68S Water test

Air gap

A physical seperation to prevent backflow

Air gap distance

twice the diameter of the outlet, never less than one inch

Check valve

Self-closing device that is designed to allow the flow of fluids in one direction

The safe drinking water act (SDWA)

Federal law that ensures the quality of Americans' drinking water

16 December 1974

The safe drinking water act (SDWA) Date signed into law

National Secondary drinking water regulation (NSDWR)

Concerned with aesthetic quality of water/ Not Federally Enforced

Physical qualities of potable water standards

C.O.T.T
1. Color
2. Odor
3. Turbidity
4. Temperature

Ground water Sources

Typically a well or spring/ used for smaller water systems

Factors that need to be considered with water source selection

1. Sources of pollution
2. Hydrological studies
3. Proposed intake location
4. Water uses indentified for the particular water source

Qualities of an approved water disinfectant

1. Use in water before it enters the distribution system to ensure all pathogenic microbes are destroyed
2. Residual concentrations are maintained

Marginal Chlorinating

Application of chlorine to produce the desired TAC residual

Super Chlorination

1. Application of chlorine in greater concentrations than are needed
2. Gives control over taste and odor

Criteria for defining a waterborne disease outbreak

1. Two or more persons must experience a similar illness
2. A single case of chemical poisoning
3. A single case of Amebic meningoencephalitis

Steps in solving a waterborne disease outbreak

1. Prepare of field Work
2. Establish the existence of an outbreak
3. Verify the diagnosis
4. Define and identify cases
5. Describe and orient the data
6. Develop hypothesis
7. Evaluate hypothesis
8. Refine hypothesis
9. Implement controls
10. Communicate findings

Sodium Thiosulfate

De-chlorinating agent

Time to run water when collecting sample

2-3 minutes

How to collect water sample of pool

1. Collect from shallow and deep ends
2. Plunge bottle 6 inches below surface at a 45 degree angle

Time requirements for sample collection

1. one hour for unrefrigerated
2. six hours for refrigerated
3. if mailed: no more then 30 hours

Chemical Qualities of water standards

1. Presence/absence of constitutes
2. Interaction between constitutes
3. pH
4. Hardness/softness od water

Microbiological qualities of water standards

1. The presence of microorganisms indicates potential for disease transmission
2. Coliform testing is used as an indicator
3. Occur in intestines of warm blooded animals

Coliform Bacteria group

1. Escherichia coli (e-coli)
2. Klebsiella pneumonia
3. Enterobacter Aerginosa

Sanitary standards for water storage

1. The overflows must be located with their tops six inches above grade
2. the bottom of the tank must be higher than the water table; a minimum of 8 feet.
3. the ground around the tank must be sloped away to provide drainage.

LaMotte Kit Components

1. Chlorine color comparator ( 0.1-1.0 mg/l)
2. Chlorine color comparator (1.0-6.0 mg/l)
3. pH color comparator(6.8-8.2 mg/l)
4. Tablets: DPD # 1,2,3,4 and phenol red
5. Tablet crusher
6. Test tube, glass and cap: marked from 5ml-10ml

Which tablet do you use to find the FAC (free available chlorine)?

DPD # 1

Which tablet do you use to find the TAC (total available chlorine)?

DPD # 4

Which tablet do you use to find the pH?

Phenol red

How much time do you have to color match with the LaMotte kit?

Should be completed within 1 minute

How do you calculate CAC (Combined available chlorine)?

CAC = TAC - FAC

Operator Maintenance for the LaMotte Kit

How long should a sample bottle be in the incubator?

24 hours

What temperature should the incubator be at for water sampling?

35+/- 0.5C

How do you know if the water sample is negative for Coliforms or E. Coli?

the sample would be colourless

What can you do if the water sample is "less yellow" than the comparator?

Place the sample back in the incubator for an extra 4 hours, but no more then 28 hour total.

After placing the sample in the incubator for 4 extra hours, how can you tell in the sample is positive?

The colour will intensify

After placing the sample in the incubator for 4 extra hours, how can you tell in the sample is Negative?

The color will stay the same/ not intensify

How can you tell if a water sample is positive for Coliforms or E. Coli?

The sample color will be equal to or darker than the comparator.

How can you tell if a water sample is E. Coli positive?

The sample color and fluorescence will be equal or greater than the comparator.

What is the max amount of time a water sample can be in the incubator?

24 to 28 hours

How do you dispose of a negative water sample?

1. Pour sample into the sink and flush with water
2. Rinse containers and dispose in the trash

How do you dispose of the positive water sample?

Open each sample and add household liquid bleach up to the top of the container and wait 20 minutes. Pour sample down into the sink and flush with water

Aerobic

Organism that requires oxygen to grow

Anaerobic

Organism that DOES NOT require oxygen to grow

Facultative anaerobes

Can grow with or without oxygen, but does better with oxygen

What is the most important characteristic of aerobic and facultative anaerobes?

They are Rod Shaped (bacilli)

Heterotrophic plate count (HPC) Purpose

1. Provides a method of monitoring
2. Reduces problems in the detection of low densities
3. Monitors the effectiveness of chlorine
4. Indicates the existence of sediment accumulation

Most important rule of media prep

Prepare in accordance with manufacturers instructions

What is the method most used for water sampling in pools?

Membrane filter method

How do you place a Petri dish in an incubator?

1. Inverted
2. Stacked no more then 4 high
3. Not touching any other stack or the top

Contents of Quanti-tray system

1. IDEXX sample bottle
2. Colilert reagent
3. Quanti-tray
4. IDEXX Quanti-tray sealer

Charateristics of quanti-tray

1. accurate test can detect a single organism
2. easy to use. Eliminates the use of media and colony counting
3. Flexible system which allows for both presence and absence test and quantification test