CLH's three largest insider shareholders as of September 09, 2026 are Alan S Mckim (Exec Chair, Cto., 2.07Mn shares), Alan S Mckim (Exec Chair, Cto., 2.07Mn shares), Michael Louis Battles (Co Ceo, 94.36K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Michael Louis Battles | Co Ceo | 94,355 | 0 | 94,355 | 19.4% | 12 Aug, 2026 |
| 2 | Eric W Gerstenberg | Co Ceo | 56,793 | 0 | 56,793 | 11.7% | 18 Aug, 2026 |
| 3 | Brian P Weber | Evp (Chesi) | 47,914 | 0 | 47,914 | 9.9% | 06 Jul, 2026 |
| 4 | George L Curtis | Exec. Vice President (Chesi) | 44,291 | 0 | 44,291 | 9.1% | 11 Aug, 2026 |
| 5 | Alan S Mckim | Exec Chair, Cto. | 30,154 | 0 | 30,154 | 6.2% | 20 Jul, 2026 |
| 6 | Michael J Twohig | Evp (Chesi) | 28,857 | 0 | 28,857 | 5.9% | 29 Mar, 2023 |
| 7 | Thomas J Shields | Director | 28,762 | 0 | 28,762 | 5.9% | 26 May, 2022 |
| 8 | Sharon M. Gabriel | Evp/Cio (Chesi) | 20,706 | 0 | 20,706 | 4.3% | 06 Jul, 2026 |
| 9 | Rebecca Underwood | President Evp Facilities | 18,373 | 0 | 18,373 | 3.8% | 06 Jul, 2026 |
| 10 | Eric J. Dugas | Evp Chief Financial Officer | 17,620 | 0 | 17,620 | 3.6% | 14 Aug, 2026 |
| 11 | Robert Speights | President, Industrial Services | 16,310 | 0 | 16,310 | 3.4% | 28 May, 2025 |
| 12 | Jeroen Diderich | Evppresident Of Salesservice | 16,152 | 0 | 16,152 | 3.3% | 03 Jun, 2026 |
| 13 | John R. Welch | Director | 10,889 | 0 | 10,889 | 2.2% | 22 May, 2026 |
| 14 | Charles H. Ii Geer | Evp, Industrial Services | 10,799 | 0 | 10,799 | 2.2% | 06 Jul, 2026 |
| 15 | Andrea Robertson | Director | 8,979 | 0 | 8,979 | 1.8% | 03 Aug, 2026 |
| 16 | John T Preston | Director | 7,044 | 0 | 7,044 | 1.5% | 22 May, 2026 |
| 17 | Robert W. Harrison | Evp, Ehs | 6,648 | 0 | 6,648 | 1.4% | 17 Mar, 2026 |
| 18 | Marcy L. Reed | Director | 5,733 | 0 | 5,733 | 1.2% | 22 May, 2026 |
| 19 | Eugene G Banucci | Director | 5,598 | 0 | 5,598 | 1.2% | 12 Jun, 2023 |
| 20 | Jeffrey Herbert Knapp | Evp Hr (Chesi) | 5,311 | 0 | 5,311 | 1.1% | 24 Nov, 2021 |
| 21 | Karyn Polito | Director | 4,127 | 0 | 4,127 | 0.9% | 22 May, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 14 Aug, 2026 | Eric W Gerstenberg | Co Ceo | Disposed S | 2,500 | $321.34 | $803.35K | 56,793 | Direct |
| 01 Jul, 2026 | Eric W Gerstenberg | Co Ceo | Disposed F | 564 | $290.74 | $163.98K | 59,293 | Direct |
| 01 Jul, 2026 | Eric J. Dugas | Evp Chief Financial Officer | Disposed F | 447 | $290.74 | $129.96K | 17,620 | Direct |
| 01 Jul, 2026 | Michael Louis Battles | Co Ceo | Disposed F | 1,032 | $290.74 | $300.04K | 94,355 | Direct |
| 01 Jul, 2026 | George L Curtis | Exec. Vice President (Chesi) | Disposed F | 1,757 | $290.74 | $510.83K | 44,291 | Direct |
| 03 Aug, 2026 | Andrea Robertson | Director | Disposed S | 789 | $314.01 | $247.75K | 8,979 | Direct |
| 17 Jul, 2026 | Alan S Mckim | Exec Chair, Cto. | Disposed F | 1,265 | $310.58 | $392.88K | 30,154 | Direct |
| 01 Jul, 2026 | Charles H. Ii Geer | Evp, Industrial Services | Disposed F | 40 | $290.74 | $11.63K | 10,799 | Direct |
| 01 Jul, 2026 | Sharon M. Gabriel | Evp/Cio (Chesi) | Disposed F | 359 | $290.74 | $104.38K | 20,706 | Direct |
| 01 Jul, 2026 | Eric J. Dugas | Evp Chief Financial Officer | Disposed F | 447 | $290.74 | $129.96K | 13,532 | Direct |
| 01 Jul, 2026 | Rebecca Underwood | President Evp Facilities | Disposed F | 311 | $290.74 | $90.42K | 18,373 | Direct |
| 01 Jul, 2026 | Alan S Mckim | Exec Chair, Cto. | Disposed F | 1,343 | $290.74 | $390.46K | 31,419 | Direct |
| 01 Jul, 2026 | Eric W Gerstenberg | Co Ceo | Disposed F | 564 | $290.74 | $163.98K | 38,313 | Direct |
| 01 Jul, 2026 | Brian P Weber | Evp (Chesi) | Disposed F | 814 | $290.74 | $236.66K | 47,914 | Direct |
| 01 Jun, 2026 | Jeroen Diderich | Evppresident Of Salesservice | Disposed F | 1,717 | $281.00 | $482.48K | 16,152 | Direct |
| 20 May, 2026 | Alison A. Quirk | Director | Acquired A | 652 | $0.00 | $0 | 3,630 | Direct |
| 20 May, 2026 | Marcy L. Reed | Director | Acquired A | 652 | $0.00 | $0 | 5,733 | Direct |
| 20 May, 2026 | Karyn Polito | Director | Acquired A | 652 | $0.00 | $0 | 4,127 | Direct |
| 20 May, 2026 | John T Preston | Director | Acquired A | 652 | $0.00 | $0 | 7,044 | Direct |
| 20 May, 2026 | Shelley Jr Stewart | Director | Acquired A | 652 | $0.00 | $0 | 4,523 | Direct |