Storm events present challenges for wastewater treatment facilities every year, and this year has been no different for communities across Minnesota. The MPCA would like to recognize the city of Mora for investing in its wastewater infrastructure and thank its wastewater staff for their efforts in responding to a July 2018 storm event. The combined efforts directly helped protect environmental and human health.
On the morning of July 12, Mora received 8.25 inches of rain in about 3.5 hours. Seven Mora staff members worked continuously in response to the rain event, and as a result no sanitary sewer overflows or releases were reported.
“Having knowledgeable and reliable staff is the main factor to all of this. Everyone remained calm, even at times when it seemed to be overwhelming, going above and beyond to help and accomplish what needed to be done safely,” said Joe Kohlgraf, public works director for Mora, a city of 3,571 in central Minnesota.
In addition to having capable staff, Mora completed a significant wastewater infrastructure upgrade in 2017. A little more than $7 million in state funding helped finance the upgrades, which also results in far less phosphorus in its discharge to the Snake River.
Kohlgraf identified three actions that kept everything up and running during the recent storm:
- New main lift station capacity. “Our old pump set-up consisted of three pumps that would do about 1,600 gpm [gallons per minute] and would not have kept up with this storm event. Our three new pumps were pushing around 2,200 gpm and kept that up for the majority of the day. Without this upgrade, we would have been calling the duty officer and bypassing,” he said.
- Replaced old boat clarifiers with new clarifiers. Had the old boat clarifiers been in place, the ability to perform wastewater treatment would have likely been compromised.
- Back-up power at main lift station. The new generators would have allowed operations to continue even if the power had been out for an extended period.
Following the storm event, Mora is continuing to focus efforts on reducing inflow and infiltration within the collection system. “We are currently scheduling sewer smoke testing to improve our system and pushing our sump pump policy again to keep issues like we had in this event to a minimum in the future,” Kohlgraf said.
The MPCA would like to thank Mora wastewater professionals, and all statewide wastewater professionals, for their dedication and commitment to improving the environment and enhancing human health.