The lecturer discredits the claim in the reading passage that bottled water is better than tap water. First, she refutes the assertion that bottled water is healthier by pointing out that 40 percent of all water in bottles comes from city water sources. In other words, it is just tap water in a bottle. Furthermore, she contends that bottled water is actually less healthy than tap water because it contains a lower level of fluoride, a mineral that retards tooth decay.
Second, she maintains that minerals actually make the water taste better. Sodium, calcium, magnesium, and fluoride keep water from tasting flat. She backs up this statement by citing a taste test by Good Morning America in which 45 percent of the participants chose New York City tap water over bottled water.
Third, she concedes that it would be possible to recycle the plastic bottles used for bottled water, but she points out that only 15 percent of all water bottles are ever recycled, which means that 59. 5 million of the 70 million bottles used daily in the United States are thrown into landfills. 
The lecturer discredits the claim in the reading passage that bottled  
water
 is better than  
tap
  water
.  
First
, she refutes the assertion that bottled  
water
 is healthier by pointing out that 40 percent of all  
water
 in  
bottles
  comes
 from city  
water
 sources.  
In other words
, it is  
just
  tap
  water
 in a  
bottle
.  
Furthermore
, she contends that bottled  
water
 is actually less healthy than  
tap
  water
  because
 it contains a lower level of fluoride, a mineral that retards tooth decay.
Second, she maintains that minerals actually  
make
 the  
water
 taste better. Sodium, calcium, magnesium, and fluoride  
keep
  water
 from tasting flat. She backs up this statement by citing a taste  
test
 by  
Good
 Morning America in which 45 percent of the participants chose New York City  
tap
  water
 over bottled water.
Third, she concedes that it would be possible to recycle the plastic  
bottles
  used
 for bottled  
water
,  
but
 she points out that  
only
 15 percent of all  
water
  bottles
 are ever recycled, which means that 59. 5 million of the 70 million  
bottles
  used
 daily in the United States  
are thrown
 into landfills.