What are the general water quality characteristics of surface water supplies

low calcium and magnesium content (soft water), turbidity, suspended solids, some color, and microbial contamination.

What are the general water quality characteristics of groundwater supplies

contains dissolved solids, dissolved gases, high hardness, free of suspended solids, and free of microbial contamination.

What are the general water quality characteristics of groundwater supplies

contains dissolved solids, dissolved gases, high hardness, free of suspended solids, and free of microbial contamination.

How can the sustained yield of an aquifer be exceeded

if a well draws out more water than is replaced, causing subsidence (settling of the ground as water is removed).

List the three basic water rights

Appropriative, prescriptive, and riparian.

What is the purpose of a sanitary survey

determine how much water is available and if it is safe to drink/use.

When conducting a sanitary survey, what protective measures should be investigated regarding use of the watershed

control fishing, boating, landing of airplanes, swimming, wading, ice cutting, and permitting animals on shoreline areas.

List the common physical characteristics of water

water color, turbidity, temperature, taste, and odor.

What causes turbidity in water

the presence of suspended material in water.

Chemical analysis of a domestic water supply measures what three general types of chemical concentrations

inorganic chemicals, organic chemicals, and general mineral constituents.

Why are coliform bacteria used to measure the bacteriological quality of water

they are always present in fecal wastes and outnumber other pathogenic organisms.

What tastes/odors are caused by algae

fishy, aromatic, grassy, septic, musty, and earthy.

Increased organic loadings from algal blooms can cause what kinds of water quality problems

increased color and increase in chlorine demand, leading to increased costs.

What is the influence of algal blooms on dissolved oxygen

DO increases as algae produces it via photosynthesis.

What problems are caused by anaerobic conditions in reservoirs

hydrogen sulfide may be produced by anaerobic bacteria as they consume organic matter.

What is the primary purpose of reaeration-destratification programs in domestic water supply reservoirs

eliminate, control, or minimize negative effects on domestic water quality that occur during periods of thermal stratification and DO depletion.

How can water quality be improved by reaeration destratification

add DO to zones that become anaerobic during thermal stratification.

List two basic methods of maintaining/increasing DO in reservoirs when thermal stratification occurs

destratification through aeration, and adding DO to the hypolimnion (hypolimnetic aeration/oxygenation).

What are nonsettleable solids

also called colloidal matter, bacteria, clay/silt that does not
easily settle and must be coagulated.

What happens in the coagulation/flocculation processes

particulates clump together in coagulation with chemicals and clump further in the flocculation process.

What is the primary purpose of flash mixing

mix chemicals with raw water containing
particulates that do not easily settle/filter out.

Why are both primary coagulant and coagulant aids used in coagulation

primary coagulants remove the electrical charge while aids add density and toughness to prevent floc breakdown.

List four methods of mixing coagulant chemicals into the plant flow

hydraulic mixing using flow energy in the system, mechanical mixing, diffusers and grid systems, and pumped blenders

Describe the results of inefficient mixing during flocculation

ineffective collisions and poor flocculation of particulates; may tear the floc apart.

What is the minimum recommended detention time for flocculation

5-20 minutes for direct filtration and 30 minutes for conventional filtration.

What is the advantage of vertical flocculators over horizontal flocculators

they require less maintenance as they eliminate submerged bearings and packings.

Why are the compartments in flocculation basins separated by baffles

prevent short circuiting of water; water following a path may flow too fast, not enough time to settle/react.

Why is coagulation-flocculation treatment important to other treatment processes

for efficacy purposes, reduce THM production, reduce pathogens.

What is the most important consideration in coagulation-flocculation process control

selection of the proper type and amount of coagulant chemicals to be used.

Which processes remove suspended solids after the CF process

sedimentation and filtration.

List the typical functions performed by an operator in the normal operation of the CF process

monitor process performance, evaluate water quality conditions, check and adjust process controls and equipment, and visually inspect facilities.

How is the effectiveness of solids removal process normally monitored

visual observations and laboratory testing.

Which lab tests would you use to monitor the CF process

water quality indicators used to evaluate coagulant dosage and process performance include turbidity, temperature, alkalinity, pH, color, and chlorine demand.

What would you look for when visually observing the performance of a CF process

leaves, twigs, odors, and organic matter.

Why do many operators prepare flow v. detention time curves for basins in their plans

allows for easy selection of stirring times when performing jar tests.

What is the goal in setting up a jar test

see how chemicals chemical doses, mixing times, and other parameters will affect the plant’s performance on a smaller scale.

Why should jar test samples have the same temperature as water in the plant

temperature can affect floc formation; running at different temperatures can provide information on how temperature affects the process.

Why are anionic and nonionic polymers used as coagulant aids often prepared as dilute solutions

dilution prevents a viscous material from being formed.

List the four zones into which a typical sedimentation basin can be divided

Inlet zone, settling zone, sludge zone, outlet zone.

