Heritage-Crystal Clean (HCCI) 10-Q5 May 212021 Q1 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 27, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 27, 2021
Document Transition Report	false
Entity File Number	001-33987
Entity Registrant Name	HERITAGE-CRYSTAL CLEAN, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-0351454
Entity Address, Address Line One	2175 Point Boulevard
Entity Address, Address Line Two	Suite 375
Entity Address, City or Town	Elgin
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60123
City Area Code	847
Local Phone Number	836-5670
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	HCCI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		24,197,966
Entity Central Index Key	0001403431
Current Fiscal Year End Date	--01-01
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021
Current assets:
Cash and cash equivalents	$ 46,669	$ 67,575
Accounts receivable - net	52,614	48,479
Inventory - net	25,530	24,978
Assets held for sale	2,446	2,446
Other current assets	5,574	8,005
Total current assets	132,833	151,483
Property, plant and equipment - net	154,747	153,016
Right of use assets	76,089	78,942
Equipment at customers - net	23,930	23,111
Software and intangible assets - net	18,484	19,576
Goodwill	35,541	35,541
Other assets	677	0
Total assets	442,301	461,669
Current liabilities:
Accounts payable	31,017	29,663
Current portion of lease liabilities	18,988	19,198
Contract liabilities - net	2,235	1,983
Accrued salaries, wages, and benefits	5,201	6,647
Taxes payable	10,136	10,592
Other current liabilities	5,306	4,918
Total current liabilities	72,883	73,001
Lease liabilities, net of current portion	57,584	60,294
Long-term debt, less current maturities	0	29,656
Deferred income taxes	24,517	21,218
Total liabilities	154,984	184,169
STOCKHOLDERS' EQUITY:
Common stock - 26,000,000 shares authorized at $0.01 par value, 23,390,434 and 23,340,700 shares issued and outstanding at March 27, 2021 and January 2, 2021, respectively	234	233
Additional paid-in capital	201,758	201,148
Retained earnings	85,325	76,119
Total stockholders' equity	287,317	277,500
Total liabilities and stockholders' equity	$ 442,301	$ 461,669

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 27, 2021	Jan. 02, 2021
Statement of Financial Position [Abstract]
Common stock, shares authorized (in shares)	26,000,000	26,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	23,390,434	23,340,700
Common stock, shares outstanding (in shares)	23,390,434	23,340,700

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Revenues
Revenues	$ 99,966	$ 101,479
Rental income	5,416	5,785
Total revenues	105,382	107,264
Operating expenses
Operating costs	76,771	83,250
Selling, general, and administrative expenses	12,188	11,522
Depreciation and amortization	3,782	5,268
Other (income) expense - net	(108)	272
Operating income	12,749	6,952
Interest expense – net	324	214
Income before income taxes	12,425	6,738
Provision for income taxes	3,219	1,447
Net income	$ 9,206	$ 5,291
Net (loss) income per share: basic (in dollars per share)	$ 0.39	$ 0.23
Net (loss) income per share: diluted (in dollars per share)	$ 0.39	$ 0.23
Number of weighted average shares outstanding: basic (in shares)	23,373	23,239
Number of weighted average shares outstanding: diluted (in shares)	23,509	23,422
Service revenues
Revenues
Revenues	$ 57,700	$ 63,757
Product revenues
Revenues
Revenues	$ 42,266	$ 37,722

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid–in Capital	Retained Earnings	Total Heritage-Crystal Clean, Inc. Stockholders' Equity	Non-controlling Interest
Beginning balance (in shares) at Dec. 28, 2019		23,191,498
Beginning balance at Dec. 28, 2019	$ 265,631	$ 232	$ 200,583	$ 64,182	$ 264,997	$ 634
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,291			5,291	5,291
Distribution	(634)					(634)
Issuance of common stock – ESPP (in shares)		4,102
Issuance of common stock – ESPP	122		122		122
Non-controlling interest acquisition	(2,678)		(2,678)		(2,678)
Share-based compensation (in shares)		52,312
Share-based compensation	1,069		1,069		1,069
Share repurchases to satisfy tax withholding obligations	(791)		(791)		(791)
Ending balance (in shares) at Mar. 21, 2020		23,247,912
Ending balance at Mar. 21, 2020	$ 268,010	$ 232	198,305	69,473	268,010	0
Beginning balance (in shares) at Jan. 02, 2021	23,340,700	23,340,700
Beginning balance at Jan. 02, 2021	$ 277,500	$ 233	201,148	76,119	277,500	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,206			9,206	9,206
Distribution	0
Issuance of common stock – ESPP (in shares)		6,072
Issuance of common stock – ESPP	122		122		122
Share-based compensation (in shares)		43,662
Share-based compensation	1,218	$ 1	1,217		1,218
Share repurchases to satisfy tax withholding obligations	$ (729)		(729)		(729)
Ending balance (in shares) at Mar. 27, 2021	23,390,434	23,390,434
Ending balance at Mar. 27, 2021	$ 287,317	$ 234	$ 201,758	$ 85,325	$ 287,317	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 27, 2021	Mar. 21, 2020	Jan. 02, 2021
Cash flows from Operating Activities:
Net income	$ 9,206	$ 5,291
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	3,782	5,268
Uncollectible provision	474	189	$ 1,919
Share-based compensation	1,218	1,069
Deferred taxes	3,299	1,459
Other, net	376	(424)
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(4,609)	275
(Increase) decrease in inventory	(552)	262
Decrease in other current assets	2,557	1,040
Increase (decrease) in accounts payable	1,345	(5,273)
(Decrease) increase in accrued liabilities	(893)	1,320
Cash provided by operating activities	16,203	10,476
Cash flows from Investing Activities:
Capital expenditures	(5,411)	(9,842)
Proceeds from sale of assets	149	0
Cash used in investing activities	(5,262)	(9,842)
Cash flows from Financing Activities:
Payment of Term Loan	(30,000)	0
Debt Issuance Costs	(804)	0
Repayment of principal on finance leases	(436)	(210)
Share repurchases to satisfy tax withholding obligations	(729)	(791)
Proceeds from the issuance of common stock	122	122
Payments of deferred and contingent consideration	0	(199)
Distributions to noncontrolling interest	0	(3,312)
Cash used in financing activities	(31,847)	(4,390)
Net decrease in cash and cash equivalents	(20,906)	(3,756)
Cash and cash equivalents, beginning of period	67,575	60,694	60,694
Cash and cash equivalents, end of period	46,669	56,938	$ 67,575
Supplemental disclosure of cash flow information:
Income taxes paid	947	31
Cash paid for interest	108	92
Supplemental disclosure of non-cash information:
Payables for construction in progress	$ 754	$ 465

Organization and Nature of Oper

Organization and Nature of Operations	3 Months Ended
Organization and Nature of Operations	Mar. 27, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	ORGANIZATION AND NATURE OF OPERATIONS Heritage-Crystal Clean, Inc., a Delaware corporation and its subsidiaries (collectively the “Company”), provide parts cleaning, hazardous and non-hazardous containerized waste, used oil collection, wastewater and vacuum, antifreeze recycling and field services primarily to small and mid-sized industrial and vehicle maintenance customers. The Company owns and operates a used oil re-refinery where it re-refines used oils and sells high quality base oil for lubricants as well as other re-refinery products. The Company also has multiple locations where it dehydrates used oil. The oil processed at these locations is primarily sold as recycled fuel oil. The Company also operates multiple wastewater treatment plants and antifreeze recycling facilities at which it produces virgin-quality antifreeze. The Company's locations are in the United States and Ontario, Canada. The Company conducts its primary business operations through Heritage-Crystal Clean, LLC, its wholly owned subsidiary, and all intercompany balances have been eliminated in consolidation. The Company has two reportable segments: "Environmental Services" and "Oil Business." The Environmental Services segment consists of the Company's parts cleaning, containerized waste management, wastewater and vacuum services, antifreeze recycling activities, and field services. The Oil Business segment consists of the Company's used oil collection, recycled fuel oil sales, used oil re-refining activities, and used oil filter removal and disposal services. No customer represented greater than 10% of consolidated revenues for any of the periods presented. There were no intersegment revenues. Both segments operate in the United States and, to an immaterial degree, in Ontario, Canada. As such, the Company is not disclosing operating results by geographic segment. The Company’s fiscal year ends on the Saturday closest to December 31. The most recent fiscal year ended on January 2, 2021. Each of the Company's first three fiscal quarters consists of twelve weeks while the last fiscal quarter consists of sixteen or seventeen weeks. In the Company's Environmental Services segment, product revenues include sales of solvent, machines, absorbent, accessories, and antifreeze; service revenues include servicing of parts cleaning machines, containerized waste removal services, wastewater and vacuum services, field services, and other services; rental income includes embedded lease income from certain of our parts cleaning contracts. In the Company's Oil Business segment, product revenues primarily consist of sales of re-refined base oil, re-refinery co-products and recycled fuel oil; service revenues include revenues from used oil collection activities, collecting and disposing of waste water and removal and disposal of used oil filters. Due to the Company's integrated business model, it is impracticable to separately present costs of tangible products and costs of services. COVID-19 Pandemic We are closely monitoring the spread and impact of the COVID-19 pandemic and are continually assessing its potential effects on our business and our financial performance as well as the businesses of our customers and vendors. The Company cannot predict the duration or severity of the COVID-19 pandemic, and we cannot reasonably estimate the financial impact the COVID-19 outbreak will have on our results and significant estimates going forward.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 27, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company's significant accounting policies are described in Note 2, "Summary of Significant Accounting Policies," in the Company's Annual Report on Form 10-K for the fiscal year ended January 2, 2021. There have been no material changes in these policies or their application during the third quarter of fiscal 2021. Recently Issued Accounting Standards Adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2020-04: Reference Rate Reform (Topic 848) March 12, 2020 In March 2020, the FASB issued ASU 2020-04: Reference Rate Reform which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the discontinuance of LIBOR or another referenced rate. The guidance may be applied to any applicable contract entered into before December 31, 2022. The Company plans on applying the accounting standard to contracts, hedging relationships, and other transactions affected by the discontinuance of LIBOR on a prospective basis. The Company is currently evaluating the impact of this guidance on the consolidated financial statements.

