Nevada Rural Water Assists Utility with Decontamination

MIDAS, Nev. – When the Midas Water Cooperative in rural Elko County, Nev. tested positive for total coliform in repeated samples, they contacted the Nevada Rural Water Association for assistance.

Aaron Hughes, a training specialist with the Nevada Rural Water Association, visited Midas to help inspect and disinfect the system.

“I started by conducting a survey of the #1 wellhead, tank, the chlorination system and the sanitary condition of the well house,” Hughes said.

The well and tanks showed no signs of breaches or leaks. The ladder was locked, hatches sealed, concrete pad for the tank had no visible cracks, the overflow was properly protected, the water level target in working order and sample cabinet locked. However, when water from the tank was tested, there was no chlorine residual.

“We determined the chlorination system was broken, but Well #2 could supply chlorination for the system,” Hughes said.

Hughes and Midas General Manager Gene Casci isolated the well from the rest of the system and began to shock chlorinate the well. Since the process required four to six hours of contact time, Hughes and Casci began working on Well #2.

“The chlorinator hadn’t been in operation,” Hughes said. “It was working, but needed fine tuning for the system.”

Hughes provided training on dosage and how to use the utility’s testing equipment to determine and maintain the appropriate dosage. Water treatment equipment must be controlled so the amount and the timing of chlorine added, ensures the chemical reaches an appropriate level for a long enough time to be effective.

After the appropriate contact time, and with the chlorine feeder operating correctly, they began flushing the wells and testing the chlorine residuals. When the water tested at the required levels, the disinfection was complete and testing showed “coliform absent” results. Assistance from the Nevada Rural Water Association helped return the water utility to routine monitoring and provided the operations specialists with better training to understand and control their system.