What are launders

sedimentation basin and discharge channels consisting of overflow weir plates and conveying troughs.

Three possible shapes for sedimentation basins

rectangular, circular and square, double deck.

List advantages/disadvantages of double deck sedimentation basins

surface area is doubled, but are more costly and if an issue arises in either deck, the entire operation must be shut down.

Why are rectangular basins preferred over circular ones

less likely to short circuit and particle removal issues.

During operation of a solids-contact unit, what items should be of particular concern to the operator

a uniform sludge blanket is formed and maintained throughout the soldis removal process.

How would you calculate the detention time for a sedimentation basin

dividing the volume of the basin by the flow going into the basin.

What problems are caused by reduced effective water depth from excessive sludge buildup

high flow velocity, sludge scouring, and degradation of process efficiency.

Name two kinds of launders used in basin outlets

V-notch weirs, and orifices in pipes.

List two advantages of solids-contact units

capital and maintenance costs, and volume adjustment of sludge blankets.

How can the level of the sludge blanket be determined in solids-contact units

placing sampling taps at various depths along the wall of the solids-contact reactor.

What should be done when a rapid change in turbidity is expected

early application of an increased chemical dose.

How is the proper chemical dose selected when operating a solids-contact unit

jar testing.

List the devices that may be used to provide recirculation in a solids-contact unit

impeller, turbine, pumping unit, or air injection.

How is the percentage of slurry present in the reaction zone determined

performing a volume over volume test (settled slurry/total sample volume)

Under what circumstances are sedimentation basins needed to treat water

remove suspended solids and reduce load on the filters

What is the difference between normal operations and abnormal operations

normal operations are within operating ranges while abnormal operations are unusual or difficult to handle operations.

The actual performance of sedimentation basins depends on what two major factors

turbidity of the water and temperature of the water.

How can an operator determine if sludge lines are free flowing

if sight glasses are incorporated in the sludge discharge piping.

What should be changed if the sludge line plugs frequently

frequency of sludge removal must be increased.

How often should visual observations of sedimentation process performance be conducted

frequently/day by day.

In the routine operation of the sedimentation process, what types of records should be maintained

influent/effluent turbidity and influent temperature, process production inventory, and process equipment performance.

What water quality indicator is used as a rough measure of sedimentation basin process removal efficiency

measurement of turbidity levels.

What problems can be created by a sudden increase in settled water turbidity

filtration error.

What actions might an operator take if the sludge is rising or floating in a sedimentation basin

observe floc settling characteristics (dispersion, size, settling rate), evaluate process performance, perform jar tests, make changes and verify response to process changes.

Why should photographs be taken during shutdown and startup procedures

provide a visual record of events that may be difficult to illustrate when a basin is full of water.

List steps in the shutdown process for a sedimentation basin

stop flow to basin, install isolation gates, turn off sample pumps and sludge removal, lock out and tag electric switches and equipment, dewater basin, grease and lubricate all gears, sprockets, mechanical parts that were submerged to avoid freezing/breakage.

How frequently should turbidity be monitored

several times per shift.

How are sedimentation process water samples obtained for analysis

immediately taken in clean plastic/glass containers and without contaminants.

What items should an operator look for after a sludge pump has been started

check for noises, vibration, temperature, leaks, suction and discharge pressures.

List typical functions performed as part of a sedimentation process preventative maintenance program

keep motors free of dirt and moisture, ensure good ventilation, check pumps and motors for leaks, noise, vibration, etc, maintain lubrication, inspect alignment of shafts and couplings, check bearings, check proper valve operation, check free flow of sludge in sludge removal collection and discharge systems.

What types of safety hazards are associated with sludge removal equipment

electrical, mechanical, open surface water, valve and pump vaults, sumps.

What is the difference between conventional and direct filtration

conventional filtration involves coagulation, flocculation, and sedimentation, while direct omits sedimentation and flocculation is reduced/omitted as well.

List the particle removal mechanisms involved in the filtration process

sedimentation on media, adsorption, biological action, absorption, and straining.

List the four classes of filters

gravity filtration, pressure filtration, diatomaceous earth, slow
sand filtration.

Define garnet

reddish glassy mineral sands made of silicates (calcium, magnesium, iron, and manganese)

What material is used for precoat and body feed operation

diatomaceous earth.

What material is most often used to support granular filter materials

gravel.

What units are commonly used to express filtration rate

gal/min/ft^2 or L/sec/m^2

What is the major operational difference between sand and dual media filters

sand filters have light fine grains on the top to stop floc, dual media filters have larger diameter grains in the top layer to stop larger particulates.

What two main factors influence the time period before a filter becomes clogged

amount of suspended solids in the water, and filtration rate.

Under what conditions is the filtration process stopped and the filter taken out of service for cleaning/backwashing

filter clogged, breakthrough occurs, or sufficient time has passed.

