By mid-August 2026, people in Table View, Parklands and Blouberg, on Cape Town’s northern coast, had been losing sleep for weeks to a low hum at night. Reports later spread to Milnerton and Edgemead. Ward councillor Sue van der Linde set up a WhatsApp line for complaints and had logged 148 by early September. She told EWN the sound seems to move, which makes it hard to pin down.

The obvious culprits were checked one by one. The Astron oil refinery was investigated and ruled out. So was the Potsdam water treatment plant. The area’s pump stations were cleared too, since the noise wasn’t reported on nights they were over-pumping. The public-address system at the Koeberg nuclear station was discounted. Still on the list: emergency-drill loudspeakers, data-centre cooling fans, transformers, and ships waiting in Table Bay, with the wind carrying sound inland.

On Sept. 10 the City offered its first lead. Sewer crews clean pump-station wells between midnight and 4 a.m. with vacuum and jetting trucks, which can be loud. The City is comparing those schedules against residents’ reports, but hasn’t said the work is to blame. Van der Linde also said she was checking an undisclosed site before dawn. Meanwhile residents swap recordings and frequency readings online, with theories ranging from the Milnerton Fault to, half-jokingly, aliens.