Well, the rate of which it's growing will be told by the derivative of the population equation.

so take the derivative of P(t):

P(t) simplified is: 3000+60t+3000t^2

derivative of P(t)=90+6000t

then plug in 1 for t

90+12000=12090

so when t=1 the population is growing at a rate of 62 bacteria per hour

(plug into calculator to check)