Hawaii-American Water Co., a private company that provides sewer service to more than 30,000 people in Hawai'i Kai and part of Kuli'ou'ou, is seeking approval for a rate increase of 16.7 percent. It is the company's third rate increase request in four years.

If the new rates are approved by the Public Utilities Commission, the sewer bill for residents in single-family homes would rise to $63.65 per month over two years. Residents in multifamily residences such as condominiums would see their bills increase to $53.40 per month.

The company is looking to generate an additional $1.3 million, or about 15.9 percent, in revenue per year. About 42 percent of the additional revenue will cover rising operational costs, while the rest will finance ongoing upgrades to the 40-year-old sewer system, including refurbishing the plant's anaerobic digesters and relining the system's concrete pipes to prevent pipe breaks and disruptions in service, the company has said.