CLEAN HARBORS INC

Ticker: CLH CUSIP: 184496107 Class: EQTY

DF DENT & CO INC's Holding History (CIK: 0000934999)

Note: Option positions (PUT/CALL) are excluded.

Q1 2014

Shares 1,262,457 Value ($000) $69,170 Avg Close $54.49 Range $44.95 - $60.47

Q4 2013

Shares 1,364,140 Value ($000) $81,794 Avg Close $57.66 Range $51.77 - $64.12

Q3 2013

Shares 1,217,731 Value ($000) $71,432 Avg Close $55.80 Range $50.23 - $59.80

Q2 2013

Shares 1,089,399 Value ($000) $55,047 Avg Close $55.73 Range $50.37 - $61.28

Period	Shares	Value ($000)	Average Close	Price Range
Q1 2014	1,262,457	$69,170	$54.49	$44.95 - $60.47
Q4 2013	1,364,140	$81,794	$57.66	$51.77 - $64.12
Q3 2013	1,217,731	$71,432	$55.80	$50.23 - $59.80
Q2 2013	1,089,399	$55,047	$55.73	$50.37 - $61.28