Fig. 2. Evolution of NO3–N, Cl, and dissolved organic carbon (DOC) concentrations and pH for a period of 3 mo before and 37 mo after (Day -80 to Day 1125) sewage sludge application. * refers to sludge applications at Days 0 (Month 0), 340 (Month 11), and 522 (Month 17). Values between -80 and 0 correspond to analysis performed on soil waters before the first sludge application.