WALHALLA — Oconee County Treasurer Greg Nowell said Monday he has requested an investigation by the state Department of Revenue (DOR) that county taxpayers have been overcharged millions of dollars during the past four years.

County officials responded by also calling for an inquiry and said they “welcome the review.”

Nowell said he spoke by phone with Mike Horton of DOR’s property division.

“I requested they come in and do an investigation,” Nowell said. “I just want them to come in and check it out for themselves.”

Nowell’s move comes at the heels of his revelation Friday that he thinks Oconee taxpayers have been overcharged $72 million. He said it started with an innocent mistake in the county auditor’s office that resulted in Duke Energy’s tax being shorted by $8 million in 2004.

Nowell contends the error dragged along until 2006 when Duke rectified by paying a $24 million lump sum to the county. After the $24 million was added to the tax rolls in 2006, Nowell said it was left on the rolls. Nowell contends the county has been budgeting and collecting too much money from taxpayers.

County Administrator Dale Surrett said Monday that Auditor Linda R. Nix and Finance Director Phyllis E. Lombard have told him they believe the millage rate was set correctly.

It is Nix’s responsibility, as the county elected auditor, to establish the millage rate.

“Oconee County staff and elected officials reviewed the tax rates before they were set and have reviewed them again since the County Treasurer made his assertion,” Surrett said. “The County Auditor will be forwarding all supporting information to the South Carolina Department of Revenue so that this matter can be quickly resolved.”

Nix said Nowell has not provided her with information and she looks forward to a full DOR review. Nix added that as far as the 2008 tax bill is concerned, she plans to present a millage recommendation to County Council in September.

In the meantime, a DOR spokeswoman confirmed on Monday that the agency had received a request from Nowell to review the matter. However, the spokeswoman, Adrienne R. Fairwell, said it was too preliminary to say what DOR would do.

“We do not have any of the facts at this point,” Fairwell said. “Generally, all requests are dealt with on a case-by-case basis, and this case we’d have to first find out what is being alleged.

“It also depends on the nature of the request and what is being challenged as to what we do,” Fairwell added.

The last time a DOR inquiry was undertaken in Oconee, it was at the request of the state delegation about reassessment issues stemming from state tax reform enacted in 2006. That DOR inquiry delayed the mailing of tax bills for a reported 35 days.

The Oconee County Council and the state delegation engaged in a public dispute concerning the enacted 2006 tax-reform legislation. Counties had the option under the new reassessment provisions to delay implementing it for a year, which is what the state delegation asked county officials to do. They refused, triggering the dispute.

The 2006 property tax bills signed by Gov. Mark Sanford eliminated the school-operating portion of property taxes levied on owner-occupied residential property on one hand, while providing for minimum countywide reimbursements of $2.5 million, which would grow as a function of the Consumer Price Index (CPI) and population growth.

As part of the reform, a constitutional amendment passed in the fall of 2006 capped property taxes at 15 percent over any five-year period.

Nowell is disputing that the reassessment calculated by county officials for fiscal year 2007-08 was not revenue neutral as the law provides because the $24 million Duke payment was left on the rolls.

Fairwell, the DOR spokeswoman, said state law requires the county treasurer to issue a refund or give taxpayers a credit in the following year if an illegal millage has been set.