Plumbing School Year 3 Module 3

The contact time is determined by several factors:

--The type and amount of contamination in the system --The concentration of chlorine used --The pH level of the water --The temperature of the water

A water conditioner should be installed if the iron content tests higher than

0.2 ppm

Staining of plumbing fixtures may be caused by iron concentration as low as

0.3 ppm

Treat the water supply system if testing reveals sulfur content greater than

1 ppm

Water should be treated if its turbidity is greater than

10 ppm

The approximate amount of water that a gallon of bleach at a solution of 1 parts per million can disinfect is

10,000 gallons

A gallon of chlorine bleach at a solution of only 1 ppm will treat about

10,000 gallons of water

While chlorination will kill bacteria with an exposure of 30 minutes, the pasteurization process uses heated water to kill harmful organisms in as little as

15 seconds

Untreated water passes through a heat exchanger, where it is heated to about

150 degrees Farenheit

A pump draws the water into an electric heating chamber. There, the temperature of the water is raised to

161 degrees F for at least 15 seconds

In a pasteurization system, in order to kill organisms in the water, the electric heating chamber raises the temperature of the water to

161 degrees F for at least 15 seconds

The amount of hardness in one grain is

17.1 ppm

Commercial laundry bleach has

19 percent sodium hypochlorite

Most residential pasteurized systems disinfect water at a slow hourly rate typically

20-24 gallons per hour

If using a solution of at least 50 parts per million of chlorine, you let the system stand for

24 hours

When disinfecting a water supply system once the system has been completely installed, a solution of at least 200 ppm of chlorine can be used if the system is allowed to stand for

3 hours

Calcium hypochlorite is available in power and tablet form and contains anywhere from

30 percent to 75 percent chlorine

One gallon of domestic laundry bleach has a sodium hypochlorite content of

5.25 percent

A gallon of domestic laundry bleach contains

5.25 percent sodium hypochlorite

A gallon of chlorine bleach at a solution of 5 ppm will treat about

50,000 gallons of water

The percentage of impurities removed from water by distillation systems

99%

Oxidizing agent

A chemical that is used for oxidation and is made up largely of oxygen

Alum

A chemical used for coagulation. It consists of aluminum and sulfur

Chlorinator

A device that distributes chlorine in a water supply system

K value

A mathematical variable used to determine contact time based on the highest pH level and lowest temperature of the water in a water supply system

Grains per gallon

A measure of the hardness of water. One grain equals 17.1 ppm of hardness

Turbidity unit

A measurement of the percentage of light that can pass through a sample of water

Precipitate

A particle created by coagulation that settles out of the water.

Ion exchange

A technique used in water softeners to remove hardness by neutralizing the electrical charge of the mineral atoms.

Adsorption

A type of absorption that happens only on the surface of an object

Point-of-use (POU) unit

A water conditioner that is located at an individual fixture

Point-of-entry (POE) unit

A water conditioner that is located near the entry point of a water supply

Ion

An atom with a positive or negative electrical charge

Solenoid valve

An electronically operated plunger used to divert the flow of water in a water conditioner.

Contamination

An impairment of potable water quality that creates a hazard to public health

Pollution

An impairment of the potable water quality that does not create a hazard to public health but affects the water's taste and appearance

Floc

Another term for precipitate

____________________ removes iron and sulfur from water

Chlorine

Water conditioner

Device used to remove harmful organisms and materials from water.

Pasteurization

Heating water to kill harmful organisms in it.

When calculating the contact time for chlorinating a water system to disinfect it, a plumber must determine the system's

K value

Time=

K value/concentration in ppm

Diatomaceous earth

Soil consisting of the microscopic skeletons of plants that are all locked together

Contact time

The amount of time that a chlorine solution must remain in a water supply system in order to disinfect it, as determined by the type and amount of contamination in the system, the concentration of chlorine used, the pH (acidity or alkalinity) level of the water, and the temperature of the water.

Coagulation

The bonding that occurs between contaminants in the water and chemicals introduced to eliminate them.

