Questions & Answers
When pressure testing a new line, how much pressure do you add? - ✔✔1.5 times normal pressure,
up to 150 pounds, whichever is greater
What would cause a repeat Bac-T sample? - ✔✔Incomplete form, not enough sample, silt or slime in
the bottle, positive e-coli, all of the above
What are the layers of stratification? - ✔✔Upper layer - Epilimnion. Middle layer - Thermocline.
Bottom Layer - Hypolimnion.
What standard must bleach meet? - ✔✔NSF (National Sanitation Foundation)
What is the Solid contact unit? - ✔✔Also known as a Sludge blanket unit, it is an all-in-one unit,
handling mixing, flocculation and sedimentation, with an upward flow.
What is the number one sludge removal process in Texas? - ✔✔Lagooning/Lagoons.
What are the Log removals for cryptosporidium, giardia and viruses? - ✔✔Cryptosporidium - Log 2,
99%. Giardia - Log 3, 99.9%. Viruses - Log 4, 99.99%.
Which two filter membranes remove the most NTUs? - ✔✔RO (Reverse Osmosis), and Nano Filtration
What are lime and soda ash used for removing? - ✔✔Hardness
What purpose does aeration serve in the softening process? - ✔✔Releases CO2 which helps keep
hardness in solution.
What is the Jar Test Process? - ✔✔Unknown
, What can replace primary coagulation? - ✔✔Cationic polymers.
What tells you that the chloramine ratio is off? - ✔✔The presence of di and tri chloramines, and
excessive free ammonia.
What is the Right to Know law? - ✔✔Typically included in the MSDS. The law includes employers
providing information, training and PPE for various chemicals worker may be exposed to.
What is the action level for Lead and Copper in the Lead and Copper Rule? - ✔✔0.015 mg/L for Lead,
1.3 mg/L for Copper
What is the Baylis Curve? - ✔✔A curve that shows the relationship between pH values and Alkalinity
What two acids in water react with chlorine to form Trihalomethanes? - ✔✔Humic and Fulvic
What chemical analysis deals with changes in color at pH of either 4.5 or 8.3? - ✔✔Alkalinity
What lab test is the most significant for establishing chemical dosage for coagulating water? -
✔✔Alkalinity and pH
What factors affect coagulation? - ✔✔Turbidity, pH, and temperature
What is the single most important factor in influencing coagulation? - ✔✔pH
What is soda ash used for in the water treatment process? - ✔✔Adjusting pH
What is the maximum flow rate through a sand filter? - ✔✔2-4 GPM/ft2