TOC as a Surrogate for Chemical Control in Potable Reuse

Abstract

Key Takeaways:

• TOC monitoring is a chemical control strategy used to (1) protect consumers from known and unknown organics including potentially toxic compounds, (2) minimize DBP formation, and (3) track process performance.
• TOC has many properties of an ideal surrogate because it can be monitored: (1) in real-time and at high-frequency, (2) with sensitivity and accuracy across wide concentration ranges, and (3) by reliable commercial technologies.
• TOC concentrations do not always correlate with toxicity.
• TOC limits for purified waters vary across the world depending on treatment requirements, end-use, source water quality, and complementary control strategies.
• TOC limits should be paired with targeted and non-targeted monitoring (mass spectrometry and/or bioassays) to assess the health risks posed by toxic organics and disinfection byproducts.