List four types of surface wash systems for filters

Baylis, fixed-grid, rotary, and air scour.

What aspects of the filtration process are controlled by the filter control system

flow rates through the filter by maintaining an adequate head above the media surface.

What is the primary purpose of using activated carbon as filter media

remove tastes and odors.

What is inline filtration

addition of filter aids to the filter inlet pipe.

What water quality factors affect the floc formation during inline filtration

variable turbidity and bacterial levels.

When is direct filtration used

when source water is low in turbidity, color, plankton, and coliform organisms.

What factors must an operator measure to control the performance of the filtration process on a day to day basis

turbidity (influent and effluent), and filter performance.

What is the most important water quality indicator used to monitor the filtration process

effluent water turbidity.

How can filter effluent turbidity be measured on a continuous basis

by an in-process turbidity meter.

List some of the typical functions performed by operators in the normal operation of the filtration process

monitor process performance, evualte water quality conditions and make appropriate changes, check and adjust process equipment, backwash filters, evaluate filter media condition, visually inspect facilities.

What could cause a sudden increase in head loss through a filter

lack of depth penetration.

How would you change the operation of a filter if there was a sudden increase in head loss through the filter

adjust filter aid chemical feed rate or reduce filtration rate.

What is meant by bumping a filter

opening backwash valve during a filter run to dislodge trapped solids and increase filter run length.

List the type of process calculations an operator is expected to perform

filter operation, backwashing, water production, and percent of water production used to backwash filters.

How are filter backwash rates usually given

gal/min/ft^2 or L/sec/m^2 of surface area.

Calculate the percent of water filtered used for backwashing if a filtration plant uses 0.12M gallons for backwashing during a period when a total of 5M gallons of water was filtered

2.4

What types of records should be kept when operating a filtration process

water quality, operation, water production, percent of water production for backwashing, and equipment performance.

How would you identify an upset or failure in the filtration/pretreatment process

abrupt changes in turbidity, pH, alkalinity, TON, temperature, chloring demand/residual, or color.

List indicators of abnormal filtration process conditions

mudballs in filters, media cracking/shrinkage, media boils during backwash, excessive media loss or disturbance, shorter filter runs, uncleanable filters, algae on walls and media.

How could you make a quick determination of filtration removal efficiency

changes of source water quality, pH, and alkalinity.

What problems may be encountered during backwash

mudball formation, filter cracks/shrinkage.

How does a filter become air bound

release of dissolved air in saturated cold water due to a decrease in pressure.

Under what conditions may clean filters be put back into service

when a dirty filter is removed, to decrease filtration rates, or increase production for increased demand.

When are filters routinely taken off for backwashing

when media is clogged, turbidity breakthrough occurs, or water demand is reduced.

Why should the surface wash system be activated just before the backwash cycle starts

aid in breakdown and removal of solids, prevent mudball development.

What should be done if a filter will be out of service for a prolonged period

drain water to avoid algal growth.

List types of equipment used in the filtration process

filter control valves, backwash/surface water pumps, flowmeters and level/pressure gauges, water quality monitors (turbidity meter), process monitors for head loss and water levels, mechanical and electrical filter control systems

What should be done before starting a piece of mechanical equipment such as a backwash pump

be sure it has been serviced and operational status is positively known.

What safety hazards may be encountered when working around mechanical equipment

rotating equipment, energized valves, pumps and other pieces of equipment, chemical spills

What is the SWTR definition of surface water

all water open to the atmosphere and subject to surface runoff.

What is the SWTR definition of surface water

all water open to the atmosphere and subject to surface runoff.

Particle counts can be used as a substitute for indicating the potential removal of what two microorganisms that are a threat when found in drinking water

giardia and cryptosporidium cysts.

Particle counters can be used to enhance the performance of which water treatment process

N/A

What is the difference between turbidity meter and particle counter measurements

N/A

What two factors influence the effectiveness of disinfection on microorganisms

reactions with organics and reducing agents.

List chemical agents that have been used for disinfection other than chlorine

bromine, iodine, ozone, bases.

What is a major limitation of the use of ozone

solubility.

How is chlorine dosage determined

add chlorine needed for chlorine demand and chlorine residual.

How is chlorine demand determined

chlorine does not react any longer with organic/inorganic materials.

List two inorganic reducing chemicals with which chlorine reacts rapidly

hydrogen sulfide and ammonia.

How do chlorine gas and hypochlorite influence pH

chlorine gas lowers pH by forming HCl, hypochlorite raises pH forming hydroxyl ions.

How does pH influence the relationship between HCl and OCl- - HCl favors formation of hypochlorus acid, OCl- is formed from HOCl at pH 8.5 or higher.

N/A

What is breakpoint chlorination

adding chlorine until demand has been satisfied.

An operator’s decision to use chloramines depends on what factors

quality of raw water, plant regulations, operational practices, and distribution system practices.

