 Influents Spring 2009 Hamilton |
Model-based evaluation of alternatives for treating Wet Weather Flows
Process modeling is a powerful tool to assist with the design, evaluation, and optimization of wastewater treatment systems. One potential application of dynamic modeling is for evaluating alternatives for treating wet weather flows (WWFs). WWFs are intermittent and highly variable in both flow rate and pollutant concentration, making the treatment systems inherently dynamic. The City of Hamilton, Ontario owns and operates one of the largest and most complex combined sewer systems (CSSs) on the Great Lakes. Over 600 km of combined sewers collect sanitary and storm water for treatment at the Woodward Avenue Wastewater Treatment Plant. |
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Wastewater Treatment
Wastewater is the mixture of liquid and solid materials that are flushed down toilets, sinks and drains. This material then flows through a network of pipes that make up the city’s sanitary sewer system
As a result, treatment of wastewater is an essential process that prevents contamination and protects our waterways, drinking water resources and natural water resources. |
Wastewater Treatment Process |
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Renewable Power from wastewater process – Cogeneration Facility
The City of Hamilton opened Hamilton Renewable Power Incorporated in September 2006. This 1.6 megawatt cogeneration facility takes methane gas created by the wastewater treatment process and produces electricity and heat. The cogeneration facility converts 32 per cent of the available energy in the digester gas to electrical energy (electricity) and 48 per cent to thermal energy (heat).
It is anticipated the Facility will meet the electrical needs of approximately 1,600 households and will reduce approximately 6,500 tonnes of Green House Gas every year and approximately 130,000 tonnes of Green House Gas over the 20-year contract lifetime of the project. This environmentally sustainable business venture will provide the City of Hamilton with an annual net savings of approximately $800,000 through energy sales to the province and heat that is harvested from the engine to be used in the wastewater facilities.
For more information about this please view the Integration of a Digester Gas Co-Generation Facility at Woodward Avenue Wastewater Treatment Plant document. |
Combined Sewers
The older portions of the City of Hamilton’s sewer system collects both domestic sewage and stormwater runoff in a single pipe called a combined sewer. This mixture, called combined sewage, is then sent to the Woodward Avenue Wastewater Treatment Plant for treatment.
Combined Sewer Overflow Storage Tanks
The City of Hamilton's Pollution Control Plan (completed in 1991) recommended the construction of a number of Combined Sewer Overflow storage tanks to reduce the frequency and volume of combined sewer overflow to local receiving waters. The storage tanks catch the overflows before it enters the receiving waters. The tanks store the excess combined sewage during rainstorms, and later send the contents to the Wastewater Treatment Plant where it can be treated after the storms subside.
The tanks are filled by gravity, and when flows subside after a rainstorm, their liquid contents are drained or pumped back into the combined sewer system and conveyed to the Woodward Avenue Wastewater Treatment Plant where they are treated. Solids, which have settled to the bottom of the tank, are then washed from the tank’s floor by a system of spray nozzles or sediment flushing tanks, to reduce odours from the tank. The wash water is collected in a trough at the bottom of the tank and is also pumped back into the combined sewer system and sent to the Treatment Plant for treatment.
Combined Sewer Overflow Storage Tanks in Hamilton
|
Tank |
Date |
Volume (m3) |
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Greenhill #1 |
1988 |
83,500 |
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Bayfront Park |
1993 |
21,000 |
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James Street |
1993 |
3,200 |
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Main/King |
1997 |
77,100 |
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Eastwood Park |
1997 |
27,350 |
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Greenhill #2 |
2003 |
66,750 |
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Royal Avenue |
2007 |
15,000 |
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Ewen |
pending |
5,935 |
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Red Hill Valley |
Under construction |
14,200 (in-line) | |