0379-3982 0379-3982 S0379-39822017000300047 10.18845/tm.v30i3.3272 Costa Rica Costa Rica 00 09 2017 00 09 2017 30 3 47 58

[1] OMS 2016 [2] 2013 [3] 2013 220-53 [4] 2015 [5] 2004 50-3 [6] 2011 [7] MINAE 2007 [8] APHA-AWWA-WEF 2012 [9] 2010 [10] 2011 [11] 2010 [12] USDA NRCS 2014 [13] 1993 11-44 [14] DEQ [15] 2012 25 4 4 34-9 [16] 2016 40 1 1 89-105 [17] SFE [18] WHO 2015 [19] FAO 2002 [20] 2009