Form 8-K

8-K — CLEAN HARBORS INC

Accession: 0000822818-26-000024

Filed: 2026-05-14

Period: 2026-05-14

CIK: 0000822818

SIC: 4955 (HAZARDOUS WASTE MANAGEMENT)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — clh-20260514.htm (Primary)

EX-99.1 (terranovapressrelease.htm)

GRAPHIC (clh-20260514_g1.jpg)

GRAPHIC (image.jpg)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K

8-K (Primary)

Filename: clh-20260514.htm · Sequence: 1

clh-20260514

0000822818false00008228182026-05-142026-05-14

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 14, 2026

CLEAN HARBORS, INC.

(Exact name of registrant as specified in its charter)

Massachusetts

001-34223

04-2997780

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

42 Longwater Drive Norwell MA 02061-9149

(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code (781) 792-5000

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol

Name of each exchange on which registered

Common Stock, $0.01 par value

CLH

New York Stock Exchange

Item 8.01 Other Events.

On May 14, 2026, Clean Harbors, Inc. issued a press release announcing the completion of its acquisition of Terra Nova Solutions. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number Description

99.1

Press Release dated May 14, 2026

104 The cover page to this Current Report on Form 8-K, formatted in iXBRL (Inline eXtensible Business Reporting Language)

SIGNATURES

Pursuant to the requirements of the Securities and Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Clean Harbors, Inc.

(Registrant)

May 14, 2026 /s/ Eric J. Dugas

Executive Vice President and Chief Financial Officer

EX-99.1

Filename: terranovapressrelease.htm · Sequence: 2

Document

Exhibit 99.1

Press Release

Clean Harbors Announces Acquisition of Terra Nova Solutions

•$225 Million All-Cash Acquisition Adds Regional Hazardous and Non-Hazardous Waste Services Provider with Permitted Assets

•Transaction Enhances Technical Services and Field Services Businesses

•Expects ~$4 Million of Annual Synergies, Resulting in Implied Post-Synergy Multiple of 11.8x

NORWELL, Mass. – May 14, 2026 – Clean Harbors, Inc. (“Clean Harbors” or the “Company”) (NYSE: CLH), the leading provider of environmental and industrial services throughout North America, today announced the acquisition of Terra Nova Solutions, a regional provider of hazardous and non-hazardous waste solutions for $225 million, which the Company plans to fund with available cash.

Based in the Carolinas, Terra Nova operates five sites that support high-margin, recurring revenue streams including wastewater treatment, solidification and waste processing. Clean Harbors expects the business to generate $45 million to $50 million of annual revenue and approximately $15 million of Adjusted EBITDA. An estimated $4 million of synergies are anticipated after the first full year of operation, which would give the acquisition a post-synergy multiple of 11.8 times.

“We continue to prioritize M&A transactions with strong return profiles that enhance our core businesses,” said Mike Battles, Co-Chief Executive Officer. “We believe Terra Nova will be an ideal strategic fit to our waste-handling network. They are a recognized regional leader in waste treatment and processing that brings to us a blue-chip, long-tenured customer base. In addition, Terra Nova has multiple service offerings that align well with our Technical Services and Field Services businesses, including drum collection, wastewater treatment, tank cleaning and vacuum services. We expect the transaction to create incremental cross-selling opportunities.”

Eric Gerstenberg, Co-Chief Executive Officer, said, “For more than 20 years, Terra Nova and its predecessor company have served the Carolinas region with a variety of environmental and waste solutions. Its locations have the annual capacity to treat 35 million gallons of wastewater, along with more than 85 million gallons of solidification capacity. Their 150 specialized trucks and tankers will be a welcome addition to our vehicle fleet. We also believe their more than 100 customer-focused employees will benefit from the opportunities for career advancement within our larger organization. We look forward to incorporating those talented folks into the Clean Harbors family.”

Clean Harbors • 42 Longwater Drive • PO Box 9149 • Norwell, Massachusetts 02061-9149 • 800.282.0058

Davis, Malm & D’Agostine, P.C. served as legal advisor to Clean Harbors. Raymond James served as exclusive financial advisor and Willkie Farr & Gallagher LLP served as legal advisor to Terra Nova Solutions.

About Clean Harbors

Clean Harbors (NYSE: CLH) is North America’s leading provider of environmental and industrial services. The Company serves a diverse customer base, including a majority of Fortune 500 companies. Its customer base spans a number of industries, including chemical, manufacturing and refining, as well as numerous government agencies. These customers rely on Clean Harbors to deliver a broad range of services such as end-to-end hazardous waste management, emergency spill response, industrial cleaning and maintenance, and recycling services. Through its Safety-Kleen subsidiary, Clean Harbors also is a leading provider of parts washers and environmental services to commercial, industrial and automotive customers, as well as North America’s largest re-refiner and recycler of used oil. Founded in 1980 and based in Massachusetts, Clean Harbors operates in the United States, Canada, Mexico, Puerto Rico and India. For more information, visit www.cleanharbors.com.

