California Water Distribution Grade 3 Questions & Answers

R.P.P.A. - ANSWERSReduced pressure principal assembly. Backflow prevention for back siphonage and back pressure. AnswerAmerican Public Works Association color codes. White,pink,red,yellow,orange, blue, purple and green - ANSWERSWhite=proposed excavation Pink=temporary survey markings red=electric power yellow=gas,oil and steam orange=communications(phone/cable) blue=water purple=reclaimed water green=sewer and storm drains. AnswerDistance between water and sewer lines. - ANSWERSRunning parallel-at least 10ft apart. Perpendicular crossing-water lines at least 1ft above sewer. Common trench-water and sewer must not be in same trench. AnswerWater main and force main regulations. - ANSWERSParallel-at least 10ft apart. Perpendicular crossing-Water lines at least 1ft above and force main should be encased 10ft in both directions. New water lines installed over force mains should be rated to 200psi or equivalent. Force mains over 1000ft must have clean outs every 600ft. AnswerFire extinguishers Class A, B, C, D and K - ANSWERSA=ordinary combustibles. Wood, paper, cloth trash and plastic. B=Flammable liquids. Gasoline, petroleum oil and paint. C=Energized electrical equipment. Motors, transformers and appliances. D=Combustible metals. Potassium, sodium, aluminum and magnesium. K=Cooking oils and grease. AnswerDrawdown - ANSWERSDifference between the static pumping level and the pumping water level. AnswerResidual drawdown - ANSWERSA lowered water level that remains for a period of time after pumping has been stopped. AnswerCone of depression - ANSWERSDepressed water surface around a well when pumps are operating. AnswerWhat is Coliform Bacteria? - ANSWERSA group of bacteria found in the intestines of warm blooded animals. Also found in plants, soil, air and water. It's positive test is and indication that the water is polluted and may contain pathogenic (disease causing) organisms. Most coliform bacteria are not necessarily bad for you, but are used as an indicator to warn of more harmful bacteria. Testing this way is the easiest, most efficient and least expensive way. E. coli, however, is a type of coliform bacteria (fecal) that can make people sick. Answer4 types of corrosion - ANSWERSChemical: Low PH/ soft water Electrical: Galvanic reaction of dissimilar metals where one erodes the other. Erosion: Velocity greater than 5 feet per second erodes pipes and bends like sandpaper over time. Also increases dissolved oxygen content in highly oxygenated water. Biological: Living organisms-Iron bacteria and sulfate reducing bacteria. Common in ground water. AnswerWhat is corrosion? - ANSWERSThe gradual decomposition of a material over time by a chemical action. AnswerTier 1 violations - ANSWERSDirectly and immediately affect public health. -Fecal coliform positive. -Nitrite, nitrate or total MCL violation. -Chlorine Dioxide MRDL violation. -Turbidity MCL violation. -Perchlorate MCL violation. AnswerRelationship between Nitrates and methemoglobinemia. - ANSWERSNitrates are ingested and converted in the body to a substance that reacts with oxyhemoglobin, the oxygen carrying blood protein, to form methemoglobin, which cannot carry oxygen. Enough can be formed to deprive body tissues of oxygen causing blue skin color(blue baby disease) and respiratory problems. Answer2 Groups involved in Nitrification - ANSWERSAmmonia oxidizing bacteria Nitrite oxidizing bacteria AnswerLead and Copper Rule - ANSWERSObjective: control the corrosiveness of finished water to limit the amount of lead and copper leached from pipes and fittings. Collect first draw samples(sitting for at least 6 hours) from high risk residents. Provides action levels instead of MCL's. Action levels: Lead .015 ppm -Copper 1.3 ppm Calls for lead free pipes and fixtures. Less than or equal to 8% lead in pipes. Less than or equal to 0.2% lead in solder Utilities not in compliance must modify treatment techniques until they are in compliance. AnswerDynamic Water - ANSWERSWater moving AnswerVolatile - ANSWERSA liquid capable of going from liquid to gas at a relatively low temperature. AnswerFlexural strength - ANSWERSResistance