Water Treatment Grade 4 exam prep
what is the MCL for haloacetic acids (HAA5)?
.06 mg/L
the stage 1 DBPR established an MCL of _____ for TTHM ( total THMs)
.08 mg/L
water being served to the public for a population greater than 3300 must not have a disinfection residual entering the distribution system below ______ for more than 4 hours
.2 mg/L
Where ground frost is expected the riser pipes in a meter pit should be atleast how far away from any wall of the meter box to prevent freezing
1-2 inches
what is the action level of copper
1.3 mg/L
a community water system must post the consumer confidence report on a publicly accessible website if it serves more than
100000 people
what is the maximum weir loading for light alim floc in solids contact basins
10gpm/ft
new polyvinyl chloride pipe has a c-value of about
150+
the safe drinking water act defines a public water system as a supply of piped water for human consumption that has at least _______ service connections, or serves _______ or more persons 60 or more days each year
15;25
An ion exchange softener is treating a flow rate of 125 gpm. what is the operating time in hours if the softener unit treats 297000 gallons before it requires regeneration?
39.6 hr
water systems are required to achieve at least________ removal and or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.
4 log
which of the following is the first level of dissolved solids that is considered unfit for human consumption
4000 mg/L
how many atoms of oxygen are present in Ca(HCO3)2?
6
water use rates for a community are typically highest at what time of day
6 p.m. to 10 p.m.
what is the optimal ph range for the removal of particulate matter when using alum as a coagulant
6.5 to 7.2
public water systems that cannot meet the required removal of TOCs can comply if the source water TOC level is ________ calculated quarterly as a running annual average
<2.0 mg/L
which forces will pull particles together once they have been destabilized in the coagulation-flocculation proccess
Van der Waals force
the rule the landowners can capture all the water under their land is called
absolute ownership
what system is based on the principle that the owner of the land owns everything beneath that land all the way down to the center of the earth
absolute ownership
the main objective of a customer complaint response system is to
address the customers concerns
dissolved air flotation is particularly good for removing
algae
the filter backwash recycle rule applies to what sizes of systems
all sizes
where are the sampling points located for required sampling of turbidity in a community water system
at points where the water enters the distribution system including all filter effluents of a surface water treatment plant
An example of _______ is determining the lowest monthly average during a 12 month monitoring of giardia and virus inactivation
benchmarking
Conductivity is a measure of the ability of an aqueous solution to do what
carry current
CaCO3 is the _______ of calcium Carbonate
chemical formula
the Surface water treatment rule does not specify which of the following treatment technology
chloramine disinfection
Water meter pits are usually used in
cold climates
under the SWTR, disinfection residual must be collected at the same location in the distribution system as
coliform samples
water that is to be analyzed for inorganic metals should be codified with
concentrated nitric acid
which of the following would be the most probable solution to control algae in the source water if the algae were clogging the filters at the water plant
control nutrients
what is the principal source of excessive lead and copper in customers water
corrosion of household plumbing
when a water source is destroyed or damaged due to some disaster that causes total contamination which of the following would be a short term goak
draw water from an adjoining system or systems
where are the sampling points located for required sampling of natural radionuclides in a community water system
each entry point to the system
What is Head Loss
energy used by water when moving from point to point
where are the sampling points located for required samplings of organics (except THMs) in a community water system
entry points to the distribution system
which of the following is a common mistake that operators make in regard to flocculation units
excessive flocculation time
A bypass valve would be used with a
gate valve
which type of sample should always be collected for determining the presence of coliform bacteria
grab sample
in the multi tube fermentation method which type of culture media is used in the confirmed test
green lactose bite broth
The pH of a Water sample Is greater than the PHs so the Langlier index
indicates the water is scale forming
a regulated organic contaminant concentration that exceeds the MCL
is a teir 2 violation requiring public notification withing 30 days
Lime is commonly used for corrosion control because
it can adjusts both PH and Alkalinity
Raw water temperature that approaches the freezing point has what effect on coagulation and flocculation proccess
it slows down the speed of the proccess by making floc settle slower and making the water denser
conventional sedimentation has a _________ removal of cryptosporidium oocysts
less than .5-log
which type of sludge cannot be discharged to a sanitary sewer system because its deposits might build up and block sewers
lime sludge
A conventional water treatment plant in a rich farming area has to treat water high in nitrates. which if the following is it's best course of action in the long term
manage watershed to prevent nitrates from entering the water system
operators must balance satisfying regulations on the amount of certain chlorinated organic compounds with
meeting disinfection limits
jar tests are expressed in
milligrams per liter
The first step to calculating percent by weight of an element in a compound is to determine the
molecular weight
Molarity is the number of
moles of solute per liter of solution
ferric sulfate has what advantage over alum as a coagulant
more dense floc
if a water system collects at least 40 samples per month for the analyses of total coliforms, what percentage of total coliform samples are acceptable for the system to remain in compliance with the maximum contaminant level for total coliforms
no more than 5%
what term refers to the number of equivalent weights of solute per liter of solution
normality
______ is a measure of the hydrogen ion concentration presence in water
pH
what is PHs?