Business Combinations

Business Combinations	3 Months Ended
Business Combinations	Mar. 27, 2021
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS On March 31, 2020, the Company completed the acquisition of certain assets of Gro America (“Gro”), which has expanded our network of wastewater processing facilities and augmented our field services capabilities to better serve our customers throughout the Midwestern United States. The purchase price was $10.0 million subject to certain adjustments, including a working capital adjustment, and was allocated based on our estimates and assumptions of the approximate fair values of assets acquired and liabilities assumed on the acquisition date. Goodwill recognized from the acquisition of Gro America represents the excess of the estimated purchase consideration transferred over the estimated fair value of the assets acquired and liabilities assumed. Factors leading to goodwill being recognized consist of the Company's expectations of synergies from combining operations of Gro America and the Company as well as the value of intangible assets that are not separately recognized, such as assembled workforce. Transaction costs incurred in conjunction with the acquisition of Gro America were immaterial. The results of Gro America are consolidated into the Company’s Environmental Services segment. On December 27, 2019, the Company acquired the remaining ownership interest in one of our subsidiaries in the amount of $2.7 million. On October 8, 2019, the Company completed the acquisition of certain assets of California Environmental & Litho, Inc., which provided regulated waste disposal, transportation, manifesting, labeling and profiling services to printing, photographic, automotive and body shop industries in the Bay Area, Central Valley & Northern California. No facilities were acquired in the transaction and all service employees and activity have been consolidated in existing branch territories. Total consideration for the acquisition was approximately $0.5 million. Factors leading to goodwill being recognized are the Company's expectations of synergies from combining operations of California Environmental & Litho, Inc., and the Company as well as the value of intangible assets that are not separately recognized, such as assembled workforce. On March 25, 2019, the Company completed the acquisition of certain assets of All Valley Disposal, Inc., an environmental services provider based in Fresno, California. Consideration for the acquisition paid at closing was $0.6 million. Contingent upon the achievement of certain business performance metrics, total consideration for the acquisition could reach a maximum of approximately $1.0 million. Factors leading to goodwill being recognized are the Company's expectations of synergies from combining operations of All Valley Disposal, Inc. and the Company as well as the value of intangible assets that are not separately recognized, such as an assembled workforce. The results of All Valley Disposal are consolidated into the Company’s Environmental Services segment. On February 1, 2019, the Company purchased the assets of W.S. Supplies, Inc. ("WSS") pursuant to an Asset Purchase Agreement. The Company purchased the assets of WSS to expand the Company’s Environmental Services segment in the mid-west. The purchase price was $0.5 million subject to certain adjustments, including a contingent consideration provision, and is allocated based on our estimates and assumptions of the approximate fair values of assets acquired on the acquisition date. The results of WSS are consolidated into the Company’s Environmental Services segment. On January 11, 2019, the Company purchased the assets of the consumer division of GlyEco, Inc. ("GlyEco") pursuant to an Asset Purchase Agreement. The Company purchased the assets of GlyEco's consumer division to expand the Company’s antifreeze line of business while expanding geographically. The purchase price was $1.6 million subject to certain adjustments, including working capital adjustments, and is allocated based on our estimates and assumptions of the approximate fair values of assets acquired on the acquisition date. Factors leading to goodwill being recognized are the Company's expectations of synergies from combining operations of GlyEco and the Company as well as the value of intangible assets that are not separately recognized, such as assembled workforce. The results of GlyEco are consolidated into the Company’s Environmental Services segment. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed, net of cash acquired, related to each acquisition: As of March 27, 2021 (thousands) Gro America California Environmental & Litho All Valley Disposal GlyEco WSS Accounts receivable $ 752 $ 67 $ 36 $ 107 $ — Inventory — 3 18 291 28 Property, plant, & equipment 1,490 15 252 746 154 Equipment at customers — — — — 24 Intangible assets 5,300 445 310 251 298 Goodwill 2,541 3 384 251 — Accounts payable (78) — — — — Total purchase price, net of cash acquired $ 10,005 $ 533 $ 1,000 $ 1,646 $ 504 Less: working capital adjustment — — — 23 — Less: contingent consideration — 120 250 — — Less: to be placed in escrow — — 100 — — Net cash paid $ 10,005 $ 413 $ 650 $ 1,623 $ 504

Revenue

Revenue	3 Months Ended
Revenue	Mar. 27, 2021
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Revenue is recognized when our performance obligations under the terms of a contract with our customers are satisfied. Recognition occurs when the Company transfers control by completing the specified services at the point in time the customer benefits from the services performed or once our products are delivered. The Company measures progress toward complete satisfaction of a performance obligation satisfied over time using a cost-based input method. This method of measuring progress provides a faithful depiction of the transfer of goods or services because the costs incurred are expected to be substantially proportionate to the Company’s satisfaction of the performance obligation. Revenue is measured as the amount of consideration we expect to receive in exchange for completing our performance obligations. Sales tax and other taxes we collect with revenue-producing activities are excluded from revenue. In the case of contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation based on the relative stand-alone selling prices of the various goods and/or services encompassed by the contract. We do not have any material significant payment terms as payment is generally due within 30 days after the performance obligation has been satisfactorily completed. The Company has elected the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that we otherwise would have recognized is one year or less. In applying the guidance in Topic 606, there were no judgments or estimates made that the Company deems significant. Contract Balances — Contract assets primarily relate to the Company’s rights to consideration for work completed in relation to its services performed but not billed at the reporting date. Contract liabilities primarily consist of advance payments of performance obligations yet to be fully satisfied in the period reported. Our contract liabilities and contract assets are reported in a net position at the end of each reporting period. We disaggregate our revenue from contracts with customers by major lines of business for each of our segments, as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. The following table disaggregates our revenue by major lines: For the First Quarter Ended, March 27, 2021 March 21, 2020 Total Net Sales by Major Lines of Business (thousands) Environmental Services Oil Business Total Environmental Services Oil Business Total Parts cleaning, containerized waste, & related products/services $ 38,833 $ — $ 38,833 $ 40,290 $ — $ 40,290 Vacuum Services & Wastewater Treatment 13,692 — 13,692 14,618 — 14,618 Field Services 4,096 — 4,096 9,623 — 9,623 Antifreeze Business 6,988 — 6,988 6,677 — 6,677 Environmental Services - Other 441 — 441 480 — 480 Re-refinery Product Sales — 30,054 30,054 — 25,436 25,436 Oil Collection Services & RFO — 4,617 4,617 — 3,289 3,289 Oil Filter Business — 1,245 1,245 — 1,066 1,066 Revenues from Contracts with Customers 64,050 35,916 99,966 71,688 29,791 101,479 Rental income 5,407 9 5,416 5,765 20 5,785 Total Revenues $ 69,457 $ 35,925 $ 105,382 $ 77,453 $ 29,811 $ 107,264 The following table provides information about contract assets and contract liabilities from contracts with customers: (thousands) March 27, 2021 January 2, 2021 Contract assets $ 80 $ 72 Contract liabilities 2,315 2,054 Contract liabilities - net $ 2,235 $ 1,982 During the fiscal quarter ended March 27, 2021, the Company recognized $2.1 million of revenue that was included in the contract liabilities balance as of January 2, 2021. The Company has no assets recognized from costs to obtain or fulfill a contract with a customer. We do not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less.

Accounts Receivable

Accounts Receivable	3 Months Ended
Accounts Receivable	Mar. 27, 2021
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Accounts Receivable — Net, includes amounts billed to and currently due from customers. The amounts due are stated at their net estimated realizable value. The allowance for doubtful accounts is our best estimate of the amount of probable lifetime-expected credit losses in existing accounts receivable and is determined based on our historical collections experience, age of the receivable, knowledge of the customer and the condition of the general economy and industry as a whole. The Company does not have any off-balance-sheet credit exposure related to its customers. Accounts receivable for the first quarter ended March 27, 2021, and the fiscal year ended January 2, 2021 consisted of the following: (thousands) March 27, January 2, Trade $ 52,396 $ 47,191 Less: allowance for uncollectible accounts 2,553 2,502 Trade - net 49,843 44,689 Related parties 2,771 3,276 Other — 514 Total accounts receivable - net $ 52,614 $ 48,479 The following table provides the changes in the Company’s allowance for uncollectible accounts for the first quarter ended March 27, 2021, and the fiscal year ended January 2, 2021: (thousands) March 27, January 2, Balance at beginning of period $ 2,502 $ 2,221 Provision for uncollectible accounts 474 1,919 Accounts written off, net of recoveries (423) (1,638) Balance at end of period $ 2,553 $ 2,502

Inventory

Inventory	3 Months Ended
Inventory	Mar. 27, 2021
Inventory Disclosure [Abstract]
Inventory	INVENTORY The carrying value of inventory consisted of the following: (thousands) March 27, January 2, Solvents and solutions $ 6,740 $ 6,672 Used oil and processed oil 7,500 6,345 Machines 5,364 5,704 Drums and supplies 4,269 4,423 Other 2,012 2,221 Total inventory 25,885 25,365 Less: machine refurbishing reserve 355 387 Total inventory - net $ 25,530 $ 24,978

