Practice exam 2

how many stages are in a breakpoint chlorination curve 3 2 1 4

4

Under the Surface Water Treatment Rule, what must the reduction of viruses be through filtration and disinfection? 99% 99.9% 90% 95%

99.9%

which of the following is not a type of coliform test multiple tube fermentation method membrane filter method DPD Colilert method

DPD

how is the rate of head loss affected by a more uniform filter media faster slower unaffected more breakthroughs

slower Head loss is a measure of the reduction in the total head of the fluid as it moves through a fluid system. more uniform media = more even distribution of particles = more even/uniform filtering = slower loss of 'pressure' (head)?

what is the purpose of surface washing in a filtration unit clear under drain expand filter media prevent loss of media break up mud balls

break up mudballs

what is one of the causes of hardness in water arsenic nitrate calcium manganese

calcium

what is the health effect of consuming water with high levels of lead blue baby syndrome breathing problems diarrhea cardiovascular effects, increased blood pressure and incidence of hypertension

cardiovascular effects, increased blood pressure and incidence of hypertension

what is the likely cause of a pinging noise in a pump? water hardness frequent starting and stopping cavitation corrosion

cavitation

what is formed when free chlorine reacts with ammonia ammonium hydroxide ammonium chloroform chloramine ammonium nitrate

chloramine

which of the following will most likely lead to the lowest concentration of THM's in treated water sodium hypochlorite chlorine gas chloramines calcium hypochlorite

chloramines

chlorine demand is best described as which of the following? chlorine dose + chlorine residual chlorine dose - chlorine residual chlorine dose x chlorine residual the amount of chlorine required to linger in the pipeline

chlorine dose - chlorine residual

which of the following categories does bacteria belong to dissolved settleable inorganic colloidal

colloidal

which of the following is true about soluble iron and manganese carcinogens reddish brown black colorless

colorless they are soluble, so they are dissolved in the water and not precipitated out or able to oxidized in the air

what are the two types of aquifers confined and unconfined static and pumping cationic and anionic eutrophic and oligotrophic

confined and unconfined

What is adsorption? constituent is sucked in constituents sticking to the surface of a substance molecule is converted from aqueous phase to solid phase contaminant breaks into smaller particles

constituents sticking to the surface of a substance

which type of filtration process is approved by the surface water treatment rule nanofiltration conventional water treatment ion exchange microfiltration

conventional water treatment

what is the problem with very soft water scaling leads to kidney disease corrosion THM formation

corrosion soft water contains a low amount of ions, degrades piping

what is a pathogen algae lauryl tryptose MTBE disease-causing microorganism

disease causing microorganism

what is the term used to describe the upper layer of a stratified reservoir epilimnion thermocline hypolimnion metalimnion

epilimnion

what is an example of a natural organic matter iron manganese fallen leaves arsenic

fallen leaves

what is the source of fecal coliform bacteria sand feces leaves inorganics

feces

what is considered to be a quick remedy to address a sudden increase in filtered water turbidity feed a filter-aid chemical to the filter influent increase plant flowrate backwash less frequently reduce speed of rapid mixer

feed a filter-aid chemical to the filter influent

which of the following controls the efficiency of removing suspended solids in the sedimentation process minimize mudball formation sodium hydroxide flowrate proper backwashing

flowrate

why is it harmful to backwash at a high velocity forms mudballs flushes some media into spent backwash water increases buildup (headloss) forms THM's

flushes some media into spent backwash water

what is the main drawback of using sodium hypochlorite to disinfect water expensive formation of THM's difficult to procure most dangerous form of disinfectant to store at plant

formation of THM's

What occurs on the right side of the breakpoint chlorination curve chlorine is destroyed by reducing compound formation of chlororganics chlororganics partially destroyed free available chlorine residual begins to form

free available chlorine residual begins to form

what is a typical characteristic of chlorine gas greenish yellow color blue color orange color brown color

greenish yellow color

which of the following will least likely impact the formation of flocs during the coagulation and flocculation process alkalinity pH temperature hardness