pH saturation
which type of valve would be particularly useful for throttling the flow of corrosive liquids
pinch valve
a typical coliform colony in the membrane filter method has the following characteristics
pink to dark red with a green metallic sheen
fuel oil will permeate which type of pipe
polyethylene pipe
which chemical used for stabilization of potable water is a bacterial nutrient?
polyphosphate
what is the major cause of short circuiting in a sedimentation basin
poor inlet baffling
continuous chlorine residual monitoring is required where the water enters the distribution system under the SWTR when the
population served is >3300 people.
which type of pipe joint permits flexible pipe alignment is inexpensive to manufacture and is easy to assemble
push on joint
unslaked lime
quicklime
the rule that a landowner has the right to the groundwater as long as it does not harm a neighbor us called
reasonable use
a water system using conventional filtration treatment does not have to use enhanced coagulation to achieve the total organic carbon percent removal if
the treated water quarterly running average TOC is less than 2.0 mg/L
typically, the greatest amount of water in residential use can be attributed to the
toilet
which rule most directly guards against the presence of escherichia coli in the water supply
total coliform rule
Buildup of corrosion products ( a process known as ______) or uncontrolled scale deposits can seriously reduce pipeline capacity and increase resistance to flow
tuberculation
the lower the _____, the more difficult it us to form proper floc
turbidity
what is the MCLG of substances that are expected carcinogens
zero
under the enhanced coagulation requirement ls of the DBPR treatment plants must remove specific percentages of total organic carbon based on their source water total organic carbon and what other factor
Alkalinity levels
which rules applies when the most important issue is priority, where water rights are based on who has used the water for the longest time
Appropriation-permit systems
which type of special photometer is used to analyze for heavy metals in water
Atomic Absorption Spectrophotometer
the three reasons that lime is the most common chemical used for PH and Alkalinity Adjustment
Availability, Inexpensive, easy to feed
list four components of a typical rectangular sedimentation basin
Baffle, Adjustable Weirs, Sludge Pump, Collector drive
which type of pipe joint is available in both bolted and bolt less flexible pipe joint designs
Ball and Socket Joint
all positive samples in the presence absence test must be confirmed using
Brilliant Green Bile tubes
Describe the characteristics of carbon dioxide
Colorless odorless and naturally occurring in all water
Static Suction Lift
Difference in water placement
wastewater water quality discharge requirements could be exceeded if which of the following chemicals are used for corrosion control in the water system
Hexametaphosphate
in regard to the testing of coagulant effectiveness which method is the most readily available to most operators and has been commonly used for years
Jar test
list 3 undesirable effects of implementing a water concentration program
Less income difficulty in droughts, and delay in developing additional sources
which of the following will increase pH, Hardness, and Alkalinity?
Lime
what chemical element is used to remove chlorine from water
NA2S2O3
what are two general categories of carastrophies that can disrupt the operation of a water source
Natural and human disasters
which disinfectant would work best against Cryptosporidium
Ozone
in describing pump operation what type of curve shows the relationship between power and capacity
P-Q curve
which of the following does the saturation point of calcium carbonate primarily depend upon
PH
list 4 characteristics of raw water that must be considered in selecting a treatment chemical
PH, Temperature, Alkalinity, TOC, and Color
what steps are involved in the MTF method
Presumed, Confirmed, Completed tests
the rule of reasonable sharing of water is usually called
Riparian Doctrine
which regulation basically requires that surface water systems maintain specified C x T values before the treated water reaches the first customer
SWTR
When water high in calcium bicarbonate is softened by ion exchange
Sodium Bicarbonate remains in the product water
If enteric disease causing protozoans have been found in the effluent of a water plant which of the following is the most probable solution
Using the multi barrier approach- coagulation, Flocculation, Sedimentation, and Filtration
What is Power
Work done in a given time
Of the metals tin, Zinc and Aluminum which us the most likely to corrode
Zinc
as solids settle to the bottom of a sedimentation basin
a sludge layer develops
a solution consists of two parts; a solvent and a
solute
what is the primary test used to indicate poor sedimentation
test for turbidity