Property, Plant, and Equipment

Property, Plant, and Equipment	3 Months Ended
Property, Plant, and Equipment	Mar. 27, 2021
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT Property, plant, and equipment consisted of the following: (thousands) March 27, January 2, Machinery, vehicles, and equipment $ 139,642 $ 138,496 Buildings and storage tanks 72,939 72,938 Land 5,911 5,909 Leasehold improvements 6,930 6,929 Construction in progress 9,775 8,023 Total property, plant and equipment 235,197 232,295 Less: accumulated depreciation 80,450 79,279 Property, plant and equipment - net $ 154,747 $ 153,016 (thousands) March 27, January 2, Equipment at customers $ 83,091 $ 81,881 Less: accumulated depreciation 59,161 58,770 Equipment at customers - net $ 23,930 $ 23,111 Depreciation expense for the first quarter ended March 27, 2021 and March 21, 2020 was $2.5 million and $4.4 million, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
Goodwill and Other Intangible Assets	Mar. 27, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill is measured as a residual amount as of the acquisition date, which in most cases results in measuring goodwill as an excess of the purchase consideration transferred plus the fair value of any noncontrolling interest in the acquiree over the fair value of the net assets acquired, including any contingent consideration. The Company tests goodwill for impairment annually in the fourth quarter and in interim periods if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company's determination of fair value requires certain assumptions and estimates, such as margin expectations, market conditions, growth expectations, expected changes in working capital, etc., regarding expected future profitability and expected future cash flows. The Company tests goodwill for impairment at each of its two reporting units, Environmental Services and Oil Business. The following table shows changes to our goodwill balances by segment from January 2, 2021 to March 27, 2021: (thousands) Oil Business Environmental Services Total Goodwill at January 2, 2021 Gross carrying amount $ 3,952 $ 35,541 $ 39,493 Accumulated impairment loss (3,952) — (3,952) Net book value at January 2, 2021 $ — $ 35,541 $ 35,541 Goodwill at March 27, 2021 Gross carrying amount $ 3,952 35,541 $ 39,493 Accumulated impairment loss (3,952) — (3,952) Net book value at March 27, 2021 $ — $ 35,541 $ 35,541 The following is a summary of software and other intangible assets: March 27, 2021 January 2, 2021 (thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 30,860 $ 18,068 $ 12,792 $ 30,857 $ 16,934 $ 13,923 Software 9,739 5,718 4,021 9,592 5,645 3,947 Non-compete agreements 3,609 3,240 369 3,607 3,212 395 Patents, formulae, and licenses 1,769 856 913 1,769 850 919 Other 1,738 1,349 389 1,738 1,346 392 Total software and intangible assets - net $ 47,715 $ 29,231 $ 18,484 $ 47,563 $ 27,987 $ 19,576 Amortization expense was $1.2 million for the first quarter ended March 27, 2021, and $0.9 million for the first quarter ended March 21, 2020. The weighted average useful lives of software and other intangibles are as follows: Weighted Average Useful Life (years) Patents, formulae, & licenses 15 Customer and supplier relationships 10 Software 9 Non-compete agreements 4 Other intangibles 7 The estimated amortization expense for the remainder of fiscal 2021 and each of the five succeeding fiscal years is as follows: (millions) Fiscal Year Amortization Expense 2021 $3.7 2022 4.3 2023 3.8 2024 2.1 2025 1.1 2026 0.5 The preceding expected amortization expense is an estimate. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, the finalization of the fair value of intangible assets that have been acquired from business combinations, disposal of intangible assets, accelerated amortization of intangible assets, and other events.

Accounts Payable

Accounts Payable	3 Months Ended
Accounts Payable	Mar. 27, 2021
Payables and Accruals [Abstract]
Accounts Payable	ACCOUNTS PAYABLE Accounts payable consisted of the following: (thousands) March 27, January 2, Accounts payable $ 30,705 $ 29,263 Accounts payable - related parties 312 400 Total accounts payable $ 31,017 $ 29,663

Debt and Financing Arrangements

Debt and Financing Arrangements	3 Months Ended
Debt and Financing Arrangements	Mar. 27, 2021
Debt Disclosure [Abstract]
Debt and Financing Arrangements	DEBT AND FINANCING ARRANGEMENTS Bank Credit Facility On March 18, 2021, Heritage-Crystal Clean, LLC, (the “Company”), entered into an Amended and Restated Credit Agreement (the "Agreement"), by and among the Company, its parent, Heritage-Crystal Clean, Inc., and the Company’s subsidiaries identified therein and Bank of America, N.A., as administrative agent, JPMorgan Chase Bank, N.A., and Wells Fargo Bank, National Association. The Agreement replaces the Company's previous Credit Agreement dated as of February 21, 2017. During the first quarter the Company paid down its previous term loan, in full, of $30.0 million. The new Agreement provides for borrowings of up to $100.0 million, in the form of a revolving facility, of which $15 million can be used in the form of a Swing Line loan. Loans made under the Agreement, as amended, may be Base Rate Loans or LIBOR Rate Loans, at the election of the Borrower subject to certain exceptions. Base Rate Loans have an interest rate equal to (i) the higher of (a) the federal funds rate plus 0.5%, (b) the London Interbank Offering Rate (“LIBOR”) plus 1%, or (c) Bank of America's prime rate, plus (ii) a variable margin of between 0.50% and 1.25% depending on the Company's total leverage ratio, calculated on a consolidated basis. LIBOR rate loans have an interest rate equal to (i) the LIBOR rate plus (ii) a variable margin of between 1.50% and 2.25% depending on the Company's total leverage ratio. Amounts borrowed under the Agreement are secured by a security interest in substantially all of the Company's tangible and intangible assets. The Company incurred $0.8 million of debt issuance costs related to the amended credit agreement. As of the Effective date of March 18, 2021, the effective rate on our term loan was 1.90%. The Credit Agreement contains customary terms and provisions (including representations, covenants, and conditions) for transactions of this type. Certain covenants, among other things, restrict the Company's and its subsidiaries' ability to incur indebtedness, grant liens, make investments and sell assets. The Credit Agreement also contains customary events of default, covenants and representations and warranties. Financial covenants include: • An interest coverage ratio (based on interest expense and EBITDA) of at least 3.5 to 1.0; • A total leverage ratio no greater than 3.0 to 1.0, provided that in the event of a permitted acquisition having an aggregate consideration equal to $10.0 million or more, at the Borrower’s election, the foregoing 3.00 to 1.00 shall be deemed to be 3.50 to 1.00 for the fiscal quarter in which such permitted acquisition occurs and the three immediately following fiscal quarters and will thereafter revert to 3.00 to 1.00. The Credit Agreement places certain limitations on acquisitions and the payment of dividends. On July 27, 2017, the Financial Conduct Authority, which regulates LIBOR, announced that it intends to phase out the London Interbank Offered Rate by the end of 2021. We expect that widespread use of LIBOR will transition to alternative interest rates in the near future. Since loans made under our Credit Agreement may be LIBOR based loans, the phasing out of LIBOR may adversely affect interest rates that could result in higher borrowing costs and higher interest expense. The Company is currently evaluating its options under our Credit Agreement, but at this time we cannot reasonably estimate the impact to our financial statements. Debt at March 27, 2021 and January 2, 2021 consisted of the following: (thousands) March 27, 2021 January 2, 2021 Principal amount $ — $ 30,000 Less: unamortized debt issuance costs — 344 Long-term debt, less current maturities $ — $ 29,656 For the first quarter ended March 27, 2021, the Company recorded interest expense of $0.3 million with respect to our term loan and credit line, and related amortization of debt issuance costs. For the first quarter ended March 21, 2020, the Company recorded interest expense of $0.4 million of which $0.3 million was with respect to our term loan, and $0.1 million related to amortization of debt issuance costs. The Company's weighted average interest rate for all debt through the first fiscal quarters of 2021, and 2020, was 2.04% and 3.7%, respectively.

Segment Information

Segment Information	3 Months Ended
Segment Information	Mar. 27, 2021
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The Company has two reportable segments: "Environmental Services" and "Oil Business." The Environmental Services segment consists primarily of the Company's parts cleaning, containerized waste management, wastewater and vacuum service, antifreeze recycling activities, and field services. The Oil Business segment consists primarily of the Company's used oil collection, used oil re-refining activities, and the dehydration of used oil to be sold as recycled fuel oil. No single customer in either segment accounted for more than 10.0% of consolidated revenues in any of the periods presented. There were no intersegment revenues. Both the Environmental Services and Oil Business segments operate in the United States and, to an immaterial degree, in Ontario, Canada. As such, the Company is not disclosing operating results by geographic segment. Segment results for the first quarters ended March 27, 2021, and March 21, 2020 were as follows: First Quarter Ended, March 27, 2021 (thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Service revenues $ 53,303 $ 4,397 $ — $ 57,700 Product revenues 10,747 31,519 — 42,266 Rental income 5,407 9 — 5,416 Total revenues $ 69,457 $ 35,925 $ — $ 105,382 Operating expenses Operating costs 51,880 24,891 — 76,771 Operating depreciation and amortization 1,579 948 — 2,527 Profit before corporate selling, general, and administrative expenses $ 15,998 $ 10,086 $ — $ 26,084 Selling, general, and administrative expenses 12,188 12,188 Depreciation and amortization from SG&A 1,255 1,255 Total selling, general, and administrative expenses $ 13,443 $ 13,443 Other (income) - net (108) (108) Operating income 12,749 Interest expense – net 324 324 Income before income taxes $ 12,425 First Quarter Ended, March 21, 2020 (thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Service revenues $ 60,960 $ 2,797 $ — $ 63,757 Product revenues 10,728 26,994 — 37,722 Rental income 5,765 20 — 5,785 Total revenues $ 77,453 $ 29,811 $ — $ 107,264 Operating expenses Operating costs 56,404 26,846 — 83,250 Operating depreciation and amortization 2,271 2,055 — 4,326 Profit before corporate selling, general, and administrative expenses $ 18,778 $ 910 $ — $ 19,688 Selling, general, and administrative expenses 11,522 11,522 Depreciation and amortization from SG&A 942 942 Total selling, general, and administrative expenses $ 12,464 $ 12,464 Other expense - net 272 272 Operating income 6,952 Interest expense – net 214 214 Income before income taxes $ 6,738 Total assets by segment as of March 27, 2021 and January 2, 2021 were as follows: (thousands) March 27, 2021 January 2, 2021 Total Assets: Environmental Services $ 218,214 $ 217,297 Oil Business 165,066 160,165 Unallocated Corporate Assets 59,021 84,207 Total $ 442,301 $ 461,669

