|
| Shock
Chlorination by Dry Pellets (calcium hypochlorite) |
| Dry chlorine pellets, containing 70% available chlorine
often much easier to handle and use than liquid bleach. Dry chlorine
pellets can be used for sanitizing wells, cisterns, storage tanks
and piping systems. The amount of pellets used will depend on the
amount of water in the system to be sanitized. |
| 1. |
Keep pellet containers tightly closed and
child resistant locking devices in place. Pellets may cause eye damage,
don’t breathe, get on skin or get in eyes. Use gloves, protective
clothing, and eye goggles during procedure. |
| 2. |
Never use bare hands or cloth gloves to handle pellets,
use plastic scoop or container to add pellets. |
| 3. |
Clean the well house, springhouse or storage
tank or reservoir. Remove debris and scrub or hose off any dirt or
other deposits or interior surfaces. Pump to remove any suspended
solids or foreign matter in the water if possible. Scrub interior
surfaces with a strong chlorine solution containing ½ gallon
household bleach, or ¼ gallon of pool chlorine to each 5 gallons
of water, or by crushing five pellets in five gallons of water. |
| 4. |
Determine how much chlorine to use to disinfect
your well or holding tank by consulting Table 2. If you don’t
know your well depth, contact your well driller as they often keep
records that will show the depth of the well. |
| As a general rule, 8 oz. of
dry chlorine pellets with 70% available chlorine, dissolved
in 1000 gallons of water, will produce 50 ppm of total
chlorine residual. |
| 8 oz = ½ lb which = 200 pellets. |
|
|
| Table 2 Wells: Pounds of 1 gram
dry pellets needed for disinfection to obtain approximately a 50 ppm
chlorine solution in the well. |
| Well
Casing Diameter |
Distance
From Water Level to Bottom of Well (Water Depth) |
| 0’ – 50’ |
50’ – 100’ |
100 – 200’ |
200’ - 300’ |
300’ – 400’ |
400’ – 500’ |
| 4” |
0.1 |
0.4 |
0.8 |
1.2 |
1.5 |
2.0 |
| 6” |
0.5 |
1.0 |
1.8 |
2.5 |
3.5 |
4.5 |
| 8”– 12” |
1.2 |
2.5 |
5.0 |
7.2 |
10.0 |
12.0 |
| 12” – 16” |
3.0 |
6.0 |
12.5 |
19.0 |
25.0 |
31.0 |
| 20” - 24” |
7.0 |
14.0 |
28.0 |
42.0 |
56.5 |
71.0 |
| 30” – 36” |
16.0 |
32.0 |
63.5 |
95.0 |
127.0 |
159.0 |
|
| 5. |
Drop one pellet into the well and listen
to hear if it hits the water. If the pellet hits the water, drop one-half
of the number of pellets needed into the well. These will sink to
the bottom and sanitize the lower part of the well. |
| 6. |
Mix the remaining pellets with a few gallons
of water in a clean plastic container, dilute this mixture by ten
times, and pour the solution into the well. |
| 7. |
If possible, circulate the water from the
well by connecting a garden hose to a nearby hose bib or sill cock,
and feed the water back down into the well. This will also wash down
the sides of the well and insure proper mixing. After approximately
15 minutes a strong chlorine odor should develop. To be more precise
use a chlorine test kit to make sure the chlorine is over 50 ppm. |
| 8. |
Water should be pumped from the well into
the pressure tank and plumbing system. All water faucets should be
turned on in the house and all outside fixtures and hose bibs including
fire hydrants, watering troughs, and other supply lines to other buildings,
until a 50 ppm chlorine residual is detected. |
| 9. |
At this point, turn off the fixtures and
let remain the pipes a minimum of 2 hours, up to 12 hours, or overnight. |
| 10. |
After the chlorine has been left in the
well and the plumbing system if applicable for a minimum of two hours,
the chlorinated water can be flushed out. Large amounts of chlorinated
water should not be discharged into the septic tank or onto lawns,
gardens, streams, rivers or lakes. The small amount of chlorinated
water that remains in the household plumbing, can be discharged into
the septic system. |
| 11. |
Backwash water softeners; flush the water heater; and replace all
filters if present. |
| 12. |
For wells and piping systems that have
bacterial contamination or have been flooded, resample the water and
retest for coliform, after all the chlorine residual is gone. |
| 13. |
If bacteria are detected again, repeat procedures above. Until a
safe test result is obtained, use an alternate known safe water source
or boil the water. |
| Sanitizing and Disinfecting Storage
Tanks |
| 1. |
Clean the storage tank or reservoir. Remove
debris and scrub or hose off any dirt or other deposits or interior
surfaces. Pump to remove any suspended solids or foreign matter in
the water if possible. |
| 2. |
Scrub interior surfaces of storage or reservoir
if applicable with a strong chlorine solution containing ½
gallon household bleach, or ¼ gallon of pool chlorine to each
5 gallons of water. |
| 3. |
Inspect the storage tank for cracks, leaks
around the lid or man-way, or vents. Make sure no insects, rodents
or other debris can enter the tank during normal operation of the
tank and water system, by making sure the lid is tight fitting, and
any vents are properly screened. |
| 4. |
Use the chart below (Table 3) to add enough
chlorine bleach in the tank, to bring up the chlorine residual in
the tank to the desired level. If you are using tank and need to continue
to use the water in the tank after chlorination, consider adding enough
chlorine to bring the levels up to 5 or 10 ppm and let sit for 12
hours or more. |
| 5. |
If a thorough disinfection is needed and
time is short, use a 50 ppm or 100 ppm residual and let sit for 2
to 6 hours. Drain and flush tank if using these higher levels of chlorine.
