Summary descriptions

We are a not-for-profit Ontario water association of 1,700-plus professionals in the wastewater industry. We are committed to keeping Ontario's water clean. Our Ontario water association trains and certifies wastewater professionals, disseminates technical information, and promotes sound policies to benefit society through protection and enhancement of our water environment. Join today the Ontario water association, the preeminent organization of technical and professional individuals dedicated to the preservation and enhancement of Ontario’s water environment, we provide a valuable network for those involved in pollution abatement. We are a member association of WEF, an international organization with a vision of "Clean Water Everywhere".

Clean water Ontario is a hot topic. In July the US Congress passed a massive Energy Bill, signed by the President in August, that was the subject of intense debate for over five years. The bill fails to address the threat of global warming, provides billions of dollars in subsidies to the oil, gas, coal and nuclear industries, does not provide new investment in clean, renewable energy and does nothing to provide a sustainable energy future or to help consumers with rising energy costs. Clean water Ontario is aware of this. Let’s unite our forces and make the clean water of Ontario a priority.

The effluent must be disinfected to protect health. Effluent disinfection policy is issued through the Clean Water Act, State Water Code, Health and Safety Code, and other laws. The plant has been given daily limits, which are necessary for protecting human health, preventing fish kills, or preventing mortality to aquatic organisms. Below are summaries of relevant disinfection provisions of the NPDES permit. Effluent disinfection is a must. Enterococci effluent limits reflect the best bacteriological protection parameter for lightly used saltwater areas, and it has been chosen as the bacteriological parameter for the plant's effluent disinfection. The bacteriological standard had been total coliform prior to the 2003 permit.
 

An ecological pyramid indicates energy passing along from autotrophic organisms to carnivores at the top of the chain – and it includes the global water environment. Those at the bottom of the food chain are usually the smallest in size but not always, and are almost inevitably the largest in number. Those who feed off these primary producers are less in number, usually because they are larger and require more than one portion of prey per meal as a means of fulfilling nutritional requirements for a larger organism. The global water environment provides the basis for development. This situation continues to the top of the chain, where few secondary consumers are eaten by an even smaller amount of tertiary consumers. This is typical of a food chain in a global water environment community.

Research programs were undertaken to establish the stability of waste activated sludge generated from waste activated sludge treatment plants, both nutrient removal and conventional, and determine what further treatment is required to produce a substantially stabilised (ie. Non-odorous) sludge. It has been previously thought that waste activated sludge from extended aeration plants (sludge age of approximately 25 days) was sufficiently stabilised to permit dewatering and stockpiling without odour generation. However, experience at a number of treatment plants with large unaerated mass fractions for biological removal of nitrogen and phosphorus has demonstrated that these waste activated sludges are generally odorous.

Primary and secondary sludge thickening is beneficial to the anaerobic digestion process because it reduces biomass volume tank size and heating requirements. The BCUA utilizes four 65’ diameter gravity thickeners, and one centrifuge to thicken sludge prior to digestion. The gravity sludge thickening process consists of pumping both primary and secondary sludge into a gravity sludge thickening tank where the sludge is mixed and agitated gently by a rotating mechanism. The solids tend to settle to the bottom of the tank where they are pumped into the anaerobic digesters. The thickening tank supernatant is pumped to the headworks or primary effluent channel for treatment.

There are a number of ways that items can 'escape' from sewage systems and sewage treatment works, finding their way into rivers and the sea and possibly ending up on beaches. Sewage screening is important. One of the treatment processes at the beginning of sewage works is called sewage screening. Screens come in a range of sizes and shapes and their main function is to remove solid matter. Many works have been upgrading their screens and will have installed 6mm or even 3mm bar or mesh. 6mm bar screens will remove any objects that exceed 6mm in one dimension. A 3mm mesh screen will remove any objects that exceed 3mm in two dimensions.

In wet weather, combined sewers overflow into nearby receiving waters, where they cause pollution. To lessen this pollution, various measures have been developed, including storage of overflows in tanks and subsequent treatment at a central wastewater treatment plant. The older combined sewer overflow tanks may be undersized, however, and can overflow, while providing only limited treatment (by settling) of the CSOs passing through these tanks. The effectiveness of existing combined sewer overflow facilities needs improvement. Environment Canada has been supporting remediation of pollution in the Areas of Concern in the Great Lakes Basin . This particular study has been done by NWRI in support of the Toronto Waterfront Remedial Action Plan.

The removal of dissolved organic matter and nutrients from the wastewater takes place in the biological treatment step. It is done by the interaction of different types of bacteria and microorganisms, which require oxygen to live, grow and multiply in order to consume the organic matter. The resulting sludge (not a return activated sludge) from this process is called activated sludge. The non- returned activated sludge exists normally in the form of flakes, which besides living and dead biomass contain adsorbed, stored, as well as organic and mineral parts. The activated sludge flakes settle down to the bottom and can be separated from the cleaned wastewater. The main part of the separated sludge, which is transported back to the aeration basin, is called return activated sludge.