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 27, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES LEASES Lessee The Company leases buildings and property, railcars, machinery and equipment, and various types of vehicles for use in our operations. Each arrangement is evaluated individually to determine if the arrangement is or contains a lease at inception. The Company has lease agreements with lease and non-lease components and we have elected to not separate lease and non-lease components for all classes of underlying assets. In addition, our lease agreements do not contain any material residual guarantees or restrictive covenants. Leases may include variable lease payments for common area maintenance, real estate taxes, and truck lease mileage. No leases are tied to a market index rate or CPI. Variable lease payments are not included in the initial measurement of the right-of-use assets or lease liabilities, and are recorded as lease expense in the period incurred. Options to extend or terminate a lease are included in the lease term when it is reasonably certain that we will exercise that option. We have elected not to record leases with an initial term of 12 months or less on the balance sheet and instead recognize those lease payments on a straight-line basis over the lease term. Leases with initial terms in excess of 12 months are recorded as either operating or financing leases in our Consolidated Balance Sheet. Right-of-use assets represent the Company's right to use an underlying asset during the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Our lease right-of-use assets are measured at the initial measurement of the lease liability, adjusted for any lease payments made prior to the lease commencement date, less any lease incentives received and other initial direct costs incurred. Our lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use an incremental borrowing rate based on the information available at commencement date, including lease term, in determining the present value of future payments. Our leases have remaining terms ranging from less than one month to approximately 11 years and may include options to extend or terminate the lease when it is reasonably certain that the option will be exercised. Lease expense is recognized on a straight-line basis over the lease term. Our finance leases include a fleet of mobile equipment. The components of lease expense were as follows: For the First Quarter Ended (thousands) March 27, March 21, Finance lease cost: Amortization of right-of-use assets $ 578 $ 322 Interest on lease liabilities 112 74 Total finance lease cost $ 690 $ 396 Operating lease cost $ 5,405 $ 6,051 Short-term lease cost 995 1,360 Variable lease cost 702 1,033 Total lease cost $ 7,102 $ 8,444 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from financing leases $ 112 $ 66 Operating cash flows from operating leases $ 5,760 $ 6,523 Financing cash flows from financing leases $ 436 $ 210 Right-of-use assets obtained in exchange for new finance lease liabilities $ 250 $ 3,264 Right-of-use assets obtained in exchange for new operating lease liabilities $ 1,820 $ 588 Weighted-average remaining lease term (years) Finance leases 5.9 6.6 Operating leases 4.4 4.9 Weighted-average discount rate Finance leases 3.2 % 3.4 % Operating leases 5.6 % 5.8 % Future annual minimum lease payment commitments as of March 27, 2021 were as follows: (thousands) Year 1 $ 22,826 Year 2 19,275 Year 3 15,078 Year 4 10,827 Year 5 7,325 thereafter 11,308 Total minimum lease payments $ 86,639 Less: imputed interest 10,067 Lease liability $ 76,572 Lessor The Company is a lessor of portions of a buildings and property, railcars, and equipment such as embedded leases of parts cleaning machines. Each of the Company’s leases is classified as an operating lease, and the vast majority are short-term leases. Variable lease payments include real and personal property taxes, which are based on the lessee’s pro rata portion of such amounts, and excess mileage charges which are computed as the actual miles traveled in a calendar year minus the maximum average mileage allowance as specified per the contract. Options to extend the lease beyond the original terms range from day- to-day renewals to increments of five-year extensions. Options to terminate the lease range from immediate termination upon return of the asset to various written notification periods following a minimum lease term. Options for a lessee to purchase the underlying asset are not contractually specified but may be negotiated on a case-by-case basis. Significant judgments made in determining whether a contract contains a lease include assessments as to whether or not the contract conveys the right to direct the use of an identified asset. Significant judgments made in allocating consideration between lease and non-lease components include techniques applied in estimating the relative stand-alone selling prices of the lease and non-lease components of the contract in cases where a stand-alone selling price is not directly observable. No leased assets are covered by residual value guarantees. The Company manages the risk associated with the residual value of leased assets through such means as performing periodic maintenance and upkeep activities and the inclusion of contractual terms that hold the lessee responsible for damage incurred to leased assets. Contained in Note 7, “Property, plant, and equipment,” are disclosures concerning the Company’s underlying assets under operating leases. The Company has made an accounting policy election to exclude from the consideration in the contract, and from variable payments not included in the consideration in the contract, all taxes assessed by a governmental authority that are both imposed on and concurrent with a specific lease revenue-producing transaction and collected by the lessor from a lessee. The Company recognizes rental income on a straight-line basis for that portion of the consideration allocated to the embedded lease component of certain of our parts cleaning contracts. We also recognize rental income on certain subleases of railcars and portions of buildings and property. Rental income was as follows: First Quarter Ended, March 27, 2021 March 21, 2020 (thousands) Environmental Services Oil Business Total Environmental Services Oil Business Total Parts Cleaning $ 5,407 $ — $ 5,407 $ 5,765 $ — $ 5,765 Railcars — — — — 16 16 Property — 9 9 — 4 4 Total rental income $ 5,407 $ 9 $ 5,416 $ 5,765 $ 20 $ 5,785 Purchase Obligations The Company may enter into purchase obligations with certain vendors. They represent expected payments to third party service providers and other commitments entered into during the normal course of our business. These purchase obligations are generally cancellable with or without notice, without penalty, although certain vendor agreements provide for cancellation fees or penalties depending on the terms of the contract. The Company has purchase obligations in the form of open purchase orders o f $16.5 million as of March 27, 2021, and $20.0 million as of January 2, 2021, primarily for used oil, solvent, machine purchases, disposal and transportation expenses, and capital expenditures. The Company may be subject to investigations, claims or lawsuits as a result of operating its business, including matters governed by environmental laws and regulations. The Company may also be subject to tax audits in a variety of jurisdictions. When claims are asserted, the Company evaluates the likelihood that a loss will occur and records a liability for those instances when the likelihood is deemed probable and the exposure is reasonably estimable. The Company carries insurance at levels it believes are adequate to cover loss contingencies based on historical claims activity. When the potential loss exposure is limited to the insurance deductible and the likelihood of loss is determined to be probable, the Company accrues for the amount of the required deductible, unless a lower amount of exposure is estimated. As of March 27, 2021 and January 2, 2021, the Company had ac crued $3.2 million

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 27, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company deducted for federal income tax purposes accelerated "bonus" depreciation on the majority of its capital expenditures for assets placed in service in fiscal 2011 through the first quarter of 2021. Therefore, the Company recorded a noncurrent deferred tax liability as to the difference between the book basis and the tax basis of those assets. As of the first quarter of fiscal 2021, the Company's remaining Federal Net Operating Loss ("NOL") was $14.4 million, which will begin to expire in 2034. There are also state NOLs of varying amounts, dependent on each state’s conformity with bonus depreciation. The remaining deferred tax asset related to the Company's state and federal NOLs was a tax effected balance of $3.6 million. In December 2019, the FASB issued ASU 2019-12, (Topic 740): Simplifying the Accounting for Income Taxes. ASU 2019-12 intends to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application of Topic 740. This guidance is effective for fiscal years beginning after December 15, 2020, including interim periods therein. The adoption of ASU 2019-12 does not have a material effect on the Company’s financial statements. The Company's effective tax rate for the first quarter of fiscal 2021 was 25.9% compared to 21.5% in the first quarter of fiscal 2020. The rate increase is principally attributable to the opposing effect of non-deductible expenses in a projected loss year as compared to a projected income year. The Company establishes reserves when it is more likely than not that the Company will not realize the full tax benefit of a position. The Company had a reserve of $2.8 million for uncertain tax positions as of March 27, 2021. The gross unrecognized tax benefits would, if recognized, decrease the Company's effective tax rate.

Share-based Compensation

Share-based Compensation	3 Months Ended
Share-based Compensation	Mar. 27, 2021
Share-based Payment Arrangement [Abstract]
Share-based Compensation	SHARE-BASED COMPENSATION Restricted Stock Compensation/Awards Annually, the Company grants restricted shares to its Board of Directors. The shares become fully vested one year from their grant date. The fair value of each restricted stock grant is based on the closing price of the Company's common stock on the date of grant. The Company amortizes the expense over the service period, which is the fiscal year in which the award is granted. In addition, the Company may grant restricted shares to certain members of management based on their services and contingent upon continued service with the Company. The restricted shares vest over a period of approximately three years from the grant date. The fair value of each restricted stock grant is based on the closing price of the Company's common stock on the date of grant. The following table shows a summary of restricted share grants and expense resulting from the awards: Compensation Expense (thousands, except share amounts) First Quarters Ended, Unrecognized Expense as of, Recipient of Grant Grant Date Restricted Shares March 27, 2021 March 21, 2020 March 27, 2021 March 21, 2020 Chief Executive Officer February, 2017 500,000 $ — $ 89 $ — $ 296 Members of Management February, 2018 116,958 — 142 — 472 Special Incentive Grant April, 2018 350,000 298 344 1,354 3,084 Members of Management May, 2019 23,560 59 50 203 408 Members of Management February, 2020 41,138 38 165 355 705 Board of Directors April, 2020 14,988 — 66 — 219 Chief Executive Officer February, 2021 500,000 394 — 5,923 — Members of Management February, 2021 35,898 22 184 635 — On January 8, 2021, the Company and Mr. Brian Recatto entered into an amended Executive Employment Agreement (the “Amended Agreement”) which was effective on February 1, 2021. Pursuant to the Amended Agreement, we replaced in its entirety section 4.3 of the First Amendment to the Executive Employment Agreement relating to equity compensation that was effective February 1, 2017. As of February 1, 2021, Mr. Recatto received a one-time award of 500,000 shares of restricted stock, subject to the achievement of performance criteria established by the Compensation Committee of the Board of Directors pursuant to the Company's 2019 Incentive Plan. The award date for such Performance-Based Restricted Stock was on February 1, 2021. Such award was granted pursuant to and governed by the terms of the 2019 Incentive Plan and an award agreement in a form provided by the Company. The Performance-Based Restricted Stock one-time award of 500,000 shares received on February 1, 2021, shall vest on January 31, 2025 if Mr. Recatto is employed by the Company on that date, in an amount determined by applying the applicable percentages from the chart below, with the common stock price increases to be determined based on the increase in the price of the Company’s common stock (if any) from the closing price of the common stock as reported by Nasdaq on the amended agreement commencement date ($21.77) and the common stock price on the potential vesting date (determined by using the weighted average closing price of a share of the Company's common stock for the 90-day period ending on the vesting date). If the stock price does not increase by $5.00, then no shares shall vest. During the first quarter of fiscal 2021, the Company recorded approximately $0.4 million of compensation expense related to this award. In the future, the Company expects to recognize compensation expense of approximately $5.9 million over the remaining requisite service period, which ends January 31, 2025. The fair value of this restricted stock award as of the grant date was estimated using a Monte Carlo simulation model. Key assumptions used in the Monte Carlo simulation to estimate the grant date fair value of this award are a risk-free rate of 0.29%, expected dividend yield of zero, and an expected volatility assumption of 53.07%. Vesting Table Increase in Stock Price From the Amended Agreement Commencement Date to the Vesting Date Total Percentage of Restricted Stock Less than $5 per share increase —% $5 per share increase 25% (vest in 125,000 shares) $10 per share increase 50% (vest in 125,000 shares) $15 per share increase 75% (vest in 125,000 shares) $20 or more per share increase 100% (vest in 125,000 shares) Provision for possible accelerated vesting of award If the average closing price of the Company's common stock increases by the marginal levels set forth in the above vesting table for any consecutive 180 day period between the award date and final vesting date, Mr. Recatto shall become vested in 50% of the corresponding total percentage of restricted shares earned on the last day of the 180 day period. In addition, on each of December 31, 2021, December 31, 2022, and December 31, 2023, to the extent Mr. Recatto remains employed by the Company under the Amended Agreement on such date, Mr. Recatto shall receive a grant of restricted stock as of such date valued at Five Hundred Thousand Dollars ($500,000), with the number of shares of restricted stock constituting such grant determined by applying the average closing price for a share of the Company’s common stock for the 90-day period ending on such date. Such awards of Time-Based Restricted Stock shall be granted pursuant to and governed by the terms of the 2019 Incentive Plan and an award agreement in a form provided by the Company. The Time-Based Restricted Stock shall vest only if Mr. Recatto remains employed by the Company under the Amended Agreement through December 31, 2023; provided, that, upon a Change of Control of the Company (as such term is defined in the Amended Agreement), all shares of the Time-Based Restricted Stock awarded up through the date of closing of the Change in Control shall become vested, and no further award of Time-Based Restricted Stock shall be awarded. During the first quarter of fiscal 2021, the Company recorded approximately $0.1 million of compensation expense related to this award. The following table summarizes the restricted stock activity for the first quarter ended March 27, 2021: Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at January 2, 2021 646,634 $ 18.28 Granted 535,898 22.02 Vested (35,497) 15.00 Forfeited (340,754) 15.05 Nonvested shares outstanding at March 27, 2021 806,281 $ 22.28 Employee Stock Purchase Plan

