Bainbridge Island city staff are scrambling to repair overcharges to islanders’ sewer bills — as well as customer relations — after a flurry of complaints poured into city hall.

The city began fielding criticism over unusually high charges on sewer utility bills for September and October.

“There was an error in the sewer charge sometime in the last few weeks,” said Councilman Steve Bonkowski. “The city is now in the process of notifying all individuals where the error was made, and making the correction.”

Bonkowski was among city officials who residents took their concerns to at city hall when they recently noticed the unexpected overcharge in their sewer bills.

Approximately half of the city’s sewer customers were overcharged in the September/October billing cycle.

The charges vary from customer to customer, but one islander reported getting overcharged $178.

The error was the result in the switch from summer to fall sewer rates, or more accurately put, the lack of a switch.

The city uses an annual formula to offset higher usage of the sewer in the summer, so islanders don’t get bombarded with significantly higher bills in the hotter, sunnier months.

“During the summer months, because people are watering their lawns, the city has a formula in place that stabilizes the billing, so sewer isn’t billed at the summer consumption rates because it would artificially inflate (islanders’) sewer billing,” explained City Manager Douglas Schulze.

But the city failed to correctly bill sewer customers for the September/October bill, resulting in too-pricey bills for many islanders.

The matter was escalated when a customer who noticed the troubling charge went to city hall.

The citizen didn’t come away with a pleasant experience. The issue traveled via email to city officials and found its way to the desk of the city manager, Schulze said.

“It wasn’t very flattering recollection of the experience,” he recalled. “It wasn’t the ‘Nordstrom quality’ of service one might expect to receive.”

Schulze personally wrote the resident and expressed his commitment to make “significant changes” to improve the quality of service provided by the city.

“It is my objective as city manager to create an environment where people are confident they can come to city hall to get the assistance they need and expect,” he wrote to the resident.

Schulze said that the city’s finance department has already tackled the last billing cycle to find the errors.

Each citizen who was overcharged will receive a credit on their next bill, in addition to an apology and explanation.