The sludge dewatering system works like this: Liquid sludge is pumped through an in-line static mixer where it is blended with polymer. From there, the sludge/polymer mixture continues into the Sludge Dewatering Unit. The same pump is utilized since mixing occurs on the fly and in-line. Once in the Sludge Dewatering Unit, solids are dewatered in a predetermined period of time. In a properly designed Dewatering System, 60-70 percent of free water should have drained within a matter of minutes if flow rate, polymer, and filter media are properly mated during the design phase. In many applications, solids will reach a dryness of 12-20 percent within 18-24 hours. Solids of this dryness should easily pass the Paint Filter Test.

Anaerobic sludge digestion is widely used to stabilize concentrated organic solids removed from settling tanks, biological filters and activated sludge plants. Sludge digestion renders the sludge suitable for reuse purposes such as land fill and garden mulch (local authority permitting). Sludge digestion tanks are normally covered with concrete or steel roof structures of different shape and structural design. Dome shaped covers are often used both in steel or concrete construction, steel covers can be fixed or floating. Floating covers in primary digestion tanks have a number of advantages. The more uniform gas pressure provides a high degree of operating safety and the maintained relationship between liquid level and mixing devices fitted on floating covers results in greater operating consistency.

Most First Nation communities use sewage lagoons for wastewater treatment. Sewage lagoons are man-made ponds or dyked depressions which rely on natural processes of mainly bacteria and algae to reduce organic matter to acceptable levels. Lagoons should be placed some distance from the community and oriented in such a fashion that winds do not carry odours towards the residences. The two types of sewage lagoons used are facultative and aerated.

The sewage is first pumped using three enclosed screw raw sewage pumps which provide a means of lifting the incoming sewage from the sewer system. We are not at the grit removal stage yet. The sewage then passes through the bar screens for rag removal. When the sewage moves to the grit tanks, the grit removal process starts. These tanks reduce the velocity of the sewage so that heavy particles may fall to the bottom. The solids are pumped to an auger pump that separates the water from the grit while the water moves onward. The grit (mostly inorganic solids) goes to a dumpster which is taken to a landfill. There may be two complete grit removal systems that are rotated in operation for equal hours.

Small wastewater ponds, built as decentralized plants without aeration systems, are many times used in remote sites for the treatment of municipal wastewater. By overloaded wastewater ponds the degradation capacity can be improved by using artificial aeration systems. Moreover, the area of a planed wastewater pond can be considerably reduced compared with that of a naturally aerated pond. Up to now only stationary operated aeration systems have been used, which are connected to the electricity grid. Where this connection is lacking, the use of decentralized, renewable energy systems is a sensible alternative.

Because of the uniqueness of the wastewater operators, we have established a category tailored especially to their needs: Professional Wastewater Operators. To qualify one must be actively employed by the responsible operating entity on the facility site on a day-to-day basis in the operation and maintenance of wastewater collection facilities, wastewater treatment facilities, or wastewater laboratories provided for such treatment facilities. You must be part of the wastewater operators league. Again there is a choice of membership, being a WEAO only or a WEF member which includes membership in the WEAO. Join today the Ontario water association, the preeminent organization of technical and professional individuals.

Facts: 1. NWRI expertise is supporting development of best practice guides (prepared under the leadership of the National Research Council and the Federation of Canadian Municipalities) - Source Controls for Storm Sewer Systems, Control of Infiltration and Inflow, and Source Controls for Sanitary Sewers - that will guide Canadian municipalities in managing urban waters and infrastructure assets. These studies are carried out in collaboration with the Great Lakes Sustainability Fund. 2. A pumping station will be constructed at Battery Park which will discharge settled clear water to the lake after it is disinfected by UV radiation. The station will also send settled solids to the sanitary sewer via a 600mm forcemain, which will mostly be situated inside an existing storm culvert. The forcemain will connect to the existing 1,500mm sanitary sewer (the mid-town interceptor sewer) north of King Street.

Incineration is widely used in Canada to reduce the volume of waste. Hundreds of incinerators -- including industrial kilns, boilers, and furnaces -- combust municipal and hazardous waste, while many more are used to burn medical waste. Whether waste incineration poses a health risk to incinerator employees or to people living and working nearby has been the subject of much debate. When operated properly by well-trained employees, modern waste incinerators and incineration pose little risk to public health. But older designs, human error, and equipment failure can result in higher-than-normal, short-term emissions that need to be studied further. Three federal agencies asked the Research Council to assess the relationship between waste incineration and human health.

Sewage treatment system of small communities requires the easy maintenance control. In addition, for large fluctuation in the influent load, the stable treatment performance is obtained, and further as there are many cases that the water-intake is made for the city and agricultural water in the downstream of the river where the effluent is discharged, the high removal performance is also required for the nutrients like nitrogen and phosphorus. Under such a background, the intermittent aeration system with single reactor (generally called the two-beat system) was developed. The intermittent aeration system with single reactor (the intermittent aeration system for short) is that, a submerged mechanical aerator for both anoxic and aerobic treatment is installed in a reactor of complete mixing type.

