However, this very small fraction detracts from the fact that in absolute terms it is rather large volumes that are used. For a well requiring 4 million gallons of water, about 40,000 gallons of additives are pumped in. The greatest risks associated with these chemicals occur during their transportation, as tanker trucks must use the local roads to bring them to the drill pads. An accident involved spilled contents would have significant public safety and environmental consequences.