It shall be the fixed policy of the Borough,
in acting upon all petitions for the improvement of streets and alleys
and the curbing thereof, where so desired, that the property owners
affected by such improvement and construction shall, in their petition,
in addition to the agreement that the property owners so affected
and abutting on such improvement shall pay the cost thereof in the
proportions heretofore or hereafter to be agreed upon between the
Borough and the property owners, request that the Borough shall first
cause to be prepared a proper engineering plan and specifications
with a survey covering the grades, utility lines, drains, sewers and
the like which will be involved in such improvement, which plans and
specifications shall be first approved by the Borough Council, and,
if so approved, it shall be the duty of the Borough, through its proper
officers, to make a preliminary estimate of the cost thereof, and,
before any contract is let or the work started, the property owners
affected by such improvement shall deposit and pay to the Borough
1/2 of the estimated cost, the balance to be paid as provided by the
ordinance to be enacted covering the improvement.