Recharge of recycled water and assessing source water quality

The scope of this study was to further investigate how natural organic matter (NOM) from drinking water and soluble microbial products (SMP) generated in the wastewater treatment process engrave their character on TOC in water reuse systems. Previous studies at the Mesa Northwest Water Reclamation Plant (Arizona) demonstrated a clear correlation between source water TOC and treated effluent TOC. This study expanded me investigation to water reclamation plants in Arizona and California with varying source water quality and treatment processes. Higher source water TOC clearly correlated with higher reclaimed water TOC. Reclaimed water organic matter was lower in molecular weight and was only slightly more aromatic and less aliphatic as compared to drinking water from surface water sources. Although, residual organic carbon in reclaimed water is increased by soluble microbial products (SMPs) according to XAD-8 and XAD-4 fractionation results. The similarity of drinking water and reclaimed water ¹³C-NMR spectra demonstrate that structure and composition of the isolates are dominated by natural organic matter (NOM). Since TOC in reclaimed water may be dominated by NOM which is a function of local source water sources, regulations regarding surrogate parameters such as TOC should consider drinking water source concentrations.