What are the three primary methods by which chloramines are produced

preammoniation followed by later chlorination, concurrent ammonia and chlorine addition, post chlorination/ammoniation.

Why is the applied chlorine to ammonia nitrogen ratio usually greater than the actual chlorine to nitrogen ratio leaving the plant

chlorine demand will reduce amount of chlorine available from combined residual.

Incomplete nitrification causes the production of nitrite, producing what problems in water disinfection

rapid reduction of free chlorine and interferes with measuring free chlorine,
leading to loss of chlorine/ammonia, increase in count of heterotrophic plate count bacteria.

What actions should an operator take when there is a sudden absence of chlorine residual in the distribution system

Retesting for chlorine residual, then checking chlorination equipment,
and finally searching for a contamination source that could cause an increase in the chlorine demand.

How does the length of chlorine contact time affect the disinfection process

With good initial mixing the longer the contact time the better the disinfection.

How is the efficiency of a disinfectant measured

Time in minutes of disinfectant’s contact in the water and concentration of the disinfectant residual.

List the two most common points of chlorination in a water treatment plant

Pre chlorination and post chlorination.

Under what conditions should waters not be pre chlorinated

Raw water containing organic precursor compounds and tasting orders when phenolic compounds are present.

What are the benefits of pre chlorination

Control of algae and slime growths, control of mud-ball formation, improved coagulation, reduction of tastes and odors, increased chlorine contact time, and increased safety factor in disinfection of heavily contaminated waters.

List the major parts of a typical hypo chlorinator system

solution, pump/ejector, treated wastewater from plant.

What are the two most common methods of feeding hypochlorites to the water being disinfected

The hypochlorites solution may be pumped directly into the water or the
hypochlorite solution is pumped through an ejector.

How is the rate of gas flow in a chlorinator measured

Through use of a rotameter.

What is the primary advantage of vacuum system chlorinators

Safety.

What type of container is commonly used to store hypochlorite

Plastic containers.

How large a supply of hypochlorite should be available

One week supply

What is the purpose of the fusible plug

Prevent buildup of excessive pressures and the
possibility of rupture due to a fire or high surrounding temperatures.

What is removed by the upper and lower valves of ton chlorine tanks

Upper valve releases chlorine gas, lower valve releases liquid chlorine.

When are mouthbit chemical cartridge respirators used

Only for escape.

How can copper tubing be prevented from getting kinks or dirt inside the tubing

Use of a sling to hold the tubing when disconnecting it from an empty container to prevent the tube from flopping around.

Why are one ton tanks placed on their sides with the valves in a vertical position

So that either chlorine gas or liquid chlorine may be removed.

What would you do before attempting to start any chlorination system

Read the manufacturer’s literature and your plant’s operation and maintenance instructions.

What should be the chlorine residual in the most remote part of the distribution system

0.2 milligrams per liter.

Why should a hypo chlorite feed pump be operated in the upper end of its range (at 6 or 7 in a range of 0 to 10)

So that the strokes or pulses from the pump will be close together. This way, the chlorine will be fed continuously to the water being treated.

When starting a gas chlorinator, how is the system checked for chlorine gas leaks

With a chlorine leak detector.

List the steps to follow when shutting down a chlorinator for a long time period

Have safety equipment available in the event of a chlorine leak, close chlorine container gas outlet valve, Allow chlorine gas to completely evacuate the system through the injector. Chlorine gas pressure gauges will fall to 0PSI on the manifold and the chlorinator. Close chlorinator gas discharge valve. The chlorinator may remain in this condition indefinitely and is ready to be plugged back into surface by reopening the chlorinator discharge valve and the chlorine gas container valve. Turn off the chlorinator power switch, lock out, and tag. Secure the chlorinator
gas manifold and chlorinator valve in closed position.

Normal operation of a chlorinator includes daily inspection of what facilities or areas

Container storage areas.

What is the purpose of evaporators

Evaporators are used to convert liquid chlorine to gaseous chlorine for use by gas chlorinators.

What abnormal conditions could be encountered when operating an evaporator

The evaporator water level is low. Low water temperature in the evaporator, no chlorine gas flow to the chlorinator.

What are possible chlorinator abnormal conditions

Chlorine leak in the chlorinator, gas pressure is too low less than 20PSI, injector vacuum is too low, low chlorine residual.

How can you determine if the chlorine residual analyzer is working properly

Determine the actual chlorine residual and compare it with the residual reading from the chlorine analyzer.

What is the suggested free chlorine residual for treated water

0.5 to 1.5 mg/L

What is the suggested free chlorine residual for the farthest points in the distribution system

0.2 mg/L

How would you determine if you were chlorinating at the breakpoint –

Increase the chlorine dose rate.

If chlorine is escaping from a cylinder, what would you do

turn the container so that the leaking side is on top

How can chlorine leaks around valve stems be stopped

By closing the valve or tightening the packing gland nut.

