HILO » The county water bill for a typical Big Island family could rise by $4 on a current bill of $73 under a proposal by the Department of Water Supply.

The proposal involves changing how much electrical cost the department passes on to customers to pump water. The current system is to change the electrical surcharge once a year, based on electrical costs from the previous year. The new plan would change it every two months, when the regular water bill comes out.

A hearing on the proposal will be held Oct. 28 at 9 a.m. at the department's office at 889 Leilani St. in Hilo.

Electricity is used to pump water, making the cost of electricity rise as the price of oil goes up, spokeswoman Kanani Aton explained.

Under the current system of yearly recalculation, the electrical surcharge would show a huge jump in July next year because of oil costs shooting up this year.

Under the proposal, the surcharge would go up in smaller bumps every two months and could even go down if oil prices decline enough.

The exact amount of the first increase isn't known yet because oil prices have been fluctuating. But the department is guessing the increase could be 20 cents per 1,000 gallons. For a family of five using 20,000 gallons every two months, that would translate to an extra $4 on a bimonthly bill, Aton said.

Besides the water cost and the electrical cost, the department also includes a “;standby”; charge in every bill.