Over the past few weeks you may have noticed some very foul odors coming from the Wastewater Treatment Plant on East Teton. After extended warm periods, many bodies of water tend to “turnover,” allowing odors trapped in the deeper parts of the pool to come to the surface. This can happen 2-3 times a year. In a lake it is not as noticeable, and typically just contributes to a “fishy” smell. But at the Wastewater Treatment Plant, a turnover can smell much worse.
The City of Green River Wastewater Treatment Plant was originally constructed in 1962 as a single large lagoon. Prior to that, wastewater was discharged into the river with no treatment. As the population increased in the 70’s the large lagoon was divided into smaller ones and the primary aerated cells were added. In the 80’s aeration was added to some of the lagoons and intermittent sand filters were added. This is the current configuration of our Wastewater Treatment Plant, meaning a lot of our equipment is 30 plus years old and the lagoons are older than that.
During the last couple of weeks we did have a mechanical failure on one piece of equipment that led to 2 ½ days of no aeration in the primary cells. This amplified the smell of the turnover event. Something very similar happened two years ago during a turnover event causing a period of foul odors then too. When we have a mechanical problem like this, it can take a while to get the right amount of oxygen back into the wastewater to keep the odors down. Over the last week we have seen the dissolved oxygen concentrations coming back into a more normal range, which has begun to help on the smell. We also have plans to address this in the future.
The City of Green River is currently securing a contract with an engineering firm to design a new Wastewater Treatment Plant that will treat the wastewater in a more efficient manner. The new style plant will not have the large ponds and will not experience the same kind of turnover.
In closing, we are aware of the smells coming from the plant. We are doing everything we can to minimize the smells. During turnover events we would ask for some patience since this is a consequence of the type of treatment plant we currently have. We all live in this great community and want it to be the best it can be.