Once the sample size had been calculated, the monitoring process
was designed. This process was carried out during two and a
half weeks in the month of October (15 days), for the first teaching
period, and during one week in April and two weeks in May
(17 days) for the second teaching period. At 21:30 h, when the
cleaning service has finished, the number of bags deposited at all
the points was counted. As the cleaning and canteen staff use bags
of several different colours, this made it easier to differentiate and
to quantify theMWseparately according to its source. This allowed
data about canteen waste generation and cleaning service waste
generation to be obtained.