Building Department intern creating septic system map

One of the keys to Shelter Island’s long-term ecological sustainability lies in a computer program installed on a computer at the Building Department.

Summer intern Henry Read, an Islander and graduate of Mercy High School in Riverhead, spends eight hours a day analyzing the local terrain with the “Pictometry” application. He’s been tasked with creating an online database of Shelter Island’s septic systems for the Town Geographic Information System (GIS) site.

“What we hope to do at the local level is build a better system for spotting potential problems,” Town Engineer John Cronin, said.

Mr. Read studies civil engineering at Manhattan College. He contacted the Building Department after reading an advertisement in the Reporter. “I have always loved the environment [here],” he said, “and working on Shelter Island is even more special.”

In June Bob DeLuca, president of the Group for the East End, told the board that creating a database is “crucially important to developing informed recommendations and ultimately solutions for what is increasingly important water quality issues facing our entire region.”

The environmental organization then gave a grant to the town of $4,000 to pay for Mr. Read’s work.

Septic tanks collect waste from homes and disperse the sewage into a draining field. The process relies largely on soil to decontaminate any impurities released from the tank. A functioning septic system will only “leech” a specified amount of waste into the ground; too much refuse will create a stench, kill grass and vegetation and most critically, pollute local water sources. Problems arise when aging septic tanks begin to malfunction. Mr. Read noted that Superstorm Sandy accelerated the process for some systems, but added that “the main problem is that they’re so old.”

Building codes mandate that newly built or renovated homes install complying septic tanks. Older homes, however, often have out-of-date systems that the town can’t force owners to replace. The Suffolk County Stormwater Management Program warns that, “Pollution from failing treatment systems ultimately affects all aspects of our life on Long Island.”

At a Town Board meeting in June, Mr. Cronin said the situation is “going to get worse without some radical changes.”

The Building Department’s first step in addressing the problem was to hire Mr. Read. By the end of the summer, he hopes to have mapped about one-third of properties on Shelter Island. When the database is completed and uploaded to the GIS site, town officials along with the Suffolk County Department of Health Services will have “a readily available tool to spot [septic tanks] that may pose a greater environmental or public health risk,” according to Mr. Cronin.

Shelter Island’s terrain magnifies the dangers posed by inadequate systems. Beachfront homes must construct wide draining fields, since the high water table prohibits deep wells.

“The current design standard for septic systems does not adequately address the removal of certain wastewater constituents,” Mr. Cronin said, adding that it is an increasing problem to the environmental health of the Island

One use for Mr. Read’s database is to use it in conjunction with independent laboratory tests. By matching bodies of water with high levels of coliform to aging septic tanks, engineers will, be able, to a certain extent, pinpoint the source of pollution.

Fecal coliform — along with nitrogen-based compounds also found in septic waste — can obliterate local ecosystems. A study released in June by The Nature Conservancy concluded that nitrogen pollution plays a major role in killing sea grass populations on the Eastern Seaboard. A similar investigation by the Department of Transportation determined that sewage released into a reservoir promotes algae growth, which depletes the water’s oxygen supply.

Mr. Read hopes to map the systems of Shelter Island’s oldest homes by hand, but currently works only from his desk at the Building Department. The software program he relies on has proven invaluable, he said. The company behind Pictometry uses low-flying airplanes to map buildings and changes in terrain.

Reference points on buildings allow Mr. Read to determine the size and location of each septic system.

The first batch of data, the plans of roughly 250 houses, was submitted this week to a consultant, who will determine whether the information compiled by Mr. Read is compatible with the Town GIS.

In spite of the challenges posed by Shelter Island’s aging septic infrastructure, Mr. Cronin is optimistic. Suffolk County is in the early stages of revising their septic system requirements and Mr. Cronin hopes future legislation will provide tax breaks or grant money to homeowners that upgrade problematic tanks.

Shelter Island will consider options for continuing Mr. Read’s work once the intern returns to Manhattan College in the fall. Mr. Cronin noted that the Town Board would likely support the completion of the database, “based on the perceived success during this summer’s effort.”