Which treatment method, surface or well water, poses a higher risk for organic material leading to TTHM formation?

The treatment method that poses a higher risk for organic material leading to the formation of trihalomethanes (TTHMs) is surface water. Surface water, such as that from lakes, rivers, and reservoirs, often contains a higher level of organic matter compared to well water. This organic material, which includes natural organic compounds from decaying vegetation and other biological processes, can react with chlorine and other disinfectants used during water treatment to form TTHMs.

TTHMs are a byproduct of chlorination, and their formation is closely related to the concentration of organic precursors present in the water source. Since surface water is typically exposed to a larger array of environmental factors, including runoff and organic inflow, it tends to have higher levels of these organic substances. In contrast, well water usually has a lower concentration of organic material due to the filtration and natural purification processes that occur as water percolates through soil and rock layers, making it less likely to contribute to TTHM formation.

Groundwater from wells typically exhibits fewer organic contaminants and, therefore, poses a lower risk in this regard. Likewise, desalination processes focus on removing salts and do not generally involve organic matter in the same way as surface or groundwater sources, which makes