Summer 2011

Natural Wonder

Cape Cod Home  /  Summer 2011 / , ,

Writer: Andrea McHugh

A “living” swimming pool on Nantucket is both an ecologically sensitive choice— and a naturally stunning treasure.

Nantucket living swimming pool

Nantucket homeowners decided to take a different, more eco-friendly route by embellishing their home with a living swimming pool.

Thirty miles out to sea and seemingly detached from the rest of the world, Nantucket has served as a tranquil summer escape for generations. Already graced with stunning natural beauty, it seems an unwritten rule that even the most luxurious homes, whether newly constructed or renovated centuries-old dwellings, should blend into the already extraordinary landscape.

When one family sought to add a pool to their expansive 12-acre estate on Nantucket’s south shore, they sought a design that would merge seamlessly into the captivating surroundings. In lieu of a conventional pool, the homeowners turned to R.P. Marzilli & Co. of Medway, Massachusetts, to create a natural or “living” pool that would boast chlorine-free water and abundant vegetation creating a refreshing sustainable oasis on the property.

Robert Marzilli has been building lush landscapes for more than 25 years, but to meet the specifications of this project on Nantucket, he worked with Biotop GMBH, the first natural pool company in Europe. Throughout the past two and a half decades, Biotop has developed the system, know-how, and technical equipment to create the first ecologically natural, filtered swimming pool. While Biotop boasts more than 3,500 natural pools worldwide, including both residential and publically utilized pools, the Nantucket project is the company’s first foray into the United States.

With a Biotop pool the central swimming area is bordered or surrounded by a wall that acts as a divider from a wealth of flora and fauna, called the regeneration zone, where organic impurities and excess nutrients are decomposed by the plants and microorganisms, acting as a natural filter. Underneath the surface, a series of remarkable systems are at work. Water flows over a curved self-cleaning sieve that skims out the impurities, such as undesirable mucilaginous algae. The water streams naturally into a submerged pump house, transporting it into the natural pool through pressure lines. A phosphorous filter developed by Biotop ensures that the water remains pure and clear as it circulates.

Nantucket living swimming pool

The chlorine-free pool was created by the European company Biotop, their first pool in America.

“We had a lot of [Biotop] hardware brought over from Austria, which meant we needed to import material and re-engineer some of those pumps so they would meet U.S. standards and not metric standards,” Marzilli explains. The company was given a two-year window in which to complete the vast project by the clients, which not only included importing the equipment, but commissioning an array of aquatic plants, perennials, and more natural elements grown specifically for the natural pool.

Marzilli worked with New York-based James Corner Field Operations, an internationally-acclaimed landscape architecture firm that contracted Piet Oudolf, a famed planting designer who works globally, but calls the Netherlands home. “He knows more about perennials than most others in the industry,” says Marzilli. The softscape designer, says Marzilli, worked in concert with Field Operations and R.P. Marzilli & Co. to bring the project from vision to reality. Of course, getting there, quite literally in this case, was the hard part.

“We had to figure out how to get it all to the island,” Marzilli recalls. “We were given a completion date—and that didn’t move. As much as we’re all given a footprint, there are inevitable time and weather obstacles.” Marzilli notes that this particular project was one of the largest his company has taken on in its long history.

To put it in perspective, R.P. Marzilli project manager Dave Buckley says this natural pool’s total area is approximately 18,000 square feet, with the swimming area accounting for nearly half of that. “With this particular project, the issue was scale,” says Buckley. “It’s essentially the size you would see at a water park.” Piece by piece, plant by plant, components from around the world made their way to the Massachusetts island.

Nantucket living swimming pool

The natural pool adds to the serenity of the house’s large landscape, and makes the 12-acre property feel like a true oasis.

Despite the challenges, the team that orchestrated the project created a natural preserve-like space that is as vast as it is breathtaking. “It’s almost like walking in a park,” says Marzilli of the peaceful, living sanctuary. “You’re able to meander though the property on pathways in between thousands of perennials and grasses.”

Taking a site and starting from ground up while creating a natural pool amidst other estate features including five buildings, a grass tennis court, and a croquet court, took careful consideration, Marzilli says. “Making it all work was a cohesive effort by designers, contractors, and a team of professionals, giving this homeowner an escape retreat.”

When it comes to the price tag of a conventional versus natural pool, Buckley says the costs can vary per square foot depending on the size and detailing of the feature. The larger installations can be comparable to a standard gunite swimming pool. “It’s also a very viable option to transform a standard in-ground pool into a natural pool,” adds Buckley.

Eco-friendly natural pools are an increasingly popular choice for homeowners looking for chemical-free alternatives. A popular misconception is that a natural pool will resemble a murky lagoon more than it will a pristine sanctuary. But advanced state-of-the-art Biotop technology combined with Mother Nature’s magic can create a clear ecologically sensitive environment—and a glimmering natural treasure—for generations to come.

For information on R. P. Marzilli & Co., call (508) 533-8700 or go to

Andrea McHugh is a former editor of Newport Life magazine and a freelance writer living in Newport, Rhode Island.

Andrea McHugh