that will service the
Core District of Victoria, British Columbia, a modified triple bottom line analysis was conducted
to identify technologies that meet the Province’s goals of cost effective, environmentally
sustainable socially responsible wastewater treatment. One element of this analysis was to
evaluate the impact of a combination of solids stabilization and end use alternatives on the net
greenhouse gas (GHG) emissions of the future utility. If managed appropriately, biosolids
production and utilization is a way to offset emissions from wastewater treatment operations and
accrue carbon credits. Long-term benefits to Capital Regional District (CRD) include compliance
with municipal carbon neutrality goals as well as potential revenue from the development of
carbon trading markets.
Analysis revealed significant carbon credits could be achieved with sludge stabilization by
anaerobic digestion and biosolids utilization in mine reclamation. The greatest reduction in GHG
emissions was achieved when the biogas from digestion was cleaned to natural gas line quality
for introduction to the commercial grid. Co-generation proved to be less beneficial due to the low
GHG intensity of the commercial power source available in the region. Additional carbon credits
are obtained from mine reclamation due to improvement of soil productivity and carbon
sequestration potential. However, it was also found that all of the end uses which capitalized on
either the fertilizer value or energy content of biosolids can provide significant benefits to a
wastewater utility.
Results of this analysis enabled the CRD to make an informed decision about how to produce
and use biosolids to maximize benefits from a sustainability perspective. However, it should be
noted that the findings of this study are contrary to other studies in the published literature. This
is attributed to the low GHG intensity associated with the power utility in the region (0.000022
tonne-CO2e/kWh). This observation suggests that utilities and engineering practitioners should
be conducting site specific inventory analysis and use great care when evaluating literature
reported results to make process decisions.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, 500K-1M, Waste Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Green Infrastructure, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Sugar Creek WWTP
Charlotte, North Carolina
When complete, the Sugar Creek WWTP Expansion Project increases the capacity of a 90-year old facility
from 20 mgd to 34 mgd in two sequential phases. Considering the uncertainty associated with rising
energy costs, regulatory requirements for greenhouse gas (GHG) emissions, and the desire to be a leader in
environmental stewardship, Charlotte-Mecklenburg Utilities (CMU) integrated carbon footprint analysis
into the Project. This analysis determined the base case carbon footprint – a 20 mgd facility, and measured
that against each of the incremental expansions – first to 28 mgd and subsequently to 34 mgd.
Completing the carbon footprint analysis for the Expansion Project:
- Provides a baseline for GHG for potential regulatory requirements.
- Drives energy optimization and energy efficiency into the design process.
- Considers GHGs in the alternatives evaluation.
- Quantifies a success story for CMU for this Expansion Project.
This analysis looked at the relative GHG emissions of process configuration alternatives considered and
discusses ideas for reducing the overall carbon footprint impact of the Sugar Creek WWTP expansion. In
addition, this paper quantifies the GHG emissions related to wastewater process components in general.
As a result of the Sugar Creek WWTP Expansion Project’s energy efficiency initiatives, CMU avoids an
estimated 1,595 metric tons of carbon dioxide equivalent emissions by 2014. Reduced emissions continue
to increase as influent flows increase over time, thus further reducing CMU GHG emissions on a unit flow
equivalent basis. Continued expansion to the Sugar Creek WWTP West Side process facilities can be
expected to reduce GHG emissions by nearly 30% (over alternative locations for treatment) by 2034. As
expected, indirect emissions associated with electricity purchases comprise over 80% of the overall
emissions for the Sugar Creek WWTP. Thus, the most significant impact that CMU can make is to
continue to focus on energy efficient design and operation.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Green Infrastructure, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Donald C. Tillman (DCT) and Los Angeles-Glendale (LAG) Water Reclamation Plants
Los Angeles, California
The principal source of nitrogen compounds in the Los Angeles River is from the City of Los
Angeles upstream plants, Donald C. Tillman (DCT) and the Los Angeles-Glendale (LAG) Water
Reclamation Plants (WRP’s). These WRP’s were major contributors, with up to 75% of the total
dry weather nitrogen load during dry weather periods. In 2007, the City has completed a nitrogen
removal program to reduce the nitrogen mass discharge from its WRP’s. As part of the process, a
comprehensive research effort was undertaken involving bench, pilot and full scale testing to
identify the most effective way to upgrade and optimize the existing WRP’s. The combined
findings were then used to upgrade WRP’s to “full” BNR plants without derating, carbon and
alkalinity addition utilizing the MLE (Modified Ludzack Ettinger) process. This paper will focus
on the MLE process design and treatment practices successfully implemented at the City’s
WRP’s.
Metric Used:
Posted: May 20th, 2011 | Filed under: 100K-500K, 500K-1M, Stormwater, Waste Water Treatment, Water Treatment | Tags: Environmental Impact, Improved Nitrogen Removal, Improved Nutrient Removal, Plant Optimization, Plant Sustainability | No Comments »