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Residents > » Water and environment > » Drinking water > » Drinking Water Quality> » How to care for your water storage tank

How to care for your water storage tank

Carlsbad Springs Trickle­Feed Water Distribution System

Do I need to treat my drinking water?Why do I need to clean the tank?Removing residue and sediment from your water storage tankKeeping your tank clean – How to disinfect your tank with chlorine bleachSafety FeaturesTank InformationContact Information

Do I need to treat my drinking water?

Drinking water is provided to Carlsbad Springs using a “trickle feed” water distribution system which supplieswater at a controlled rate and a reduced pressure to a storage tank located inside of the residentshomes. While City of Ottawa drinking water does not require further treatment once it enters the home,residents on the trickle feed system may need to perform occasional care and maintenance on their waterstorage tank.

Why do I need to clean the tank?

Accumulations of residues and sediments in your water tank are not usually a health concern but they canaffect the taste and odour of your drinking water and should be removed periodically.

Residues are thin films of organic materials such as algae that cling to the sides of the tank.Sediments are natural deposits of minerals such as calcium that settle to the bottom of your storagetank.

How do I remove residue and sediment from the water storage tank?

The pump outlet connection in your water storage tank is placed higher than the tank bottom to allowsediments and residues to settle to the bottom of the tank. Periodically residues and sediments should beremoved by using one of the following methods.

Before you start

Inform everyone in the house that you are cleaning the tank.

Do not use the flushing water for cooking or drinking.Fill up a jug of water for cooking and drinking purposes.

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Equipment : Note:

Clean long handled brush, orClean stick, orClean spray hose with nozzle

This method is suggested if you are removingresidue from the tank walls.

It will not remove all the sediment because the tankoutlet is located below the tank bottom.

Fill up a jug of water for cooking and drinking purposes.Do not use the cloudy water for eating or drinking.Consider using the water for other purposes such as: gardening, flooding a rink, washing your car orwatering your plants, etc.

Method 1 – Stir sediment and drain the water

Shut off the water:

Shut off the fill valve that supplies water to the reservoir tank

(The valve is located near your water meter)

Stir sediment and scrape the residue:

Stir the sediment in the tank until the water becomes cloudy and the sediment is suspended in thewater. (Use a clean spray hose, brush or stick)Open a cold water tap to drain the water.( choose a tap as close to the tank as possible )Spray or scrape the remaining residue and sediment from the tank bottom and sides.

Drain the water in the tank:

Drain the water until there is approximately 30 cm (1 foot ) remaining in the tank.Open the fill valve to provide more water to flush the sediment from the tank.Drain and flush until the water is no longer cloudy.Close the cold water tap.

Be careful not to drain the tank dry as this may damage the pump.

Method 2 – Siphon the sediment from the bottom of the tank

Hoses and clamps:

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Equipment : Note:

Flexible hoseClamp ( Optional )

You do not have to drain and refill the tank usingthis method but you need access to a nearby drain ora sump pit that is lower than the outlet of the tankthat you are draining.

Equipment : Note:

Hoses are available from a hardware store or beer & wine making supply store.Only use the hose for cleaning your water tank.Rinse the hose and hang it to dry after use.Store it in a clean plastic bag and mark the contents.

Fill the hose with water:

Connect the end of the siphon hose to the tap on the water pump.Immerse the other end of the hose 30 cm (1 ft) beneath the surface of the water in the tank.Close the lid of the tank to temporarily hold the hose in place.Open the tap to slowly purge the air and fill the hose with water.

When water flows from the pump end of the hose it will act as a vacuum and draw water from inside the tank.Remember to keep the end of the hose in the tank beneath the surface of the water or else you will losesuction.

Prepare the siphon hose:

Place a clamp on the pump end of the hose to prevent the water from escaping , orKink the pump end of the hose with your hands.Disconnect the end of the hose from the pump. Place the clamped or kinked end of the hose near the floor drain.Release the clamp allowing the water to flow.If water does not flow, air has entered the line or the hose is blocked or kinked.Secure the end of the hose or weight it down to keep it in place while it drains.

Suction the sediment:

Keep the hose submerged in the tank and remove the lid.Carefully drop the end of the hose to the bottom of the tankMove the end of the hose slowly back and forth to draw off the sediment.Continue “vacuuming” until the sediment is removed.Break the suction by lifting the end of the hose above the surface of water

Try not to disturb the bottom of the tank too much or else you may have to drain the entire tank to remove thecloudy water ( see Method 1 )

Keeping your tank clean – How to disinfect your tank with chlorine bleach

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Chlorine Bleach (6% non­scented)GogglesRubber gloves

The procedure is meant to be done with waterin the tank – draining and filling the tank is notrequired.