Earnings Per Share

Earnings Per Share	3 Months Ended
Earnings Per Share	Mar. 27, 2021
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table reconciles the number of shares outstanding for the first quarters of fiscal 2021 and 2020, respectively, to the number of weighted average basic shares outstanding and the number of weighted average diluted shares outstanding for the purposes of calculating basic and diluted earnings per share: First Quarter Ended, (thousands, except per share amounts) March 27, 2021 March 21, 2020 Net income $ 9,206 $ 5,291 Weighted average basic shares outstanding 23,373 23,239 Dilutive shares for share–based compensation plans 136 183 Weighted average diluted shares outstanding 23,509 23,422 Net income per share: basic $ 0.39 $ 0.23 Net income per share: diluted $ 0.39 $ 0.23

Other (Income) Expense - Net

Other (Income) Expense - Net	3 Months Ended
Other (Income) Expense - Net	Mar. 27, 2021
Other Income and Expenses [Abstract]
Other (Income) Expense - Net	OTHER (INCOME) EXPENSE - NETOther (income) expense - net was $0.1 million of income for the first quarter of fiscal 2021, compared to a net $0.3 million of expense in the first quarter of 2020.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 27, 2021
Accounting Policies [Abstract]
Fiscal Period	The Company’s fiscal year ends on the Saturday closest to December 31. The most recent fiscal year ended on January 2, 2021. Each of the Company's first three fiscal quarters consists of twelve weeks while the last fiscal quarter consists of sixteen or seventeen weeks.
Recently Issued Accounting Standards Adopted	Recently Issued Accounting Standards Adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2020-04: Reference Rate Reform (Topic 848) March 12, 2020 In March 2020, the FASB issued ASU 2020-04: Reference Rate Reform which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the discontinuance of LIBOR or another referenced rate. The guidance may be applied to any applicable contract entered into before December 31, 2022. The Company plans on applying the accounting standard to contracts, hedging relationships, and other transactions affected by the discontinuance of LIBOR on a prospective basis. The Company is currently evaluating the impact of this guidance on the consolidated financial statements.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
Business Combinations (Tables)	Mar. 27, 2021
Business Combinations [Abstract]
Schedule Estimated Fair Values of Assets Acquired, Net of Cash Acquired	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed, net of cash acquired, related to each acquisition: As of March 27, 2021 (thousands) Gro America California Environmental & Litho All Valley Disposal GlyEco WSS Accounts receivable $ 752 $ 67 $ 36 $ 107 $ — Inventory — 3 18 291 28 Property, plant, & equipment 1,490 15 252 746 154 Equipment at customers — — — — 24 Intangible assets 5,300 445 310 251 298 Goodwill 2,541 3 384 251 — Accounts payable (78) — — — — Total purchase price, net of cash acquired $ 10,005 $ 533 $ 1,000 $ 1,646 $ 504 Less: working capital adjustment — — — 23 — Less: contingent consideration — 120 250 — — Less: to be placed in escrow — — 100 — — Net cash paid $ 10,005 $ 413 $ 650 $ 1,623 $ 504

Revenue (Tables)

Revenue (Tables)	3 Months Ended
Revenue (Tables)	Mar. 27, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue by Major Lines	The following table disaggregates our revenue by major lines: For the First Quarter Ended, March 27, 2021 March 21, 2020 Total Net Sales by Major Lines of Business (thousands) Environmental Services Oil Business Total Environmental Services Oil Business Total Parts cleaning, containerized waste, & related products/services $ 38,833 $ — $ 38,833 $ 40,290 $ — $ 40,290 Vacuum Services & Wastewater Treatment 13,692 — 13,692 14,618 — 14,618 Field Services 4,096 — 4,096 9,623 — 9,623 Antifreeze Business 6,988 — 6,988 6,677 — 6,677 Environmental Services - Other 441 — 441 480 — 480 Re-refinery Product Sales — 30,054 30,054 — 25,436 25,436 Oil Collection Services & RFO — 4,617 4,617 — 3,289 3,289 Oil Filter Business — 1,245 1,245 — 1,066 1,066 Revenues from Contracts with Customers 64,050 35,916 99,966 71,688 29,791 101,479 Rental income 5,407 9 5,416 5,765 20 5,785 Total Revenues $ 69,457 $ 35,925 $ 105,382 $ 77,453 $ 29,811 $ 107,264
Contract Assets and Contract Liabilities from Contracts with Customers	The following table provides information about contract assets and contract liabilities from contracts with customers: (thousands) March 27, 2021 January 2, 2021 Contract assets $ 80 $ 72 Contract liabilities 2,315 2,054 Contract liabilities - net $ 2,235 $ 1,982

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
Accounts Receivable (Tables)	Mar. 27, 2021
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts Payable	Accounts receivable for the first quarter ended March 27, 2021, and the fiscal year ended January 2, 2021 consisted of the following: (thousands) March 27, January 2, Trade $ 52,396 $ 47,191 Less: allowance for uncollectible accounts 2,553 2,502 Trade - net 49,843 44,689 Related parties 2,771 3,276 Other — 514 Total accounts receivable - net $ 52,614 $ 48,479 The following table provides the changes in the Company’s allowance for uncollectible accounts for the first quarter ended March 27, 2021, and the fiscal year ended January 2, 2021: (thousands) March 27, January 2, Balance at beginning of period $ 2,502 $ 2,221 Provision for uncollectible accounts 474 1,919 Accounts written off, net of recoveries (423) (1,638) Balance at end of period $ 2,553 $ 2,502

Inventory (Tables)

Inventory (Tables)	3 Months Ended
Inventory (Tables)	Mar. 27, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	The carrying value of inventory consisted of the following: (thousands) March 27, January 2, Solvents and solutions $ 6,740 $ 6,672 Used oil and processed oil 7,500 6,345 Machines 5,364 5,704 Drums and supplies 4,269 4,423 Other 2,012 2,221 Total inventory 25,885 25,365 Less: machine refurbishing reserve 355 387 Total inventory - net $ 25,530 $ 24,978

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	3 Months Ended
Property, Plant, and Equipment (Tables)	Mar. 27, 2021
Property, Plant and Equipment [Abstract]
Summary of Property, Plant, and Equipment	Property, plant, and equipment consisted of the following: (thousands) March 27, January 2, Machinery, vehicles, and equipment $ 139,642 $ 138,496 Buildings and storage tanks 72,939 72,938 Land 5,911 5,909 Leasehold improvements 6,930 6,929 Construction in progress 9,775 8,023 Total property, plant and equipment 235,197 232,295 Less: accumulated depreciation 80,450 79,279 Property, plant and equipment - net $ 154,747 $ 153,016 (thousands) March 27, January 2, Equipment at customers $ 83,091 $ 81,881 Less: accumulated depreciation 59,161 58,770 Equipment at customers - net $ 23,930 $ 23,111

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
Goodwill and Other Intangible Assets (Tables)	Mar. 27, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table shows changes to our goodwill balances by segment from January 2, 2021 to March 27, 2021: (thousands) Oil Business Environmental Services Total Goodwill at January 2, 2021 Gross carrying amount $ 3,952 $ 35,541 $ 39,493 Accumulated impairment loss (3,952) — (3,952) Net book value at January 2, 2021 $ — $ 35,541 $ 35,541 Goodwill at March 27, 2021 Gross carrying amount $ 3,952 35,541 $ 39,493 Accumulated impairment loss (3,952) — (3,952) Net book value at March 27, 2021 $ — $ 35,541 $ 35,541
Schedule of Finite-Lived Intangible Assets	The following is a summary of software and other intangible assets: March 27, 2021 January 2, 2021 (thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 30,860 $ 18,068 $ 12,792 $ 30,857 $ 16,934 $ 13,923 Software 9,739 5,718 4,021 9,592 5,645 3,947 Non-compete agreements 3,609 3,240 369 3,607 3,212 395 Patents, formulae, and licenses 1,769 856 913 1,769 850 919 Other 1,738 1,349 389 1,738 1,346 392 Total software and intangible assets - net $ 47,715 $ 29,231 $ 18,484 $ 47,563 $ 27,987 $ 19,576 The weighted average useful lives of software and other intangibles are as follows: Weighted Average Useful Life (years) Patents, formulae, & licenses 15 Customer and supplier relationships 10 Software 9 Non-compete agreements 4 Other intangibles 7
Finite-lived Intangible Assets Amortization Expense	The estimated amortization expense for the remainder of fiscal 2021 and each of the five succeeding fiscal years is as follows: (millions) Fiscal Year Amortization Expense 2021 $3.7 2022 4.3 2023 3.8 2024 2.1 2025 1.1 2026 0.5

