Class D Water Operator <: questions and answers verified A+| download to ace tests| fall 2024

Class D Water Operator &lt: questions and answers verified A+| download to ace tests| fall 2024Class D Water Operator &lt: questions and answers verified A+| download to ace tests| fall 2024Class D Water Operator &lt: questions and answers verified A+| download to ace tests| fall 2024 What are some physical characteristics of water? - correct answers-Temperature, turbidity, color, taste, odor What are some chemical characteristics of water? - correct answers-Hardness, pH, solids, and gases What is turbidity? - correct answers-the amount of suspended matter, such as clay, silt, organic matter, and microorganisms in water T/F Water is never found pure in nature. - correct answers-True Is turbidity more of a problem in groundwater or surface water? - correct answers-Surface water A system's filtered water must be _______ Nephelometric Turbidity Units (NTU) or less in at least 95% of the measurements taken each month, and no sample can exceed _____ NTU. - correct answers-0.3 1 T/F True color is dissolved in water (in solution) and cannot be removed by filtering. - correct answers-True. Tea in water is an example of true color. Suspended color is called _______ color. - correct answers-apparent Color above ______ units is objectionable in a public water supply. - correct answers-15 units A scale called the ________ measures odor. - correct answers-Threshold Odor Number (TON) Odor greater than a scale of _______ is undesirable. - correct answers-3 Taste and odors in water result from _______, bacteria, decaying organic matter, gases, and chemicals such as manganese, zinc, copper, iron, magnesium, sodium, and potassium. - correct answers-algae Chemical characteristics of water generally cannot be detected by sight, smell, or taste and must be determined by __________. - correct answers-laboratory analysis Chemical laboratory analysis must be sampled _______ per year for surface water and normally _______ for groundwater. - correct answers-once/year for surface water once every three years for groundwater Water weighs ______ lbs/gal. - correct answers-8.34 lbs/gal T/F For water, 1 mg/L is equal to 1 part per million (ppm) by weight. - correct answers-True Which two minerals mainly cause hardness in water? - correct answers-Calcium and magnesium Is hardness more of a problem in groundwater or surface water? - correct answers-Groundwater Water is considered hard when it exceeds _______. - correct answers-100 mg/L of calcium carbonate The pH scale ranges from _____ to _____. - correct answers-0 to 14 On the pH scale: 0 to &lt;7 is ______. 7 is _______. &gt;7 to 14 is ______. - correct answers-Acidic Neutral Basic or alkaline Sulfuric, hydrochloric, and nitric acids can be used to ______ pH. Caustic, lime, or soda ash can be used to ______ pH. - correct answers-Lower Raise Suspended solids can be removed by ________. - correct answers-Filtration Can dissolved solids be removed by filtration? - correct answers-No Total dissolved solids should not exceed________. - correct answers-1000 mg/L What are three common gasses found in water? - correct answers-Hydrogen sulfide, carbon dioxide, and methane Excess ________ can cause blue baby syndrome. - correct answers-Nitrogen or Nitrates What is the major source of nitrogen into drinking water? - correct answers-Fertilizer and animal waste carried by rainwater runoff What is the EPA primary MCL (maximum contaminant level) for fluoride? - correct answers-4.0 mg/L At what level will fluoride cause mottling of teeth, a condition known as fluorosis? - correct answers-4.0 mg/L What is the state of Texas secondary standard for fluoride? - correct answers-2.0 mg/L Trihalomethanes (THM) and Haloacetic Acids (HAA) are byproducts of drinking water ________. - correct answers-chlorination THM's and HAA's are byproducts formed when chlorine reacts with dissolved _________. - correct answers-natural organic matter, mostly plant life Combining chlorine with _______ greatly reduces THM and HAA formation. - correct answers-ammonia Is surface water or groundwater more likely to contain natural organic matter? - correct answers-surface water What is chloramine? - correct answers-Chlorine combined with ammonia What is free chlorine? - correct answers-Chlorine not combined with ammonia. Most groundwater systems do not have organic matter (which could cause THM and HAA byproducts) and therefore are allowed to use uncombined chlorine, called free chlorine. Why are most surface water treatment plants required to combine chlorine with ammonia (chloramine) before disinfecting the treated water? - correct answers-Surface water usually contains natural organics, and combining chlorine with ammonia greatly reduces THM and HAA formation. What is the MCL (maximum contaminant level) for THMs? - correct answers-0.08 mg/L What is the MCL (maximum contaminant level) for HAAs? - correct answers-0.06 mg/L The MCLG (maximum contaminant level goal) for lead is zero. What is the action level for lead? (in 10% or more of the samples) - correct answers-0.015 mg/L The MCLG (maximum contaminant level goal) for copper is 1.3 mg/L. What is the action level for copper? (in 10% or more of the samples) - correct answers-1.3 mg/L For lead and copper samples, how long must water be in the pipe with no flow before the sample is taken? - correct answers-6-18 hours What type of sample requires a one-liter, first