Septic systems not sole cause of Lake Osakis pollution
Editor's note: The following information was provided by the Minnesota Board of Water and Soil Resources.
Inspections of septic systems around Todd County lakes indicate that they're not the culprit of pollution.
This summer's round of septic system inspections on properties ringing eight Todd County lakes will bring to 25 the number of lakes inventoried since 2011, including Lake Osakis.
The cumulative $811,760 budget includes five rounds of Clean Water Fund grants from the Minnesota Board of Water and Soil Resources.
The results help gauge lakes' health, determine pollution sources and encourage septic fixes.
Inventories targeted phosphorus-sensitive lakes — those the Minnesota Pollution Control Agency identified as most likely to become significantly murkier if nutrient loads increased.
So far, data collected has cleared lakeshore property owners of being the biggest source of pollution — and in one case killed an idea to build a giant collection pipe around a lake.
It also eased tensions.
"What we've got is shoreland people and farmers. There's a dynamic among those groups that needed work," said Todd County Soil and Water Director Tim Stieber. "They were kind of blaming each other."
Stieber said the inventories replaced suspicions with facts.
"By going around the lakes, we can ensure the shoreland people are doing what they're supposed to be doing," Stieber said.
The inventory covered 17 lakes from 2011 through 2016. Less than 5 percent of the 2,329 properties researched during that period were out of compliance. About 12 percent were awaiting final test results. The remaining 83 percent were compliant.
"Especially with the Sauk River Watershed, those lakes are not the greatest of lakes. The Sauk River is polluted. The headwater, Lake Osakis, is polluted — 7,000 acres of pea soup. It's an incredible fishery, but I can't believe a lake that large is in that bad of shape," said Chris Arens, Todd County land use planner.
"The thought was that one of the large contributors to that was the septic systems around the lake because it's highly developed," Arens said.
On some lakes, compliance was as high as 94 percent.
On Lake Osakis, 86 percent of the 335 septics inspected were found in compliance initially; 14 percent were subsequently updated. (Because inspections are valid for only three years, the county cannot assume that 100 percent of the septics are now in compliance.)
"Yet the water quality seems to be doing worse," Arens said. "I think lakeshore owners get a bad rap. I'm a lakeshore owner myself. I want my water quality to be great and I want property values to be high."
In Todd County, only a triggering event such as a property sale or building permit requires an inspection and upgrade. The county keeps a record of failed septics.
In the short term, the whole-lake inspection approach has resulted in landowners willingly upgrading.
"This has helped us to get people in compliance because they know we've gone around the whole lake," Stieber said. "It's like a group thing."
Arens is dividing this summer's inspection duties with one other employee.
The process works this way:
A landowner receives a notification letter. If they're home when he arrives, Arens explains what he's about to do — collect soil borings from a 3-inch-diameter hole he'll bore near the drainfield. His tools: tiling spade, post-hole digger, pry bar, 3-inch auger with extensions.
If the landowner isn't home, Arens leaves a hand-written note explaining what he's done and asking them to have the tank pumped and inspected. Grant dollars allow Todd County to reimburse landowners up to $125 for that service, which is the second part of the inspection.
If the two-part inspection shows a failing system, landowners are asked — but not required — to hire a licensed subsurface sewage treatment system designer to devise a replacement.
"We are making sure that each of the systems around the lakes is built to specifications. If they are, we know they're protecting water," Stieber said.
People live around all but about 35 of Todd County's 118 lakes.
The summer 2017 work will leave the county only 10 lakes shy of surveying all of those the MPCA classified as highly phosphorous sensitive. That's the next potential grant target, although it's more elusive because the remaining lakes are scattered, not tied to a single watershed.
The $811,760 received to date includes $529,674 in CWF grants, and $282,086 in matching dollars from landowners and the county. It has involved the Sauk River Watershed District, and spawned related grants to help low-income residents upgrade failing systems.