Table 1.

Values for septic tank final effluent orthophosphate concentrations (mg P l−1)

ReferenceMeanRangeStandard deviationNumber of samples
IEPA (2006)14.2
BGS (2007)15.82
Allhajjar et al (1989)134.7–39170
Canter & Knox (1985)255–30
Harman et al. (1996)98
Keegan (2014)2010–298
Nilsson (1987)0.9–25.1
Robertson & Blowes (1995)95
Robertson et al. (1998)0.05–4.9
Robertson (2003)6.3–1317
Wilhelm et al. (1996)8.96