Add Chlorine Bleach (Sodium Hypochlorite) to disinfect your tank:

1) Add 3 Tablespoons (45 mL) of unscented household bleach (6% chlorine solution) to the top of the tank. Ifyou have two separate tanks, add 1­1/2 Tablespoons (22.5 mL) of bleach to each tank.

2) For a 550 Litre tank (120 Imperial Gallons), this will result in 1 ­ 3 mg/L of free chlorine in the tank. NOTE: Ifyour tank volume is different than 550 Litres, use a ratio of 1 Tablespoon (15 ml) bleach for every 200 Litres ofwater.

3) Wait for 1 hour.

4) Run each cold water tap for 1 minute to flush your household plumbing.

5) Resume normal use of tap water.

Adding 45 mL of bleach to a 550 Litre water tank will produce a concentration of 1­3 mg/L of free chlorine in thedrinking water. This amount is considered safe to drink and is typically found in municipal drinking waterthroughout Canada. The additional chlorine may cause a mild chlorine smell in your water for a few days butthis is not a health concern.

Covering your tank to prevent the growth of algae

Natural and artificial light can sometimes lead to the growth of algae in the tank. Although this is normally not ahealth concern, you can minimize the amount of algae growth in your water storage tank by keeping the tank indarkness. Cover the tank with a curtain or a heavy sheet.

Safety features and precautions

Float valve and air gap:

Your water storage tank is equipped with two safety features to protect your home and the safety of yourdrinking water; the float valve and the air gap.

The float valve regulates the level of water in the tank and prevents it from overflowing. Drinking water fromthe City’s central water supply enters your storage tank through a float valve located at the top of the tank (seeillustration page XX).

There is an intentional space left between the highest water level of the water and the height of the float valvecalled the air gap. The air gap is an important safety feature that prevents water from your tank from flowingback into the distribution system and contaminating the City water supply. Do not alter this safety feature byaltering the float or adding a hose to the valve.Pump Shut­Off Feature:

Be careful to not run the tank dry because this may damage the water pump. Each tank is equipped with ashut off feature to protect the pump. However your water pump may be damaged if this sensor malfunctions,and your pump continues to operate without water. Keep the level of water in the tank above 30 cm (1 foot)before you operate the pump. If you have to completely drain the tank turn the pump off at the switch when the

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water level is less than 30 cm and allow the tank to drain by gravity.

To ensure protection of your community’s water supply, it is important not to tamper with the float valve or theair gap. Please do not alter this air gap safety feature by adding a hose to the valve or by altering the float.

Going out of Town?

Good water quality depends on a continuous supply of clean treated water. With regular household water use,your storage reservoir will refill 1 to 2 times every 24 hours. If you are going away for more than 3 daysconsider draining your water tank to ensure good quality drinking water when you return.

Drain your tank before you leave:

Turn off the fill valve.Use up the water in the tank until it is gone; orOpen a tap to drain the water until the tank is empty.Turn off the pump at the switch.

When you return:

Close taps.Open the fill valve.Fill the tank until it is about half full.Turn on the pump at the switch; andOpen several cold water taps, for approximately 10 minutes, to flush any stagnant water out of yourplumbing system.

Tank Information

What size is the storage tank?

Homeowners were provided with several different tank options depending on the size of the family and thespace available for a storage tank inside the home. The largest tank size will provide the homeowner with up to2,700 Litres per day. Standard tank sizes are as follows:

Description Volume Height Diameter

Single

Tank

550 L

<120 Imp. Gal.>

760 mm

(30 in.)

1220 mm

< 48 in.>

Double

Tank

< 2 x 225 L >

550 L

<120 Imp. Gal.>

650 mm

(25 ½ in.)

927 mm

< 36 ½ in. >

Single 400 L 760 mm 990 mm

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Single

Tank

400 L

< 87 Imp. Gal. >

760 mm

(30 in.)

990 mm

< 39 in>

Who is responsible for the tank?

The water tank, float valve and water pump is part of the home plumbing system that is owned and maintainedby the homeowner. The water meter is owned and maintained by the City.

Contact us for additional information.

Customer Services BranchCity of OttawaEnvironmental Services Department TTY: (613) 580­2401 951 Clyde Ave. Ottawa, ON K1Z 5A6

Telephone: 3­1­1 Fax: 613­728­6928TTY: (613) 580­2401 E­mail: info­water@ottawa.ca