Big Bend Water District (BBWD) is the supplier of potable water to the community of Laughlin, the sole source of which is the Colorado River. “The BBWD has over 15,000 acre feet per year as an allotment, but historically Laughlin rarely uses more than 5,000 acre feet of that allotment. BBWD can treat a maximum of 15 million gallons per day. Over a 12-month period, the average per-day flow through the treatment plant is three to four million gallons a day. Intake for the BBWD is located in the Colorado River just north of the Laughlin Bridge; most of the water in the river is a result of snow melt in the Rocky Mountains.
The job of the treatment plant is to remove impurities from the water and make it safe for drinking. The BBWD uses ozone as a disinfectant at the facility. Ozone is generated on-site and prevents the formation TTHMs, which the EPA limits in water.
Trihalomethane – or TTHM – is a by-product of chlorine, when it is used to disinfect drinking water. Ozone can remove some of the precursor compounds that form TTHM and reduces the total amount of chlorine that can form them. While more expensive to generate than other oxidants the tradeoff is a lot less taste and odor issues and much lower TTHMs. BBWD treats with chlorine, the EPA requires the district to maintain a disinfectant residual in the system because it is a surface water system.