To find the unit rate of gallons per minute, divide the total gallons of water moved by the total time in minutes.
\[ \text{Unit rate} = \frac{\text{Total gallons}}{\text{Total time (minutes)}} \]
Given that the pump moves 330 gallons in 22 minutes:
\[ \text{Unit rate} = \frac{330 \text{ gallons}}{22 \text{ minutes}} = 15 \text{ gallons per minute} \]
So, the unit rate is 15 gallons per minute.