hardness

what is the purpose of flocculation mix coagulants with raw water add chlorine prior to filtration slowly stir water to bring smaller flocs together to form larger ones oxidize minerals

slowly stir water to bring smaller flocs together to form larger ones

what would cause a filter to begin backwashing low chlorine concentration presence of THM head loss temperature

head loss higher pressure = higher head loss, so it means a lot of stuff has built up on the filters, causing more pressure/ head loss -- meaning the system should backwash to get all that crap out and help filter efficiency

what happens over the course of a filter run time headloss decreases headloss is unaffected headloss increases headloss goes to zero

headloss increases the amount of pressure lost (headloss) increases because more shit and debris clogs the filters, so it makes it harder for the filter to do its thing

what is the drawback of using UV for disinfection DBPs involves storage of toxic chemicals high energy cost longer contact time required

high energy cost

which of the following is not used to mix coagulants hydraulic mixing mechanical mixing diffuser horizontal paddle wheel

horizontal paddle wheel York uses static mixing

what are the 4 zones of a clarifier inlet, outlet, settling, sludge inlet, outlet, settling, skimming inlet, outlet, settling, baffles settling, baffles, skimming, sludge

inlet, outlet, settling, sludge

what is the first priority in water treatment production of drinking water at a reasonable cost production of safe drinking water production of an aesthetically pleasing drinking water production of drinking water that does not leave scale deposits

production of safe drinking water

what is the amount of water than can be withdrawn from an aquifer without significant environmental impact well drawdown safe yield cone of depression specific yield

safe yield

why would a water purveyor switch from chlorine gas to sodium hypochlorite eliminate THMs safety to minimize liquid chemical storage at plant to eliminate the usage of free chlorine at the plant

safety I assume because the liquid hypo would be easier to handle and spot a leak on, rather than deadly chlorine gas

what is a thermocline - a thin but distinct layer in a reservoir in which temperature changes more rapidly with depth than it does in the layers above or below - epilimnion - hypolimnion - deepest layer

- a thin but distinct layer in a reservoir in which temperature changes more rapidly with depth than it does in the layers above or below

which of the following is a grab sample time proportional sample taken on a one time basis without consideration of flow or time flow proportional a collection of numerous individual discrete samples taken at regular intervals over a period of time

sample taken on a one time basis without consideration of flow or time

what information should be identified on the sampling container sampling location, date, and time concentration of all constituents probable cause of contamination type of treatment used at the plant

sampling location, date, and time

what is a common problem associated with hardness in water corrosion blue baby syndrome high blood pressure scaling

scaling hardness causes mineral deposits and leaves residues on surfaces and skin. Causes buildup in plumbing and dries skin out

what is an example of non-community, non-transient water system rest stop subdivision retirement community school

school

In which part of the water treatment plant are 99% of the suspended solids removed? coagulation disinfection flocculation sedimentation and filtration

sedimentation and filtration

what is short circuiting in a clarifier electrical problems in the control panel negative electrical charge on colloid electrical charge neutralized by alum shorter settling time in the basin

shorter settling time in the basin

what is the concentration of chlorine gas 12.5% 100% 65% 22.5%

100%

which of the following is not part of the Surface Water Treatment Rule - applies to all public water systems (PWSs) using surface water sources or groundwater sources under the direct influence of surface water - requires most water systems to filter and disinfect water from surface water sources of GWUDI - establishes maximum contaminant level goals (MCLGs) for viruses, bacteria, and Giardia Lamblia - all water systems are allowed to use disinfection only for surface water sources that meet criteria for water quality and watershed protection

- all water systems are allowed to use disinfection only for surface water sources that meet criteria for water quality and watershed protection

what is the purpose of packing in a pump - increase the pressure and flow of a fluid - transmit input power from the driver to the impeller/s mounted on the shaft - control the leakage of water along the pump shaft and prevent air from entering along the shaft when the pump is in a suction lift condition - keep the shaft or rotor in correct alignment with the stationary parts under the action of radial and transverse (axial) loads

