The Metropolitan St. Louis Sewer District Board of Trustees will decide today — Nov. 8 — whether to raise customers’ wastewater and stormwater rates beginning next year.

The Board of Trustees will meet at 5 p.m. at MSD headquarters, 2350 Market St.

Board members unanimously agreed in October to give tentative approval to those proposed rate increases, which would finance more than $950 million in sewer improvements by 2012. The district serves all of the city of St. Louis and 90 percent of St. Louis County.

As proposed earlier this year, MSD customers would see a 64-percent increase in wastewater-service rates. That 64-percent rate hike would be done in incremental increases from 2008 through 2012.

While the average MSD customer now pays $22.38 per month for sewer service, the rate-hike proposal would push that average bill to $25.74 per month in 2008 to $36.79 per month by the district’s 2012 fiscal year.

And instead of a 24-cent monthly flat fee paid by all district customers for stormwater service, the district has proposed a system based on the amount of impervious — or non-absorbent— property on an owner’s lot.

Impervious property includes non-absorbent property like driveways, roofs, garages and parking lots.

The proposal calls for the district to begin charging 12 cents for each 100 square feet of impervious property in 2008 and then gradually raise that level in increments to 29 cents per 100 square feet of non-absorbent land by 2014.

If the stormwater-service rate increase is approved by the district’s Board of Trustees, MSD then would eliminate two existing property taxes totaling as much as 17 cents per $100 of assessed valuation.

The proposed stormwater-rate change would bring in an estimated $85 million to go toward stormwater projects by 2014, ac-cording to district officials.