The Longview City Council will discuss raising next year’s utility rates at Thursday night’s workshop.

City staff members are proposing a rate increases of about 15 percent for water, 9 percent for sewer, 7 percent for stormwater and 2.5 percent for solid waste, Public Works Director Jeff Cameron said Monday, adding that he’ll finalize details by Thursday.

Raising rates by the above percentages would increase the average residential customer’s monthly water bill in 2010 from $26.98 to $31. The sewer bill would rise from $46.65 a month to $50.85 a month.

Since 2007, the City Council has bumped up water rates by 29 percent and sewer rates by 17 percent, not including increases proposed for 2010.

The city is in the midst of a multi-year utility rate hike to raise millions of dollars needed to plan, design and build alternatives to the city’s aging water and sewer treatment systems. Also, Longview must shoulder a portion of the $34 million federally mandated upgrades to the Three Rivers Regional Wastewater Treatment Plant, which serves Longview, Kelso, Beacon Hill Sewer District and parts of Cowlitz County.

The 7 p.m. workshop is in the upstairs training room at City Hall, at the corner of 15th Avenue and Broadway.