Osceola Water Works recently sent letters to customers regarding the non emergency issue of two drinking water violations after routine monitoring in August.
Water samples from August showed that 37 percent of turbidity (cloudiness) measurements were over 0.3 turbidity units. Standard requirements is no more than 5 percent of samples can be over 0.3 turbidity units per month. A water sample from Aug. 10 revealed levels of 1.9 turbidity units, where the standard is 1 turbidity unit. The higher levels of turbidity increase chances of the water containing disease-causing organisms.
While turbidity itself is not a concern, it can be troublesome for the disinfection process giving aid in microbial growth. Such organisms include bacteria, viruses and parasites which can cause symptoms of nausea, cramps, diarrhea and associated headaches.
None of the testing showed any disease-causing organisms in the drinking water.
“We have two intakes in the lake and we never really use the lower one but that’s what we did to try to get away from the algae,” said Brandon Patterson, Osceola Water Works Superintendent.
Osceola Water Works and the Iowa DNR have determined that the problem occured due to a large blue green algae bloom in West Lake, which is Osceola’s source of drinking water. A second sourse of turbidity was found to be an increase of manganese in the water.
“We took samples at the lower level and we were better with the algae but that’s where we had the trouble with the manganese because it tends to be lower in the water,” said Patterson.
After adjusting the treatment processes and adding sodium permanganate Osceola Water Works has been in compiance since Aug. 19.
“We’re still seeing issues even though we’re back in compliance. Unfortunately we’re probably looking at some plant upgrades to be able to treat these problems that we’ve had with our source water,” said Patterson. “Every year it seems like our source water at West Lake is worsening... We’re probably at the point where we need to be putting in some system upgrades.”
The row crop around West Lake and the nearness of the lake to the treatment plant a big part in the issues with the source water. When treatment plants are farthur from the source water it allows the water to have more space to be filtered.