Citizen scientists tracking bacteria in Rehoboth Beach lakes

In an effort to provide data to state and local officials to make informed decisions, a group of citizen volunteers have been cataloging bacteria levels in Rehoboth Beach’s three freshwater lakes for three years.

The morning of Aug. 20, the two volunteers were former city Commissioner Jay Lagree, who can see Silver Lake from his house, and Save Our Lakes Alliance 3 President Rick Hardy, who lives off Lake Comegys. Other volunteers include longtime property owner Ken Konesey, who lives near Lake Gerar, and current city Commissioner Craig Their, who lives near Silver Lake.

“We love the lakes and we want them to be as healthy as possible,” said Lagree.

Lagree and Hardy were efficient in their data collecting, stopping at four spots in about 40 minutes. There were two samples taken in Silver Lake and two in Lake Gerar. Hardy had already gotten the Lake Comegys sample on the way to Lagree’s house.

The data is collected once a week, spring to fall, and the process is the same at each location. A bucket of water is pulled from the lake to measure pH levels. A meter is dipped into the lake to measure dissolved oxygen, dissolved oxygen percentage, specific conductance, salinity and water temperature. A Secchi disk is dropped into the lake to measure depth and turbidity. A sample of the water is taken from the bucket, labeled and placed into a cooler with ice to be tested for bacteria. The same thing is done at all three lakes.

There are varying opinions on how healthy the lakes are, said Hardy. Collecting data and applying scientific analysis allows the different organizations to see firsthand, he said.

The current group of volunteers in Rehoboth is a small part of a statewide effort, and it’s not the first time data has been collected in the lakes.

Ed Whereat, University of Delaware Citizen Monitoring Program coordinator, oversees that effort. Before 2017, he said, occasional sampling was performed within the Rehoboth lakes at the request of the state in response to fish kills or algae blooms. In 2017, a resident volunteer began regular monitoring in the summer season, followed by a high school student in 2018. After a lull of a few years, a partnership with SOLA3 was formed.

If it wasn’t for the consistent monitoring effort by the volunteers over the past three years, there wouldn’t be much attention given to monitoring the water quality in the lakes, said Whereat. The data is shared with the Delaware Department of Natural Resources and Environmental Control, providing valuable information at a minimal cost.

“A shared goal is the development of a management plan involving the municipal partners,” said Whereat. “This will involve more attention to improved stormwater and shoreline management, and the incorporation of the lakes into a more formal water-quality assessment structure, guided by the state and [Environmental Protection Agency].”

Between the three lakes, there are 42 storm drains. It’s an ongoing challenge, but Lagree said the lakes are doing vitally important things. He said sediment found in stormwater has a chance to settle before being flushed out into the ocean, and the lakes collect water in the event of a huge storm, which helps with flooding.

Lagree said he thought they were on the edge of having enough data to begin to make those informed decisions. There’s a feeling the lakes can’t be healthy, but that’s not the case, he said.

In general, said Whereat, the amount of enterococcus, which is the bacteria the state measures to issue recreational water advisories, exceed levels for safe swimming, but are within limits for paddling. It does not appear the lakes contribute substantially to the bacteria levels on the ocean beaches, he said.