Calorific value

Amount of heat released when something is burned (7)

Chemical oxygen demand (COD)

Amount of oxygen required to chemically oxidise the organic material in an effluent (4)

Cistern-flush toilet

Toilet with a cistern (tank) containing water used to flush wastes away; requires connection to a piped water supply (5)

Closed questions

Questions with a limited number of possible answers (3)


Materials that can be burned (7)

Commercial opportunities

Ways in which private sector organisations could provide products or services on a commercial basis for profit (13)

Commercial waste

Solid waste produced by the commercial sector (retail, education, banking, government, etc.) (1)


Devices that use blades to shred rags, paper, etc. in wastewater at a treatment works (6)

Community-led total sanitation and hygiene (CLTSH)

Method for mobilising communities to completely eliminate open defecation by triggering collective behaviour change and installing and using latrines, and encouraging good hygiene practices (13)

Compact (solid waste)

To reduce the volume occupied by landfilled waste by drivng a tractor or other heavy vehicle over the waste (10)


Soil-like substance made from decayed organic matter that is used to improve soil (5)


Aerobic treatment of organic waste to produce a useful soil conditioner (8)

Construction and demolition waste

Solid waste from the demolition of old buildings, roads, etc., and from the construction of new ones (1)

Controlled landfill

Landfill site where measures are taken to reduce environmental pollution (10)


Strongly acidic or alkaline substances that can dissolve many materials and destroy living tissue (10)


Removal of sludge from pit latrines and septic tanks (6)


Serious disruption of the functioning of society, causing widespread human, material or environmental losses (14)

Disposal (of waste)

Getting rid of waste that cannot be treated in any other way, usually by landfill (8)


System of perforated pipes in trenches to allow the liquid effluent from a septic tank to soak into the ground (6)

Last modified: Sunday, 2 October 2016, 1:52 PM