Контекст:

A major Southern California municipality servicing a population of over 100,000 uses potable water source wells to supplement its surface water supply of drinking water. The wells began experiencing high bacteria levels, sulfur odors, and reduced production capacities. The primary problem identified was bacterial fouling and biomass accumulation in the wells. The municipality attempted remedial treatments with sodium hypochlorite and hydrogen peroxide. While initial flow-back results were promising, bacterial contamination levels equivalent to pre-treatment were observed within a few days. Additionally, no improvement was seen in the production capacity of the wells. Some of the wells had experienced up to a seventy percent decline in productivity while retaining the original rest water levels in the well, indicating severe fouling