Fig. 5. Time course of total P and phosphate P in raw wastewater input and in drainage water from aerated lysimeters (AIR) and lysimeters vented to the leachfield (LEACH). The wastewater loading rate was changed from 12 to 4 cm d^–1 on 21 Apr. 2003. Values are means (n = 3). Bars represent one standard deviation. Significant differences between AIR and LEACH treatments (P < 0.05) for a particular sampling date are indicated with an asterisk (*).