A pile of backlogged tax appeals in Marion County could mount even higher in coming weeks as the Nov. 19 deadline to pay the latest installment of property taxes approaches.

The increasing logjam could mean homeowners facing sticker shock over their most recent assessments will have a long wait to get their appeals settled.

The delay can be traced back to 2007 property tax bills, which were based on 2006 assessments and brought about 22,000 appeals.

Since the deadline to file those appeals closed last summer, the assessor’s office has addressed about 7,300. But progress has been gradual as a lean staff tries to resolve them while figuring out new assessments so the next round of tax bills, to be released in April, are completed in time.

“We’re trying to have a systematic approach,” said Marion County Assessor Greg Bowes, “but with more than 20,000 appeals, you can’t get to everybody today.”

Meanwhile, appeals from more recent bills are flowing in to add to the burden. So far, Bowes’ office has logged 6,000 appeals — a fraction of the total — of 2008 bills, which are based on 2007 assessments. It hasn’t even begun to count the appeals that have come in from the most recent bills that arrived in October.

Some predict that number could be huge.

Overall, about two-thirds of homeowners saw their assessments decrease or remain even. But in places such as Center and Washington townships, about 16 percent of residential properties have increased more than 10 percent in assessed value.

Councilman Ben Hunter, who represents the Irvington neighborhood on the city’s Eastside, said he’s received an “inordinate” amount of e-mails from homeowners who think their most recent assessments are inflated. The outcry has prompted him to hold a town hall meeting later this month to address the issue and inform residents about filing appeals.

Andrea De Mink is among those who plan to appeal. She said the assessment on her Irvington home has jumped from about $90,000 in 2005 to almost $249,000 as of the most recent assessment. She’s had to tighten her budget, she said, because the increase has added so much to her mortgage payment. And she knows she could be in for a long wait to see any adjustment.

“They’re backlogged quite a bit,” she said. “In the meantime, nothing changes for us until that appeal happens.”

Bowes said older areas where homes have been maintained tend to see the biggest spikes in assessed values. That’s in part because the values are still catching up with the market-based system first implemented for 2002 assessments.

Compounding the problem is that state law required the most recent assessment to use sales data from 2006 and 2007, when the housing market was stronger and home prices were higher. With the current housing downturn, that makes bills seem even more inflated, said Sandy Bickel, a local tax attorney who runs her own practice.

“The market has changed so dramatically in the last two years,” Bickel said. “That’s not the norm.”

The backlog also has fueled outrage over recent bills, Bowes said, because if a taxpayer has an unresolved appeal, the new assessed value seems artificially high.

But he said there’s hope of resolving more appeals soon. His staff aims to file data for the next tax cycle by Thanksgiving. Then it can focus on appeals until March, when the next round of assessments will begin.

The deadline to appeal is Dec. 14.