Safe Harbor Statement

Any statements contained herein that are not historical facts are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are generally identifiable by use of the words “believes,” “expects,” “intends,” “anticipates,” “plans to,” “seeks,” “will,” “should,” “estimates,” “projects,” “may,” “likely,” “potential,” “outlook” or similar expressions. Such statements may include, but are not limited to, statements about the Terra Nova Solutions acquisition, future financial and operating results, plans, strategy, objectives and goals, cost management initiatives, pricing and productivity initiatives, contingent liabilities, liquidity, business, economic and market conditions, trends, customer demand, impacts of tariffs and new legislation, acquisitions, growth opportunities, expectations, challenges and other statements that are not historical facts. Such statements are based upon the beliefs and expectations of Clean Harbors’ management as of the date of this press release only and are subject to certain risks and uncertainties that could cause actual results to differ materially, including, without limitation: operational and safety risks; risks relating to the failure of new or existing technologies; cybersecurity risks; the occurrence of natural disasters or other catastrophic events, as well as their residual macroeconomic effects; risks associated with retaining and hiring key personnel; environmental liability and product liability risks relating to hazardous waste management and other components of the Company’s business; negative economic, industry or other developments, including market volatility or economic downturns; risks associated with management’s assumptions relating to expansion of the Company’s landfills; reductions in the demand for emergency response services at industrial facilities or on roadways, railways or waterways, and other remedial projects and regulatory developments; reductions in the demand for oil products and automotive services and volatility in oil prices in the markets the Company serves; changes in statutory and regulatory requirements and risks relating to extensive environmental laws and regulations; risks associated with existing and

Clean Harbors • 42 Longwater Drive • PO Box 9149 • Norwell, Massachusetts 02061-9149 • 800.282.0058

potential litigation; risks associated with the Company’s identification and execution of strategic capital expenditures, acquisitions and divestitures and their related liabilities; risks relating to the availability and sufficiency of the Company’s insurance coverage, self-insurance, surety bonds, letters of credit and other forms of financial assurance; the impact of new tax legislation or changes in tax regulations and interpretations; the imposition of trade sanctions or tariffs; fluctuations in interest rates and foreign currency exchange rates; risks relating to the Company’s indebtedness and covenants in its debt agreements; risks associated with certain anti-takeover provisions under the Massachusetts Business Corporation Act and the Company’s By-Laws, and those items identified as “Risk Factors” in Clean Harbors’ most recently filed reports on Form 10-K and Form 10-Q. Forward-looking statements are neither historical facts nor assurances of future performance. Therefore, readers are cautioned not to place undue reliance on these forward-looking statements. Clean Harbors undertakes no obligation to revise or publicly release the results of any revision to these forward-looking statements other than through its filings with the Securities and Exchange Commission, which may be viewed in the “Investors” section of Clean Harbors’ website at www.cleanharbors.com.

Contacts:

Eric J. Dugas

Jim Buckley

EVP and Chief Financial Officer

SVP Investor Relations

Clean Harbors, Inc.

781.792.5100

InvestorRelations@cleanharbors.com

Buckley.James@cleanharbors.com

Clean Harbors • 42 Longwater Drive • PO Box 9149 • Norwell, Massachusetts 02061-9149 • 800.282.0058

GRAPHIC

Filename: clh-20260514_g1.jpg · Sequence: 6

Binary file (35395 bytes)

Download clh-20260514_g1.jpg

GRAPHIC

Filename: image.jpg · Sequence: 7

Binary file (9996 bytes)

Download image.jpg

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 9

v3.26.1

Cover

May 14, 2026

Cover [Abstract]

Document Type

8-K

Document Period End Date

May 14, 2026

Entity Registrant Name

CLEAN HARBORS, INC

Entity Central Index Key

0000822818

Amendment Flag

false

Entity Incorporation, State or Country Code

Entity File Number

001-34223

Entity Tax Identification Number

04-2997780

Entity Address, Address Line One

42 Longwater Drive

Entity Address, City or Town

Norwell

Entity Address, State or Province

Entity Address, Postal Zip Code

02061-9149

City Area Code

781

Local Phone Number

792-5000

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Entity Emerging Growth Company

false

Title of 12(b) Security

Common Stock, $0.01 par value

Trading Symbol

CLH

Security Exchange Name

NYSE

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Cover page.

+ References

No definition available.

+ Details

Name:

dei_CoverAbstract

Namespace Prefix:

dei_

Data Type:

xbrli:stringItemType

Balance Type:

Period Type:

duration

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

Period Type:

duration

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

Period Type:

duration

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

Period Type:

duration

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

Period Type:

duration

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

Period Type:

duration

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

Period Type:

duration

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

Period Type:

duration

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

Period Type:

duration

- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

+ Details

Name:

dei_SecurityExchangeName

Namespace Prefix:

dei_

Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

Period Type:

duration

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

Period Type:

duration