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Waterloo Water

posted Dec 5, 2011, 7:34 AM by George Finlay   [ updated Nov 14, 2017, 7:36 AM by Nat Cauldwell ]
In 1984 Mike Lazaridis, Mike Barnstijn, and Douglas Fregin, a trio of t
alented geeks, started a new company in Waterloo Ontario and called it Reseach In Motion (RIM). They succeeded beyond their wildest dreams with a gadget named Blackberry. With rapId growth at RIM, the University of Waterloo, and thriving insurance companies in town, there was a real population growth spurt in the area.

Along with increased load on the power grid, roads, and schools, this growth spurt meant an increased demand for water. They had been relying solely on ground water, primarily from the Waterloo Moraine, a huge glacial sand and gravel aquifer right under the town and surrounding region, left behind by the retreating Laurentide ice sheet about 20,000 years ago. 

There were already about 120 wells pumping 44 million gallons a day to an area with about 400,000 permanent residents as well as many businesses. To provide for a predicted 700,000 residents as well as increased business expected in the area by 2040, the Waterloo Regional government began long term planning for a pipeline from Lake Erie. In the meantime, they instituted a program of public education to encourage conservation, and established laws to limit outdoor use of potable water. In the past ten years, population has risen by 100,000 while average daily water use has fallen from 44 million gallons to 38 million gallons.

They also began tapping the Grand River to supplement water being pumped from the aquifer. Recently we toured the Mannheim Water plant which opened in 1992, purifying water from the Grand River to supply about 20 percent of the region’s needs. The Grand River originates near Dundalk Ontario, about 50 miles to the north of Waterloo, and drains into the north shore of Lake Erie about 80 miles southeast in Port Maitland, Ontario. 

Peter Clarke, Water Quality Specialist, helped us understand the way the plant deals with the undesirable contents of the river water. At the intake a weir strains out large objects like branches and logs. Large suspended particles get a chance to settle to the bottom of a holding reservoir before the water is taken into the plant to the first of a series of treatment tanks where aluminum chlorohydrate is added to remove the electrical charge around small suspended particles and cause them to coagulate and settle. Magnafloc, a water soluable polymer from BASF is also added as a coagulant aid. Looking down into the flocculation tank with Peter it looks like a huge snow globe.

In the next tank racks of inclined Lamella plate settlers are made up of many layers to multiply the surfaces where coagulant can settle and gradually collect in the bottom, while clarified water passes through to the next stage. The sludge collected in the bottom is trucked to a landfill.

The water is then fed through chambers where it is exposed to bubbles of ozone which is produced onsite by electrolyzing oxygen. Ozone is a strong oxidizer lethal to most water-borne microorganisms including cysts. At levels that can be used in drinking water treatment, chlorine, the most widely used primary disinfectant, has proved ineffective against Cryptosporidium cysts formed by a protozoa found in feces that can cause a potentially severe intestinal infection. Ozone inactivates these cysts, as does ultraviolet treatment, to which the water is exposed downstream after the next stage, filtration..

The already dramatically clearer water percolates through beds of sand and granular activated charcoal or anthracite to filter off finer suspended particles and absorb dissolved gases.

These beds are also home to thriving colonies of microorganisms, referred to as the “biological filter”.  They consume an array of undesirable substances, including nitrates and organic contaminants. University of Waterloo graduate student Ryan Snider recently completed a study on new methods to keep those good bugs thriving while clearing the build up of material caught in the filter. He and his advisor Dr. Monica Emelko are now working on implementing the changes Ryan’s research showed effective. They found that using slightly coarser grained activated charcoal and backwashing with non-chlorinated water significantly improved the performance of the microorganisms.

In the next treatment stage, excited by an electric current, mercury vapor inside quartz lamps emits light in the wavelengths 100 to 280 nanometers, referred to as germicidal ultra-violet (UV-C). Thymine, one of the four basic components of DNA is forced by UV-C to form an extra covalent bond that prevents enzymes from accurately copying the information in the DNA strand. This prevents the microbes from reproducing. It is effective against bacteria and viruses that cause polio, hepatitis, diphtheria, cholera, dysentery, typhoid, tuberculosis and many other diseases.

As effective as the ozone and UV treatments are, they do not protect the finished water from reinfection during delivery through the water mains. For that, chlorine remains the most effective tool. Besides an unpleasant odor, the introduction of chlorine into finished water may produce some level of trihalomethane (THM) such as chloroform when the chlorine combines with organic material still present in small quantities after filtration, especially in water from surface sources. There is evidence that THMs are carcinogens. The Mannheim plant introduces chloramines, compounds of chlorine and ammonia in place of free chlorine in the final treatment step. This reduces the level of free chlorine needed to protect the finished water, and therefore reduces THM levels. As an added benefit, the unpleasant odor of chlorine is also reduced in water finished with chloramines.

A striking feature of Water Service in Waterloo is the open publication of detailed information on water quality. For example, though there was not yet a defined maximum concentration in Ontario for 1,4 Dioxane in 2003, nor a requirement to test for it , the decision was made to start testing in the Waterloo system. When it was found in significant concentrations in ground water  feeding the Greenbrook Pumping Station, they published the finding and started treatment for it. Hydrogen peroxide and ultraviolet light are now being used together to oxidize this toxic organic compound, widely used in the past to stabilize the solvent trichloroethane.

In Waterloo like many other areas, bottled water companies have had success promoting their product by skillful use of advertising. Fuji Water, for example, has millions of customers convinced there is something inherently superior about water shipped from an island on the other side of the globe.
The Waterloo system to their credit is countering those marketing campaigns with good efforts of their own. Their website includes detailed information about water in formats useful at all public education levels from grade school to research studies. They have a water truck, labelled with the system logo, that makes appearances at pubic events to refill spectators’ own reusable water containers.



All in all, the Waterloo water system is a leader in its field.
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Nat Cauldwell,
Dec 6, 2011, 8:53 AM
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Nat Cauldwell,
Dec 6, 2011, 1:21 PM
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Nat Cauldwell,
Dec 6, 2011, 8:53 AM
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Plates.jpg
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Nat Cauldwell,
Dec 6, 2011, 8:51 AM
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Nat Cauldwell,
Dec 6, 2011, 8:54 AM
ą
Nat Cauldwell,
Dec 6, 2011, 1:21 PM
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