Water, Waste, and Environmental Sanitation
What the exam tests
This domain covers potable water, backflow prevention, ice, waste handling, sewage and general environmental sanitation.
Water and ice
Use potable water for food preparation, handwashing, ice and cleaning food-contact surfaces. Ice is a food: make it from potable water, store it covered and use a dedicated scoop, never a glass or hands. Do not use ice as a coolant for food or drinks. Protect water lines with backflow prevention - an air gap is best; vacuum breakers or check valves where approved. Submerged hoses and cross-connections can siphon contaminated water into the supply.
Waste and sewage
Segregate waste at source: food waste, recyclables, grease/oil and general waste. Use covered, leak-proof bins, empty them frequently and clean them. Never store waste in preparation areas. Grease traps must be maintained; blocked drains attract pests and cause overflow. Sewage lines must be separate from food areas and have traps. Restrooms and locker rooms need ventilation, handwash facilities and self-closing doors where required. Keep cleaning schedules and pest-breeding sites under control.
Worked example
A hose is left lying in a sink of dirty dishwater while the tap is on. If the water pressure drops, dirty water can be siphoned back into the potable supply. The fix is to keep the hose end above the water level (air gap) or fit an approved backflow preventer, and to store hoses off the floor.
Traps that cost marks
- Saying ice is exempt because it is frozen.
- Ignoring backflow because the water looks clean.
- Using food preparation sinks for mops or waste.
- Assuming a grease trap never needs cleaning.