WWater treatment
WAgricultural wastewater treatment
WAir classifier
WArcata Wastewater Treatment Plant and Wildlife Sanctuary
WBest management practice for water pollution
WBigBelly
WBioconversion of biomass to mixed alcohol fuels
WBiofilter
WBioswale
WCheck dam
WCivic amenity site
WCyclonic separation
WDry cask storage
WEvaporation pond
WFacultative lagoon
WFly ash
WGarbage disposal unit
WGasification
WIncineration
WLandfill liner
WLandysh
WMaterials recovery facility
WMoving bed biofilm reactor
WPolyphosphate-accumulating organisms
WPondcrete
WPUREX
WPyrolysis
WRain garden
WRotating biological contactor
WSanitary engineering
WScottish Landfill Tax
WSeptic drain field
WOmni Processor
WSolvatten
WSpent fuel pool
WSupercritical water oxidation
WSustainable drainage system
WSyngas
WTrommel screen
WUltraviolet germicidal irradiation
WWaste converter
WWaste Isolation Pilot Plant
WWaste-to-energy
WWaste-to-energy plant