Water quality changes over time, it’s a fact.
Naturally, water quality changes over time. Change in quality of a construction site discharge, in particular, is caused by either variations in the quality of the source water that are too great to be addressed by the implemented treatment process or by an operational failure of the water treatment plant. Operational failure of a mechanical water treatment system is typically a result of mechanical failure, power failure or depletion of one of the treatment chemicals (CO2, coagulant, flocculant, other).
It goes without saying that, to adequately characterize variations in quality, repeat measurements are necessary.
Status quo of construction site discharge monitoring in Canada.
Currently, even the most stringent regulations in Canada, both municipal and provincial, require weekly or at most bi-weekly testing of construction site discharges typically supplemented by additional requirement to verify discharge quality during or after significant rain events.
Consider construction site discharging 24/7 at 500 US gpm (31.5 L/s) as an example.
Fig. 1. A construction site discharging effluent from their on-site treatment system at 500 US gpm.
Strict adherence to the weekly monitoring frequency would mean that this site would have discharged over 5 million US gallons (or 19 million liters) of water between two sampling events. If in that period of time there happened to be an issue with the treatment process or a drastic change in the influent water quality, this site could have discharged huge volumes of water that was potentially toxic to aquatic organisms.
Of course, pumping is unlikely to continue 24/7 for the entire duration of construction and more typical discharge flow rates usually range somewhere between 60 and 300 gpm, but you get the idea.
Can we do better?
Here, at Flowlink Environmental, we believe we CAN, and this is what we strive to achieve with our real-time monitoring and control solutions.
A real-time water quality monitor, also sometimes called a continuous water quality monitor or an automated in-line water quality analyzer, is a device that automatically measures water quality with the sufficiently small time interval between the repeated measurements. Real-time monitors can be equipped with different online sensors to measure various chemical and physical properties of water, such as pH, turbidity, temperature, dissolved oxygen concentration, conductivity, etc. Rapidly improving online sensor technology has the ability to drastically broaden the horizons for real-time water quality monitoring and create useful and exciting new applications of this technology.
Operation of a real-time monitoring system with discharge shutoff functionality combined with telemetry and cloud-based software can provide a nearly continuous record of water quality and other parameters. Flowlink intelligent software not only records, logs and displays water quality data as real-time graphs: it instantaneously reacts to the changes in water quality and power or network loss and automatically calculates chemical load in the discharged water and other useful metrics. As a result, users get access to a number of useful insights about performance of the water treatment systems in real-time which enables proactive decision making and prevention-based approach.
Interested in working with Flowlink?
If you are interested in trying out one of our systems on your project, please get in touch! We would welcome an opportunity to demonstrate the value of our technology in real life to you and show you how we can do it better!
Here you can find a convenient, up-to-date summary of guidelines for pH, turbidity and TSS across various municipalities in Lower Mainland and Fraser Valley. Web-links to the municipal bylaws are provided.