WESTFIELD CAPITAL MANAGEMENT CO LP

Position in CLH — Clean Harbors Inc

CIK 1177719 BOSTON, MA

Position in CLH

as of Mar 31, 2026 · filed May 11, 2026 Compact

Position Value

$74,862,909

+$17,276,028 QoQ

Shares Held

261,092

+6.3% QoQ

Ownership

0.494%

of shares outstanding

% of Portfolio

0.31%

of 13F equity value

Holder Rank

—

not a current holder

Holding Since

Jun 2025

4 quarters on record

Voting authority Sole 89.80053008135064.ToString("F0")% Shared 0.ToString("F0")% None 10.199469918649365.ToString("F0")%

Industrials · as of Mar 31, 2026

WESTFIELD CAPITAL MANAGEMENT CO LP holds $140,844,881 across 3 Waste Management names. CLH ranks #1 (53.2% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	CLH	Clean Harbors Inc This page	261,092	$74,862,909
2	CWST	Casella Waste Systems Inc	822,492	$65,256,515
3	WCN	Waste Connections, Inc.	4,466	$725,457

4 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-03-31	$74,862,909	261,092	+6.3%	Shares	Sole	2026-05-11
2025-12-31	$57,586,881	245,594	+0.8%	Shares	Sole	2026-02-11
2025-09-30	$56,564,612	243,582	+26.7%	Shares	Sole	2025-11-12
2025-06-30	$44,446,435	192,259	—	Shares	Sole	2025-08-12
No filing history on record for this holder in this stock.