NEHA RS/REHS COMPREHENSIVE EXAM 2026/2027
QUESTIONS AND SOLUTIONS RATED A+
✔✔What causes water hardness? - ✔✔Minerals (Dissolved calcium and magnesium
bicarbonates, sulfates, and chlorides)
✔✔Water containing Nitrates generally indicates? - ✔✔Evidence of agricultural pollution
(Note: Ammonia in the water comes from decomposition of organic matter and is
evidence of fresh water pollution.)
✔✔Microbial pollution only travels a short distance through: - ✔✔Sandy loam or clay
(most dense soil type)
✔✔which of these techniques is used to properly seal a drilled well to prevent
contamination of the water supply? - ✔✔Grouting
✔✔One of the most common reasons for the contamination of the water supply coming
from a drilled well through rock, clay or hardpan is; - ✔✔Failure to seal the well casing
properly, improper grouting
✔✔The flushometer valve is typically protected by? - ✔✔A non-pressure type vacuum
breaker
✔✔A physical cross connection? - ✔✔Is a connection which may permit/allow the flow
from an unapproved (non-potable, ie. sewer) water supply into a potable (approved)
water supply.
✔✔Which type of filter is best to use to strain/remove amoebic cysts? -
✔✔Diatomaceous Earth Filter, Slow Sand and/or Cartridge
✔✔What makes water have a color? - ✔✔Dissolved Solids
✔✔The importance of surveys for new well water? - ✔✔determine the safety and
adequacy of the water supply
✔✔Lime can be used to treat high concentrations of: - ✔✔contaminants
✔✔Which one is best used to remove/control color, taste, and odor? - ✔✔GAC-granular
activated carbon filter
✔✔Which type of filtration method is the least effective? - ✔✔Rapid sand filter
✔✔What are the four characteristics of hazardous wastes? - ✔✔TIRC - toxic, ignitable,
reactive, and corrosive
,✔✔Most institutions are? - ✔✔Their own communities
✔✔the importance of a ground fault interrupter? - ✔✔Automatically shut off the electric
power at the source
✔✔What is the most common type of injury that occurs at home? - ✔✔Falling (children
1-4)
✔✔For fire safety requirements a room must have: - ✔✔Dual Egress
✔✔Asbestos found in older homes - ✔✔Found in homes built in and before the 1970's
(found in floor tiles and acoustic plaster ceiling when it deteriorates.)
✔✔The drain line of an ice machine should connect to the sewer system through: -
✔✔An open receptacle with an air gap
✔✔Vent gasses from a coal-burning furnace combined with high moisture create: -
✔✔sulfuric acid
✔✔What is the importance of a P-Trap plumbing devise? - ✔✔prevents air from
traveling back from the sewer line into the house
✔✔The chimney should be how high above the home? - ✔✔3 feet above a flat roof or 2
feet above the tallest part of a peaked roof or wall parapet.
✔✔In tattooing which is least important? - ✔✔Single dye ??
✔✔Minimum wash temperature for hospital laundry is? - ✔✔160 degrees
✔✔Which one is associated with water percolation? - ✔✔Permeability
✔✔The majority of nasocrominal infections can be prevented by: - ✔✔Hand washing
✔✔What is a biohazard? - ✔✔A material of biological composition, especially if
infective, that constitutes a threat to people or their environment.
✔✔The biosafety containment level suitable for work involving agents of moderate
potential hazard to personnel and the environment is: - ✔✔Biosafety Level 2
✔✔What are the minimum requirements for a house? - ✔✔A) Sleeping rooms less than
40 sq ft B)living rooms less than 300 sq ft C) 1.5 people per bedroom (if one answer is
, 1.2 person per room choose that as the answer because it is not a min requirement
(overcrowding in a bedroom - minimum is >or=2xbed+2)?)
✔✔Temporary residence? - ✔✔Sleeping area of 40 sq ft
✔✔Travel trailer parks? - ✔✔Roads a minimum of 18 feet wide, maximum 25 trailer
spaces per acre, trailers 10 feet apart (Answer: all of the above)
✔✔Exposure to formaldehyde can cause - ✔✔Irritation to the respiratory passage,
contact dermatitis, disturbed sleep (all is the answer)
✔✔Muerto Canyon Virus (MCV) is a hantavirus mainly carried by: - ✔✔Deer Mice
✔✔The best humidity for a home: - ✔✔40%-60%
✔✔Building residents complaining of headache, lethargy, nausea, drowsiness -
✔✔Carbon Monoxide (CO)
✔✔Lead absorbed how many more times in children than compared to adults? - ✔✔5
times more
✔✔Relative humidity measured by: - ✔✔Psychrometer
✔✔Which place can we test radon in school? - ✔✔First floor (or lowest floor-basement
is best)
✔✔A BSC (biological safety cabinet) national performance standard has been
developed by? - ✔✔NSF (National Sanitation Foundation) and UL (Underwriters
Laboratories)
✔✔Hand washing water temperature? - ✔✔98-100 degrees F
✔✔What are the effects of substandard houses? - ✔✔More accidents
✔✔What measure should the sanitarian take if occupants of a building are complaining
of skin irritations? - ✔✔Check HVAC system
✔✔When will we start to take history during a food borne illness outbreak? - ✔✔72 prior
to the onset of symptoms
✔✔Psychrophilic bacteria best grow in what temperature range? - ✔✔Below 45 degrees
QUESTIONS AND SOLUTIONS RATED A+
✔✔What causes water hardness? - ✔✔Minerals (Dissolved calcium and magnesium
bicarbonates, sulfates, and chlorides)
✔✔Water containing Nitrates generally indicates? - ✔✔Evidence of agricultural pollution
(Note: Ammonia in the water comes from decomposition of organic matter and is
evidence of fresh water pollution.)
