Rumor has it there’s a rumor in town

By some default of the human genome, we seem programmed to spread rumors. It often seems that the harder you work to dispel these false narratives, the more tenaciously they cling.

Last week, my son and I spent an afternoon at Tanners Lake in Oakdale, where we set up a family-friendly water pollution mystery game. When I shared the event in a community Facebook group, dozens of people responded to voice their opinions about Tanners Lake.  They bemoaned a polluted lake and litter-strewn beach with barrels floating in the water, used syringes in the park, and chemical contamination. One woman said she wouldn’t swim there if it were the last beach on earth. Another person suggested that the mafia might even be dumping bodies in the water.  I began to wonder if I should be holding a family event at such a terrible place.

Tired of crowded beaches? Head to Oakdale and you’ll get this gorgeous stretch of sand all to yourself.

Two days later, I arrived at Tanners Lake Park and found a few dozen older adults playing pickleball in a tennis court. The sun was shining on a perfectly manicured lawn, and I could see a baseball diamond, basketball court, volleyball pit, and playground as well. Everything was in tip-top shape. We walked through a beautiful and lovingly-tended raingarden on our way down to the beach and stopped to admire blue flag iris, milkweed, sedges, and river birch. The beach was clean and the water was so clear that we could see bluegills guarding nests on the bottom of the lake. I looked around suspiciously for litter and graffiti, but was reassured to find none.

Tanners Lake is part of the Ramsey-Washington Metro Watershed District (RWMWD), and the district has worked hard to improve and protect water quality in the lake over the past 20 years. In fact, Tanners was one of the first lakes in Minnesota to be removed from the state’s impaired waters list (in 2004) after phosphorus levels went down and algae stopped being a problem. RWMWD currently operates an aluminum sulfate (alum) treatment facility on the north end of Tanners Lake that treats incoming stormwater runoff before it enters the lake. The alum causes the phosphorus to precipitate out and settle into a sedimentation pond instead of flowing into Tanners. As a result, the lake gets high marks for good water quality and clarity compared to most metro area lakes.

Dive in – the water at Tanner’s Lake is clear!

Between the beach and a fishing pier at Tanners Lake, my son and I encountered a small bay filled with white water lily and duckweed. “The water is super polluted!” my son announced. “Look at all the algae.” As we waded into the bay, however, I explained why that is a common misconception. Duckweed looks like algae when it is floating on the water, but if you scoop your hand in to pick it up, you’ll find that it has little tiny leaves with roots dangling below, sort of like a miniature water lily. As the name suggests, duckweed is good food for ducks and geese, and both duckweed and water lilies provide good habitat for fish and waterfowl. In fact, the day after we visited, a lucky angler caught a 65-pound sturgeon in Tanners Lake!

As we whiled away a summer’s afternoon, I grew more and more enamored with Tanners Lake Park. My son swam for two hours, chasing bluegills and playing Marco Polo with a group of patient teenagers. The pickleball players gave way to teens shooting hoops. A father and son chased each other around the park on scooters, and couples sat on benches talking quietly while gazing at the lake.

To be fair, Oakdale has its share of water quality concerns. Chemicals dumped at old waste sites operated by 3M during the 1940s and 50s eventually leached into the groundwater and contaminated public and private wells in Oakdale, Lake Elmo, Woodbury and Cottage Grove. PFOS and PFAS have been found in Raleigh Creek and Battle Creek, and the Minnesota Department of Health has issued an advisory to avoid eating fish caught in Lake Elmo due to PFOS. At the moment, however, the only water quality concern affecting Tanners Lake is a chloride impairment caused by salt washing off roads into the lake. The salt makes it hard for some species of fish to survive and reproduce, but does not affect human health or safety while fishing and swimming.

Native spiderwort blooms on the shore of Tanners Lake.

At the end of our Tanners Lake day, my husband met us for a picnic dinner in the park. We watched the sun slowly paint streaks of pink across the sky as we munched on tacos and tortas. A handful of boats bobbed in the water trailing fishing lines behind. The native spiderwort along the shoreline closed its brilliant purple petals for the evening as the sounds of giggling children floated in the air. We looked at each other and shrugged our shoulders. Despite the bad rumors about Tanners Lake, we all agreed that the park and lake are pretty great.