To help manage disinfection by-products (DBPs), the City of Santa Cruz Water Department (SCWD) used an online trihalomethane (THM) analyzer to obtain real-time and reliable data on THM and THM Formation Potential (THM-FP) levels within the Graham Hill Water Treatment Plant and distribution network. The THM-100 online THM analyzer aided the SCWD in daily operations and management of feasibility studies to reduce distribution system THM levels.