Infiltration is the process by which rainwater becomes
a. river water.
b. saltwater.
c. groundwater.
d. ocean water.

layer 3 is younger than layer 6.

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.