A farmer drilled a well into an open aquifer composed of sand and gravel. He installed a septic system downslope from the drinking well (see diagram). A few years later the septic system started to leak. Water tests showed that the well water was clean and uncontaminated by bacteria present in the septic system. Why did the septic system not contaminate the drinking water supply?
A. Gravel has a low permeability that makes it difficult for bacteria to travel from the septic system to the well.
B. The septic system is not located in the aquifer's recharge zone.
C. The bacteria were drowned in the groundwater.
D. The groundwater flow carried water away from the well.
Answer: D
You might also like to view...
What group replaced Turkish control on the eastern steppes in the 1100s?
A) Mongol B) Pashtun C) Russian D) Tibetan E) Persian
1200 UTC Convert the following time from UTC to the indicated U.S. time zones:
Which of the following is NOT true of tropical and subtropical hot desert climates?
A) They are under the influence of subtropical high pressure systems. B) In most years, they do not receive any precipitation. C) They are generally found on the western side of continents. D) Annual average temperatures are above 18°C (64.4°F).
What are the challenges for people trying to use primary sources to evaluate the quality and reliability of scientific information?
What will be an ideal response?