Where it appears to a sewerage undertaker that there are reasonable grounds for believing—
that any drain connecting with a public sewer, or any private sewer so connecting, is in such a condition as to be injurious or likely to cause injury to health or as to be a nuisance; or
that any such drain or private sewer is so defective as to admit subsoil water,
the undertaker may examine the condition of the drain or sewer and, for that purpose, may apply any test, other than a test by water under pressure and, if the undertaker deems it necessary, open the ground.
If on examination the drain or sewer is found to be in proper condition, the undertaker shall, as soon as possible, reinstate any ground which has been opened by it and make good any damage done by the undertaker.