For the last two years, Bigelow Laboratory for Ocean Sciences has worked with the Boothbay Region Water District to monitor the health of local drinking water supplies. The results to date confirm what many Boothbay residents and visitors already know: Maine continues to enjoy and benefit from healthy ecosystems and clean water.

The ongoing partnership also highlights the value of consistent monitoring and vigilance to help communities proactively respond to issues before they threaten the water supply.

“We never want to get to a point where we’re surprised or suddenly unable to use our water system because a problem emerged without us realizing,” said Rachel Sipler, a senior research scientist at Bigelow Laboratory and director of the Center for Water Health and Humans. “This work provides data to help our leaders strike a balance between keeping our ecosystem healthy and ensuring our businesses and community thrive.”

The relationship between the Water District and Bigelow Laboratory evolved out of the Clean Drinking Water Initiative, a region-wide effort by several nonprofits and municipal governments to maintain the health of Boothbay’s freshwater reservoirs. Bigelow Laboratory’s role in that partnership has been to collect and understand a suite of water quality data, leveraging the institute’s expertise and analytical capacity. Additionally, the institute brings longstanding experience in ecosystems across the world, allowing its scientists to contextualize what’s happening in Boothbay’s waterways.

“We have the experience and data to know what a healthy system looks like,” Sipler said. “We can help the community understand the dynamics of our watershed and provide the data needed to make science-informed decisions to preserve and improve the health of our watersheds.”

“This partnership between BRWD and Bigelow Laboratory provides the necessary data to support water quality assurance. One way we are leveraging this data is to seek grants which allow BRWD to be proactive rather than reactive in our efforts,” said Rebecca Jacobs, the natural resources program manager at BRWD, pointing to the Adams Pond Road realignment and buffer project as an example. “This and future projects promoting best practices will help ensure our current water quality standards. Bigelow Laboratory’s continued analysis will provide the data to reaffirm these efforts.”

Monitoring Water Health

Every week from May through October, Bigelow Laboratory scientists have monitored seven sites across Adams Pond and Knickerbocker Lake.

Testing thus far has focused on three indicators of water health.

The first is cyanobacteria, more commonly called “blue-green algae.” Cyanobacteria are a normal part of any lake ecosystem, but can become a problem when they grow out of control or produce toxins.

The research team, including Research Scientist Robin Sleith, has been using environmental DNA tools to track the abundance of cyanobacteria in Adams and Knickerbocker lakes, as well as other bodies across the region, and test whether the species present have the genetic capacity to produce toxins. The results from the Boothbay reservoirs, Sleith says, have been promising on both fronts.

“There is evidence that species in other lakes in the region have the genetic capacity to produce toxins, and we’ve seen that blooms can crop up as temperatures warm, so we’re staying vigilant,” Sleith said. “That said, we haven’t detected blooms in Adams or Knickerbocker these last two years, and the species we’re seeing here aren’t producing any of the common cyanobacteria toxins.”

Sleith adds that the eDNA tools they’re using have the advantage that they will be able to retroactively test this archive of samples for other organisms if new questions arise in the future.

Led by Senior Research Scientist Peter Countway, the research team is also using molecular tests to monitor for human and animal-associated bacteria that could indicate septic system leaks or risks from fecal contamination or contaminated runoff. The team is still working through the data collected this summer, but Countway says the samples from 2024 all tested negative for the human-associated Bacteroides bacteria.

“Traditional water quality tests can indicate the presence of bacteria like E. coli, but tell you nothing about where it came from,” he said. “The microbial source tracking we’re doing is an improvement in that it can reveal the source, differentiating pathogens that come from, say, humans versus birds.”

Although his lab is able to track several bacterial markers, Countway says this particular test is what made most sense given the region’s particular water quality concern. It’s also the go-to method approved by the EPA and has a useful system for ruling out false negatives.

“There was also no indication of false negatives, which is great because it gives us a lot of confidence that all of the samples were truly negative for the type of human bacterial contamination we targeted,” he said.

Finally, the team is monitoring all sites for several of the most common PFAS chemicals, a family of synthetic compounds often referred to as “forever chemicals.”

“Our analytical system is so sophisticated that, realistically, we can detect some amount of PFAS in every sample we analyze," said Senior Research Scientist Christoph Aeppli. “Yet, our data shows that levels at the intake for our reservoirs are well below the current drinking water limits.”

EPA’s drinking water standard for PFOS and PFOA, two of the most common chemicals, is four nanograms per liter — roughly equivalent to just a pinch of salt in an Olympic-size swimming pool (which, Aeppli adds, is already significantly more conservative than the thresholds for non-drinking water). The team has measured PFAS concentrations consistently below that threshold across multiple seasons and depths.

“The data so far have been reassuring, but we’re continuing to sample to track the small inputs of PFAS that are still making their way in the reservoirs,” Aeppli said. “To really ‘future-proof’ our system, we need to understand what all the inputs are so our community can make informed decisions about how to keep the clean water we have.”

The relationship between the institute and the agency is going strong, and the team is already planning for next year’s monitoring season. It’s just one example, Sipler says, of how Bigelow Laboratory is working to support the local community.

“We drink this water. Our children swim in this water. And we shop at the businesses that rely on this water,” Sipler said. “These ecosystems are resilient, but we have a shared interest as part of this community to ensure that it stays that way.”