Last week the Natural Resources Board (NRB) visited the Northwoods, making stops around the area to receive updates from various groups.
One of those stops was at the town hall in Manitowish Waters. There the NRB learned more about the issues with Dead Pike Lake and its iron floc problem. The Dead Pike Lake Association has been working for decades in an attempt to resolve these issues, but to no avail until recently.
Dead Pike Lake, the association said, is being adversely affected by the system of ditches and dykes created by the precursor to the DNR back in the 1950s.
Last spring, in a weeklong charette, a revision of the Powell Lake Master Plan was completed in hopes of addressing those issues as part of the overall plan revision.
The town of Manitowish Waters became involved, offering whatever assistance they could to the association. Eventually the Dead Pike Lake Association was approved for a large grant to cover the costs of having a neutral third-party environmental company complete a study on Dead Pike Lake and the effects on the lake the ditch and dyke system in the marsh may have. Last week the NRB received an update on that research from Steve Apfelbaum of Applied Ecological Services.
Apfelbaum explained the scope and schedule of the project to the board and others in attendance. Work ongoing from May to October has been largely reviewing prior reports and existing data. From October to January 2018, the next steps will be to create a complex model to evaluate existing and future conditions of Dead Pike Lake and the Powell Marsh. From January through March 2018 a matrix of possible solutions will be tested and refined using the model. From there a preliminary cost appraisal can be developed for each possible solution. Solutions will be ranked and prioritized, he said, with a final report summary due in March.
He summarized his findings to date and helped the board better understand how the conditions on Dead Pike Lake came to be as problematic as they are now. He also included bog ecology and disruptions in that ecology. Bogs, Apfelbaum said, develop aquicludes to groundwater recharge. An aquiclude is defined as a solid, impermeable area underlying or overlying an aquifer. Bogs, he said, recharge surface and groundwater only at their margins. However, ditching can disrupt.
"One of the things we learned about immediately is how the Powell Marsh has been altered and based on the literature about marsh and bog ecosystems, we learned very quickly what one of the prevailing sources of the iron is," Apfelbaum said. "It turns out that during the process of bog formation, wild fires and the accumulation of plant material over time and inorganic substances washing into a bog seals the bottom of the bog and creates an aquiclude." Once the peat layer forms, he said, water moves so slowly that bogs are not a place where there is groundwater discharge occurs.
"What we've learned is that bog bottoms are sealed, typically," he said. "What happens when you dig shallow ditches where the acidic surface water, and pH in some of these bogs are upper 3s and low 4s. Seven is neutral, he said. Four is about the acidity of undiluted vinegar. When you isolate pH4 water, it stays put. Bogs are totally internally drained, so the acidity builds up. As soon as you dig a deep ditch, which is what occurred at the Powell Marsh, what happens, as soon as you break the seal, the acidic water from the peats goes into the ground water." This puts a charge on that ditch water, he said, and that pushes into the ground water. As the ditches are drawn down near mid summer, the ground water reverses and starts discharging into the ditches. Along with that comes the iron and other materials that have been solubilized.
As soon as they hit oxygen, he said, they precipitate. Armed with this information, stakeholders could then come up with a list of possible solutions, both for Dead Pike Lake and the Powell Marsh itself.
Apfelbaum said the first step was to set aside the master plan and start with a blank slate. He looked to see what solutions have been used when this exact problem has been encountered in other places. Several of the solutions he has found include liming the lake, altering the lake level to reduce influx of groundwater and allowing beavers to re-dam the outlet. The preliminary list for the Powell Marsh included doing nothing, re-wilding the marsh by removing the ditches and old railroad grades, creating a diversion in the West Culvert and creating an alternative modified master plan. All of these, he said, are possible solutions that will be run through his model and tested to see whether they are viable solutions.
While Dead Pike Lake was recently put on the list of impaired waters due to its phosphorus content, there is no state standard for iron, Apfelbaum said. For that reason, this project is unique and different. Rather than follow a regulation delineating acceptable levels of iron for a water body, AES will use science to determine what is acceptable.
"From there we let regulations catch up with the science," he said. With that in mind, this study could have wider reaching implications for other bodies of water in the state. The science could show how many parts per million would affect various organisms in lake waters. Apfelbaum said there are no standard tests right now, either, so results can't be certified. For that reason, he said, it was important to look at this study a bit differently.
Deputy director Kurt Thiede addressed the group as well, to speak of the department's commitment to addressing the problem in Dead Pike Lake. Actions, he noted, speak louder than words and he hoped the actions the DNR has taken in recent months helped the Dead Pike Lake Association see they were committed to finding a solution.
"I have good relationships with former DNR secretary Cathy Stepp, deputy director Kurth Thiede and Senator Tiffany," said Manitowish Waters town chairman John Hanson. "He has been instrumental in moving this process along. When I first got involved, there was virtually no communication between Dead Pike Lake and the DNR. I mean, they were just miles apart. They (the association) were working with the wildlife division people, and they have a different perspective on what's going on than the water people. So I think a breakthrough was getting Dan Helsel involved in this - the water specialist - because he's got a different perspective."
Hanson said a trust was being built through a series of meetings. He has seen changes in interactions among the groups involved and felt sure a viable solution was finally at hand. That sentiment was echoed by the lake association.
"We couldn't be more pleased with the direction things are going," said Gale Wolf of the Dead Pike Lake Association. "We're positive. One thing I think is unique is we have a creativity that is going on. In the absence of a standard for iron, what they did is turn this regulatory process around. Instead of establishing the regulations and having the science follow it, let's turn that around."
Wolf felt very positive about how the study was being conducted by AES and that the outcome would be something that would be a win-win for both the lake and Powell Marsh.
Beckie Gaskill may be reached via email at email@example.com.