Accounts Payable (Tables)

Accounts Payable (Tables)	3 Months Ended
Accounts Payable (Tables)	Mar. 27, 2021
Payables and Accruals [Abstract]
Schedule of Accounts Payable	Accounts payable consisted of the following: (thousands) March 27, January 2, Accounts payable $ 30,705 $ 29,263 Accounts payable - related parties 312 400 Total accounts payable $ 31,017 $ 29,663

Debt and Financing Arrangemen_2

Debt and Financing Arrangements (Tables)	3 Months Ended
Debt and Financing Arrangements (Tables)	Mar. 27, 2021
Debt Disclosure [Abstract]
Schedule of Debt	Debt at March 27, 2021 and January 2, 2021 consisted of the following: (thousands) March 27, 2021 January 2, 2021 Principal amount $ — $ 30,000 Less: unamortized debt issuance costs — 344 Long-term debt, less current maturities $ — $ 29,656

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
Segment Information (Tables)	Mar. 27, 2021
Segment Reporting [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	Segment results for the first quarters ended March 27, 2021, and March 21, 2020 were as follows: First Quarter Ended, March 27, 2021 (thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Service revenues $ 53,303 $ 4,397 $ — $ 57,700 Product revenues 10,747 31,519 — 42,266 Rental income 5,407 9 — 5,416 Total revenues $ 69,457 $ 35,925 $ — $ 105,382 Operating expenses Operating costs 51,880 24,891 — 76,771 Operating depreciation and amortization 1,579 948 — 2,527 Profit before corporate selling, general, and administrative expenses $ 15,998 $ 10,086 $ — $ 26,084 Selling, general, and administrative expenses 12,188 12,188 Depreciation and amortization from SG&A 1,255 1,255 Total selling, general, and administrative expenses $ 13,443 $ 13,443 Other (income) - net (108) (108) Operating income 12,749 Interest expense – net 324 324 Income before income taxes $ 12,425 First Quarter Ended, March 21, 2020 (thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Service revenues $ 60,960 $ 2,797 $ — $ 63,757 Product revenues 10,728 26,994 — 37,722 Rental income 5,765 20 — 5,785 Total revenues $ 77,453 $ 29,811 $ — $ 107,264 Operating expenses Operating costs 56,404 26,846 — 83,250 Operating depreciation and amortization 2,271 2,055 — 4,326 Profit before corporate selling, general, and administrative expenses $ 18,778 $ 910 $ — $ 19,688 Selling, general, and administrative expenses 11,522 11,522 Depreciation and amortization from SG&A 942 942 Total selling, general, and administrative expenses $ 12,464 $ 12,464 Other expense - net 272 272 Operating income 6,952 Interest expense – net 214 214 Income before income taxes $ 6,738
Reconciliation of Assets from Segment to Consolidated	Total assets by segment as of March 27, 2021 and January 2, 2021 were as follows: (thousands) March 27, 2021 January 2, 2021 Total Assets: Environmental Services $ 218,214 $ 217,297 Oil Business 165,066 160,165 Unallocated Corporate Assets 59,021 84,207 Total $ 442,301 $ 461,669

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
Commitments and Contingencies (Tables)	Mar. 27, 2021
Commitments and Contingencies Disclosure [Abstract]
Components of Lease Expense	The components of lease expense were as follows: For the First Quarter Ended (thousands) March 27, March 21, Finance lease cost: Amortization of right-of-use assets $ 578 $ 322 Interest on lease liabilities 112 74 Total finance lease cost $ 690 $ 396 Operating lease cost $ 5,405 $ 6,051 Short-term lease cost 995 1,360 Variable lease cost 702 1,033 Total lease cost $ 7,102 $ 8,444 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from financing leases $ 112 $ 66 Operating cash flows from operating leases $ 5,760 $ 6,523 Financing cash flows from financing leases $ 436 $ 210 Right-of-use assets obtained in exchange for new finance lease liabilities $ 250 $ 3,264 Right-of-use assets obtained in exchange for new operating lease liabilities $ 1,820 $ 588 Weighted-average remaining lease term (years) Finance leases 5.9 6.6 Operating leases 4.4 4.9 Weighted-average discount rate Finance leases 3.2 % 3.4 % Operating leases 5.6 % 5.8 %
Future Annual Minimum Lease Payment Commitments	Future annual minimum lease payment commitments as of March 27, 2021 were as follows: (thousands) Year 1 $ 22,826 Year 2 19,275 Year 3 15,078 Year 4 10,827 Year 5 7,325 thereafter 11,308 Total minimum lease payments $ 86,639 Less: imputed interest 10,067 Lease liability $ 76,572
Rental Income	Rental income was as follows: First Quarter Ended, March 27, 2021 March 21, 2020 (thousands) Environmental Services Oil Business Total Environmental Services Oil Business Total Parts Cleaning $ 5,407 $ — $ 5,407 $ 5,765 $ — $ 5,765 Railcars — — — — 16 16 Property — 9 9 — 4 4 Total rental income $ 5,407 $ 9 $ 5,416 $ 5,765 $ 20 $ 5,785

Share-based Compensation (Table

Share-based Compensation (Tables)	3 Months Ended
Share-based Compensation (Tables)	Mar. 27, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Restricted Stock Unit Activity	The following table shows a summary of restricted share grants and expense resulting from the awards: Compensation Expense (thousands, except share amounts) First Quarters Ended, Unrecognized Expense as of, Recipient of Grant Grant Date Restricted Shares March 27, 2021 March 21, 2020 March 27, 2021 March 21, 2020 Chief Executive Officer February, 2017 500,000 $ — $ 89 $ — $ 296 Members of Management February, 2018 116,958 — 142 — 472 Special Incentive Grant April, 2018 350,000 298 344 1,354 3,084 Members of Management May, 2019 23,560 59 50 203 408 Members of Management February, 2020 41,138 38 165 355 705 Board of Directors April, 2020 14,988 — 66 — 219 Chief Executive Officer February, 2021 500,000 394 — 5,923 — Members of Management February, 2021 35,898 22 184 635 — The following table summarizes the restricted stock activity for the first quarter ended March 27, 2021: Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at January 2, 2021 646,634 $ 18.28 Granted 535,898 22.02 Vested (35,497) 15.00 Forfeited (340,754) 15.05 Nonvested shares outstanding at March 27, 2021 806,281 $ 22.28
Schedule of Restricted Stock Vesting Percentages	Vesting Table Increase in Stock Price From the Amended Agreement Commencement Date to the Vesting Date Total Percentage of Restricted Stock Less than $5 per share increase —% $5 per share increase 25% (vest in 125,000 shares) $10 per share increase 50% (vest in 125,000 shares) $15 per share increase 75% (vest in 125,000 shares) $20 or more per share increase 100% (vest in 125,000 shares)

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
Earnings Per Share (Tables)	Mar. 27, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table reconciles the number of shares outstanding for the first quarters of fiscal 2021 and 2020, respectively, to the number of weighted average basic shares outstanding and the number of weighted average diluted shares outstanding for the purposes of calculating basic and diluted earnings per share: First Quarter Ended, (thousands, except per share amounts) March 27, 2021 March 21, 2020 Net income $ 9,206 $ 5,291 Weighted average basic shares outstanding 23,373 23,239 Dilutive shares for share–based compensation plans 136 183 Weighted average diluted shares outstanding 23,509 23,422 Net income per share: basic $ 0.39 $ 0.23 Net income per share: diluted $ 0.39 $ 0.23

Organization and Nature of Op_2

Organization and Nature of Operations (Details)	3 Months Ended
Organization and Nature of Operations (Details)	Mar. 27, 2021segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 27, 2019	Oct. 08, 2019	Mar. 25, 2019	Feb. 01, 2019	Jan. 11, 2019
California Environmental & Litho
Business Acquisition [Line Items]
Purchase price			$ 0.5
All Valley Disposal
Business Acquisition [Line Items]
Purchase price				$ 0.6
WSS
Business Acquisition [Line Items]
Purchase price					$ 0.5
GlyEco
Business Acquisition [Line Items]
Purchase price						$ 1.6
Maximum \| All Valley Disposal
Business Acquisition [Line Items]
Purchase price				$ 1
One subsidiary
Business Acquisition [Line Items]
Consideration transferred		$ 2.7
Gro America
Business Acquisition [Line Items]
Purchase price	$ 10

Business Combinations - Estimat

Business Combinations - Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Jan. 02, 2021
Business Acquisition [Line Items]
Goodwill	$ 35,541	$ 35,541
Gro America
Business Acquisition [Line Items]
Accounts receivable	752
Inventory	0
Property, plant, & equipment	1,490
Equipment at customers	0
Intangible assets	5,300
Goodwill	2,541
Accounts payable	(78)
Total purchase price, net of cash acquired	10,005
Less: working capital adjustment	0
Less: contingent consideration	0
Less: to be placed in escrow	0
Net cash paid	10,005
California Environmental & Litho
Business Acquisition [Line Items]
Accounts receivable	67
Inventory	3
Property, plant, & equipment	15
Equipment at customers	0
Intangible assets	445
Goodwill	3
Accounts payable	0
Total purchase price, net of cash acquired	533
Less: working capital adjustment	0
Less: contingent consideration	120
Less: to be placed in escrow	0
Net cash paid	413
All Valley Disposal
Business Acquisition [Line Items]
Accounts receivable	36
Inventory	18
Property, plant, & equipment	252
Equipment at customers	0
Intangible assets	310
Goodwill	384
Accounts payable	0
Total purchase price, net of cash acquired	1,000
Less: working capital adjustment	0
Less: contingent consideration	250
Less: to be placed in escrow	100
Net cash paid	650
GlyEco
Business Acquisition [Line Items]
Accounts receivable	107
Inventory	291
Property, plant, & equipment	746
Equipment at customers	0
Intangible assets	251
Goodwill	251
Accounts payable	0
Total purchase price, net of cash acquired	1,646
Less: working capital adjustment	23
Less: contingent consideration	0
Less: to be placed in escrow	0
Net cash paid	1,623
WSS
Business Acquisition [Line Items]
Accounts receivable	0
Inventory	28
Property, plant, & equipment	154
Equipment at customers	24
Intangible assets	298
Goodwill	0
Accounts payable	0
Total purchase price, net of cash acquired	504
Less: working capital adjustment	0
Less: contingent consideration	0
Less: to be placed in escrow	0
Net cash paid	$ 504