- control the leakage of water along the pump shaft and prevent air from entering along the shaft when the pump is in a suction lift condition

what can be done to minimize the formation of THM - increase chlorination before filtration - increase precursors - eliminate or reduce chlorination before the filters - increase temperature

- eliminate or reduce chlorination before the filters

what is the standard requirement for conventional and direct filtration - filtered water must be less than or equal to 0.2 NTU in 95% of monthly measurements - filtered water must be less than or equal to 1.0 NTU in 95% of monthly measurements - filtered water must be less than or equal to 0.5 NTU in 95% of monthly measurements - filtered water must be less than or equal to 0.3 NTU in 95% of monthly measurements

- filtered water must be less than or equal to 0.3 NTU in 95% of monthly measurements

which of the following is not true about the total coliform rule - each total coliform-positive routine sample must be tested for the presence of fecal coliforms or E. coli - if any routine sample is total coliform positive, repeat samples are required - establishes a maximum contaminant level (MCL) based on the presence or absence of total coliforms - monthly sampling requirements are not based on population

- monthly sampling requirements are not based on population

what is an unconfined aquifer - one in which groundwater is under pressure by overlying and underlying aquitards - a well in which water rises under pressure from a permeable stratum overlaid by impermeable rock - a location where the groundwater naturally emerges from the earth's subsurface in a defined flow and in an amount large enough to form a pool - one in which groundwater possesses a free subsurface open to the atmosphere

- one in which groundwater possesses a free subsurface open to the atmosphere

what is the definition of a public water system - publicly or privately owned water system that has at least 15 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year - publicly or privately owned water system that has at least 25 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year - publicly or privately owned water system that has at least 35 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year - publicly or privately owned water system that has at least 45 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year

- publicly or privately owned water system that has at least 15 service connections, or regularly serves an average of at least 25 people daily at least 60 days per year

what is free chlorine - the residual chlorine existing in water in chemical combination with ammonia or organic amines - the sum of free and combined chlorine - inorganic chloramines - the concentration of residual chlorine in water which is present as dissolved gas (Cl2), hypochlorous acid (HCL), and/or hypochlorite ion (OCl-)

- the concentration of residual chlorine in water which is present as dissolved gas (Cl2), hypochlorous acid (HCL), and/or hypochlorite ion (OCl-)

which of the following range of pH is considered to be acidic 8-10 0-6 11-13 7

0-6

what is another name for the multiple tube fermentation test MPC MFF MDS MPN

MPN The multiple-tube fermentation technique is a three-stage procedure in which the results are statistically expressed in terms of the Most Probable Number (MPN). These stages -- the presumptive stage, confirmed stage, and completed test This method is used to determine the presence of a member of the coliform group in ground water and surface water

what agency protects the health and safety of industrial employees public utilities commission EPA OSHA NEPA

OSHA

How does PAC remove contaminants from the water? absorption disinfection adsorption filtration

adsorption

pH will increase if the following chemical is added to water CO2 iron ammonia acid

ammonia

what is a sanitary survey vulnerability assessment an analysis to determine all potential water quality impacts to a proposed well survey conducted to find ways to reduce wastewater production investigation to determine optimal location for water sampling stations

an analysis to determine all potential water quality impacts to a proposed well

what impact does precipitated manganese have on water brownish water blackish water reddish water no impact

blackish water

which of the following is the correct order of treatment for a conventional water treatment plant intake, coagulation, flocculation, filtration, sedimentation, disinfection intake, flocculation, coagulation, sedimentation, filtration, disinfection intake, coagulation, flocculation, sedimentation, filtration, disinfection intake, flocculation, sedimentation, coagulation, filtration, disinfection

intake, coagulation, flocculation, sedimentation, filtration, disinfection

Why is coliform used as an indicator organism? it reduces the complexity and cost of analysis it is accurate in identifying the strain of virus it provides detailed information about the type of parasites in the sample it provides the exact number of pathogens in the sample

it reduces the complexity and cost of analysis

what is used to evaluate new coagulants or polymers being considered for use at the plant DPD test MPN method Jar test Colilert method

