Is Something Fishy At Donner Lake?

Oct 5, 2015

Donner Lake's popular West Beach.
Credit Amy Westervelt

Donner Lake in Truckee holds some of the largest lake trout in California, but Reno Public Radio’s Amy Westervelt reports that Donner fish might not make for the healthiest meal.

Truckee residents take pride in having their own lake. At only 1.3 square miles compared to Tahoe’s nearly 200, Donner may be small, but the clear, cold lake, ringed by mountains is no less popular for swimming, paddleboarding, and fishing. It also boasts one of just a few sandy stretches in the area.

“Our beach is the community’s beach. Our goal is to keep it as affordable as possible, yet maintain it so it’s safe and clean.”

That’s Dan O’Gordon, with the Truckee-Donner recreation and parks district.

While almost everyone is worried about the long-term impacts of the drought, what most Donner regulars don’t know is that since 2012 the lake has been listed as impaired for various chemical pollutants by the California State Water Board and the Lahontan Regional Water Board. Joy, who has been coming to Donner for decades, is surprised to learn that the water quality here is anything short of perfect.

“Wow, I am shocked. No, I’m amazed.”

In studies conducted from 2006 to 2008, state researchers found high levels of chlordane in Donner. The chemical is a common component of pesticides and was banned in the U.S. in 1988. They also found arsenic and polychlorinated biphenyls, commonly known as PCBs, which are found in adhesives and flame retardants, and were banned due to their toxicity in 1979. Carly Nilson is the interim Surface Water Ambient Monitoring Program coordinator for the Sierra Nevada region. She explains that because arsenic also occurs naturally in the area, it’s tough to pinpoint how much of what has been found in Donner is problematic.

“Arsenic is an interesting one because we do actually have natural sources of arsenic in the Eastern Sierra, but some of the human sources can be paints and dyes and metals and soaps and things like that, and it also can be from certain fertilizers.”

Chlordane and PCBs are persistent in the environment, which is why they’re still around decades after their use was banned. According to Nilson, that could be bad news for human health.

“You can have long-term effects of immune deficiencies, reproductive and nervous system difficulties, and things like that.”

Fortunately, you’re not going to get a big helping of PCBs just from a swim in Donner, even if it’s part of your daily routine, as it is for many locals.

“The only way that you’re going to have this effect is if you’re eating the fish because it is a bioaccumulative pollutant. So just to specify -- if you’re eating it, it’s actually carried in the tissue, and so then it gets carried into your system as well and it gets held onto by your tissues in your body.”

Although there was some media coverage of the state’s safe eating guidelines for the fish in Donner when they were released in 2011, that document was not widely publicized and there has been little public outreach since. In fact, the list of impaired waters in the Reno-Tahoe area is pretty buried on the state waterboard’s website. Nilson is quick to point out that, despite Donner’s impairment listing, the official state guidance still allows for eating fish caught there.

“In Donner Lake, actually, there aren’t any fish that you aren’t allowed to consume – so all fish you’re allowed to consume at least once a week.”

The guidelines for Donner were last updated in 2011 and there are no plans to measure water quality in the lake again in the near future. In the meantime, Nilson says the drought could impact chemical levels in the lake. As shoreline soils dry out and erode, she says they may release previously trapped chemicals. That’s a concern, given how popular fishing is at Donner. O’Gordon lists it as one of the top recreational draws of the lake.

“I’d say number one is just swimming – this beach gets packed, and the 37 public piers along the north side are owned by the Rec department and that’s all just people hanging out on the piers. Second would be stand-up paddleboarding and boating, and third is probably fishing.”

The impaired listing hasn’t made Donner any less popular – due to the drought’s impact on various other fishing and boating spots in the region, particularly Boca and Stampede Reservoirs, the lake welcomed more visitors than ever this summer.

Following is a quick look at the impaired waterways in the Reno-Tahoe region. A complete list is available on the water board's website. 

Some of the best-known waterways in the Reno-Tahoe region are listed as impaired for chemical pollutants.
Credit Info source: Lahontan Regional Waterboard/Infographic: Amy Westervelt