Clean Edge semi-annually re-evaluates and updates the stocks included in the ISE Clean Edge Water Index (HHO). Here is a list of historical changes with most recent first.
September 2021
Additions: Stantec, Inc. (NYSE: STN)
Deletions: York Water Co. (NASDAQ: YORW)
March 2021
Additions: Energy Recovery Inc (NASDAQ: ERII) and Montrose Environmental Group (NYSE: MEG)
Deletions: Aegion Corp (NASDAQ: AEGN) and Forterra, Inc. (NASDAQ: FRTA)
September 2020
Additions: Primo Water Corp (NYSE: PRMW)
Deletions: Energy Recovery Inc. (NASDAQ: ERII)
April 2020
Additions: Algonquin Power & Utilities Corp (NYSE: AQN) and Forterra (NASDAQ: FRTA)
Deletions: Aquaventure Holdings (NYSE: WAAS) and Primo Water (NASDAQ: PRMW)
March 2019
Addition: Primo (NASDAQ: PRMW).
Removal: Forterra, Inc (NASDAQ: FRTA).
September 2018
Addition: AquaVenture Holdings Limited (NYSE: WAAS).
Removal: Connecticut Water Service, Inc. (NASDAQ: CTWS).
March 2018
Additions: Calgon Carbon Corporation (CCC); Evoqua Water Technologies (NYSE: AQUA); and Energy Recovery Inc. (NASDAQ
Removal: AquaVenture Holdings (NYSE: WAAS).
September 2017
Addition: Forterra Inc (NASDAQ:FRTA).
Removal: Energy Recovery, Inc. (NASDAQ
June 2017
Additions: A. O. Smith Corporation (AOS); Aqua Venture Holdings Limited (WAAS); Connecticut Water Service, Inc. (CTWS); Middlesex Water Company (MSEX); and York Water Company (YOWR).
Removals: Ashland Global Holdings Inc. (ASH); Cadiz Inc. (CDZI); Crane Company (CR); Layne Christensen Company (LAYN); and PICO Holdings, Inc. (PICO).