How can chlorine leaks at the valve discharge outlet be stopped

Replacing the gaskets or adapter connection.

Why should a chlorinators be located in a separate room

prevent Chlorine gas leaks from damaging equipment and harming personnel.

Why is adequate ventilation important in a chlorinator room

Remove any leaking chlorine gas that would be hazardous to personnel and damaging to equipment.

How can chlorination rates be checked against the chlorinator setting

measuring and controlling chlorine dosage.

When and how often should the weights of chlorine containers be recorded

At the same time every day.

What additional equipment is necessary to use an existing chlorination unit to produce chlorine
dioxide

A diaphragm pump, solution tank, mixer, chlorine dioxide generating tower, and electrical controls.

What hazards are associated with the handling of sodium chlorite

It is very combustible around organic compounds.

What factors could increase the maintenance record needed on chlorine dioxide generators

Dirty water, hard water, or wet chlorine.

How often should treated water residual chlorine measurements be made

At least three times per day on small systems and once every two hours on large systems.

What methods are used to measure chlorine residual in treated water

amperometric titration and DPD tests

What does an ORP probe measure in a disinfection system

A direct measure of the disinfecting power of a chlorine residual.

What happens to a microorganism when it loses an electron

They become inactivated and can no longer transmit a disease or reproduce.

What maintenance is required on ORP probes

Cleaning the unit’s sensor once a month.

What properties make chlorine gas so hazardous

Flooring gas is 2 ½ times heavier than air extremely toxic and corrosive in moist atmospheres

What type of breathing apparatus is recommended when repairing chlorine leaks

A self contained breathing apparatus

What first aid measures should be taken if a person comes in contact with chlorine gas

leave the area and remove any clothing that might contain chlorine gas. In extreme cases call 911 then begin treating the victim.

What happens when ultraviolet radiation is absorbed by the cells of microorganisms

It damages the genetic material in such a way that the organisms are no longer able to grow or reproduce

What are the three types of electrode type lamps used to produce UV radiation or UV light

low pressure low intensity, low pressure high intensity, medium pressure high intensity

What is a ballast

A type of transformer that is used to limit the currents to a UV lamp.

How is the number of UV banks per channel determined

The required UV dosage to achieve the target effluent quality

How are UV lamps installed when it is necessary to maintain within the water transmission system

UV lamps can be installed in a closed pressure vessel

What kinds of damage can the light from a UV lamp do to operators

skin burns

The UV light intensity that reaches the pathogens in the water is affected by which factors

The condition of the UV lamps and the quality of the water.

The UV unit automatically adjusts UV dose according to which factors

Based on the received dose, derive from flow and input from the intensity sensors

How is the UV dose calculated

The intensity of the UV radiation and the contact time

Why do operaters need to periodically observe the UV wiping process

To ensure proper operation of the wiping action of a bank and the proper wiping cycle

What’s preliminary steps should be followed when shutting down or starting up a UV disinfection process

Applying ahead check switches clean units prepare equipment and set
controls

How can UV light bulbs be cleaned

in an acid bath in a cleaning tank

Why must operators monitor the lamp output intensity

UV lamp burn time

What influent and effluent characteristics must be monitored

to ensure Adequate disinfection is performed by the UV lamps

Why do UV systems require extensive alarm systems

to ensure continuous complete disinfection of the water being treated

What tasks are included in the routine maintenance of UV disinfection systems

Cleaning the quartz sleeves and changing the lamps

How often should quartz sleeves be cleaned

Will depend on the quality of the water being treated and the treatment chemicals used before disinfection

What factors influence the service life of UV lamps

the the level of suspended solids in the water to be disinfected, the frequency of on/off cycles, and the operating temperature of the lamp electrodes.

How can operators determine the proper way to dispose of used UV lamps

Contacting the appropriate Regulatory agency to determine the proper way to dispose of used UV lamps

What factors influence the effectiveness of ozone disinfection

The susceptibility of the target organisms, the contact time, and the concentration of the ozone.

What are the key process control guidelines for ozone disinfection

dose, mixing, and contact time.

Why is ozone generated on site

it is very unstable and decomposes to elemental oxygen in a short time after generation.

List the problems that can be created by corrosive waters

Rusty water stained laundry bad taste and internal corrosion of pipes

What is an electrochemical reaction

Chemical change is produced by electricity or the production of electricity by chemical changes

What happens to an iron water pipe when the pipe is connected to a copper pipe

The iron will corrode if water contains dissolved oxygen and the copper will be protected.

What is the dezincification of brass

when brass corrodes leaving behind copper

What happens when copper and lead solder are in contact

The lead becomes the anode and will corrode in preference to the copper

What is a dangerous corrosion inhibitor

Inhibitors that act on the anode reaction because if there is not enough inhibitor added severe pitting will result and corrosion will be worse than if none had been added.

What will happen if a copper service line is connected to a steel water main

corrosion will occur at the anode.

