REHS CORE EXAM 2026 TEST QUESTIONS AND ANSWERS
RATED A+
✔✔Ground water samples are taken all of the following ways except:
a. bored
b. dug
c. cores
d. percolation test - ✔✔percolation test
✔✔EPA stream water quality rate for fecal coliforms is:
a. when coliforms are 200 colonies per 100 ml or less
b. no coliforms in water
c. according to city code - ✔✔when coliforms are 200 colonies per 100 ml or less
✔✔Wastewater treatment plant employee is likely to get what? - ✔✔Hepatits A
✔✔How to determine amount of coliforms in water?
a. plate count test
b. total coliform count or the COLILERT test
c. total plate count - ✔✔total coliform or the COLILERT test
✔✔Which produces the most BOD:
a. small office building
b. restaurant
c. trailer park
d. daycare/school - ✔✔restaurant
✔✔Lime coagulation, mixed media filtration and activated carbon filtration will greatly
reduce: - ✔✔EPA priority pollutants
✔✔Plants absorb certain constituents of wastewater. Using wastewater for irrigation of
consumable plant products may present a health hazard to humans if the water
contains: - ✔✔Cadmium
✔✔The reliability and interpretation of the soil percolation test are affected by all of the
following except:
a. evaluation of site investigation, soil profile, and suitability
b. size or diameter of the test hole
c. shape of the test hole
, d. saturation of soil - ✔✔shape of the test hole
✔✔Which soil is least suitable for subsurface absorption of waste water?
a. red
b. yellow
c. blue
d. mottled brown - ✔✔mottled brown
✔✔The most effective method discovered for running a percolation test is to make tests
in holes that have been: - ✔✔filled with water overnight
✔✔Which travel further in a wastewater treatment plant drain field:
a. helminth
b. bacteria
c. virus
d. protozoa - ✔✔virus
✔✔Drain field has a water table that rises 6". The best type of drain field would be: -
✔✔long narrow trench, hump
✔✔All are found at a wastewater plant except?
a. on site chemist
b. EPA certified operator
c. licensed wastewater operator - ✔✔on site chemist
✔✔Stream pollution with nitrogen (goes from NH to NO3 to NO2 to NO) effects what
downstream? - ✔✔Fish, Ecosystems
✔✔EPA Priority Pollutants are: - ✔✔Sulfur Dioxide, Carbon Monoxide, Ozone, Nitrogen
Dioxide, Promethium, Lead
✔✔If there is a disaster and there is no running water for flushing toilets, what would be
the best way to control raw sewage?
a. Dig a trench and have lime to cover the odor
b. Privy toilet with a fluid reservoir
c. Pit or privy toilet with a dug out hole
d. Bucket with sealed container and sanitized disposable bags
e D and C above - ✔✔D and C above
RATED A+
✔✔Ground water samples are taken all of the following ways except:
a. bored
b. dug
c. cores
d. percolation test - ✔✔percolation test
✔✔EPA stream water quality rate for fecal coliforms is:
a. when coliforms are 200 colonies per 100 ml or less
b. no coliforms in water
c. according to city code - ✔✔when coliforms are 200 colonies per 100 ml or less
✔✔Wastewater treatment plant employee is likely to get what? - ✔✔Hepatits A
✔✔How to determine amount of coliforms in water?
a. plate count test
b. total coliform count or the COLILERT test
c. total plate count - ✔✔total coliform or the COLILERT test
✔✔Which produces the most BOD:
a. small office building
b. restaurant
c. trailer park
d. daycare/school - ✔✔restaurant
✔✔Lime coagulation, mixed media filtration and activated carbon filtration will greatly
reduce: - ✔✔EPA priority pollutants
✔✔Plants absorb certain constituents of wastewater. Using wastewater for irrigation of
consumable plant products may present a health hazard to humans if the water
contains: - ✔✔Cadmium
✔✔The reliability and interpretation of the soil percolation test are affected by all of the
following except:
a. evaluation of site investigation, soil profile, and suitability
b. size or diameter of the test hole
c. shape of the test hole
, d. saturation of soil - ✔✔shape of the test hole
✔✔Which soil is least suitable for subsurface absorption of waste water?
a. red
b. yellow
c. blue
d. mottled brown - ✔✔mottled brown
✔✔The most effective method discovered for running a percolation test is to make tests
in holes that have been: - ✔✔filled with water overnight
✔✔Which travel further in a wastewater treatment plant drain field:
a. helminth
b. bacteria
c. virus
d. protozoa - ✔✔virus
✔✔Drain field has a water table that rises 6". The best type of drain field would be: -
✔✔long narrow trench, hump
✔✔All are found at a wastewater plant except?
a. on site chemist
b. EPA certified operator
c. licensed wastewater operator - ✔✔on site chemist
✔✔Stream pollution with nitrogen (goes from NH to NO3 to NO2 to NO) effects what
downstream? - ✔✔Fish, Ecosystems
✔✔EPA Priority Pollutants are: - ✔✔Sulfur Dioxide, Carbon Monoxide, Ozone, Nitrogen
Dioxide, Promethium, Lead
✔✔If there is a disaster and there is no running water for flushing toilets, what would be
the best way to control raw sewage?
a. Dig a trench and have lime to cover the odor
b. Privy toilet with a fluid reservoir
c. Pit or privy toilet with a dug out hole
d. Bucket with sealed container and sanitized disposable bags
e D and C above - ✔✔D and C above
