|
| 2. |
Hook up a 24 gallon per day output metering pump
to the line, using a injection check valve so the water cannot back-feed
into the metering pump. See Figure 2. If metering pump has a different
output, adjust speed of pump or solution strength. In this procedure,
a concentrated chlorine residual will be injected while the pipes
are under line pressure from the street or city-water system, so a
check valve is used on the piping, to prevent the water from backing
up into the metering pump. Make sure to use a metering pump that can
develop pressures higher than the line pressure you are injecting
into. |
| 3. |
Determine
flow rate. Open up the faucets hot and cold and read the water
meter to determine gallons per minute. |
| 4. |
Use the formula and example below to adjust
the metering pump: |
| NEW! You can use
our Online Metering Pump Selector
on the left of this
page to calculate how many gallons/liters of bleach you
will use per day. |
| Example:
Compute metering pump setting to achieve 100 ppm applied chlorine
dosage in a water stream flowing at 5 gallons per minute, using
full strength household bleach: |
| 5 gpm x 100 ppm x 1440 (minutes/day) |
 |
| 52,500 (ppm of laundry bleach) |
|
= |
13.7 gallons per day |
| Output of pump is 24 gallons per day. The example
above calls for 13.7 gallons a day output. |
| 13.7 gallons per day |
|
| 24.0 gallons per day |
|
= |
.57 or 57% Set metering pump speed to 57%, which is 13.7 gal/day |
|
| 5. |
Run the water in the house or piping until
the bleach solution has filled all the pipes and a strong odor of
chlorine is coming from the fixtures or faucets, both hot and cold.
If possible, test the water at each fixture to verify that there is
at least a 50 ppm chlorine residual, using a DPD method test kit.
|
| 6. |
Allow the water to sit for 12 hours. Retest
for chlorine residual. If the water contains less than 10 ppm of chlorine,
repeat entire procedure. The slime, scale, and odor-producing bacteria
will interact with the chlorine and reduce the amount of chlorine
residual in the piping. If it uses up all the chlorine, or the chlorine
residual is less than 10 ppm, then the procedure may need to be repeated. |
| 7. |
Flush the piping and fixtures well to flush out
scale and colored from water from the piping. Unscrew aerators and
fixtures to avoid these items becoming plugged with sediment that
may have been loosened in the chlorination process. |
| 3.4
If the Odor Returns |
| After this procedure is completed,
the odor will be eliminated. If it returns within a few weeks, then
the chlorination procedure can be repeated. However, in many cases
the cold water will still have problems with recurring odors due to
continued presence of sulfate bacteria and low chlorine residuals
in the water. At this point all one can do is to replace the iron
piping with copper. |
| Caution:
this will often loosen up scale, iron deposits and other materials
in the piping, which can clog fixtures, appliances and valves in the
piping system, causing a lot of problems. Care should be taken when
flushing the piping, and all aerators removed to prevent clogging.
In some extreme cases of corroded piping, the piping could fail and
start to leak after this procedure. |
| Figure 4: Typical
metering pump and solution tank installation showing injection valve
in piping, using a LMI brand metering pump. |
 |
| 4.0
Odors in Water Heaters & Hot Water Pipes Only |
| If the cold water does not contain odors, but the hot
water does, then a thorough sanitizing of the water heater tank will
eliminate the odor. See the procedure below.
***If you are not familiar with the functions of your water heater,
DO NOT ATTEMPT this yourself. You can have this done by a licensed
plumber to avoid damage to your water heater, or causing electrical
problems, or gas explosions by improperly restarting the water heater
if gas. Note: If the water heater is old and corroded, cleaning the
sediment from the water and sanitizing by chlorination could cause
the water heater to leak.*** |
| 4.1
Procedure for Chlorination of Water Heaters to Eliminate Odors |
| 1. |
Turn off the manual switch if the water
heater is electric. For gas heaters, turn the control to Pilot. Make
sure the pilot is still lit so you can restart the water heater when
the procedure is completed. |
| 2. |
Close the cold-water inlet valve at the water heater. |
| 3. |
Open a nearby hot water faucet and the
T&P (temperature and pressure valve, located on the top of the
water heater) valve to relieve tank pressure. Note of caution: T&P
valves may need replacing if defective or old. |
| 4. |
Drain the water of enough water to compensate
for the bleach to be added. Use a hose connected to the drain valve
if an open drain is not adjacent to the water heater. Tip: have on
hand a hose bib cap, available at any hardware store. When the procedure
is completed, in some cases the drain valve will leak, and a hose
bib cap can be screwed on the end of the drain valve, preventing the
need for a drain valve replacement. Or replace the valve if desired
with a new drain valve. |
| 5. |
Remove T&P valve, anode rod, or disconnect
the hot water outlet pipe from the water heater. |
| 6. |
For best results and to preserve the life of your
water heater, inspect the anode rod. If corroded, replace with a new
aluminum/zinc anode rod, which will create fewer odors. |
| Figure
5 Typical gas water heater cut-away showing anode rod
and cold water dip tube. |
 |
|
| 7. |
Pour one gallon of household bleach,
or ½ gallon of pool chlorine for each 30 gallons of water
heater tank capacity. Use the T&P valve, anode rod or hot
water outlet pipe opening to pour the chlorine in. Re-pipe the
water heater and close the T&P valve. |
| 8. |
Open the cold-water inlet at the
heater and fill the tank with water. Observe the water level
through the closest hot water faucet. Close inlet valve when
the tank is full. |
| 9. |
Leave the bleach mixture in the heater
for one hour. |
| 10. |
After one hour, open the cold valve
again, open all the hot water faucets and allow the bleach mixture
to clean the hot water supply pipes. Drain the remaining chlorine
solution from the tank through the heater drain valve. |
| 11. |
Close the heater drain valve, and completely
fill the tank with fresh water. Leave the water in the tank
for 15 minutes. |
|
| 12. |
After 15 minutes, purge the hot water supply
lines and drain the water from the tank though the heater drain valve,
flushing out any sediment if present. Close the drain valve. |
| 13. |
Make sure you purge all air from hot water
lines from the open hot water faucets. Close the hot water faucet
after all the air is out of the system. |
| 14. |
Check for water leaks at all fittings used; repair as necessary. |
| 15. |
Turn on the manual electrical switch, or
turn the gas control knob back to “On” and verify that
the heater burners have lit and turned back on. |
| 16. |
Check for normal water heater operation. |
| 4.2
If the Odor Returns to the Hot Water |
| After this procedure is completed,
the odor will be eliminated. If it returns within a few weeks, then
the chlorination procedure can be repeated. However, in many cases
the cold water will still have problems with recurring odors due to
continued presence of sulfate bacteria and low chlorine residuals
in the water. |
|