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue by Major Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Revenue from Contract with Customer [Abstract]
Performance obligation timing	We do not have any material significant payment terms as payment is generally due within 30 days after the performance obligation has been satisfactorily completed. The Company has elected the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that we otherwise would have recognized is one year or less. In applying the guidance in Topic 606, there were no judgments or estimates made that the Company deems significant.
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 99,966	$ 101,479
Rental income	5,416	5,785
Total revenues	105,382	107,264
Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	38,833	40,290
Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	13,692	14,618
Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,096	9,623
Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	6,988	6,677
Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	441	480
Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	30,054	25,436
Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,617	3,289
Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,245	1,066
Environmental Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	64,050	71,688
Rental income	5,407	5,765
Total revenues	69,457	77,453
Environmental Services \| Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	38,833	40,290
Environmental Services \| Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	13,692	14,618
Environmental Services \| Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,096	9,623
Environmental Services \| Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	6,988	6,677
Environmental Services \| Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	441	480
Environmental Services \| Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Environmental Services \| Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Environmental Services \| Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	35,916	29,791
Rental income	9	20
Total revenues	35,925	29,811
Oil Business \| Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business \| Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business \| Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business \| Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business \| Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0	0
Oil Business \| Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	30,054	25,436
Oil Business \| Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,617	3,289
Oil Business \| Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 1,245	$ 1,066

Revenue - Contract Assets and C

Revenue - Contract Assets and Contract Liabilities from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Jan. 02, 2021
Revenue from Contract with Customer [Abstract]
Contract assets	$ 80	$ 72
Contract liabilities	2,315	2,054
Contract liabilities - net	2,235	$ 1,982
Revenue recognized	$ 2,100

Accounts Receivable - Summary o

Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021	Dec. 28, 2019
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Trade	$ 52,396	$ 47,191
Less: allowance for uncollectible accounts	2,553	2,502	$ 2,221
Trade - net	49,843	44,689
Related parties	2,771	3,276
Other	0	514
Total accounts receivable - net	$ 52,614	$ 48,479

Accounts Receivable - Rollforwa

Accounts Receivable - Rollforward of Allowance (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 27, 2021	Mar. 21, 2020	Jan. 02, 2021
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 2,502	$ 2,221	$ 2,221
Provision for uncollectible accounts	474	$ 189	1,919
Accounts written off, net of recoveries	(423)		(1,638)
Balance at end of period	$ 2,553		$ 2,502

Inventory - Carrying Value of I

Inventory - Carrying Value of Inventory (Details) - USD ($)	3 Months Ended
Inventory - Carrying Value of Inventory (Details) - USD ($)	Mar. 27, 2021	Mar. 21, 2020	Jan. 02, 2021
Inventory Disclosure [Abstract]
Solvents and solutions	$ 6,740,000		$ 6,672,000
Used oil and processed oil	7,500,000		6,345,000
Machines	5,364,000		5,704,000
Drums and supplies	4,269,000		4,423,000
Other	2,012,000		2,221,000
Total inventory	25,885,000		25,365,000
Less: machine refurbishing reserve	355,000		387,000
Total inventory - net	25,530,000		$ 24,978,000
Inventory impairment charge	$ 0	$ 0

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020	Jan. 02, 2021
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 235,197		$ 232,295
Less: accumulated depreciation	80,450		79,279
Property, plant and equipment - net	154,747		153,016
Equipment at customers	83,091		81,881
Less: accumulated depreciation	59,161		58,770
Equipment at customers - net	23,930		23,111
Depreciation expense	2,500	$ 4,400
Machinery, vehicles, and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	139,642		138,496
Buildings and storage tanks
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	72,939		72,938
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	5,911		5,909
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	6,930		6,929
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 9,775		$ 8,023

Goodwill and Other Intangibles

Goodwill and Other Intangibles Assets - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 27, 2021USD ($)reporting_unit	Mar. 21, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting units \| reporting_unit	2
Amortization of intangible assets \| $	$ 1.2	$ 0.9

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Goodwill Balances (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 39,493	$ 39,493
Accumulated impairment loss	(3,952)	(3,952)
Net book value	35,541	35,541
Oil Business
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,952	3,952
Accumulated impairment loss	(3,952)	(3,952)
Net book value	0	0
Environmental Services
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	35,541	35,541
Accumulated impairment loss	0	0
Net book value	$ 35,541	$ 35,541

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Software and Other Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Jan. 02, 2021
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 47,715	$ 47,563
Accumulated Amortization	29,231	27,987
Net Carrying Amount	18,484	19,576
Customer & supplier relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	30,860	30,857
Accumulated Amortization	18,068	16,934
Net Carrying Amount	$ 12,792	13,923
Weighted Average Useful Life (years)	10 years
Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 9,739	9,592
Accumulated Amortization	5,718	5,645
Net Carrying Amount	$ 4,021	3,947
Weighted Average Useful Life (years)	9 years
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,609	3,607
Accumulated Amortization	3,240	3,212
Net Carrying Amount	$ 369	395
Weighted Average Useful Life (years)	4 years
Patents, formulae, and licenses
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,769	1,769
Accumulated Amortization	856	850
Net Carrying Amount	$ 913	919
Weighted Average Useful Life (years)	15 years
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,738	1,738
Accumulated Amortization	1,349	1,346
Net Carrying Amount	$ 389	$ 392
Weighted Average Useful Life (years)	7 years

Goodwill and Other Intangible_5

Goodwill and Other Intangibles Assets - Schedule of Expected Amortization Expense (Details) $ in Millions	Mar. 27, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 3.7
2022	4.3
2023	3.8
2024	2.1
2025	1.1
2026	$ 0.5

Accounts Payable (Details)

Accounts Payable (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021
Payables and Accruals [Abstract]
Accounts payable	$ 30,705	$ 29,263
Accounts payable - related parties	312	400
Total accounts payable	$ 31,017	$ 29,663

Debt and Financing Arrangemen_3

Debt and Financing Arrangements - Narrative (Details) - USD ($)	Mar. 18, 2021	Mar. 27, 2021	Mar. 21, 2020	Jan. 02, 2021
Debt Instrument [Line Items]
Repayment of term loan		$ 30,000,000	$ 0
Debt issuance costs		804,000	0
Interest costs incurred		$ 300,000	400,000
Term loan interest costs incurred			300,000
Amortization of debt issuance costs			$ 100,000
Weighted average interest rate		2.04%	3.70%
Letters of credit outstanding		$ 3,900,000		$ 3,900,000
Current borrowing capacity		96,100,000		$ 61,000,000
Previous term loan
Debt Instrument [Line Items]
Repayment of term loan		$ 30,000,000
Agreement
Debt Instrument [Line Items]
Debt issuance costs	$ 800,000
Minimum interest coverage ratio	3.5
Maximum total leverage ratio	3
Aggregate consideration limit	$ 10,000,000
Leverage ratio at time of acquisition	3
Agreement \| Fiscal quarter of acquisition occurs and three immediately following fiscal quarters
Debt Instrument [Line Items]
Leverage ratio at time of acquisition	3.50
Agreement \| Revolving Loan Portion
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 100,000,000
Agreement \| Revolving Loan Portion \| Swing Line loan
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 15,000,000
Agreement \| Bank Credit Facility \| Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Agreement \| Bank Credit Facility \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Agreement \| Bank Credit Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Agreement \| Bank Credit Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Agreement \| Bank Credit Facility \| Bank of America's Prime Rate \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Agreement \| Bank Credit Facility \| Bank of America's Prime Rate \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Agreement \| Term Loan
Debt Instrument [Line Items]
Effective interest rate	1.90%

Debt and Financing Arrangemen_4

Debt and Financing Arrangements - Summary of Debt (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021
Debt Disclosure [Abstract]
Principal amount	$ 0	$ 30,000
Less: unamortized debt issuance costs	0	344
Long-term debt, less current maturities	$ 0	$ 29,656

Segment Information - Operating

Segment Information - Operating Segment Results (Details) $ in Thousands	3 Months Ended
	Mar. 27, 2021USD ($)segment	Mar. 21, 2020USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment	2
Revenues
Revenues	$ 99,966	$ 101,479
Rental income	5,416	5,785
Total revenues	105,382	107,264
Operating expenses
Operating costs	76,771	83,250
Operating depreciation and amortization	2,527	4,326
Profit before corporate selling, general, and administrative expenses	26,084	19,688
Selling, general, and administrative expenses	12,188	11,522
Depreciation and amortization from SG&A	1,255	942
Total selling, general, and administrative expenses	13,443	12,464
Other (income) expense - net	(108)	272
Operating income	12,749	6,952
Interest expense – net	324	214
Income before income taxes	12,425	6,738
Environmental Services
Revenues
Revenues	64,050	71,688
Rental income	5,407	5,765
Total revenues	69,457	77,453
Oil Business
Revenues
Revenues	35,916	29,791
Rental income	9	20
Total revenues	35,925	29,811
Service revenues
Revenues
Revenues	57,700	63,757
Product revenues
Revenues
Revenues	42,266	37,722
Segments \| Environmental Services
Revenues
Rental income	5,407	5,765
Total revenues	69,457	77,453
Operating expenses
Operating costs	51,880	56,404
Operating depreciation and amortization	1,579	2,271
Profit before corporate selling, general, and administrative expenses	15,998	18,778
Segments \| Oil Business
Revenues
Rental income	9	20
Total revenues	35,925	29,811
Operating expenses
Operating costs	24,891	26,846
Operating depreciation and amortization	948	2,055
Profit before corporate selling, general, and administrative expenses	10,086	910
Segments \| Service revenues \| Environmental Services
Revenues
Revenues	53,303	60,960
Segments \| Service revenues \| Oil Business
Revenues
Revenues	4,397	2,797
Segments \| Product revenues \| Environmental Services
Revenues
Revenues	10,747	10,728
Segments \| Product revenues \| Oil Business
Revenues
Revenues	31,519	26,994
Corporate and Eliminations
Revenues
Rental income	0	0
Total revenues	0	0
Operating expenses
Operating costs	0	0
Operating depreciation and amortization	0	0
Profit before corporate selling, general, and administrative expenses	0	0
Selling, general, and administrative expenses	12,188	11,522
Depreciation and amortization from SG&A	1,255	942
Total selling, general, and administrative expenses	13,443	12,464
Other (income) expense - net	(108)	272
Interest expense – net	324	214
Corporate and Eliminations \| Service revenues
Revenues
Revenues	0	0
Corporate and Eliminations \| Product revenues
Revenues
Revenues	$ 0	$ 0

