Texas Class D Water License | 100% Correct Answers | Verified | Latest 2024 Version, Exams of Water Resources Planning and Management

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Texas Class D Water License | 100% Correct

Answers | Verified | Latest 2024 Version

What removes tastes, odors, and certain organics and gases, and oxidizes iron and manganese? This process includes the incorporation of air into the water by means of spray nozzles , steps or cascades, or trays of diffusers? - ✔✔Aeration TCEQ regulation states that Shore installations , marinas, boats and houses on the watershed must have sewage? - ✔✔disposal Water aerated or chlorinated at proper pH levels oxidizes the iron and manganese, turning them into solid? - ✔✔particles Well casing and cementing protect the well from collapse and surface? - ✔✔contamination Sequestering does not remove iron from the water, but prevents it from combining with oxygen and? - ✔✔reddening The quantity of water a formation yields depends on the formations thickness and? - ✔✔permeability Cascade aerators, packed air-stripping towers, and air diffusers are used to aerate? - ✔✔water Aeration can be used to remove what from the water supply? - ✔✔iron and manganese Hydrogen sulfide has a rotten egg odor and is oxidized by? - ✔✔super-chlorination When Iron levels get this high, it can cause red stains on clothing, colored water, or turbidity? - ✔✔0. mg/L Excess Manganese can cause? - ✔✔black stains

Another method of iron control is the use of? - ✔✔sequestering agents What is a sequestering agent? - ✔✔polyphosphates Well water is sometimes? - ✔✔corrosive Low ph, dissolved gases, high temperatures, and high mineral levels can cause well water to be? - ✔✔corrosive What is the process of removing calcium and magnesium by adding lime or by exchanging ions? - ✔✔softening An ion exchange replaces calcium ions with? - ✔✔sodium ions A process available for removing arsenic, fluoride, lead, mercury, nitrate, and silver from raw water is? - ✔✔coagulation followed by sedimentation and filtration A process that forces water through a membrane is? - ✔✔reverse osmosis In reverse osmosis a sheet of synthetic material (membrane) under pressure prevents passage of dissolved materials and larger particles and ejects them in a? - ✔✔waste stream The Surface Water Treatment Rule (SWTR) requires community and non-community wells, springs, and infiltration galleries ( a subsurface tunnel that collects groundwater) to determine possible direct influence of? - ✔✔surface water Changes in groundwater quality can indicate influence of surface water organisms such as giardia cysts, algae or other? - ✔✔microorganisms

If well is deeper than 50 feet and more than 200 feet from a nearby surface water body, extensive evaluation of the influence of surface water on a water supply is? - ✔✔not required Surface water evaluations are needed on a water supply when shifts in water quality occur such as turbidity, temperature, pH, and the presence of? - ✔✔surface water organisms What are underground, water-bearing formations yielding useful quantities of water? - ✔✔Aquifiers Problems caused by what are declining water levels and subsidence (sinking of land)? - ✔✔overpumping The purpose of the well screen is to keep out birds and? - ✔✔sand the most important feature of the well screen is the size of the? - ✔✔opening The mesh size of the screen is determined by the size of the aquifer material, the size of the gravel in the gravel pack, and the type of well? - ✔✔development The gravel pack is fine gravel placed around the screen to reduce pumping? - ✔✔sand The well vent is a vacuum breaker allowing the casing to breathe as water levels change when the pump? - ✔✔cycles All public wells must be provided with a steel sealing block, a meter, a screened vent, and a sampling? - ✔✔faucet No source of contamination is allowed within how many feet of a public well? - ✔✔ 50 One way to reduce sand pumping is to decrease the pump rate and cycle? - ✔✔less

Water from a new well must not be used until bacteriological samples on three successive days show no? - ✔✔coliform Groundwater usually contains more dissolved minerals and gases than surface water but fewer? - ✔✔microorganisms Water table wells are usually? - ✔✔shallow In a water table well, the cone of depression and area around the well is? - ✔✔dewatered A sanitary control easement must cover land within how many feet of a public well? - ✔✔ 150 Livestock and septic tanks must be no closer than how many feet of a public well? - ✔✔ 50 Underground fuel tanks and septic drainage fields must be at least how many feet from a public well? - ✔✔ 150 Feedlots, sewage treatment plants, and landfills must be at least how many feet from a public well? - ✔✔ 500 A well may be developed by surging, overpumping, jetting, and? - ✔✔backwashing To disinfect a new well, a chlorine dosage of at least how much is required? - ✔✔50 mg/L A sample for physical and chemical analysis must be taken after how many hours of pumping in a well? - ✔✔36 hours Changes in well water levels or the volume of water produced can alert the operator to a drop in the water table, screen stoppage, or damage to the? - ✔✔pump

