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  • Catchment area

    A catchment area is naturally defined and set off by mountain crests and differences in ground level, which define the drainage divide. Each drop of water falling within a certain catchment area, regardless of where specifically within the catchment area, will reach the same outfall in the end: water course, lake, sea, ocean, etc.

    Each catchment area is characterized by different parameters, either geometric (surface, slope), pedologic (nature and capacity of soil infiltration), urbanistic (presence of buildings) but also physico-chemical and biologic (water quality).

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  • Construction of measurement rooms

    Turn-key installation processes for flumes and weirs in the municipal and industrial fields (aluminum plants, pulp and paper, mines, cities, etc.) with guaranteed measurement accuracy, allowing for regulation and real-time management of effluents.

    • More than one hundred flumes and weirs installed
    • Licence for contractors specialized in the field
    • Liability and environmental insurance

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  • Dilution method

    A tracer, rhodamine, is used in the dilution method, which had numerous advantages, including on-site fluorometer analytical possibilities, and is used particularly in watercourses exempt from industrial effluent. This method requires that the water be relatively pH neutral, not very coloured, with little suspended or organic material and that it contain no oxidizing agent, such as chlorine.

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  • Dye tracing

    With this technique, a non-toxic dye is added to a sink or running water and monitored for the appearance of colour in storm sewer and sanitary storm sewer manholes as well as at outfalls or discharge points in the receiving water body.

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  • Harnessing sources

    These are connections acting as entry points for parasitic water that is intermittently or continually channelled into a sewer system during heavy rains or during snow melting, as a result of various circumstances (ex: connections to French (rubble) drains, flat roof drains or gutters, reverse-slope driveway drains or sumps in sanitary networks, the presence of perforations on man-hole covers located in low-lying areas, interception of ditches and streams, storm sewer connections to the sanitary network, etc.).

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  • Infrared detector

    To measure the thickness of pond sludge, we calculate the difference between the total height (water and sludge) and the height of the water above the sludge. For these measurements, we use an infrared detector with a photoelectric receptor (electric eye). This device is highly precise.

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  • Lightweight disk method

    In order to validate measurements taken using an infrared detector, a bicycle wheel with a fine screen (mosquito netting) and a measuring tape is descended into the bottom of the water. The height of the measured water on the measuring tape when the wheel stops descending, (which indicates that it is sitting on the sludge bed) is noted and compared to the reading obtained with the infrared detector.

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  • Loads

    Loads are calculated by multiplying water volumes by concentrations.

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  • Night-time flow measurement

    To study water infiltration and harnessing in the sewer system, it is recommended to evaluate the quantities of water during the night when there are fewer users.

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  • Reel method

    The reel method may be used when the tracer method proves inadequate

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  • Reversed connections

    A service connection or equipment defect which allows blackwater to flow into areas other than a domestic or combined sewer system, such as a storm sewer system, onto the ground, into a ditch or a watercourse, when the building in question is served by a domestic or combined sewer system.

    The following are included in this definition:

    • a faulty service connection between a building and the public sewer system
    • a poor connection of a plumbing fixture inside a building
    • a double crossover between the pipelines in public sewer systems allowing for blackwater from a domestic or combined sewer system to flow into a storm sewer system
    • a leak from a domestic or combined sewer system which spills out into a storm sewer conduit, onto the ground, into a ditch or into a watercourse
    • when blackwater spills over into a storm sewer network, onto the ground, into a ditch or into a watercourse, where the building is equipped with a domestic or combined sewer

    (Source: Guide méthodologique pour la recherche et l'élimination des raccordements inversés dans les réseaux de collecte d'eaux usées municipales)

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  • Sediment

    Sediments are a mix of soil particles of various sizes. When they are transported by water, the sediments are displaced according to their size. They may travel with different nutrients, including phosphorus. In a calm zone, a property of these particles is to form a deposit by settling (sedimentation).

    Water quality and sediments are inter-related and therefore, the presence of sediments may greatly influence water quality. If water is polluted downstream of populated, cultivated and/or industrialized zones by older and/or recent influences, the sediments could be sent back into a suspended state, among other things, during floods and following works that bring about changes in the current or erosion. In this case, the sediments may accumulate or release into the water various nutrients or micropollutants, such as phosphorus, which promotes the occurrence of blue-green algae. Sediment characterization then becomes necessary.

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  • Smoke test

    Smoke tests allow for the detection of the main harnessing sources of a sanitary system. The smoke is propulsed into the sewer system to detect any illegal connections. These connections are gutters, sumps, etc. connected to the domestic sewer. They are the primary cause of storm sewer backups during heavy rains and snow melting periods in springtime.

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  • Validation of measurement equipment

    Assessment of liquid discharge

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