Segment Information - Assets by

Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Jan. 02, 2021
Segment Reporting Information [Line Items]
Assets	$ 442,301	$ 461,669
Segments \| Environmental Services
Segment Reporting Information [Line Items]
Assets	218,214	217,297
Segments \| Oil Business
Segment Reporting Information [Line Items]
Assets	165,066	160,165
Unallocated Corporate Assets
Segment Reporting Information [Line Items]
Assets	$ 59,021	$ 84,207

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	Mar. 27, 2021	Jan. 02, 2021
Lessee, Lease, Description [Line Items]
Remaining amount committed	$ 16.5	$ 20
Loss contingency accrual	$ 3.2	$ 3.9
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 month
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	11 years
Lease renewal term	5 years

Commitments and Contingencies_2

Commitments and Contingencies - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Finance lease cost:
Amortization of right-of-use assets	$ 578	$ 322
Interest on lease liabilities	112	74
Total finance lease cost	690	396
Operating lease cost	5,405	6,051
Short-term lease cost	995	1,360
Variable lease cost	702	1,033
Total lease cost	7,102	8,444
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from financing leases	112	66
Operating cash flows from operating leases	5,760	6,523
Financing cash flows from financing leases	436	210
Right-of-use assets obtained in exchange for new finance lease liabilities	250	3,264
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1,820	$ 588
Weighted-average remaining lease term (years)
Finance leases	5 years 10 months 24 days	6 years 7 months 6 days
Operating leases	4 years 4 months 24 days	4 years 10 months 24 days
Weighted-average discount rate
Finance leases	3.20%	3.40%
Operating leases	5.60%	5.80%

Commitments and Contingencies_3

Commitments and Contingencies - Future Annual Minimum Lease Payment Commitments (Details) $ in Thousands	Mar. 27, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Year 1	$ 22,826
Year 2	19,275
Year 3	15,078
Year 4	10,827
Year 5	7,325
thereafter	11,308
Total minimum lease payments	86,639
Less: imputed interest	10,067
Lease liability	$ 76,572

Commitments and Contingencies_4

Commitments and Contingencies - Rental Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Lessor, Lease, Description [Line Items]
Rental income	$ 5,416	$ 5,785
Environmental Services
Lessor, Lease, Description [Line Items]
Rental income	5,407	5,765
Oil Business
Lessor, Lease, Description [Line Items]
Rental income	9	20
Parts Cleaning
Lessor, Lease, Description [Line Items]
Rental income	5,407	5,765
Parts Cleaning \| Environmental Services
Lessor, Lease, Description [Line Items]
Rental income	5,407	5,765
Parts Cleaning \| Oil Business
Lessor, Lease, Description [Line Items]
Rental income	0	0
Railcars
Lessor, Lease, Description [Line Items]
Rental income	0	16
Railcars \| Environmental Services
Lessor, Lease, Description [Line Items]
Rental income	0	0
Railcars \| Oil Business
Lessor, Lease, Description [Line Items]
Rental income	0	16
Property
Lessor, Lease, Description [Line Items]
Rental income	9	4
Property \| Environmental Services
Lessor, Lease, Description [Line Items]
Rental income	0	0
Property \| Oil Business
Lessor, Lease, Description [Line Items]
Rental income	$ 9	$ 4

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Mar. 27, 2021	Mar. 21, 2020
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 14.4
Deferred tax asset, net operating loss carryforward	$ 3.6
Effective income tax rate, percent	25.90%	21.50%
Uncertain Tax Positions
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 2.8

Share-based Compensation - Narr

Share-based Compensation - Narrative (Details) - USD ($)	Feb. 01, 2021	Mar. 27, 2021
Mr. Recatto
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing share price as of employment commencement date (in dollars per share)	$ 21.77
Restricted stock \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)		1 year
Restricted stock \| Members of Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)		3 years
Restricted stock \| Mr. Recatto
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)		180 days
Grants in period (in shares)	500,000
Vesting threshold (in dollars per share)	$ 5
Shares vested upon achievement of share price threshold (in shares)	0
Compensation expense		$ 400,000
Unrecognized compensation expense		$ 5,900,000
Risk-free rate	0.29%
Expected dividend yield	0.00%
Expected volatility rate	53.07%
Vesting percentage		50.00%
Time-Based Restricted Stock \| Mr. Recatto
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 100,000
Grant of restricted stock	$ 500,000

Share-based Compensation - Rest

Share-based Compensation - Restricted Stock Compensation/Awards (Details) - USD ($) $ in Thousands	1 Months Ended							3 Months Ended
	Feb. 28, 2021	Apr. 30, 2020	Feb. 29, 2020	May 31, 2019	Apr. 30, 2018	Feb. 28, 2018	Feb. 28, 2017	Mar. 27, 2021	Mar. 21, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)								535,898
Restricted stock \| April, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)					350,000
Compensation Expense								$ 298	$ 344
Unrecognized Expense								1,354	3,084
Restricted stock \| Chief Executive Officer \| February, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)							500,000
Compensation Expense								0	89
Unrecognized Expense								0	296
Restricted stock \| Chief Executive Officer \| February, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)	500,000
Compensation Expense								394	0
Unrecognized Expense								5,923	0
Restricted stock \| Members of Management \| February, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)						116,958
Compensation Expense								0	142
Unrecognized Expense								0	472
Restricted stock \| Members of Management \| May, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)				23,560
Compensation Expense								59	50
Unrecognized Expense								203	408
Restricted stock \| Members of Management \| February, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)			41,138
Compensation Expense								38	165
Unrecognized Expense								355	705
Restricted stock \| Members of Management \| February, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)	35,898
Compensation Expense								22	184
Unrecognized Expense								635	0
Restricted stock \| Board of Directors \| April, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)		14,988
Compensation Expense								0	66
Unrecognized Expense								$ 0	$ 219

Share-based Compensation - Re_2

Share-based Compensation - Restricted Stock Vesting Schedule by Percentage (Details) - $ / shares	1 Months Ended	3 Months Ended
	Feb. 28, 2017	Mar. 27, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested (in shares)		35,497
Mr. Recatto \| Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Percentage of Restricted Stock Shares to Be Vested		50.00%
Mr. Recatto \| Restricted stock \| Less than $5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)	$ 5
Total Percentage of Restricted Stock Shares to Be Vested	0.00%
Mr. Recatto \| Restricted stock \| $5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)	$ 5
Total Percentage of Restricted Stock Shares to Be Vested	25.00%
Vested (in shares)	125,000
Mr. Recatto \| Restricted stock \| $10 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)	$ 10
Total Percentage of Restricted Stock Shares to Be Vested	50.00%
Vested (in shares)	125,000
Mr. Recatto \| Restricted stock \| $15 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)	$ 15
Total Percentage of Restricted Stock Shares to Be Vested	75.00%
Vested (in shares)	125,000
Mr. Recatto \| Restricted stock \| $20 or more per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)	$ 20
Total Percentage of Restricted Stock Shares to Be Vested	100.00%
Vested (in shares)	125,000

Share-based Compensation - Re_3

Share-based Compensation - Restricted Stock Rollforward (Details)	3 Months Ended
	Mar. 27, 2021$ / sharesshares
Number of Shares
Nonvested shares outstanding at Beginning of Period (in shares) \| shares	646,634
Granted (in shares) \| shares	535,898
Vested (in shares) \| shares	(35,497)
Forfeited (in shares) \| shares	(340,754)
Nonvested shares outstanding at End of Period (in shares) \| shares	806,281
Weighted Average Grant-Date Fair Value Per Share
Nonvested shares outstanding at Beginning of Period (in dollars per share) \| $ / shares	$ 18.28
Granted (in dollars per share) \| $ / shares	22.02
Vested (in dollars per share) \| $ / shares	15
Forfeited (in dollars per share) \| $ / shares	15.05
Nonvested shares outstanding at End of Period (in dollars per share) \| $ / shares	$ 22.28

Share-based Compensation - Empl

Share-based Compensation - Employee Stock Purchase Plan (Details) - $ / shares	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Common stock
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Issuance of common stock – ESPP (in shares)	6,072	4,102
Employee Stock Purchase Plan \| Employee stock
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares available employee stock purchase plan (in shares)	73,562
Weighted average fair value per share ESPP (in dollars per share)	$ 21.11

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Earnings Per Share [Abstract]
Net income	$ 9,206	$ 5,291
Weighted average basic shares outstanding (in shares)	23,373	23,239
Dilutive shares for share–based compensation plans (in shares)	136	183
Weighted average diluted shares outstanding (in shares)	23,509	23,422
Net (loss) income per share: basic (in dollars per share)	$ 0.39	$ 0.23
Net (loss) income per share: diluted (in dollars per share)	$ 0.39	$ 0.23

Other (Income) Expense - Net (D

Other (Income) Expense - Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 21, 2020
Other Income and Expenses [Abstract]
Other (income) expense - net	$ 108	$ (272)