What are 2 common deep well pumps? - ✔✔submersible and vertical turbine Gases such as methane , carbon dioxide, and hydrogen sulfide are reduced by? - ✔✔aeration Rivers, lakes and what are surface water sources? - ✔✔reservoirs Texas has how many major river basins - ✔✔ 23 What is the longest running river in Texas? - ✔✔Rio Grande A major reservoir contains at least how many acre-feet? - ✔✔5, One acre foot in a reservoir is an acre by one foot deep and equals how many gallons of water? - ✔✔325, The largest reservoir within Texas is? - ✔✔Sam Rayburn Bacteria, algae and what are common contaminants of surface water? - ✔✔chemicals TCEQ regulation states that septic tanks, absorption fields, sewers, manholes or toilets cannot be within how many feet of a lake at spillway elevation or the 50-year flood elevation? - ✔✔ 75 TCEQ regulation states that no boat ramps, marinas, docks, or fishing piers can be within how many feet of an intake? - ✔✔1, TCEQ regulation states all activities shall be restricted within how many feet of an intake? - ✔✔ 200 Most surface water is low in minerals, gases, and? - ✔✔dissolved solids

Most surface water is high in turbidity and? - ✔✔algae To protect the health of the community, treated water must be free of disease-causing organisms and harmful chemicals must be reduced to? - ✔✔safe levels Water must be low in color, turbidity, suspended solids, temperature and free of? - ✔✔taste and odor Colored water can be caused by organics, algae, iron, or? - ✔✔manganese Water should not be corrosive, deposit scale, or stain plumbing in order to protect what? - ✔✔consumer property The following are characteristics of quality water: An absence of harmful chemicals, an absence of disease-causing organisms, little or no color, turbidity , solids, odor, or taste and noncorrosive, nonstaining and non-scale forming. - ✔✔true Treatment can include aeration, screening, chemical oxidation, coagulation, flocculation, sedimentation, filtration, and? - ✔✔disinfection TCEQ required treatment for surface water includes pretreatment disinfection, taste and odor control, coagulation, sedimentation, filtration, terminal disinfection and covered storage for what? - ✔✔clear well Pretreatment removes materials that affect treatment methods. Pretreatment includes reservoir destratification, control of algae, debris removal, presedimentation, aeration, chemical oxidation and activated what? - ✔✔carbon adsorption A reservoir destratification process includes the injection of air at the bottom of the reservoir (from spring to fall) will result in mixing to destratify the what? - ✔✔lake Deep reservoirs become stratified by temperature differences where cold water is trapped below? - ✔✔warmer water

Stratified reservoirs have problems with algae, iron and manganese, and? - ✔✔hydrogen sulfide With enough sunlight and nutrients algae can bloom in a reservoir causing? - ✔✔taste and odor Using copper sulfate at what dosage will assist in controlling algae blooms? - ✔✔0.1 to 0.5 mg/L In helping remove debris at a raw water intake what will help prevent debris from damaging pumps or blocking transmission lines? - ✔✔screening What destroys microorganisms and assists in reducing taste and odor problems? This process uses chlorine, potassium permanganate, chlorine dioxide, and ozone - ✔✔chemical oxidation What is the pretreatment process called that is the most effective method in eliminating bacteria or algae by applying carbon at the raw water pumping station or in the rapid mix.? - ✔✔activated carbon adsorption The surface structure of activated carbon will trap and hold? - ✔✔organic material Sedimentation and filtration remove carbon and its bonded organics after activated carbon? - ✔✔adsorption When adding chemicals in the pretreatment process, what effects the rate of chemical reaction? - ✔✔temperature The process of chemical mixing, coagulation, flocculation, and sedimentation remove suspended and dissolved materials from water. These process are commonly used for surface water, but can be used to remove hardness or iron in? - ✔✔groundwater In coagulation and flocculation, first chemicals are mixed with water in a rapid mix zone. The chemicals cause particles to coagulate and to form? - ✔✔floc

