The new agreement, which runs through 2026, replaces the previously existing deal slated to expire in 2016. All coal will come from Westmoreland’s Kemmerer surface mine in southwest Wyoming.

The tonnage involved in both deals was not disclosed, but a Westmoreland official said that both were standard industrial use transactions, and the extension did not change the annual tonnage requirement.

CEO Keith Alessi called Tata Chemicals North America a “valued partner.”

“The contract provides the Kemmerer mine a long-term partnership with a key industrial customer and we look forward to a continued beneficial relationship,” he said.

Kemmerer, which also supplies PacifiCorp’s neighboring Naughton Power Station, has the unique classification of being a special bituminous coal mine due to the nature of the deposit in the Adaville formation. The classification allows unique reclamation standards for habitat creation and post-mine land use options.