Just go look on some of the questions on Bradley I'm sure you'll find the answer there
Answer:
Environmental sanitation
Environmental sanitation encompasses the control of environmental factors that are connected to disease transmission. Subsets of this category are solid waste management, water and wastewater treatment, industrial waste treatment and noise pollution control.
Water
Water is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients
Air
Walk, bike, carpool, or take public transit.
Reduce heating needs by making your house more energy efficient. Say no to wood fire burning.Use hand-powered or battery-operated garden tools. Know before you go. Check your tire pressure. Reduce, reuse, and recycle!Be idle-free.
It depends on how fit/active they are but there is no set amount I would say at least 10