Backwashing

The cleaning process of a fully automatic water softener

Disinfection

The destruction of harmful organisms in water

Sodium hypochlorite

The liquid form of chlorine, commonly found in laundry bleach

Precipitation

The process of removing contaminants from water by coagulation.

Distillation

The process of removing impurities from water by boiling the water into steam

Calcium hypochlorite

The solid form of chlorine. It comes in powder and tablet form.

Osmosis

The unequal back-and-forth flow of two different solutions as they seek equilibrium.

Chlorination

The use of chlorine to disinfect water

True/False: Calcium hypochlorite may form deposits in pipes.

True

True/False: If a system has iron-or sulfur-rich water, monitor and adjust the system's chlorine use regularly. High levels of alkaline in the water may slow the disinfection process. Cold water will also slow the disinfection process.

True

True/False: Soft water contains sodium chloride. Softened water may pose a health risk to people on strict low-sodium diets.

True

Ultraviolet light

Type of disinfection in which a special lamp heats water as it flows through a chamber

Turbidity in water is commonly treated by using

a diatomaceous earth filter

If the pH of a water sample is 7 or below, the water supply system should be treated for

acidity

Public water utilities use lime in treatment process to remove

acidity

An example of a highly effective adsorbent material is

activated carbon

Most objectionable water tastes and odors, other than metallic flavors and saltiness, can be eliminated by using an

activated carbon filter

Codes require that reverse-osmosis systems drain into the waste system through an

air gap

Fine solid particles can be precipitated out of water by adding

alum

Water contaminated with iron and sulfur is often referred to as

black water

At the end of each workday, all installed pipes should be

capped

Install ___________________________ to remove any residual chlorine taste from the water.

charcoal filters

In a precipitation system, the action of chemicals bonding with contaminants in the water is called

coagulation

In an ultraviolet-light system, the lamp's efficiency will be reduced by

cold water

A commonly used filter in municipal water treatment systems is

diatomaceous earth

Once a water softener is completed, the unit must be

disinfected

In situations where the water supply is from a private well, plumbers must install

disinfection devices

The principle of osmosis is that solutions tend to seek

equilibrium

The process of scouring water to remove particles and chemicals is called

filtration

Water hardness is measured in

grains per gallon

Acidity in the water can react with copper pipes that are

green

Water that contains a high percentage of minerals is called

hard water

Calcium and magnesium salts in water are the cause of

hardness

Distillation systems are effective at eliminating

hardness

After a newly installed water supply system has been flushed and disinfected, water samples should be taken and laboratory-tested for

harmful bacteria

Scale occurs when the chemical structure of calcium, magnesium, or sodium atoms is changed by

heat

An unpleasant smell from water is often due to the presence of

hydrogen sulfide

To treat a salty flavor in the water, the usual method is to

install a reverse osmosis system

A red slippery jelly formed on the side of a toilet tank is caused by

iron-eating bacteria

Iron test kits can also be used to detect

manganese

Calcium carbonate is often used to trap acid in a

neutralizing filter

An activated carbon filter will remove

organic chemicals

In addition to disinfectant properties, chlorine will

remove iron and sulfur

To give coagulants time to work, precipitation systems usually include a

retention tank

Water under high pressure is forced through a membrane in

reverse osmosis systems

In an oxidizing filter, magnesium is used to convert iron in the water into

rust

Mineral salts dissolve in water form a coating inside pipes

scale

Water hardness can be determined by using a

soap solution

Resin pellets in an ion-exchange system are saturated with

sodium

Without clean water,

the quality and span of life are drastically reduced

The two tanks in a typical residential ion-exchange system are

the resin tank and the brine tank

To allow the ultraviolet lamp to reach full intensity before water is admitted to the disinfecting chamber, units are equipped with a

time-delay switch

After pasteurization, the treated water is sent

to a pressure tank

The purpose of the quartz sleeve in UV systems is

to prevent water in the disinfecting chamber from cooling the lamp

The heating coils of a home distillation unit should be cleaned periodically with

vinegar