Customer stated sink in break room was not draining. Found standing water in sink but bathroom near this room is draining properly. Provided estimate to attempt to clear sink drain and customer agreed to work. Removed trap under sink and used cable through drain multiple times before clearing out blockage. Let water run for 10 minutes and filled sink verifying proper drainage. Got information of backflow and will provide estimate for replacement. No warranty or guarantee on drain cleaning. Thank you for choosing CPI plumbing and heating.