The City Auditor is hereby authorized and empowered to cancel when paid, any and all assessments which have been or may be entered in the mortgage records for the cost of constructing sewers, drains, and all works necessary therefor by the City.  Such cancellations may be made by endorsing a cancellation on the margin of the record as in case of release of mortgage or by executing and acknowledging a formal instrument of cancellation.  Such cancellation shall be made only where payment has been duly received by the City Treasurer and duplicate copy of the receipt for such payment has been presented to the City Auditor.