to breaking while being bending. AnswerSafe Drinking Water Act - ANSWERSPassed by congress in 1974 creating uniform national standards for drinking water quality to ensure every public water supply would meet minimum health standards. Set primary and secondary regulations. Created the Total Coliform Rule, Surface Water Treatment Rule and Lead and Copper Rule among others. AnswerTier 2 Violations - ANSWERS-All MCL or MRDL treatment technique violations except those that are Tier 1 -Monitoring Violations if elevated to Tier 2 -Failure to comply with variance or exemption conditions. Answer95 degrees for 24 Hours is? - ANSWERSTest for coliform bacteria. Will produce gas and acid in lactose or a lauryl tryptose broth. AnswerPublic water system break down. - ANSWERSCommunity Water System-Piped water for consumption with 15 or more service connections. Non Community Water System-Serves 25 or more people for 60 or more days of the year. -Transient non community- Not the same 25 people. Only test for nitrite/nitrate and coliform bacteria. Except:Rest stops, parks and motels. -Non Transient Non Community-Same 25 people. Test for everything. Except Schools and factories. AnswerNitrite/Nitrate MCL - ANSWERSMeasured as Nitrogen. -Nitrate 1 mg/L -Nitrate 10 mg/L(some communities are allowed 20) AnswerIron and Manganese MCL. - ANSWERSIron .3 mg/L Maganese .05 mg/L AnswerChlorine levels - ANSWERSMinimum Residual: .2 mg/L RCML: 2.0 mg/L (recommended maximum contaminant level) MCL: 4.0 mg/L AnswerTypes of Connecting Joints - ANSWERSPush on joint(Bell and spigot): Very common. Least expensive, quick to install. -Install:Clean bell and plain end, lube gasket and plain end. Plain end edge is beveled, push together. Concrete Pipe joints: Similar to bell and spigot, but gasket sits in groove on plain end. Restrained Joint: Used with ground movement or high thrust. Allthread and nuts. Flanged Joints:Use above ground where pipe is rigid. Ends are flanged and connected with nuts and bolts. Ball and socket: Good for deflection up to 15 degrees. Called flexible joints. Each side can move independently. Mechanical Joint: Good for high degree of deflection. Has gasket running deep into joint with a follower to force gasket onto pipe. Bolts through entire joint. AnswerCompetent person and duties - ANSWERSIndividual with excavation knowledge and training who is in charge of an excavation job and has the power to stop work in the event of a hazard. DUTIES: -Inspect trench safety daily. -Classify soil. -monitor de watering. -Ensure proper use of shoring -monitor work, account for workers AnswerSoil types - ANSWERSA Strongest: Clay B Midgrade: silt, previously disturbed soils (slope 1-1) C Worst: sand, any excavation with water (slope 2-1) AnswerCompressive strength of soil types - ANSWERSA: Greater than or equal to 1.5 tons per sq. ft. B: Greater than or equal to .05 but less than 1.5 tons per sq. ft. C: Less than .05 tons per sq. ft. AnswerPnetrometer - ANSWERSTool for measuring the compressive strength of soil to classify soil types. AnswerDepth of mains - ANSWERSMinimum 2 1/2' of cover for mains and 18" for services. Deeper if necessary in cold climates- mains placed at maximum depth of frost. AnswerStory Pole - ANSWERSTool used for measuring depth in a trench. AnswerTrench width for mains. - ANSWERS1-2ft greater than pipe diameter. AnswerLocation of service tap on main and possible issues. - ANSWERS45 degrees from top. -Too low: sedimentation can get into service line. -Too high: Air can get into service line. AnswerMain line sizes and factors. - ANSWERS6" Minimum residential 8" Minimum business 4" Should only be used for circulation. FACTORS -Minimum size able to satisfy domestic use PLUS fire protection. -Fire protection is the primary factor for water mains, tanks and pump stations. -based on velocities of 2-4 ft per second. AnswerDry Barrel fire hydrant - ANSWERSValve is located under ground and no water in hydrant when not in use. Used where freezing is a concern. 2 Types-Wet Top and dry top. -Wet top has threaded end of rod and stem submerged in water when in use. -Dry Top has threaded end of rod and stem sealed from water when in use.