JCW crews may be cleaning lines in your area, which can occasionally cause this to happen. We typically have nine crews cleaning more than 2.5 million feet of sewer lines each year! Crews typically operate between 7 a.m. and 3:30 p.m. Monday-Friday, but may be out afterhours as well. As long as your fixtures are draining okay there should be no cause for alarm. Keeping lids closed on toilets can help reduce any noise or water splashing out if the toilet bubbles. If you still have questions you may call us 24/7 at 913-715-8600.