Hangtown Creek Water Reclamation Facility (HCWRF)
City of Placerville, California
The Hangtown Creek Water Reclamation Facility (HCWRF) is located in the Sierra Nevada
foothills of Northern California. The treatment plant capacity is 101 L/s (2.3 mgd) average dry
weather flow. Substantial improvements were required to comply with new waste discharge
requirements (including nutrient removal, year-round tertiary treatment, reduction of disinfection
byproducts, and effluent cooling) and a cease and desist order, sludge treatment regulations, to
address safety issues. A substantial increase in annual operation and maintenance (O&M) cost
was probable with the addition of the upgraded treatment processes and need to meet more
stringent effluent limits.
The design strategy included upgrading critical processes and replacing inefficient outdated
technology to improve treatment plant efficiency while mitigating increases in overall operation
O&M cost. Since the City service area is of limited size and the number of connections is not
growing, controlling O&M costs was a major concern of the City.
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Posted: May 20th, 2011 | Filed under: <50K, Waste Water Treatment | Tags: Improved Treatment Plant Efficiency, O&M Cost Savings, Plant Improvement | No Comments »
District of Columbia Water and Sewer Authority (DC Water)
Washington, DC
Due to potential risks associated with transportation and handling of liquid chlorine, the District
of Columbia Water and Sewer Authority (DC Water), switched to the use of liquid sodium
hypochlorite as the disinfecting agent at the Blue Plains Advanced Wastewater Treatment Plant
(AWTP). The escalating cost of bulk purchased sodium hypochlorite prompted DC Water to
commission a study to evaluate disinfection alternatives that: 1) are compatible with existing
treatment processes; 2) meet all plant effluent disinfection requirements; and 3) reduce life cycle
costs of disinfection.
The study involved a detailed technical, economic and non-economic evaluation of the feasibility
of constructing and operating an onsite sodium hypochlorite generation facility in lieu of bulk
purchase. Economic analyses included capital and O&M costs, life cycle costs over a 30-year
time horizon, and sensitivity of price of bulk sodium hypochlorite and salt, electric power cost,
debt service on life cycle costs.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Capital Savings, Improved Plant Reliability, O&M Cost Savings | No Comments »
Microconstituents are a diverse group of relatively unmonitored and unregulated chemicals
found in consumer and industrial products that have been shown to occur at trace levels in
wastewater discharges, ambient receiving waters, and drinking water supplies. Total Organic
Carbon (TOC) is one surrogate that can be used for the organic microconstituent compounds.
The main objective of this study is to investigate the cost-effectiveness of available TOC
removal technologies for small, privately-owned wastewater treatment plants (WWTPs). The
reliabilities of each treatment process are also evaluated by comparison of their ability to comply
with regulatory effluent limits. Life-cycle cost analyses over a 20-year planning period were
performed to account for capital cost and operation and maintenance (O&M) costs at varying
flow rates.
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Posted: May 20th, 2011 | Filed under: Waste Water Treatment | Tags: Efficient Total Organic Carbon Removal, Improved Plant Reliability, O&M Cost Savings, Regulatory Compliance | No Comments »
Inland Empire Utilities Agency
Chino, California
Carollo Engineers (Carollo), together with the Inland Empire Utilities Agency (IEUA) developed
an innovative planning tool, OPTIMOTM, which uses optimization algorithms to minimize
operational costs for a complex and interconnected collection, wastewater treatment, and
recycled water system. The model applies mass and energy balances to simulate wastewater flow
routing, treatment, recycle water distribution, and energy demand and supply. The model
accounts for multiple physical and water quality constraints, while maximizing the use of
recycled water and minimizing total system operations and maintenance costs, including power,
chemical, and labor demands. This integrated model is a planning tool for IEUA that simplifies
the complex interactions of their extensive wastewater system to maximize capacity, minimize
costs, and balance risks, while meeting regulatory constraints. This paper presents the
development and application of the model to IEUA, and benefits to other agencies.
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Posted: May 3rd, 2011 | Filed under: 500K-1M, Waste Water Treatment, Water Treatment | Tags: Capital Savings, Improved System Efficiency, Maximize Capacity, Meet Regulatory Constraints, O&M Cost Savings, Reduced Risks | No Comments »
Metropolitan Water Reclamation District of Greater Chicago
Chicago, Illinois
The District’s mission includes the protection of our water environment, specifically the water
quality of Lake Michigan, the region’s drinking water source, at all times in compliance with our
NPDES permits. All of the energy management measures listed above were implemented
without compromising or diminishing our ability to meet our primary goal. As an environmental
organization, the District has a responsibility to not only to achieve its primary function of
treating wastewater, but also to do so in an environmentally responsible manner.
The measures discussed above ultimately result not only in O&M cost savings but energy use
reduction. The decrease in energy use reduces the emissions of greenhouse gases, which has
taken on a new significance with the current concern regarding global warming and its predicted
dire effects on the planet and its ecosystems. They also demonstrate how vigilant maintenance of
public systems can have benefits above and beyond the immediate results.
The success of any initiative is directly dependent on the knowledge, dedication and efforts of
personnel involved not only in establishing protocol, but also in implementing and performing
the associated tasks on the daily basis. The District’s success, as measured by the cost savings
and energy reduction shown in the tables above, demonstrates the ability of District personnel to
work collaboratively as a team. The District will continue to seek additional measures to be
implemented at all facilities to not only save taxpayer money but also to operate more efficiently
to better improve the overall environment.
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Posted: August 24th, 2010 | Filed under: >1M, Sanitary Sewer, Waste Water Treatment, Water Treatment | Tags: Energy Savings, Environmental Impact, Improved Plant Sustainability, O&M Cost Savings, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »