The city council shall designate collectors and methods as are necessary to properly collect all coins deposited in the meter boxes. The collectors shall be only those employees as are now or hereafter duly bonded in the sum of not less than $1,000 for the faithful performance of their duties. All moneys so collected shall be deposited with the collector of the village; provided a separate fund (or accounting) shall be maintained at all times of the money so deposited.