Math & Science
Convert 5m3 to L.
5000 L
What temperature is glassware calibrated to?
20 °C
What water parameter is a measure of the “cloudiness” of water? And what are its units?
Turbidity
NTU
What are the three groups of microorganisms that we are concerned with in water treatment? List in order of smallest to largest.
Smallest to largest: Virus, bacteria, protozoa.
List 4 types of PPE that you may use as an operator.
Safety glasses, high-vis vest, gloves, steel toe shoes, lab coat, etc…
What is the range of the pH scale?
0-14
What are the three types of sample collection types and which one would you use to collect bacti sample?
Grab, composite & continuous. Bacti samples are grab samples.
What two elements cause hardness in water?
Calcium & magnesium
Name the two indicator organisms most commonly tested for in water treatment.
Total Coliforms (TC) & E. Coli (EC).
State the three schedules of health based standards listed in O.Reg 169.
Microbiological, Chemical, Radiological
What are the respective units for molarity, molality, and normality?
Molarity (M) = mol/L
Molality (m) = mol/kg
Normality (N) = g-eq/L, m-eq/L
How are blowout pipettes marked?
Frosted band or two thin rings around the neck.
Conductivity is a measure of…
The ability of a solution to conduct electricity (i.e., dissolved ions in solution).
What test would be used to assess biofilm accumulation in the distribution system?
Heterotrophic Plate Count (HPC)
Give three examples of an adverse result.
- Any detection of TC or EC in a treated sample.
- Free chlorine below 0.05 mg/L or combined chlorine below 0.25 mg/L in a treated sample.
- An exceedance of any MAC listed in O.Reg 169.
- Presence of an unlisted pesticide (without an existing MAC) exceeding a concentration of 100 nanograms/L in a treated sample.
- Turbidity leaving a filter effluent line exceeding 1 NTU.
- Fluoride exceeding 1.5 mg/L in a treated sample.
*There are other possible answers!
What is the percent concentration of a 5L solution that contains 0.3L of sodium hypochlorite?
(0.3L / 5L) * 100 = 6%
List three sample preservation techniques.
Refrigeration (@ 4°C)
pH control
Chemical preservatives
Amber or opaque bottles (light control)
What is the difference between true and apparent colour?
Apparent colour – not filtered.
True colour - filtered.
Disinfection by-products (DBPs) are formed in reactions between...
Disinfectants (i.e., free chlorine) and natural organic matter.
Name two types of QA/QC samples and what they are used for.
Lab blank - prepared by lab, used to calibrate/standardize lab equipment.
Field blank - prepared by sampler, used to verify sampling accuracy.
Trip blank - prepared by lab, used to verify lab precision/accuracy.
Duplicate - sampler takes 2 samples, used to verify sample precision & repeatability.
Split - 1 sample taken in field and split in the lab, used to verify lab precision.
Spike - lab spikes sample with known concentration, used to verify lab accuracy.
Define "buffering capacity."
Buffering capacity is the ability to resist change in pH.
What is the difference between a Mohr and a Serological pipette?
Mohr – graduation ends before the tip
Serological – graduation continues to the tip
Name two water quality measurements that should be analyzed immediately.
pH, chlorine residual, temperature.
Name two disinfectants (and their chemical formulas) that can be used for secondary treatment of water.
Chlorine gas - Cl2
Sodium hypochlorite - NaOCl
Calcium hypochlorite - Ca(OCl)2
Chlorine dioxide - ClO2
Monochloramine - NH2Cl
Define a secondary standard.
Standard that is used to check (verify) the calibration but cannot to used to calibrate the instrument.