Storm sewers capture rainwater or snowmelt from residential and commercial properties. This water flows into nearby watercourses or the lake. Watercourses include creeks, streams and rivers - natural, concrete channels or underground pipes - that carry water, including stormwater and snowmelt from catchbasins into Lake Ontario. In a combined sewer, there is only one pipe which carries both sanitary and storm drainage. During wet weather, the volume of water may exceed the treatment plant's capacity and some of the water overflows untreated into the lake. Toronto has a program aimed at installing storm sewer pipes beside existing combined sewers. The storm sewers will carry stormwater and snowmelt and the old combined sewer will handle sanitary sewage only, eliminating the overflow in wet weather.

Sewage treatment is the process that removes the majority of the contaminants from waste-water or sewage and produces both a liquid effluent suitable for disposal to the natural environment and a sludge. To be effective, sewage must be conveyed to a treatment plant by appropriate pipes and infrastructure and the process itself must be subject to regulation and controls. Other wastewaters require often different and sometimes specialized treatment methods. Nuisance algae in lakes and rivers, chlorine and ammonia that are toxic to fish, growing populations and high operating costs - these are challenges facing many municipalities with sewage treatment plants.

We consider wastewater treatment as a water use because it is so interconnected with the other uses of water. If the term wastewater treatment is confusing to you, you might think of it as "sewage treatment." Nature has an amazing ability to cope with small amounts of water wastes and pollution, but it would be overwhelmed if we didn't treat the billions of gallons of wastewater and sewage produced every day before releasing it back to the environment. Wastewater treatment plants reduce pollutants in wastewater to a level nature can handle. Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals.

The Highland Creek Treatment Plant
Primary settling: The next step in the treatment process is called Primary Sedimentation where the flow enters large tanks and its velocity is reduced, allowing settleable solids in the wastewater to settle to the bottom. Sludge collectors in the tanks sweep the settled sludge (called Raw Sludge) into sludge hoppers located on the bottom of the tank at one end, from where the sludge is pumped to a sludge blending tank. There are 12 Primary Sedimentation Tanks, four 48.4 m x 28.4 m rectangular tanks, and eight 18.3 m square tanks with a total volume of approximately 26,000 m3, and a total surface area of 8,177.4 m2. Activated sludge treatment: In the activated sludge process, effluent from the Primary Sedimentation Tanks is mixed with Return Activated Sludge from Final Sedimentation Tanks. This mixed liquor is aerated in Aeration Tanks. The activated sludge is made up of micro-organisms containing bacteria, which are a natural part of wastewater used to break down the organic solids in water.

Water treatment goes back thousands of years although early forms consisted of little more than boiling and filtering the water to get clean drinking water.
In the mid-1800s the transmission of disease through drinking water was discovered and the need for clean drinking water increased. Water utilities in the United States began disinfecting water in the 20th century. The results were dramatic-a great decline in waterborne diseases such as typhoid, cholera, dysentery, and hepatitis, which had caused thousands of deaths throughout the country and still do in countries that don't treat their water. The treatment and disinfection of drinking water to get clean drinking water has saved more lives than all the doctors and hospitals in history.

Pollution is an unwelcome concentration of substances that are beyond the environment's capacity to handle, there is therefore need for pollution prevention. These substances are detrimental to people and other living things. This is why we need pollution prevention. In an undisturbed ecosystem, all substances are processed through an intricate network of biogeochemical cycles, such as the nitrogen and carbon cycles. During these cycles, substances are taken up by plants, move through the food chain to larger and more complex organisms, and when the latter die, are decomposed (broken down) into simpler forms to be used again when they are taken up by plants. The pollution prevention is necessary.

Water pollution is an unwelcome concentration of substances that are beyond the environment's capacity to handle, there is therefore need for water pollution control. These substances are detrimental to people and other living things. This is why we need water pollution control. In an undisturbed ecosystem, all substances are processed through an intricate network of biogeochemical cycles, such as the nitrogen and carbon cycles. During these cycles, substances are taken up by plants, move through the food chain to larger and more complex organisms, and when the latter die, are decomposed (broken down) into simpler forms to be used again when they are taken up by plants. Water pollution control is necessary.

Join today the water environment association, the preeminent organization of technical and professional individuals dedicated to the preservation and enhancement of Ontario’s water environment, we provide a valuable network for those involved in pollution abatement. We are a member association of WEF, an international organization with a vision of "Clean Water Everywhere". We are a not-for-profit water environment association of 1,700-plus professionals in the wastewater industry. We are committed to keeping Ontario's water clean. Our water environment association trains and certifies wastewater professionals, disseminates technical information, and promotes sound policies to benefit society through protection and enhancement of our water environment.