Constantine wants to raise sewer rate 10 percent

King County Executive Dow Constantine proposed Thursday to raise the wholesale sewer rate by $3.25 — to $35.15 a month — starting Jan. 1.

That represents a 10 percent increase in the rate King County charges Seattle and most suburbs for treating wastewater. Cities and utility districts include other costs in their retail bills, which now average $48.86 per household.

Homeowners with new sewer hookups would pay an additional $50.45 "capacity charge" each month — up $1.38 from the fee.

If approved by the Metropolitan King County Council, Constantine's plan would keep rates 91 cents lower than projected a year ago. The reduction was achieved by putting off some capital projects and switching from biennial to annual rate increases.

Constantine also proposed to stop putting off interest payments on bonds — a practice known as "capitalized interest" — that meant lower rates in the early years and higher rates later on. That change, he said in a statement, "helps protect our high bond rating and lead to lower costs over the long term."

Most of the sewer rate pays for the $1.8 billion Brightwater sewage-treatment plant under construction near Woodinville and other capital projects started in the past decade.

County officials this week replaced a contractor on a portion of the tunnel being dug to carry treated waste from Brightwater to Puget Sound. A damaged boring machine idled since last May will be removed from the tunnel and replaced by another contractor's machine that has successfully excavated a four-mile tunnel segment.

The rise in wholesale rates would slow after 2012, but would top $42 in 2015 under Constantine's plan, he told the County Council.

Constantine's proposal to adjust rates yearly and structure debt more conservatively follows recommendations made by the county's wholesale customers. The Metropolitan Water Pollution Abatement Advisory Committee, which represents those customers, told Constantine in a letter this month that it "remains concerned" about the rate trend.

"The inevitable prospect of a sewer rate and capacity charge that combined will exceed $100 for new homes and equivalent businesses in King County is extraordinary by both local and national standards and threatens to further inhibit a slow economic recovery," the committee wrote.

Constantine, in an issue paper delivered to the County Council on Thursday, showed the Seattle-area monthly retail rate of $48.86 near the middle of a group of nine cities, whose 2009 rates ranged from $16.23 in Oakland to $120.82 in Atlanta.

Keith Ervin: 206-464-2105 or kervin@seattletimes.com