Depreciation is calculated on a straight-line basis over the expected useful lives of the asset as follows:
Leasehold improvements
Shorter of useful life (5 years) or unexpired period of lease term
The following table summarizes the carrying amounts of held property, plant and equipment, including leasehold improvements, as of June 30, 2025 and 2024:
June 30,
20252024
Leasehold improvements - at cost
$535,276 $567,296 
Sand Mining Permits292,918 — 
Total property, plant and equipment828,194 567,296 
Less: Accumulated depreciation
(520,455)(465,052)
Total plant and equipment - net
$307,739 $102,244 

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.