jar test

Coliform is most likely to be found in which of the following water supply? deep well shallow well artesian lake

lake

what does the addition of carbon dioxide do to the pH of the water raises it lowers it unaffected by it creates instability of pH

lowers it

which of the following is not considered free residual chlorine hypochlorous acid hypochlorite ion monochloramine chlorine

monochloramine

When is Brilliant Green Bile used to test for coliform? membrane filter method multiple tube fermentation method colisure method MF method - E. Coli

multiple tube fermentation method membrane filter method -- The membrane filter technique is one of the basic procedures used in the detection of coliform. The procedure involves filtering a certain volume of sample, plating the filter on a specific medium, and incubating at the desired temperature.

where would you most likely see high levels of nitrate in the groundwater supply near agricultural land in very deep wells near military bases near swamps

near agricultural land

what is a typical characteristic of a colloidal particle in raw water positive charge on the surface negative charge on the surface neutral charge on the surface cationic attributes

negative charge on the surface

what is the reason for adding coagulants at the flash mixer stir flocs together oxidize iron and manganese neutralize negative charge on colloids pre-chlorination

neutralize negative charge on colloids In York, alum is added as a coagulant. alum first has to destabilize the particles before they can be mixed together to form the floc.

which of the following is true about fusible plugs on a chlorine container use it as a point of connection always remove it before use never remove it should be removed during maintenance

never remove it these are metal alloy plugs that are designed to melt at a specific temperature. Temp depends on the type of chemical that is in the storage container with this plug. - The fusible plugs found on chlorine cylinders, ton containers and larger containers are designed to melt and allow the pressure inside the container to decrease to safer levels. If the pressure is allowed to build within the cylinder, there is the possibility of a catastrophic release of the entire contents of that container - The fusible plug is made of a metal alloy designed to melt. Once the plug melts away, the gaseous chlorine will spew out of the small hole. As the temperature of the released chlorine near the hole drops and chlorine icing slows the leak, the pressure inside the cylinder is also decreasing. This cycle will continue until all the chlorine is escaped or the leak is capped.

what contaminant causes blue baby syndrome copper nitrate lead arsenic

nitrate

which of the following impacts the color of source water sodium pressure organics, such as soil and leaves temperature

organics, such as soil and leaves

which of the following is an unstable form of disinfection ozonation sodium hypochlorite chloramine UV

ozonation

what is an imaginary surface to which groundwater rises under hydrostatic pressure in wells or springs draw down radius of influence pumping water level piezometric surface

piezometric surface

which of the following is not true about the total coliform rule uses a presence and absence approach compliance is determined on a monthly basis each total coliform-positive routine sample must be tested for the presence of fecal coliforms smaller systems that collect fewer than 40 samples cannot have coliform-positive results in more than 2 samples per month

smaller systems that collect fewer than 40 samples cannot have coliform-positive results in more than 2 samples per month

what chemical is used to raise the pH in water citric acid carbon dioxide sulfuric acid soda ash

soda ash

which of the following is not an example of a suspended solid silt decaying plants animal matters soluble calcium

soluble calcium

what might happen if insufficient amount of coagulants were injected into the flash mixer excessive increase in floc size scaling becomes a problem worsens DBP problem some colloids may repel each other

some colloids may repel each other DBP stands for disinfection by product

which entity is responsible for enforcing the drinking water standards state city county federal EPA

state

what is the impact of algae to water quality elevated hardness increase in cryptosporidium taste and odor problems corrosivity

taste and odor problems

what is the most common water quality complaint from customers color taste and odor problems scaling corrosion

taste and odor problems

which pathogen is smallest in size bacteria protozoa cyst virus

virus

what is static water level in a well water level when a pump is not running water level when pump is running the midpoint of the aquifer the bottom of the zone of saturation

water level when a pump is not running

when is direct filtration used instead of conventional water treatment when source water is low in turbidity, color, and coliform when source water is low in iron and manganese when source water is low in nitrates when source water has an ideal pH and temperature

when source water is low in turbidity, color, and coliform