Rick Susfalk

Peering into the nearshore’s shallow waters

Most of Lake Tahoe’s visitors swim and play along the lake’s 72 miles of shoreline. That’s also where most pollutants enter, and where a degradation in water clarity is most apparent.

While other scientists study Lake Tahoe’s water clarity in deeper waters, Rick Susfalk, an associate research scientist from the Desert Research Institute (DRI), peers into the shallow depths of the lake’s nearshore area to learn more about how pollutants are affecting where visitors play everyday.

“When we start seeing degradation, we’ll see it first in the shallower nearshore area,” Susfalk said. “We can get a better handle on it because the particulates are so much more concentrated.
Offshore it’s too dilute to be easily measured.”

Impervious surfaces, like roads and parking lots, don’t allow these pollutants to soak into the ground. Rather, they funnel pollutants into storm drains and streams, which then enter the lake if not treated. The pollutants not only cloud Lake Tahoe’s renowned clarity, but can also upend the lake’s ecology. Sediments can add more nutrients like phosphorus to the lake, which can then lead to algae growth. With enough time, Lake Tahoe’s clarity could diminish.

To prevent that from happening, Susfalk is part of a multi-institutional group of scientists working to develop a long-term monitoring program for the nearshore regions. “To solve the problem of water quality,” Susfalk said, “you not only have to look at where the pollutants are entering the lake, but also the onshore factors that create and move the pollutants toward the lake.”

Measuring the clarity of the nearshore requires monitoring buoys and a 21-foot-long jet boat that has no propeller. Both the monitoring buoys and the jet boat contain on-board measuring instruments that can give a real-time reading of the water. An example of one of the measurements is turbidity, a measure of the amount of light that gets reflected back from the particles in the water.

But the existing instruments pose issues of their own. Rick is working on developing and acquiring instruments that are more sensitive and suitable for Lake Tahoe’s clear waters.

“One of the problems with measuring pollutants in Lake Tahoe is that the water quality is so good that many traditional methods and instruments are unable to measure the low concentrations present in the lake,” said Susfalk.

Rick hasn’t always worked with water quality. His previous work in the Lake Tahoe area investigated nutrient transformation and transport through forested and developed areas. Susfalk studied the
nutrient cycles in the soils and vegetation of the upper watersheds and in developed areas where pollutants would gather before potentially streaming into the lake.

Susfalk has a background in chemistry but early in his career, he felt driven to work more in the field rather than in a lab. Now as a research scientist at DRI and an adjunct faculty member at the University of Nevada, Reno, Susfalk spends time in both settings, but with the bonus of Lake Tahoe’s scenic background.

“I decided if I was going to work 80 hours a week, I would rather work outside in the environment than a smelly chemistry lab,” Susfalk said. “I like to understand what I see around me. And you can’t go wrong working at Lake Tahoe.”