(2)The water used for testing shall be free from petroleum and shall not be passed through any pipe or pump ordinarily used for the conveyance of petroleum:Provided that where the licensing authority is satisfied that it is not reasonably possible to convey water by pipes or pumps other than those ordinarily used for conveyance of petroleum, he may permit use of a petroleum pipe or pump for the conveyance of water subject to such conditions as he may impose.