In coagulation and flocculation, after floc is created, the water passes into a tank where mixers slowly agitate the water. This process is know as? - ✔✔flocculation Common coagulating chemicals are alum, ferrous sulfate, and ferric chloride. Lime or soda ash raise or lower the pH and what is used to enhance the coagulation and flocculation? - ✔✔polymers (calgon) What kind of test assists the operator in determining which chemical, and how much to apply in the coagulation and flocculation process? - ✔✔jar tests Turbidity, pH, temperature, alkalinity, and chemical dosage as well as the amount and characteristics of suspended materials in raw water will influence? - ✔✔coagulation Very low turbidity waters where turbidity is of a colloidal nature , are difficult to coagulate. Very finely suspended solids (turbidity) will require an increase or a decrease in coagulant dosages? - ✔✔increase The what of water is the most important factor in effective coagulation.? - ✔✔pH Usually the warmer or colder of water, the slower the chemical reaction of coagulation? - ✔✔colder When temperature decreases , the viscosity of the the water increases and the rate of floc settling is? - ✔✔decreased Chemical dosages will be determined by a series of jar tests. The chemical dosage should be such that no concentrations over 10 NTU preferably as low as how many NTU shall go onto the filter? - ✔✔ 5 After the floc forms the water flows into a? - ✔✔sedimentation basin. A detention time of at least how many hours is required to allow the floc to settle? - ✔✔6 hours

The settled floc is called? - ✔✔sludge Sludge blanket clarifiers (upflow clarifiers) mix, coagulate, flocculate, and settle in the same unit. The flow rises through the sludge blanket, encouraging filtering and? - ✔✔settling Thick sludge blankets must not be allowed to form in sedimentation basins because they could create taste and odor problems an change the chemical quality of the? - ✔✔water Sludge is disposed of in lagoons, discharged into sanitary sewers, or dewatered and hauled to? - ✔✔sanitary landfills What is the final step in removing suspended matter and chlorine-resistant microorganisms? - ✔✔filtration A filter has 24 to 30 inches of porous material such as sand or anthracite coal called? - ✔✔filter media A common filter is the? - ✔✔rapid sand filter As water percolates through the media, the filter will gather solids. As the solids increase, there will be a loss of head (pressure) through the filter due to increased? - ✔✔friction When the head loss is how many feet, the filter must be backwashed? - ✔✔6 to 10 Operators may use other criteria such as filter effluent, turbidity or length of filter time to decide when to? - ✔✔backwash If backwashing is done improperly what forms in the media causing it to crack and clog? - ✔✔mudballs Filtration rates range from 2 to how many gallons per minute? - ✔✔ 4

The state requires pressure filters to operate at? per square foot. - ✔✔2 gpm TCEQ requires disinfection of surface water prior to? - ✔✔storage TCEQ requires facilities for pretreatment disinfection and terminal? - ✔✔disinfection Chemicals used to disinfect include chloramine, chlorine, chlorine dioxide, and? - ✔✔ozone Chlorination of surface water may lead to the formation of trihalomethanes and? - ✔✔haloacetic acids Treated water is stored at the plant in the? - ✔✔clear well A system's filtered water must be less than or equal to? Nephlometric Turbidity Units in at least 95% of the measurements taken each month. No sample can exceed? - ✔✔0.3 NTU, 1 NTU Systems serving less than 500 persons may reduce turbidity sampling to once per? - ✔✔day Inadequate disinfection must be reported to the state the? business day. - ✔✔next No more than 5% of the distribution samples can have inadequate residuals for how many consecutive months? - ✔✔ 2 To assess the adequacy of disinfection contact time, tracer study data must be submitted to the? - ✔✔state Fluoride in drinking water is beneficial or detrimental depending on the amount present. Studies indicate moderate levels of fluoride (0.7 to 1.0 mg/L) reduce? - ✔✔cavaties Waters high in natural fluoride (above 2.0 mg/L) cause - ✔✔mottling

Water from rivers, lakes, and reservoirs is called - ✔✔surface water 40 % of of public water systems use? - ✔✔surface water Sodium aluminate, aluminum sulfate, ferrous sulfate, and ferric chloride are all? - ✔✔coagulants What causes small particles in water to clot together forming floc, and this process, flocculation, forms larger particles that settle more readily? - ✔✔coagulants Turbidity, pH, temperature, alkalinity, and chemical dosage affect? - ✔✔coagulation To remove suspended solids and chlorine-resistant microorganisms, surface water must be? - ✔✔disinfected What is the final step in removing suspended matter and chlorine-resistant microorganisms? - ✔✔filtering Most surface water is low in minerals, gases, and? - ✔✔dissolved solids A filter must be? when a head loss of 6 to 10 feet occurs. - ✔✔backwashed Pretreatment includes lake destratification, control of algae, debris removal, presedimentation, aeration, ? and activated carbon adsorption? - ✔✔chemical oxidation Quality water has low amounts of color, turbidity, solids, and? - ✔✔taste and odor The most effective treatment for taste and odor is adsorption with? - ✔✔activated carbon

