by Phillip Manning ~ September 23rd, 2015
The Talkeetna sewer lagoon has had its share of difficulty this year. In July and August, the amount of dissolved oxygen in the treated water was too low, and the amount of fecal coliform bacteria was too high. Now, efforts are underway to try to get the system back into balance.
Terry Dolan, Director of Public Works for the Mat-Su Borough, says that fecal coliform measurements for September are not complete, yet, but that dissolved oxygen is back within compliance. Oxygen is part of the natural process that the lagoon uses to breakdown unwanted bacteria in the treated water. Last month, borough staff began using pumps to introduce more air into the mix in the hopes that the system would come back into compliance.
Dolan says the system, when working correctly, should not need aeration, but that issues of oxygen transfer, lack of ultraviolet radiation, and other factors caused the lagoon to start underperforming. It is his hope that the system will once again operate at equilibrium once the numbers are brought back into line.
Two tests for fecal coliform were conducted last month. Terry Dolan says the first test came back with a result of more than seventy times the allowed amount. He says that number is consistent with wastewater when it flows into the lagoon, not out of it. Dolan says he does not know how that sample was taken, since a contractor did the collecting. He ordered a second test, which was still out of compliance, but was lower than the first result by more than an order of magnitude. Dolan says the first result cannot be ignored, but that a jump to that level of fecal coliform indicates something was wrong with the data.
Kara Kusche with the state Department of Environmental Conservation says the Talkeetna lagoon has been issued a notice of violation to the borough for the levels of fecal coliform and dissolved oxygen for eight out of the past sixteen months. Kusche said in an email that the state is aware of the corrective action the borough is taking, and that everyone hopes it will be successful.