The Board of Water Supply overcharged more than 50,000 customers, who will receive a credit in their next sewer and water bill.

Moani Wright-Van Alst, Board of Water Supply spokeswoman, said the credit will range between 8 cents to $58. The majority of the affected customers live between Waianae and Aiea.

She said the error was caused by a delay in meter readings. The overbilling error was discovered after the Board of Water Supply received several complaints.

Billing periods for these customers were longer than the usual 60 days because BWS meter readings were delayed, the Board of Water Supply reported. The meter readings were delayed anywhere from two days to three weeks.

Sewer fees went up on July 1, which also increased the bills.

Water and sewer bills are issued bi-monthly.

For more information on how BWS water charges are calculated, visit www.boardofwatersupply.com. An explanation of the City’s sewer charge calculations is available on the ENV website at www.envhonolulu.org.