Water Quality Guidelines And Standards Flashcards
What makes risk different from hazard?
Risk is the likelihood of a hazard
Enumerate the 2 characteristics of water quality guidelines
- Represents the concentration of constituent that does not pose any significant health risk over a lifetime of consumption
- Based on human & usual domestic consumption
Which is true?
A.Water quality guidelines values are the basis of water quality standards.
B.The Philippine Standards for Drinking Water of 2007 are based on the Philippine Environmental Protection Agency (EPA) guideline values.
C.The Philippine Standards for Drinking Water of 2007 only applies to people working in water supply system; general public not included.
A
Most conmonly used indicator bacteria in water testing
Coliforms
Enumerate two types of coliforms for which water is tested.
- total coliform
2. fecal/thermotolerant coliform
What does it mean when coliforms are present?
Water sample is Contaminated with excreta; other organisms may also be present
What does it mean when coliforms are present in chlorinated water?
Failure in chlorination system
Residual chlorine - what is its purpose?
Needed to make sure that there are no more possible pathogens/disease-causing microbes in the water supply
Which is false?
A. Fecal bacteria is the only bacteria indicative of a health hazard.
B. It is more practical to test total coliform rather than residual chlorine.
C. Both are false
D. NOTA
B
Baliktad
Which is false? A. Fecal bacteria die off with time. B. Fecal bacteria die in low temperature. C. BOTA D. NOTA
B
Heat dapat
Nutrient medium used in Multiple Tube Method
MacConkey agar
In multiple tube method, presence of coliform bacteria is confirmed with what color change? What does the color change indicate?
Purple to yellow.
Acid production
Identify the method
A number of tubes are incubated containing diff volumes of water sample & by observing the number of positive reactions it is possible to derive the MPN of coliform bacteria
Multiple Tube method
Why is multiple tube method not very accurate?
You are only estimating the most probable number of coliform present
In Membrane Filtration Technique, what kind of membrane is used?
Cellulose membrane
In which method can you count all the colonies present? A. Multiple Tube method B. Membrane Filtration technique C. BOTA D. NOTA
B
Main disadvantage of PNSDW 2007 microbio standard
less than 1 colony is hard to interpret
Minimum frequency of sampling for Level I point source
Once in 3 months
Minimum frequency of sampling for Level II communal faucet
Once in two months
Minimum frequency of sampling for Level III (household faucet) is once a month, regardless of population size served. T/F?
F
Sa less than 5000 lang ito
Minimum frequency of sampling for Level III (household faucet), pop size- 5000 to 100,000
1 sample per 5000 population, monthly
Minimum frequency of sampling for Level III (household faucet), pop size- more than 100,000
20 samples + 1 additional sample per 10,000 population
Answer the ff:
A.Minimum frequency of sampling for emergency supplies of drinking water.
B.Purpose for testing
A.before delivery to users
B.check residual chlorine
Minimum frequency of sampling for water refilling stations, and water vending machines
One sample monthly
Why is more freq sampling needed for water refilling stations
Filter system is prone to contamination
Differentiate water quality guidelines from water quality standards
Water quality standards are intended for direct enforcement; non-compliance results to penalties. This is not the case for water quality guidelines
T/F
Trihalomethanes formed are carcinogenic
T
How is groundwater contaminated by arsenic?
arsenic-containing minerals are exposed to air, leading to oxidization
How does Cadmium leach into corroded pipes and solders?
acidic water
How does nitrate affect hemoglobin?
associated with methemoglobinemia (blue baby syndrome) by decreasing oxygen-bearing capacity of Hb
most common source of lead in water
plumbing systems
Which is false about benzene?
A. human carcinogen fr industrial effluents
B. amount is declared when it’s below detection limit
C. primary parameter ito
B
amount is not declared when it’s below detection limit
Differentiate apparent color fr true color
apparent color - color readily observed by the eye
true color - color observed after filtering
Which is false?
A.Turbid water has increased oxygen content
B.higher pH of water has more chloride ions
C.lower pH can cause corrosion and leaching
D. NOTA
A
reduced dapat
Define residence time
how long a water source will last
How is there seawater intrusion in drinking water?
reclamation, soil composition, overextraction
Which is false?
A. Sulfate is a laxative but not a purgative
B. Sulfate may be found in naturally occurring geological deposits.
C. BOTA
D. NOTA
A
both dapat
How is groundwater contaminated by arsenic?
arsenic-containing minerals are exposed to air, leading to oxidization
How does Cadmium leach into corroded pipes and solders?
acidic water
How does nitrate affect hemoglobin?
associated with methemoglobinemia (blue baby syndrome) by decreasing oxygen-bearing capacity of Hb
most common source of lead in water
plumbing systems
Which is false about benzene?
A. human carcinogen fr industrial effluents
B. amount is declared when it’s below detection limit
C. primary parameter ito
B
amount is not declared when it’s below detection limit
Differentiate apparent color fr true color
apparent color - color readily observed by the eye
true color - color observed after filtering
purpose of alum
coagulant
Which is false?
A.Turbid water has increased oxygen content
B.higher pH of water has more chloride ions
C.lower pH can cause corrosion and leaching
D. NOTA
A
reduced dapat
Define residence time
how long a water source will last
How is there seawater intrusion in drinking water?
reclamation, soil composition, overextraction
Which is false?
A. Sulfate is a laxative and a purgative
B. Sulfate may be found in naturally occurring geological deposits.
C. Coagulation and sedimentation improve microbiological characteristics of water.
D. NOTA
C
only filtration and disinfection improve it
Suspended solids in wastewater are processed via a certain method. Sequence its steps A. analyzed gravimetrically B. oven dried C. filter wastewater D. weighed E. retained solid on filter paper
C E B D A
What is oxygen demand in wastewater? What does it indicate or imply?
amount of oxygen required to oxidize organic chemicals present in water; indicates how polluted the water is
Difference between chemical & biological oxygen demand
biological = consumed by microbes chemical = consumed by other organic matter
How is chemical oxygen demand measured?
boil sewage with acid dichromate solution
How is biological oxygen demand measured?
allow sample to stand at 20 deg C for 5 days, then calculate amount of oxygen used up during oxidation of organics by microbe
Identify: shows the concentration of dissolved oxygen in water, particularly fr significant point source of water pollution
oxygen sag curve
enumerate zones of oxygen sag curve
clean
decomposition
septic
recovery
Which is false?
A. more organic matter, less dissolved oxygen available
B. higher rate of de-aeration, higher oxygen demand
C.more turbulent water, less oxygen dissolution in water
D. NOTA
C
more dapat
The ff increase from Class AA to Class D except A.chloride B.true color C.dissolved oxygen D.phosphate
C
The ff increase from Class AA to Class D except A.temperature B.total suspended solids C.nitrate D.BOD
A
