Darien To Address Elevated Arsenic Levels Found At Great Island

DARIEN, CT — First Selectman Monica McNally gave an update on Great Island during last Monday's Board of Selectmen meeting and said the town will address the issue of elevated arsenic levels which have been found in several locations on the 60-acre parcel of land.

The presence of arsenic is the result of pesticide use on agricultural crops raised on the island a century ago, McNally added in her biweekly newsletter to the community last Friday. McNally did not specify where exactly the arsenic was found, or what the measured levels were.

"Traditional remediation methods for this, such as soil blending or soil removal and replacement, although they are effective, they are expensive and disruptive," McNally said during last Monday's selectmen meeting. "My own research led to an eco-friendly and cost-effective potential solution - phytoremediation."

The process uses hyper-accumulator plants, McNally explained. In this case, soybean plants, arugula, sunflowers and mustard greens can be planted to absorb the arsenic that's in the soil.

The town is initiating a pilot program over a quarter acre of land on Great Island in conjunction with GZA, an environmental consulting firm, to determine the effectiveness of the phytoremediation process.

The pilot program will include soil testing, planting, regular assessment throughout the summer, and then the safe disposal of plants at the end of the season, followed by the sowing of rye grass for winter protection.

As part of her update, McNally also shared that the town has completed the interview process for the four resident-at-large positions on the Great Island Advisory Committee. The nine-member committee will oversee post-acquisition tasks and advise on the future of the property.

McNally said there were 45 residents who expressed interest in joining the committee. The Board of Selectmen is expected to vote to appoint the four resident members on July 3.

At this time, there is no public access to Great Island. Before opening it to the public, Darien is maintaining the property and taking steps to ensure safety for when residents can finally visit.

McNally said these steps include:

• The installation of 12 "No Public Access" and six "24-hour video surveillance" warning signs, in addition to trail cameras across the property.
• Addressing safety concerns at the jetty by removing protruding pipes and safety marker buoys.

• Designing two schematic driveway plans for the main entrance.

• Initiating routine property maintenance, including tree and stump removal and safety-related structural adjustments.

• Developing plans for the safe removal and replacement of transformers and oil tanks on the property.

"I want to thank everyone for their support on this project, and I want to thank you for your patience as we move forward," McNally said last week. "We're dedicated to transforming Great Island into a treasured asset for all residents, respecting both its environmental integrity and the community value."

Darien officially closed on the Great Island property in May.

The town originally came to a $103 million agreement to acquire the property last year, but after a lengthy due diligence process in which the town said it had to rectify some issues that cropped up, the final purchase price was lowered to $85 million.

Great Island is considered one of the largest remaining undeveloped pieces of land in the area, and town officials have called the purchase a once-in-a-lifetime opportunity.

Structures on the property include equestrian facilities, a deep-water dock, 13,000 square foot manor, three-bedroom stone house, farmhouse, beach cottage and a seaside bungalow.

The land was originally bought by the Ziegler family in the 1880s. Most recently it was controlled by the Steinkraus branch of the family.

Plans for town-use of the property have not been developed yet.