What effect of stray current corrosion may be evident to homeowners

When pitting penetrates fixtures or pipes resulting in leaks.

What causes erosion corrosion in copper tubing

High velocities

List the chemical factors that influence corrosion

PH alkalinity chlorine residual levels of dissolved solids dissolved gases and the types and concentrations of various minerals present in the water

Why does water with a higher dissolved solids content have a greater potential for corrosion

Solids dissolved in water are present as ions and increase salt content of the water increasing conductivity

What is the impact of calcium carbonate on corrosion

It acts as a corrosion control measure

What is the most common type of corrosion cell

Oxygen concentration cell

Where can an oxygen concentration cell be started

In the dead end of a water main

How can pits be started on a metallic surface underwater

Anything that will shield the metal surface from dissolved oxygen in the water

What is a tubercle

A Mound of iron rust

Why is corrosion of water system facilities a public health concern

To protect the public from the harmful effects of lead copper or other toxic metals in drinking water

How can corrosion rates be measured

By inserting special steel specimens called coupons in the water mains. After a period of time the coupons are removed and the loss of weight and nature of corrosion damage are measured.

How can leaks in pipes be detected

The observation of wet spots above a pipeline

How can you detect a film of calcium carbonate that is too thin to see

when they drop of dilute hydrochloric acid is placed on an obvious cathodic area

What does a loss of dissolved oxygen in the water flowing in a distribution system indicate

N/A

What toxic metals may enter drinking waters from the customer’s plumbing due to corrosive
water

N/A

When is a water considered stable

When it is just saturated with calcium carbonate

How can water be tested to determine if it is under saturated or supersaturated with calcium carbonate

The CCPP or the Langelier index

The Langelier index is determined by what equation

Langelier index = pH - pHs

What is the meaning of pHs

pH at which water having the same alkalinity and calcium content is just saturated with calcium carbonate

Why do some waters not have a meaningful pHs value

They have a low calcium content and alkalinity

What do rusty or red water complaints indicate

Where they are occurring and how they can be corrected

How can the corrosivity of a water be reduced

Treating the water with chemicals so that it is saturated or slightly supersaturated with calcium carbonate

What chemicals may be added to waters to reduce the corrosivity

Quicklime, hydrated lime, soda ash, and caustic soda

What chemicals may be required for corrosion control if the product of calcium hardness multiplied by the alkalinity Is less than 1000

Calcium and carbonate

What chemicals will be required for corrosion control if the product of calcium hardness multiplied by the alkalinity is greater than 5000

caustic soda or lime

How can the proper chemical dose be determined to produce water that is just saturated with calcium carbonate

May be determined graphically or by a trial and error calculation that is practical only with the help of a computer

List one advantage and one limitation of using zinc compounds instead of lime or caustic for corrosion control

scaling is reduced (water hardness)

Where is the application of cathodic protection practical in water treatment plants

reduce corrosion of metal to water or soil.

What is the best measure of the corrosivity of soil

soil resistivity measured using a soil resistance meter

How can electrolysis of water mains be caused by other utilities

stray currents generated by cathodic protection installed by other utilities.

How can internal pipe corrosion be detected and controlled

detected through rusty water complaints and examining the pipes for pitting/tubercles/corrosion evidence, must be treated to achieve calcium carbonate saturation.

How can external pipe corrosion be detected and controlled

indicate by pinhole leaks or rust on outside of pipes, cathodic protection can suffice, or have the pipe replaced with PVC/plastic pipes, cement coated line

List the important elements of the 1991 lead and copper rule

MCL goals, monitor lead, treatments for lead/copper, public notification and education, utilities record keeping and reporting, variances and exemptions regulations and compliance schedules based on population size.

What is the definition of an action level in the lead and copper rule

value measured in the 90 th percentile at the consumer’s tap

What are the accepted potable water corrosion control treatments

N/A

How do chemical inhibitors control lead and copper in water distribution systems

providing s coating that prevents corrosion

How must a utility attempt to educate the public if it fails to meet the lead action level

EPA developed public education program must be initiated

How frequently may taste and odor problems occur at a water treatment plant

They may occur locally on a persistent seasonal occasional or infrequent basis

What are the most common types of water quality complaints received by a water utility

Taste odor and colored water

What is the most damaging effect of problems for a water utility

The loss of public confidence in the water utilities ability to provide a safe high quality water

List the major causes of tastes and odors in a water system

geosmin, MIB, chlorine, chloramines, aldehydes, phenols and chlorophenols

Where could conditions develop in a water system

Algal blooms and source waters disinfectants used and the water distribution system

Which two compounds can produce earthy and musty odors in the water

geosmin and MIB

Which inorganic chloramine causes the least odor problems in treated water

Trichloramine

Name two groups of bacteria that are known to produce compounds in water

actinomycetes

What common blue green algae are associated with odors ranging from earthy musty to septic

anabaena, aphanizomenon, oscillatoria, microcystis

What are the two general ways in which microbial populations can contribute to unpleasant tastes and odors in water

