The Tamayamé, the Native American Tribal members of the Santa Ana Pueblo, north of Albuquerque, NM, are committed to natural resource conservation and future economic development. In the late 1990s, they built a water reclamation facility and began reusing treated effluent to irrigate the Pueblo’s golf course. Although they were pleased with the safety and environmental benefits of using on-site hypochlorite, they continued to struggle with biofilm in the distribution line, as well as other operational issues.
In 2007, the Pueblo upgraded to a MIOX® mixed oxidant generator. They maintained the same safety benefits of on-site generation, while eliminating biofilm, reducing maintenance, and cutting costs.
A case for wastewater reclamation
To meet the ever-growing demand on limited water supplies, water recycling and reuse are quickly moving from optional to necessary. Wastewater reuse is among the effective ways to ensure that our communities and industries have consistent access to this critical resource. One of the most compelling uses for reclaimed wastewater is agricultural irrigation, with one of the more common applications being golf course irrigation. According to EPA guidelines, golf course irrigation requires wastewater to be treated to the Tertiary/Advanced level of treatment. Unlike wastewater that is discharged into a receiving stream, reclaimed water requires maintenance of a residual disinfectant in the treated water to prevent recontamination during the reuse application. Neither UV nor membrane filtration, both common choices for discharged wastewater, offer a disinfection residual. Therefore, any wastewater treatment facility that wishes to recycle water must treat with a chlorine disinfectant in order to provide a measurable residual.
Traditionally, gas chlorine has been used for wastewater disinfection. However, legislation and public concern about safety are moving treatment plants away from this option. Two other common options are purchasing hypochlorite in bulk or generating it on site. Although bulk hypochlorite has become the defacto choice for many utilities, poisonous gas chlorine can still form if the hypochlorite is inadvertently mixed with an acid. In addition, since hypochlorite delivered in bulk is typically at a 15% concentration or less, a large amount of water weight is needlessly transported, requiring more frequent deliveries, increasing damage to the road, and creating a large carbon footprint from transport emissions. In contrast, generating hypochlorite on site requires only the transport of common sodium chloride salt. On-site generation also eliminates the potential for creating hazardous chlorine gas and cuts transport requirements and carbon emissions by approximately 80% in contrast to bulk hypochlorite.