How to care for your water storage tank

Transcription

1 19/05/2016 How to care for your water storage tank City of Ottawa 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 Trickle Feed 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 tank Keeping your tank clean How to disinfect your tank with chlorine bleach Safety Features Tank Information Contact Information Do I need to treat my drinking water? Drinking water is provided to Carlsbad Springs using a trickle feed water distribution system which supplies water at a controlled rate and a reduced pressure to a storage tank located inside of the residents homes. 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 water storage 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 can affect 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 storage tank. 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 allow sediments and residues to settle to the bottom of the tank. Periodically residues and sediments should be removed 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. and environment/drinking water and wells/how care your water storage tank 1/6

2 19/05/2016 How to care for your water storage tank City of Ottawa 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 or watering your plants, etc. Method 1 Stir sediment and drain the water Equipment : Clean long handled brush, or Clean stick, or Clean spray hose with nozzle Note: This method is suggested if you are removing residue from the tank walls. It will not remove all the sediment because the tank outlet is located below the tank bottom. 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 the water. (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: and environment/drinking water and wells/how care your water storage tank 2/6

3 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. Equipment : Note: Flexible hose Clamp ( Optional ) You do not have to drain and refill the tank using this method but you need access to a nearby drain or a sump pit that is lower than the outlet of the tank that you are draining. 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 lose suction. Prepare the siphon hose: Place a clamp on the pump end of the hose to prevent the water from escaping, or Kink 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 tank Move 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 the cloudy water ( see Method 1 ) Keeping your tank clean How to disinfect your tank with chlorine bleach Equipment : Note: and environment/drinking water and wells/how care your water storage tank 3/6

4 Chlorine Bleach (6% non scented) Goggles Rubber gloves The procedure is meant to be done with water in the tank draining and filling the tank is not required. 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. If you have two separate tanks, add 1 1/2 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: If your tank volume is different than 550 Litres, use a ratio of 1 Tablespoon (15 ml) bleach for every 200 Litres of water. 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 1 3 mg/l of free chlorine in the drinking water. This amount is considered safe to drink and is typically found in municipal drinking water throughout Canada. The additional chlorine may cause a mild chlorine smell in your water for a few days but this 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 a health concern, you can minimize the amount of algae growth in your water storage tank by keeping the tank in darkness. 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 your drinking 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 from the City s central water supply enters your storage tank through a float valve located at the top of the tank (see illustration page XX). There is an intentional space left between the highest water level of the water and the height of the float valve called the air gap. The air gap is an important safety feature that prevents water from your tank from flowing back into the distribution system and contaminating the City water supply. Do not alter this safety feature by altering the float or adding a hose to the valve. Pump Shut Off Feature: Be careful to not run the tank dry because this may damage the water pump. Each tank is equipped with a shut 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 and environment/drinking water and wells/how care your water storage tank 4/6

5 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 the air 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 days consider 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; or Open 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; and Open several cold water taps, for approximately 10 minutes, to flush any stagnant water out of your plumbing 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 the space available for a storage tank inside the home. The largest tank size will provide the homeowner with up to 2,700 Litres per day. Standard tank sizes are as follows: Description Volume Height Diameter Single 550 L 760 mm 1220 mm Tank <120 Imp. Gal.> (30 in.) < 48 in.> Double 550 L 650 mm 927 mm Tank <120 Imp. Gal.> (25 ½ in.) < 36 ½ in. > < 2 x 225 L > Single 400 L 760 mm 990 mm and environment/drinking water and wells/how care your water storage tank 5/6

6 Single 400 L 760 mm 990 mm Tank < 87 Imp. Gal. > (30 in.) < 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 maintained by the homeowner. The water meter is owned and maintained by the City. Contact us for additional information. Customer Services Branch City of Ottawa Environmental Services Department TTY: (613) Clyde Ave. Ottawa, ON K1Z 5A6 Telephone: Fax: TTY: (613) E mail: info water@ottawa.ca and environment/drinking water and wells/how care your water storage tank 6/6