Using Historical LCR and Water Quality Data to Evaluate Corrosion Control Treatment
Journal - American Water Works Association - October 2018
Tyler Bradley and Nicola Horscroft
DOI: 10.1002/awwa.1143
Historical Lead and Copper Rule (LCR) regulatory sampling data from the Philadelphia Water Department were examined to explore their potential value for guiding a water utility’s progress with regard to optimal corrosion control treatment (OCCT). If a system has established a stable water treatment process with consistent corrosion control treatment (CCT) and has achieved continued decreases in lead levels during regulatory sampling, then the information collected during LCR monitoring can be used as an important data set of a broader OCCT evaluation and will help inform the benefit of additional changes in CCT. Since water utilities have LCR data dating back to 1992, these data should be used to make informed decisions. This research also showed that the addition of orthophosphate has resulted in a significant decrease in lead levels at the customer tap. Additionally, profile sampling was performed to show that first‚Äźdraw 1 L samples following a 6 h stagnation period provide a good representation of the lead concentrations measured from lead service line and home plumbing samples at the same sites and may be used to indicate overall changes in lead concentrations at the tap resulting from CCT for this system.