Metabolic byproducts and cellular material of common aquatic microorganisms

Why does water sometimes have better qualities before treatments than after treatment

When cells die they rupture and cellular material is released into the water

When should the application of an algicide be considered

When the dominant algae is identified as a producer, when algae is not a dominant organism in the population, And sensory or chemical analysis indicates an increase in the order of the water

What types of minerals in runoff waters can lead to oxygen depletion

Nitrogen and phosphorus

How can the nutrient levels in a water supply be increased

reuse of sludge lagoons

What causes the diurnal dissolved oxygen cycle

Algae that produce and consume oxygen

What factors can cause contamination of a water supply by septic tank and leach field systems in rural areas and in resort and vacation developments

they may be located too close to rivers and improperly set

How can industrial waste discharges cause taste and odor problems

Directly adding odorous compounds such as phenols and aromatic hydrocarbons to the water and adding nutrients that result in causing algal blooms

What are the sources of most chemical spills

The result of accidents at industrial plants chemical storage facilities or during transportation

Why are many municipal water intake facilities located upstream from major agricultural areas

To avoid possible termination of the water supply by fertilizers microbial contaminants pesticides and herbicides

List some sources of agricultural wastes that may cause problems in a water supply

animal wastes, Previously applied fertilizers pesticides herbicides and the spreading agent used to apply them

How do debris and sludge cause tastes and odors

microorganisms grow in the organic material

What parts of the plants are likely locations for algal colonization

In the sedimentation basin and filter walls and weirs

What are the most likely sources for the development of tastes and odors

Any part of the system that are used to store transport or regulate untreated water may provide a suitable habitat for organisms that produce objectionable tastes and odors due to an absence of chlorine residual

What kind of survey is used to identify the sources of tastes and odors in raw water

sanitary survey

How do the chemicals used in a water treatment plant interfere with a search for the source of tastes and odors

Treatment chemicals such as chlorine and powdered activated carbon tend to mask any changes in quality that may be occurring within the plant

Where are the potential sources of tastes and odors within a water treatment plant

Algal growth due to poor housekeeping practices

What are the main causes of tastes and odors in the distribution system

Microbiological activity, disinfection residuals and their byproducts, organic or mineral compounds from system materials, and external contaminants from cross connections

What types of complaints would alert you to the potential of a cross connection

Complaints about a musty septic or other strange odor in the water

Which two components should be incorporated into a taste and odor monitoring program

Routine counting and identification of source water algal populations and attached algae in the

plant, and sensory analysis such as a taste threshold test of source and distribution system waters and plant profiles when needed

N/A

What happens when settled sledges and other debris are allowed to accumulate in the bottoms of channels and tanks in a water treatment plant

these areas will become septic and impart a foul taste and odor to the water

When are portions of water treatment plants usually taken out of service for inspection and cleaning while the remainder of the plant continues to operate

During the winter months when flows are lower and a full plant capacity is not needed to meet water demands

Why should treatment equipment be capable of operating properly at all times

The
prevention of episodes at the consumers tap

What sensory method uses a trained panel to identify tastes and odors in both the treatment process and distribution system

The taste threshold test

List the two broad categories of taste and odor treatment methods

Removal and destruction

How does the use of chlorine influence taste and odors when water contains algae

It leads to an increase in odor to to the destruction of algal cells by chlorine

How can tastes and odors caused by algae be removed most economically in a water treatment plant

Through the use of improved coagulation

Aeration is best suited for treating what type of taste and odor problems

reduced inorganic compounds such as ferrous iron or manganous manganese

What are the two basic ways that aeration systems can be designed

passing water through the air or passing air through the water

What types of odors can often be decreased significantly by chlorination

N/A

Under what circumstances might the use of chlorine be the wrong treatment for a taste and odor problem

N/A

How would you respond to a permanganate overdose

Adding powdered activated carbon or increasing the pH

Why must permanganate storage facilities be dry and well ventilated

Moisture can cause caking of the material

Why are adequate permanganate dust control and ventilation importance for equipment protection

Prevents breathing in of the dust which is irritating to the eyes mucous
membranes and skin

Why should laboratory and pilot scale testing of the effectiveness of ozonization as a taste and odor control process be conducted before full scale installation

Due to the specialized equipment requirements

Why must chlorine dioxide be generated on site

it is highly unstable

What types of taste and odor producing wastes have been treated successfully by using chlorine dioxide

industrial pollution

What two forms of activated carbon are used in water treatment

Powdered activated carbon or granular activated carbon

What terms are used to describe the adsorptive capacities or ratings of activated carbons

The basis of a phenol number or an iodine number

Why should PAC be applied at the plant flash mixing facilities

Carbon must contact the material to be removed for adsorption to occur

What would you do if a caked layer of carbon starts to form on the surface of the water in the slurry tank

