WATER QUALITY FINAL EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026

WATER QUALITY FINAL EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026 EHS Knowledge to understand all phases of potable water management - Answers -Water cycle and its relation to geology -Accurate testing and sampling of water -Interpretation of water analysis results -Diseases associated with contaminated water -Chemical, physical, biological and radiological contaminants associated with water -Effect of actual and potential sources of pollution in water supplies -Water treatment system design -Water system design -Land use issues related to the development of water systems -Water conservation and reclamation methods For reliable indication of bacteriological quality and safety of potable water supply: - Answers -Biological and chemical standards -Reference to describe how water samples are properly collected, transported and preserved -Frequency source and distribution system water samples are analyzed -Guidelines for removal of organic and inorganic compounds -Water conservation techniques to inspect/detect problems with water distribution systems -Proper use of filtration processed or removal of suspended matter -Water quality standards Potable Water - Answers -Aesthetically acceptable -Free from apparent turbidity, color, odor, objectionable taste, -Free from disease causing organisms -Reasonable temperature Potable water management - Answers -Science and practice of protecting surface and groundwater resources used for the production of drinking water Definition of public water system - Answers -At least 15 connections or -Regularly services an average of at least 25 individuals daily at least 60 days per year 1974 Safe Drinking Water Act - Answers -Addressed concerns about contaminated water and uneven state supervision of drinking water -Required EPA to set enforceable standards for health-related drinking water contaminants -Primary (enforceable) and secondary (non-enforceable) maximum contaminant levels (MCLs) 1996 Amendment to SDWA - Answers State supervision of capacity development -Fund to assist small system with compliance -Consumer Confidence Reports Surface Water - Answers -Open to the atmosphere and subject to surface runoff -Rivers, lakes, wetlands, or estuaries -Often a source of disease-causing organisms -Vulnerable to contamination -Always requires treatment before it is safe to drink Ground Water - Answers -Openings or voids in the earth that are filled with water -Pumped from underground aquifers through drilled wells or from springs -Protected by layers of soil and other subsurface materials, usually requires minimal treatment Ground water under the influence of surface water - Answers Shallow aquifers, from aquifers near surface water sources, or from sources not well-protected through natural geology may be subject to influence from surface water sources. Treated like surface water. The Multiple Barrier Approach to safe drinking water is focused on: - Answers -Prevention of contamination -Source selection -Source protection -Appropriate treatment Potential Contaminants of safe drinking water - Answers -Microbiological contaminants -Nitrate- "blue baby syndrome" -Byproducts of disinfection -Lead -Arsenic -Radon -Pesticides -Solvents used by commercial and industrial facilities Municipal Treatment Processes - Answers -Coagulation-Flocculation -Sedimentation and flotation -Filtration- granular media filters, slow sand filters, rapid filtration, pressure filters -Disinfection Coagulation-flocculation - Answers -Combining small particles into big ones -This pre-treatment technique is essential to remove particles Coagulation - Answers -Aided by Alum (hydrated aluminum sulfate) 5-50 mg/l or other polymers Flocculation - Answers Small particles into bigger ones Sedimentation and Flotation - Answers -Sedimentation: gravity settling of solids after flocculation -Flotation: gas bubbles agglomerate with solid particles and float -Removal at bottom and top of the tank -Occurs in tanks or basins for at least 24 hours Filtration - Answers -Removal of suspended matter as it passed through beds of porous materials -Types of material removed: clay, silt, colloids, metal salt precipitates, lime-softening precipitates, iron and manganese precipitates and microorganisms -Reduces risk of bacteria, virus, Giardia and Cryptosporidium -Results in high-clarity water with few particulates (important for disinfection) Types of Filters for Municipal Treatment Processes - Answers -Granular Media filter -Slow sand -Rapid filtration -Pressure filter Granular Media Filter - Answers -Most Common Type Used -Vessel open or closed to atmosphere -Gravity flow or pressurized -Common materials: sand, crushed anthracite coal, garnet, activated carbon Often used in conjunction with another filter system Slow Sand Filter - Answers -Very low filtration rate, gravity flow -Solids mostly removed by thin layer at top -Grain size 0.25-0.35 mm -Inexpensive to construct and operate -Good for small areas with good source water -Effective for removal of Giardia Rapid Filtration - Answers -Larger grain size (0.5-0.7 mm or higher) and greater sand depth than slow sand filter