On Jan. 23, there was significant flooding at the Rawlins Wastewater Treatment Plant. While the flooding started after a breaker was tripped, city officials are still unsure of the cause.
One major safeguard against flooding events at the plant is an automatic gate system, which is supposed to close off the area where flood waters could enter the plant. During the Jan. 23 event, this gate system did close automatically when the power was lost. This prevented untreated water from entering the plant.
“The recirculated water was the source of flooding because we did not have the same gate system for our recirculation line,” said Mira Miller, community relations coordinator for the city of Rawlins. The recirculation line takes water from the aeration ponds and brings it back into the plant for a second cleaning, which helps keep the treatment bacteria healthy. In a statement, city officials stated that they intend to install an automatic gate system for this recirculation line. It’s seen an increase in use after the upgrade to the aeration system.
“In regards to our electrical system, our generator is in good shaped. It was purchased in 2016 and tests itself every Tuesday,” Miller added. For an unknown reason, the main breaker tripped and the generator’s electricity was not able to flow into the system. City engineers and electricians are working on solving the problem to prevent this from happening in the future.
When the break was tripped, an alarm did sound. This alarm indicated a major failure and that immediate action was required. City staff cleared the alarm remotely without taking appropriate actions. In order to prevent this mistake from happening in the future, the system is being modified so that the alarm cannot be cleared remotely. A staff member will now be required to go on-site to clear any alarms.
A second round of alarms was supposed to go off in the event of high floodwaters. Although these alarms worked during routine testing, they did not go off during the Jan. 23 flooding. Electricians are also investigating this issue.
The wastewater treatment plant has standard operating procedures that will be upgraded and clarified. The city will also invest in more in-depth training of staff.
Miller noted that the flooding of the wastewater treatment plant did not impact water quality or systems throughout the city, and that everyone could continue to use water, flush, and shower as normal.