The cake can be broken up using breaker bars or wooden paddles

What precautions must operators take because powdered activated carbon is so abrasive

Equipment used to feed PAC often requires more frequent inspection cleaning and
maintenance

What adjustments would you make if PAC tends to cake on the surface of the filters

adjustments to improve PAC removal in the settling process

How can carbon penetration through a filter be detected

collect a one liter sample of filter effluent and filter it through a 0.45 picometer membrane filter

What is empty bed contact time in a granular activated carbon filter

The time that the water is actually in the filter bed

What information should be recorded on a water quality complaint form

name and address of complaints location and description of complaint comments of field investigator response actions and conclusions

How should operators be kept informed of taste and odor problems

Through a standard notification procedure for complaints

What tests can operators conduct to identify problems before they reach the consumer

Routine testing of raw and finished water for quality

What factors could cause taste and odor complaints in the local area of a distribution system-

N/A

Which locations in a water supply system might contribute problem

Raw water source storage facilities raw water transmission systems and facilities at a treatment plant

Why is it important to write out an updated list of options available for treating problems

N/A

What two analysis can be used as an early warning system for taste and odor events

Routine monitoring of algal populations in conjunction with the use of sensory analysis in the form of tastes threshold test

List the five types of primary contaminants considered to be of public health importance

Inorganic contaminants, Organic contaminants, turbidity, microbial contaminants, and radiological contaminants

What criteria must be met before EPA selects a contaminant for regulation

The contaminants may have an adverse effect on the health of the people, it is known to occur or there’s a high chance it will occur in PWS often enough and at levels of public health concern, And regulation of the contaminants presents a meaningful opportunity for health risk reductions for people served by PWS

What is the purpose of a consumer confidence report rule

To improve public Health Protection by providing educational material to allow consumers to make educated decisions regarding any potential health risks pertaining to the quality treatment and management of their drinking water supply

Why are treatment technique requirements also referred to as primary standards rather than as MCLs

Testing for certain contaminants can be expensive requiring specific treatment
techniques

Why is arsenic listed as a primary contaminant

N/A

Why is nitrate in drinking water above the national standard of 10 mg/L considered an immediate threat to public health

it causes blue baby syndrome

What is the purpose of the TCR

It is the limit of total coliforms in drinking water

What is the most basic test for bacterial contamination of a water supply

test for total coliform bacteria

What does the final RTRC establish

MCL for E. Coli

What Organism is most implicated in US waterborne disease outbreaks

Giardia lamblia

How do regulation treatments techniques ensure that harmful organisms are treated

N/A

Why substitute chlorine residual testing for some of the bacteriological testing

It could give a quicker indication of the condition of the system

What is often the most corrosive chemical found in a water plant

N/A

What is one important safety precaution that should be followed at a water treatment plant

N/A

What are the symptoms of fluoride poisoning

N/A

What is the first aid procedure for skin contact with fluoride

N/A

What special training must be given to all operators who handle fluoride compounds

N/A

List the compounds most commonly used to fluoridate water

N/A

List the compounds most commonly used to fluoridate water

N/A

Which is the easiest fluoridation chemical to feed

N/A

List examples of solution feeders for liquid fluoridation chemicals

N/A

What important aspects should be incorporated into the design of a water treatment plant

N/A

Why is sodium silicofluoride not recommended to feed through a saturator

N/A

What is a saturator

N/A

Describe a downflow/upflow saturator

N/A

How can you see the level of undissolved sodium fluoride in an upflow saturator

N/A

List the types of alarms at a fluoridation plant

N/A

List the different parts of a small hydrofluosilicic acid system

N/A

Why should an operator avoid injecting solution into the top of a small hydrofluosilicic acid system pipe

N/A

What type of feeding system is typically found in a large hydrofluosilicic acid system

N/A

Why should hydrofluosilicic acid storage tanks made of plastic be housed in enclosures

N/A

What is one result of using a closed loop control system in an unattended plant using a fluoride analyzer as one of the controls

N/A

When performing the final equipment checkup, what must the operator be certain of

N/A

When reviewing fluoride feeding system designs and specifications, what should the operator check

N/A

Why must corrosion resistant drop pans and drains be provided with a fluoride feeding system

N/A

Why use alarms with a fluoride feeding system

N/A

Why must the proper position for all valves be determined in the industrial feeder startup procedure

N/A

Why record the amount of chemical left in the storage bin

N/A

After a plant shutdown, which meter provides equipment information

N/A

What benefits do the equipment manufacturer’s manuals for procedures provide

N/A

What are the benefits of overfeeding chemicals

N/A

Why should fluoridation equipment be cleaned out of the equipment is going to be shut down for an extended length of time

N/A

How can fluoride dust be removed from gears

N/A

During maintenance of fluoridation equipment, how concerned should you be about checking the feed rate by catching a given amount of fluoride over time

N/A