GOODWILL AND OTHER INTANGIBLE ASSETS
Changes in the carrying amount of goodwill are summarized as follows (in millions):
Salt
Plant NutritionCorporate & OtherConsolidated
Balance as of September 30, 2023(a)
$— $51.1 $37.7 $88.8 
Foreign currency translation adjustment
— (0.1)0.3 0.2 
Impairments
— (51.0)(32.0)(83.0)
Balance as of September 30, 2024
— — 6.0 6.0 
Foreign currency translation adjustment— — — — 
Balance as of September 30, 2025(b)
$— $— $6.0 $6.0 
(a)As of September 30, 2023, there were no accumulative impairment losses recorded.
(b)As of September 30, 2025, the Salt, Plant Nutrition, and Corporate & Other goodwill is presented net of accumulated impairment losses of $0, $51.0 million, and $32.0 million, respectively.

In the second quarter of fiscal 2024, there were indicators necessitating an interim impairment test of the Company’s goodwill based on the Company’s review of its operating performance, among other factors, for the relevant reporting units. As a result the Company recorded goodwill impairment losses related to the Plant Nutrition reporting unit and the Fortress reporting unit (included in the Corporate and Other segment) of $51.0 million and $32.0 million, respectively. See Note 2. Summary of Significant Accounting Policies and Note 15. Fair Value Measurements for additional details.

The details of definite and indefinite-lived intangible assets are as follows (in millions):

September 30, 2025September 30, 2024
Weighted Average Lives
Gross Carrying Amount
Accumulated Amortization
Net
Gross Carrying Amount
Accumulated Amortization
Net
Amortizable Intangible Assets:
Customer relationships
10 years$1.2 $(0.3)$0.9 $58.5 $(3.4)$55.1 
Trade Name
— —  0.2 (0.1)0.1 
Supply Agreement
50 years26.1 (7.7)18.4 26.8 (7.4)19.4 
SOP Production Rights
25 years24.3 (21.2)3.1 24.3 (20.2)4.1 
Lease Rights
25 years1.6 (0.9)0.7 1.7 (0.8)0.9 
Total, amortizable
$53.2 $(30.1)$23.1 $111.5 $(31.9)$79.6 
Non-amortizing Intangible Assets:
Trade Name
$0.5 $0.5 
Water Rights
0.2 0.2 
Fortress in-process Research & Development(a)
— 2.2 
Total, unamortizable
$0.7 $2.9 
(a)    See Note 1. Organization and Formation for information on the Asset Purchase Agreement, which included the sale of the Fortress in-process research and development intangible asset, during the fiscal year ended September 30, 2025.    

Aggregate amortization expense was $2.8 million, $4.3 million and $2.7 million for the fiscal years ended September 30, 2025, September 30, 2024, and September 30, 2023, respectively.

The Company recorded a loss on impairment of $53.0 million, related to Fortress customer relationships and trade name definite-lived intangible assets (included in the Corporate and Other segment) of $52.9 million and $0.1 million, respectively, during the fiscal year ended September 30, 2025. During the fiscal year ended September 30, 2024, the Company recorded a loss on impairment of definite-lived intangible assets related to the Company’s developed technology intangible asset of $15.6 million, included in Corporate and Other segment, and a loss on impairment of indefinite-lived intangible assets related to water
rights of $17.6 million included in the Plant Nutrition segment. See Note 2. Summary of Significant Accounting Policies and Note 15. Fair Value Measurements for further information.

Estimated annual amortization for the next five fiscal years for intangible assets is projected below (in millions):
Fiscal Years Ending September 30:
Projected Annual Amortization
2026$1.7 
20271.7 
20281.7 
20290.9 
20300.7 

Historical Timeline

Fiscal YearFiled
2025Dec 12, 2025Showing above
2024Dec 16, 2024
2023Nov 29, 2023
2022Dec 14, 2022
2020Feb 26, 2021
2019Feb 26, 2020
2018Mar 1, 2019
2017Feb 27, 2018
2016Mar 1, 2017
2015Feb 22, 2016

About Goodwill & Intangibles Disclosures

Goodwill and intangible asset disclosures reveal the premium paid in acquisitions and how management assesses whether that premium retains its value. Since goodwill is no longer amortized under US GAAP, the annual impairment test is the only mechanism that adjusts carrying values downward — making the assumptions behind that test critically important for investors.

Key signals: a history of goodwill impairments suggests management consistently overpays for acquisitions. Watch the gap between reporting unit fair value and carrying amount — when fair value exceeds carrying amount by less than 10-20%, a small decline in business performance could trigger a write-down. For finite-lived intangibles, examine useful life assumptions across customer relationships, technology, and trade names; aggressive estimates inflate near-term earnings. Compare total intangibles-to-total-assets ratios against peers to assess acquisition dependency. Rising goodwill as a percentage of equity can signal balance sheet fragility.