✔✔Microbial pollution only travels a short distance through: - ✔✔Sandy loam or clay
(most dense soil type)
✔✔which of these techniques is used to properly seal a drilled well to prevent
contamination of the water supply? - ✔✔Grouting
✔✔One of the most common reasons for the contamination of the water supply coming
from a drilled well through rock, clay or hardpan is; - ✔✔Failure to seal the well casing
properly, improper grouting
✔✔The flushometer valve is typically protected by? - ✔✔A non-pressure type vacuum
breaker
✔✔A physical cross connection? - ✔✔Is a connection which may permit/allow the flow
from an unapproved (non-potable, ie. sewer) water supply into a potable (approved)
water supply.
✔✔Which type of filter is best to use to strain/remove amoebic cysts? -
✔✔Diatomaceous Earth Filter, Slow Sand and/or Cartridge
✔✔What makes water have a color? - ✔✔Dissolved Solids
✔✔The importance of surveys for new well water? - ✔✔determine the safety and
adequacy of the water supply
✔✔Lime can be used to treat high concentrations of: - ✔✔contaminants
✔✔Which one is best used to remove/control color, taste, and odor? - ✔✔GAC-granular
activated carbon filter
✔✔Which type of filtration method is the least effective? - ✔✔Rapid sand filter
✔✔What are the four characteristics of hazardous wastes? - ✔✔TIRC - toxic, ignitable,
reactive, and corrosive
,✔✔Most institutions are? - ✔✔Their own communities
✔✔the importance of a ground fault interrupter? - ✔✔Automatically shut off the electric
power at the source
✔✔What is the most common type of injury that occurs at home? - ✔✔Falling (children
1-4)
✔✔For fire safety requirements a room must have: - ✔✔Dual Egress
✔✔Asbestos found in older homes - ✔✔Found in homes built in and before the 1970's
(found in floor tiles and acoustic plaster ceiling when it deteriorates.)
✔✔The drain line of an ice machine should connect to the sewer system through: -
✔✔An open receptacle with an air gap
✔✔Vent gasses from a coal-burning furnace combined with high moisture create: -
✔✔sulfuric acid
✔✔What is the importance of a P-Trap plumbing devise? - ✔✔prevents air from
traveling back from the sewer line into the house
✔✔The chimney should be how high above the home? - ✔✔3 feet above a flat roof or 2
feet above the tallest part of a peaked roof or wall parapet.
✔✔In tattooing which is least important? - ✔✔Single dye ??
✔✔Minimum wash temperature for hospital laundry is? - ✔✔160 degrees
✔✔Which one is associated with water percolation? - ✔✔Permeability
✔✔The majority of nasocrominal infections can be prevented by: - ✔✔Hand washing
✔✔What is a biohazard? - ✔✔A material of biological composition, especially if
infective, that constitutes a threat to people or their environment.
✔✔The biosafety containment level suitable for work involving agents of moderate
potential hazard to personnel and the environment is: - ✔✔Biosafety Level 2
✔✔What are the minimum requirements for a house? - ✔✔A) Sleeping rooms less than
40 sq ft B)living rooms less than 300 sq ft C) 1.5 people per bedroom (if one answer is
, 1.2 person per room choose that as the answer because it is not a min requirement
(overcrowding in a bedroom - minimum is >or=2xbed+2)?)
✔✔Temporary residence? - ✔✔Sleeping area of 40 sq ft
✔✔Travel trailer parks? - ✔✔Roads a minimum of 18 feet wide, maximum 25 trailer
spaces per acre, trailers 10 feet apart (Answer: all of the above)
✔✔Exposure to formaldehyde can cause - ✔✔Irritation to the respiratory passage,
contact dermatitis, disturbed sleep (all is the answer)
✔✔Muerto Canyon Virus (MCV) is a hantavirus mainly carried by: - ✔✔Deer Mice
✔✔The best humidity for a home: - ✔✔40%-60%
✔✔Building residents complaining of headache, lethargy, nausea, drowsiness -
✔✔Carbon Monoxide (CO)
✔✔Lead absorbed how many more times in children than compared to adults? - ✔✔5
times more
✔✔Relative humidity measured by: - ✔✔Psychrometer
✔✔Which place can we test radon in school? - ✔✔First floor (or lowest floor-basement
is best)
✔✔A BSC (biological safety cabinet) national performance standard has been
developed by? - ✔✔NSF (National Sanitation Foundation) and UL (Underwriters
Laboratories)
✔✔Hand washing water temperature? - ✔✔98-100 degrees F
✔✔What are the effects of substandard houses? - ✔✔More accidents
✔✔What measure should the sanitarian take if occupants of a building are complaining
of skin irritations? - ✔✔Check HVAC system
✔✔When will we start to take history during a food borne illness outbreak? - ✔✔72 prior
to the onset of symptoms
✔✔Psychrophilic bacteria best grow in what temperature range? - ✔✔Below 45 degrees