Don’t put large amounts of chlorine residual into drains leading
to septic tanks, and avoid discharge into creeks, rivers or lakes. |
| 6. |
Be careful if you have a steel storage
tank, as corrosion may have occurred over time, and once the tank
is cleaned it may develop leaks. |
| 7. |
If your well is a low producer, consider having
water trucked in. Often it is cheaper to have the water trucked in,
and will prevent the stress on your well to refill your holding tank. |
| 8. |
For maintenance of your tank, consider cleaning and sanitizing at
least once per year. |
| Table 3 Storage tanks: Disinfecting
with liquid household bleach (5% Sodium Hypochlorite) |
| If using pool chlorine (12%
sodium hypochlorite) use half the amounts below. |
| Storage
Tank Gallons |
Approx.
parts per million of chlorine residual achieved by adding 5% chlorine
bleach, in the amounts below. |
| 1 PPM |
5 PPM |
50 PPM |
100 PPM |
200 PPM |
| 10,000 |
10 oz. |
1.5 gallons |
10 gallons |
20 gallons |
40 gallons |
| 5000 |
5 oz. |
3 qts. |
5 gallons |
10 gallons |
20 gallons |
| 2500 |
2.5 oz. |
1.5 qt. |
2.5 gallons |
5 gallons |
10 gallons |
| 1500 |
1.5 oz |
1 qt |
1.5 gallons |
3 gallons |
6 gallons |
| 1000 |
1 oz. |
12 oz |
1 gallon |
2 gallons |
4 gallons |
| 500 |
1 Table-spoon |
6 oz |
½ gallon |
1 gallon |
2 gallons |
| 250 |
1.5 - 2 teaspoons |
3 oz. |
1 qt. |
½ gallon |
1 gallon |
| 100 |
1 teaspoon |
1.5 Table-spoons |
1 pint or 2 cups |
1 qt |
½ gallon |
| Table 4 Storage
tanks: Disinfecting with dry 1 gram chlorine pellets |
| 1 cup pellets = 200 pellets = ½ lb |
2 cups pellets = 400 pellets = 1 lb |
| 25 pellets in 100 gallons = 50 ppm |
50 pellets in 100 gallons = 100 ppm |
| Storage
Tank Gallons |
Approximate
parts per million of chlorine residual achieved by adding dry chlorine
pellets in the amounts below. |
| 1 PPM |
5 PPM |
50 PPM |
100 PPM |
200 PPM |
| 10,000 |
1 cup |
2.5 cups |
5 lbs |
10 lbs |
30 lbs |
| 5000 |
½ cup |
1.3 cup |
5 cups |
5 lbs |
15 lbs |
| 2500 |
30 pellets |
2/3 cup |
2.5 cups |
5 cups |
15 cups |
| 1500 |
18 pellets |
¼ cup |
1.5 cups |
3 cups |
9 cups |
| 1000 |
12 pellets |
32 pellets |
1 cup |
2 cups |
6 cups |
| 500 |
6 pellets |
16 pellets |
½ cup |
1 cup |
3 cups |
| 250 |
3 pellets |
8 pellets |
¼ cup |
½ cup |
1.2 cups |
| 100 |
1 pellets |
3 pellets |
25 pellets |
¼ cup |
½ cup |
| Useful Measurements: |
|
| 1 cup = 8 fluid oz. |
1 pint = 16 fluid oz. |
| 1 quart = 32 fluid oz. |
1 gallon = 128 fluid oz. |
| 1 teaspoon = 1/6 fluid oz. |
3 teaspoons = 1 tablespoon |
| 1 fluid oz. = 29.6 milliliter (ml) |
20 drops = 1 ml. |
| Fig. 1 Well &
submersible pump: to shock chlorinate this type, remove ½”
plug or air vent to drop pellets or chlorine down the well. DO NOT
REMOVE TOP BOLTS. |
 |
| Well Seal : top of well has
four bolts, one ½” plug, and
one hole for pump wire. In this type, pump
pipe or drop pipe typically comes out the
top of the well cap or seal. Do not remove
top bolts for access without consulting a
well driller or pump installer. |
 |
|
|
|
 |
| ***Wells equipped
with a packer style jet pump (not shown) can
be thoroughly disinfected only through the
removal of the pipe and jet from the well.
Shallow well jet pumps (not shown) must be
disconnected in order to disinfect the well.*** |
|
|
|
|
| Fig. 2 Well & submersible
pump: to shock chlorinate this type, open cap on top. |
 |
| Well
Cap Styles |
 |
|
|
|
|
| Caution:
if you are not familiar with your well design
or construction do not attempt to open it
or shock-chlorinate. |
| Consult
a licensed water treatment technician, well
driller or pump installer, call us (831) 476-0515
or e-mail us at info@advanced-water-systems.com
for more information. |
|
|
|
|
|
