|
Red Deer's first water treatment plant (1950s) |
Upgraded and completed in 1983 |
 |
The mission of the Water Treatment Plant is, "to provide high quality treated water to meet volume demand for our customers by using the best available and economical technologies, by continuing to train and challenge employees, and by conforming to the regulatory requirements of the Province of Alberta. Health, environmental, and aesthetic considerations are of the utmost importance to The City of Red Deer in achieving customer satisfaction."
The Purpose of Water Treatment
The main purpose of water treatment is to eliminate pathogens and chemicals of concern that may exist in the source water supply (i.e., river). Pathogens are defined as agents that cause infection in a living host. Chemicals of concern are those shown to cause a negative impact on human health. Treatment requirements are continually reviewed in the context of changing source water characteristics, our understanding of pathogens and chemicals of concern, and improvements in treatment technology.
Watershed
The Red Deer river supplies drinking water for the City of Red Deer, as well as many other cities and towns. The river has its source in the Rocky Mountains and flows east and south to enter the South Saskatchewan River. The watershed area for the Red Deer River is approximately 49,650 sq km.
Municipal Water Treatment
The City of Red Deer supports a multiple barrier approach to potable water treatment. If one barrier should fail, other treatment barriers are in place to ensure the safety of the water supply. These barriers are:
Raw material intake. Raw or untreated water enters the treatment process via an in stream above surface intake structure. The water flows into the Low Lift Pumphouse. A rough screen in the pumphouse removes large debris such as sticks, branches, and weeds.
Low Lift Pumphouse. Large vertical turbine pumps are used to move the raw water into the treatment facility. Treatment chemicals such as potassium permanganate and powder activated carbon (PAC) can be added in the pumphouse to help control taste and odor.
Clarification
Clarification involves three major process steps: coagulation, flocculation, and sedimentation.
Coagulation. A chemical process that modifies the nature of the raw water to encourage the subsequent development of floccules (agglomerations of small particles present in the water). The coagulant chemical is injected into the vortex of the Low Lift Pumps to get good mixing and to allow as much time as possible for the chemical reaction to occur.
Flocculation. A mixing process that promotes the formation of larger heavy floccules. Red Deer uses a new-patented system called “Ballasted Flocculation”, where very fine sand that has been coated with a polymer is introduced into coagulated water. Addition of the micro-sand increases the density of the floccules; this allows more efficient subsequent settlement.
Sedimentation. Sedimentation occurs when the floc particles created in the flocculation process become heavy enough to settle down to the bottom of the settling tank. The floc sludge is passed through a supporting process that allows recovery and reuse of the micro-sand.
Filtration
Red Deer uses dual media filters, composed of fine quartz sand and anthracite coal, to remove fine particulate matter from the water. There are 5 processes at work in a media filter. These are sedimentation, adsorption, flocculation, and biological metabolism.
Chemical Disinfection
Disinfection is the final water treatment process. Red Deer use chlorine gas to reduce the bacteria and virus populations to a safe level. Chlorine is the most commonly used disinfectant chemical in the water treatment industry. Chlorine levels in water called “residual chlorine” are easily measured and provide instant feedback on water quality.
UV Disinfection
Some pathogens, such as Giardia and Cryptosporidium, are resistant to chlorine disinfection. Ultraviolet (UV) disinfection sterilizes (i.e., unable to reproduce) a variety of pathogens that are more resistant to chlorine disinfection. A UV process was recently installed in the treatment plant.
Additional Treatment
There are three additional treatment steps before the treatment process is complete.
Fluoridation. Fluoride is added to the water to help prevent tooth decay
Water stabilization. Caustic soda is added to adjust the pH of the water so that it is neither scale forming or acidic.
Chloramination. Ammonia is added to form chloramines residual in the water. This ensures adequate disinfection in the distribution system.
For more information contact Environmental Services either by phone at (403) 342-8750, Monday through Friday between 7:30 a.m. and 4:30 p.m., or by e-mail at environmentalservices@reddeer.ca.
| 