Lime (calcium hydroxide) is applied to water to adjust pH or? - ✔✔alkalinity The process of using chemicals to clot particles together is called coagulation and? - ✔✔flocculation Detention time in sedimentation basins must be at least how many hours? - ✔✔ 6 Backwashing should expand the filter bed by? - ✔✔30 to 50 % Chemicals used in disinfection are chloramine, chlorine, chlorine dioxide, and - ✔✔ozone Disinfection destroys disease causing microorganisms called? - ✔✔pathogens Disinfection destroys disease-causing microorganisms called? - ✔✔pathogens Disinfection kills pathogens without? which kills all microorganisms. - ✔✔sterilization What is sodium hypochlorite? - ✔✔liquid bleach All water in storage or transported through the distribution system must have a disinfectant? - ✔✔residual A disinfectant residual is the amount of? left over after the demand has been satisfied. - ✔✔chlorine Chlorine is used for taste and odor control, oxidation of iron and manganese, oxidation of hydrogen sulfide and disinfection of? - ✔✔repairs Calcium hypochlorite comes in granular and powder form and is made by reacting chlorine with? - ✔✔lime

Disinfection capacity for drinking water must be what percentage greater than the highest expected dosage? - ✔✔50% Dosage is the amount of chemical applied in mg/L or ppm. Demand is the amount of chemical used up by reducing agents. What is the amount of chemical remaining after reacting with demand/ - ✔✔residual DOSAGE = DEMAND + - ✔✔residual What is the minimum disinfection residual in the distribution system for free chlorine? - ✔✔0.2 mg/L What is the minimum disinfection residual in the distribution system for chloramine? - ✔✔0.5 mg/L What is the maximum free chlorine or chloramine residual for all community and non-transient, non community water systems? - ✔✔4 mg/L DPD (diethyl-p-phenylene-diamine) measures the chlorine residual in water in mg/L. The DPD and chlorine reaction turns the water a pink to? color. - ✔✔red ? and water make two acids: hydrocloric (HCL) and hypochlorous (HOCL), the disinfectant. - ✔✔chlorine The TCEQ allows no more than? mg/L of chlorine dioxide in the distribution system. - ✔✔0. Ozone is made of? oxygen atoms instead of two - ✔✔ 3 95% of all distribution residual readings must be above the minimum for how many consecutive monthly periods? - ✔✔ 2 Waterborne or water-carried pathogens live and grow in the intestines of infected? - ✔✔people

Every water sample is tested for waterborne diseases - ✔✔false Water samples are tested for? that indicate fecal contamination. - ✔✔microorganisms The total coliform group of? are the indicators of fecal contamination? - ✔✔bacteria If used in public drinking water, bleach must be NSF approved. What does NSF stand for? - ✔✔National Sanitation Foundation Sodium Thiosulfate is put into bacteriological sample bottles to? the water. - ✔✔neutralize Before taking a bacteriological sample you must? the service line. - ✔✔flush The monthly bacteriological sample should be marked? - ✔✔distribution In order to not have your samples rejected they should be in the lab before how many hours? - ✔✔ 30 You must notify the public about acute violations within how many hours? by radio and television using the words "Minor Health Concern." - ✔✔ 24 In the event of low distribution pressure (below 20 psi), water outages, repeated unacceptable microbiological samples , or failure to maintain adequate chlorine residuals, special precautions must be instituted by the? - ✔✔water system In Texas, all public water systems must have? facilities. - ✔✔chlorination Chlorination is the most important process in the production of? water. - ✔✔potable Calcium hypochlorite will cause explosions or fires if it contacts? material. - ✔✔organic

At room temperature, chlorine gas is greenish-yellow, has a pungent odor is? times heavier than air. - ✔✔2 1/ The maximum sustained gas withdrawal rate from 150-lb, cylinders (vacuum transmissions) is? lbs(s)./day per degree F. - ✔✔ 1 Disinfection capacity for drinking water must be? % greater than the highest expected dosage. - ✔✔ 50 Small water systems often use? to disinfect their water supply. - ✔✔hypochlorinators Hypochlorinators consist of a mixing tank, water,? hypochlorite, or? hypochlorite and a chemical pump.

• ✔✔sodium/calcium Gas chlorinators use a rotameter to meter chlorine in? or grams/hr. - ✔✔lbs/day Chlorinator rooms must have? level and? level screened vents> - ✔✔high/floor In chlorinator rooms,? must be provided to determine the amount of disinfectant used and the amount remaining daily. - ✔✔scales EPA requires any private, municipal, or industrial entity storing or using? pounds or more chlorine to have a chemical risk management program? - ✔✔2, Heat-sensitive pressure relief plugs in chlorine containers melt at about? degrees F. - ✔✔ 160 Hold an open bottle of? % ammonia hydroxide under a suspected chlorine leak. - ✔✔ 10 In case of leaks, the best source of help is the? - ✔✔supplier

After contacting chlorine gas, wash in a safety shower or with a? - ✔✔garden hose