The Osceola city council approved 5-0 entering a contract agreement with Veenstra & Kimm (V&K) regarding effluent reuse improvements at the new wastewater treatment plant at their Feb. 6 meeting.
The effluent recirculation concept has been a somewhat regular topic at Osceola city council meetings since last summer, with new information provided at the Feb. 6 meeting.
Project recap
The project proposes to recirculate effluent from the new wastewater treatment plant back into the West Lake watershed. The effluent would be recirculated on a periodic basis, such as during the winter months to help bring water levels back up in West Lake, which is Osceola’s only water source. In August, the council approved a professional agreement with V&K to study the recirculation concept.
At a water town hall meeting in October, Osceola city administrator Ty Wheeler estimated that four months of recirculation would see an estimated 43 to 69 million gallons provided, with eight months at 178-276 million gallons, or about 600-800,000 gallons per day. Data has also suggested that the water that would be recirculated into West Lake would be at the same level, or even better, than the current water, as the effluent would be void of nutrients.
A wastewater reuse plan was submitted to the Iowa Department of Natural Resources (DNR) for review in October. For funding, the city would like to use state and local recovery funds through the American Rescue Plan, which must be state revolving fund loan eligible; the city has applied for and been approved for the state revolving fund loan, planning and design loan. The cost last fall was estimated at $16.5 million, with a projected timeline to finish of about two years.
If the effluent recirculation plan is approved by the DNR, it would be the first of its kind in Iowa.
At the Dec. 5 Osceola city council meeting, council approved 5-0 a resolution to take action regarding the authorization, approval and securement of an interest-free loan that could be rolled into a future loan, or retired, and will not exceed $1,000,000.00. This was done on the recommendation of the city’s bond counselor, to allow for flexibility on the project.
Some additional work will have to be done with the recirculation project, including running a pipeline from the wastewater treatment plant to a secondary outfall at a southern finger of West Lake, south of Ivy Street, as well as some modifications done at the treatment plan to include additional filters to treat the effluent.
Findings
Mark Seip with V&K was present at the Feb. 6 council meeting to give a review of the reuse project.
Seip said that V&K had sent responses to the DNR earlier that day, in reply to several “open-ended” questions the DNR had, such as how much chloride (salt) storage will be needed. Seip said it was hard to give a DNR definitive answer, as the amount of chloride storage needed is dependent on different factors.
To treat the effluent, the proposal is that it will go through tertiary treatment steps before going back into West Lake. Part of that treatment would include a reverse osmosis system and the waste stream, or reject, would have a high concentration of chloride waste. What is rejected would be cleaned again to concentrate it more before needing to store the chloride byproduct.
In some locations, the byproduct is discharged into a large river or other water source, but that is not feasible in Osceola.
As the DNR will require the project to have a long-term storage plan for the byproduct, new concepts are being looked into, including drilling an injection well, which Seip said the DNR was open to.
An injection well is a type of well used to place, or inject, fluid underground. The type of injection well that is constructed is based on the type and depth of the fluid to be injected.
While Seip has previously worked with Petrotek, a company that drills reject wells for radioactive materials, he said that similar to recirculation, it’s not something that has really been seen here before.
“We haven’t seen it done in Iowa. It’s common - it’s just like effluent reuse - it’s common in the west, southwest [United States], but this is another one of those issues: how do you get rid of this waste no one wants,” said Seip.
An injection well would either be drilled next to an effluent reuse building, or inside of it. The chloride waste would then be injected deep into the ground, deeper than the Jordan aquifer, and be sleeved, giving the well a 40-50 year lifespan before needing to be re-lined.
To construct an injection well, the work would be done with Region 7 EPA, and would be a separate cost from the recirculation project. The estimated cost for an injection well is between $2-4 million.
City comments
“This has been a bit of adventure, [more] than what we maybe thought it was going to be,” said Wheeler about the recirculation concept during his city administrator report.
Wheeler said the project is now up to about $17 million in cost, as the deep-well injection complicates things more than just capturing and recirculating effluent into West Lake.
Councilman Dr. George Fotiadis questioned at what point the recirculation project loses its cost-effectiveness for the water that would be obtained. He also questioned if it was the same waste stream that would be encountered if they were to drill into the Jordan Aquifer, to make a Jordan Well.
“Even this provides for no growth,” said Fotiadis, in regards to the water that would be produced.
The injection well concept was new to all at the Feb. 6 meeting, and will be looked into more.
Minutes from the Feb. 6 meeting are available in the legal section of this paper.