Mystic — StoneRidge resident Jan Kepner hadn't been swimming in nearly 10 years but on a hot Monday afternoon, she hit the the pool and completed four laps before getting out.

"It felt great," she said, sinking into a poolside lawn chair. "But my arms are getting tired."

It was warm in the indoor saltwater pool on a hot day, but about a dozen residents and their friends and family members swam their way to the finish line, completing about 150 laps in the pool to simulate the 1.7-nautical mile journey across Narragansett Bay.

The event raised money and awareness for Save The Bay, an environmental organization that advocates for a healthy ecosystem in Naragansett and Little Naragansett bays. The group will hold its 40th annual swim across Narragansett Bay on Aug. 13.

Joan Weigel, 86, of Quaker Hill dragged along her granddaughter and frequent fundraising companion Blaze Wiersch to the event at StoneRidge. Sitting poolside afterwards, they compared their laps — Weigel had finished 5 in the pool, while Wiersch had completed 10 — to the total distance across Narragansett Bay.

"Good," Weigel said laughing. "We would have drowned just a short distance from shore."

StoneRidge began the partnership in March, sponsoring the Westerly-based South Coast Center of Save the Bay as well as the Artists for the Bay fundraiser, in an effort that grew out of the retirement community's conservation committee, said StoneRidge Executive Director Rich Kisner.

The executive director of Save the Bay, Jonathan Stone came to meet with StoneRidge residents and committee members last week to answer questions about the environment.

The swim is the organization's biggest fundraiser every year, said Leanne Danielsen, events manager for Save The Bay, raising about $350,000 to conduct water testing, policy research and a variety of advocacy and education programming. The goal this year is to have 500 swimmers participate in the swim.

The idea of a "virtual swim" of the bay came from a Brown University professor who strongly supported the Save the Bay mission but spent every summer in Italy, so he decided to hold a virtual swim there. StoneRidge is the first "group virtual swim" but Save The Bay may look into doing more and bringing more education to communities like StoneRidge.

"Awareness is huge in addition to fundraising," Danielsen said.

David Prescott, the South County Coastkeeper for Save the Bay said Little Narragansett Bay off Stonington suffers from elevated bacteria levels and low oxygen levels.

These symptoms are the challenges "Save the Bay" faces as it enters its 40th year, as the visibility of both problems along the sprawling 317-mile watershed of the Wood-Pawcatuck River and their sources has become less obvious.  

Prescott said people ask his organization, "isn't the bay saved?" as they notice clearer waters in the harbors and obvious sources of pollution like dyes and sewage now eliminated.

However the impact of overfertilization and development along the watershed has moved to the bottom of the bay, in algaes like cladorpha, a "green Brillo pad"-looking plant that chokes out diversity along the bottom of the bay.

"We're not seeing tar balls in the bay anymore," he said. "What we're seeing is the impact from each and every one of us."

For Jan Kepner and her husband, longtime boaters along New England, and among the many residents who had fond memories of recreation along the coast in southeastern Connecticut, the focus on education was important.

"It's not that people are purposefully destroying the waterways, it's just people are not paying attention," Kepner said.

But Prescott hopes partnerships like the one with StoneRidge will enable knowledge to spread from parent to child, and vice versa.

"It's complicated to get local residents and tourists to see what they do on land has an impact on the river ... it puts the onus on us," he said.

n.lynch@theday.com