Saturday, July 20, 2024

Deep Dive into FLBS: Sampling for Flathead Swimmers

by Ian Withrow
| July 27, 2022 12:00 AM

It’s predawn in Polson, the sun still tucked behind the towering Mission Mountains as I ease my car into the unpaved parking lot of Boettcher Park. The sky is an array of pastel pinks and ashy blues. A gentle breeze stirs the air, carrying with it the fresh and slightly sweet aromas of the cottonwoods nearby.

Across the park, some thirty yards away on the far side of playground equipment, early morning Flathead Lake waves lap gently against a gravel erosion control beach that runs along Boettcher Park’s public swimming area. On one side of the beach, a dock extends out into Polson Bay, where it will serve as the jumping off point for cannonballs and amateur diving competitions when the morning breeze fades away and the day’s temperatures begin to climb.

You might believe this to be a beautiful moment, and by nearly all accounts it is. But there’s just one thing. Despite my car being the only vehicle in the entire parking lot, and not another human soul in sight, a large area of the park off to my left is alive with movement. Hundreds of black marble eyes peer at me through the early morning haze. I most certainly am not alone.

As I climb out of my car in Boettcher Park, they emerge. Rising from the shadowed grass, an overwhelming number of Canada Geese honking, sleeping, flapping their wings. There must be fifty, no sixty of them, and my reaction to their presence is something akin to Doctor Grant’s when he first bears witness to that Brachiosaurus in the film Jurassic Park.

But I can’t stand in awe for too long. I’ve come to Boettcher Park on this early morning for a reason, and these geese (combined with forecasted hot temperatures on the horizon) are very much involved. Grabbing a cooler housing several sterilized water sample bottles, I gather as much of courage as I can muster, and defiantly make my way to the public swimming dock.

For over half a decade, the Bio Station has played a collaborative role alongside the Flathead Lakers, Confederated Salish & Kootenai Tribes, and Flathead Lake Open Water Swimmers (FLOW) to support a public swimming area monitoring program called the Swim Guide Project.

Originally started by Polson resident and FLOW founder Mark Johnston, this community organized and funded program is now overseen by the Flathead Lakers, and delivers free, real-time water quality information about Flathead Lake samples analyzed at the Bio Station. This water quality data can be found on the Swim Guide website ( and Smartphone app along with over 8,000 beaches, lakes, rivers, and swimming holes all over the world. This helps people find nearby public swimming areas and know at a glance if those areas are safe for swimming.

What determines whether or not water is safe, you ask? That’s where the geese come in. The factors that make an area attractive for humans also apply to local wildlife. This is why you often see large gaggles of geese loitering around waterfront parks, and geese—much like myself, on the rare occasion—tend to go to the bathroom in less than convenient places.

The geese are not to blame for this—they are, after all, just doing what geese do. But all animal waste, including that of geese and humans, contains bacteria known as Escherichia Coli. Harmful if ingested, E. Coli can be in otherwise clean swimming areas, especially on hot, stagnant days or after periods of heavy rainfall. Montana Department of Environmental Quality’s threshold for safe swimming is 235 E. Coli per 100 ml of water. The Confederated Salish and Kootenai Tribes’ threshold for Flathead Lake is more conservative, at 32 E. Coli per 100 ml of water.

Through the Swim Guide Project, Citizen Scientists collect samples weekly from public swimming areas around Flathead Lake. These samples are then brought to the Freshwater Research Lab at the Bio Station, where E. Coli bacteria are quantified. The results of these analyses are then sent to the Flathead Lakers, which uploads the results to the Swim Guide website and app for public use.

When the Swim Guide first began, it monitored the water quality of three public beaches. Today, monitoring sites include: Riverside, Boettcher and Salish Point Parks in Polson; Wolf Point, Elmo and Blue Bay Tribal Parks; Volunteer Park in Lakeside; Somers Park; the City Dock in Bigfork; Flathead Lake State Park – Wayfarers, Woods Bay, Finley Point, Big Arm, West Shore and Yellow Bay Units; and the Bio Station’s shoreline.

Each week, a Citizen Scientist volunteer from the Flathead Lakers takes a lap around Flathead Lake and collects a majority of the Swim Guide samples. Gabriel Bourgeois, an FLBS intern in the Freshwater Research Lab, collects samples from the Bio Station sites.

My job is to sample one site, and one site only: Boettcher Park in Polson. Which is why I’m here on this early morning in July, hilariously outnumbered by waterfowl as I pop open the cooler at the end of the dock.

To prevent contamination and ensure an accurate bacterial count, each sample bottle must be opened for the first time underwater, well below the surface. Lying with my hips on the edge of the dock, I lean down, and plunge my arms and the sample bottle into the water. I unscrew the lid, wait until the bottle has filled completely, then screw the lid back on while it’s underwater. I pull myself up, dry the surface of the bottle, and using a black Sharpie write the date, time, and location of the sample collection on a piece of tape that wraps around the bottle.

Setting the full bottle back in the cooler, I grab another unopened sample bottle and repeat the process. Should the first sample reveal extremely high levels of E. Coli, this second sample will undergo DNA analysis by FLBS Professor Matt Church’s lab to determine if the source of the E. Coli is human waste.

Odds favor that any E. Coli will be goose-related, but if the levels are high, the team in the lab is prepared to use DNA to determine the source. Human waste could get into the lake from a cracked sewer line or a faulty septic system.

With both samples collected and safely stowed away, I get to my feet and shake the cold lake water from my hands. Now it’s off to the Bio Station, where the Flathead Lakers Citizen Scientist will soon be dropping off over a dozen samples from swimming areas around Flathead Lake. The samples head into the lab for analysis, and my role of amateur scientist is finished for the rest of the week.

It’s not heroic work. It is, by all accounts, some of the simplest sample collection done at FLBS—which may or may not be why I’ve been entrusted to sample a single site for the 2022 Swim Guide Project. And yet, when the job is done each week, I do feel a strong sense of fulfillment. Invigorated by the knowledge that I’ve played a small part in keeping watch over Flathead Lake, and that my modest effort will help others know for certain that their friends, family, and neighbors can play in our pristine waters, worry-free.

The sun is high as I write this, and from the FLBS harbor I can see families swimming and playing in the water off Yellow Bay State Park. A quick glance at the Swim Guide app tells me that the E. Coli count in that water is nominal, well below the safety standard. It’s a perfect afternoon for fun in the sun on the shores of Flathead Lake.