Islanders get advice from Nantucket on septic systems

Concerned about runoff into Island groundwater and bodies of water within and around Shelter Island, the Water Advisory Committee Nov. 21 got information from an official of another island about how to address fertilizer use affecting water quality.

Nantucket Director of Health and Human Services Roberto Santamaria told the Shelter Islanders it has been 10 years since his town implemented a program to control the nitrogen content from fertilizers affecting water quality.

The initial contact with him was made by WAC member Lisa Shaw, who brought Nantucket’s experiences in lessening problems with fertilizer use to her colleagues, and arranged the discussion with the entire committee.

“We’ve seen some great results,” Mr. Santamaria told the WAC members. But the answer isn’t complete, he said, explaining that Nantucket not only implemented strict regulations with respect to fertilizer use, but has a septic system serving much of the Island. It also has an aggressive program affecting installation of state-of-the-art I/A (Innovative/Alternative) septic systems in areas not served by the larger system.

Only 40% of residents use private wells for drinking water, while the other 60% are in Nantucket’s public water district. The population on Nantucket is much larger than Shelter Island’s, with 10,000 year-round residents who use one to two million gallons of water a day. In the summer, the population grows and water use is generally between five to eight million gallons per day, Mr. Santamaria said.

About 80% of Nantucket residents comply with requirements affecting septics and fertilizer use, but enforcement is the hardest part of the challenge for the other 20%, he said.

As for those with older septic systems, they are supposed to be checked at least every five years and if any problems are found, property owners are required to have them replaced with I/A septic systems. Nantucket doesn’t have any system of grants, but provides loans that can be repaid over a 20-year period.

WAC members agreed they want to further pursue talks with Mr. Santamaria and other Nantucket water and septic officials after they have absorbed information from this first session.