Water Treatment Plant

History

 

The City of Melville purchased the raw water reservoir (Crescent Creek Reservoir) from Canadian National Railway in 1958. The Dam was built in 1921. The City built the water treatment plant in 1959, the water treatment plant has had several upgrades since 1959.

 

In 1977 a 4546 cubic metre storage reservoir was added next to the water treatment plant to provide treated water during peak times. in 1979 the Crescent Creek Reservoir was expanded to its present day capacity of 4,406,000 cubic metres.

 

In 1983 the water treatment plant was expanded to include a new package treatment plant that would treat more water for the city's demands. This new plant removed many years of water restrictions.

 

The surface water supply was prone to drought conditions, so in 1989 the City of Melville drilled a new well near an old well site west of the city. In 1990 Canada's first Electro Dialysis Reversal (EDR) treatment plant began desalination of well water. This EDR treatment plant was designed as a drought proofing during low water years in the surface water. Because the water quality was far superior to the surface water the City decided to run this plant 24/7 and use the surface water during higher demand times.

 

The well water quality after treatment is excellent, however, the City only had one well and a treatment system that is limited to a specific quantity. The city decided to do further investigations into drilling a second well and treatment facilities to decrease the reliance on surface water. In 2003 the city drilled a new well with piping and treatment plant to follow.

 

 

The water treatment plant has a rated capacity of 6134 m3/day surface water and 1900 m3/day well water for a combined capacity of 8034 m3/day. The overview shows three plants; plant one is the original plant built in 1959 its operation is limited to filtration only because of capacity, plant two is the package plant built in 1985 and is fully functional, plant three is the EDR desalination plant built in 1990. Also included on the overview are pumps, storage, and a distribution system.

 

 

The City of Melville has two sources of supply wells and surface water. The two wells are situated just West of the City along Highway #15; one well was constructed in 1989, while the second was constructed in 2003. Surface water supply is from the Crescent Creek Reservoir approximately two kilometres West of the Water Treatment Plant. The reservoir covers an area of over 1,600,000 square metres, the reservoir's deepest portion is ten metres and has a total storage capacity of 4,406,000 cubic metres. During the winter months, the reservoir is aerated primarily to maintain the planted fish population. The lake is a popular angling area noted for its perch and pickerel catches.

 

The Water Treatment Plant is rated as a Class 4 (highest) facility according to the Water Security Agency. There are three other facilities with this rating. The treatment plant supplies treated water to the City of Melville and surrounding rural customers.

 

Well water is pumped from the Hatfield aquifer to the EDR treatment system. Iron and manganese are removed using potassium permanganate and manganese  green sand filters. The EDR desalination process removes approximately 75% of dissolved minerals. The wastewater is pumped down a disposal well. 

 

Surface water is pumped from the Crescent Creek Reservoir and is pre-treated with carbon and potassium permanganate. At the treatment plant water is treated with aluminium sulphate and poly electrolytes to remove colour and turbidity. After clarification and filtration caustic and chlorine are added to adjust pH and disinfect water prior to storage and pumping to the distribution system. The water tower is part of the distribution system and provides a constant water pressure.

 

The average consumption for each person per day is about 400 lpcd ( litres per capita per day). The average water pumped per day to the city is about 1900 cubic metres.

 

Treated well water and surface water are mixed at the treatment plant. On an annual average, the mixture of well vs surface water is 60% vs. 40% respectively. However, there are times when operational and maintenance requires one or the other to run more often. During summer months surface water is used to supplement the well water more due to higher water demands.