The investigation of the Tallevast toxic waste plume is over, state environmental regulators announced Monday. Lockheed Martin Corp., the state decided, has adequately defined the plume.

The Florida Department of Environmental Protection has approved Lockheed Martin Corp.'s latest plume maps as final despite objections raised by independent reviews of the defense giant's data.

The approval was good news for Lockheed scientists who have been trying to define the plume to state requirements for the past six years.

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Those impacted by DEP's decision - Tallevast residents and businesses - have 21 days to appeal the DEP decision with the Department's Office of General Counsel in Tallahassee. Failure to file an appeal within the 21-day period would constitute a waiver of any right to an administrative hearing, the approval letter said.

The clock started ticking, DEP said, with the receipt of the letter from William Kutash, professional geologist administrator for DEP's Southwest District.

Copies of Kutash's letter addressed to Tina Armstrong, Lockheed's program manager for the Tallevast site, were sent via e-mail Monday to leaders of FOCUS - Family Oriented Community United Strong -a resident advocacy group in Tallevast.

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Independent experts, some county officials and Tallevast residents united under FOCUS have consistently questioned Lockheed's data on the plume.

Those questions over the past two years- including a review by Wilma Subra, an environmental advocate and chemist who studied Lockheed's data for the Herald - pushed the DEP to require Lockheed to do additional testing that led to the current estimate of the plume's size at 200 acres.

Originally Lockheed maintained that the plume covered just 50 acres and was confined to the plant site.

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Washington said FOCUS would send the letter to the legal team representing more than 300 Tallevast residents and former residents in a lawsuit against Lockheed and others that claims damage from the plume.

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Lockheed has maintained from the beginning that the plume poses no health risk to residents and will have minimal if any impact on property values.