Plans must be submitted to, and approved by the Administrator on any fixed installation with individual water capacity of _____ gallons or more, or aggregate water capacity exceeding ____________ gallons.
a) 500 gallons; 1,000 gallons
b) 1,000 gallons; 5,000 gallons
c) 2,000 gallons; 10,000 gallons
d) 10,000 gallons; 25,000 gallons