Class D Water Operator Questions and Answers Already Passed

Class D Water Operator Questions and Answers Already Passed What are some physical characteristics of water? Temperature, turbidity, color, taste, odor What are some chemical characteristics of water? Hardness, pH, solids, and gases What is turbidity? the amount of suspended matter, such as clay, silt, organic matter, and microorganisms in water T/F Water is never found pure in nature. True Is turbidity more of a problem in groundwater or surface water? 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. 0.3 1 T/F True color is dissolved in water (in solution) and cannot be removed by filtering. True. Tea in water is an example of true color. Suspended color is called _______ color. apparent Color above ______ units is objectionable in a public water supply. 15 units A scale called the ________ measures odor. Threshold Odor Number (TON) Odor greater than a scale of _______ is undesirable. 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. algae Chemical characteristics of water generally cannot be detected by sight, smell, or taste and must be determined by __________. laboratory analysis Chemical laboratory analysis must be sampled _______ per year for surface water and normally _______ for groundwater. once/year for surface water once every three years for groundwater Water weighs ______ lbs/gal. 8.34 lbs/gal T/F For water, 1 mg/L is equal to 1 part per million (ppm) by weight. True Which two minerals mainly cause hardness in water? Calcium and magnesium Is hardness more of a problem in groundwater or surface water? Groundwater Water is considered hard when it exceeds _______. 100 mg/L of calcium carbonate The pH scale ranges from _____ to _____. 0 to 14 On the pH scale: 0 to <7 is ______. 7 is _______. >7 to 14 is ______. 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. Lower Raise Suspended solids can be removed by ________. Filtration