As an earth science teacher on Martha’s Vineyard for 22 years, I was embarrassed to learn that the affordable housing developers on this Island continue to plan year-round affordable multi-family housing projects inside the Lake Tashmoo watershed zone with so little notice by Island environmentalists, including myself.

Lake Tashmoo is running into serious trouble. Over the past decades additional development near the lake has resulted in additional nitrogen and phosphorous loading resulting in decreases in shellfish filterers and a reduction in sunlight through cloudy waters. The days of collecting a bushel of scallops are over.

The 2017 report on Lake Tashmoo water quality sponsored by the Mass DEP, the town of Tisbury and Tisbury Waterways specifically lists the loss of eelgrass in the lake as a critical factor in the environmental quality of its habitat. When the cloudy water and algae blooms block sunlight to the eel grass, the grass can no longer absorb CO2 and release oxygen. The oxygen-starved water can’t support the tiny marine organisms that filter feeders like scallops need to grow. The loss of filter feeders contributes to the cloudiness of the water and encourages the growth of algae. The temperature of the water over the years has been rising.

As early as 2010 a study of the lake revealed that portions of the lake were unsafe for swimming. Now, even the drop of minnows and other small fish threatens the food source for striped bass and terns.

Obviously the Tisbury planning board needs to consult with the Tisbury conservation commission to review the published information from the Mass DEP and Tisbury Waterways regarding the health of Lake Tashmoo and the expected results of planning year-round, multi-family development in the Tashmoo watershed zone.

The first public meeting on a proposed development at 299 Daggett avenue was held July 3 at 7:45 pm. While the immediate abutters were notified of the hearing, no members of the conservation commission were invited or notified.

This proposed development has a bedroom capacity of 24 people. Parking will be provided for 12 cars. The developer hinted at installing a low-nitrogen septic system, but so far there is no plan to reduce phosphorous from the graywater. Phosphorous is a major component in soaps, detergents, and shampoo. Also, studies are still mixed on the efficacy of current nitrogen-reducing septic systems. This development would transform a seasonal R50 single family home with guest house into a year-round multi-family unit with the possibility of an additional two-family development in the future. Transforming a seasonal property into year-round usage can by itself quadruple the amount of graywater and septic water leaching into the lake.

The increasing density of year-round residents in the Tashmoo watershed continues to pressure the health of groundwater surrounding the lake. Multi-family affordable housing is pushing into the Tashmoo watershed at a steady pace. Already these developments include units on Lake street and six town houses on Wentworth Way, which is off Lake street. Irene’s Way off Greenwood avenue was established many years back, and a new development on Greenwood avenue is under construction across from Camp Jabberwocky. The proposed multi-family development at 299 Daggett avenue will lie in line with the other developments along the east side of Tashmoo. All groundwater from these developments leaches directly into the lake.

Surface water from rain also washes into and ultimately soaks into the ground and leaches into the lake carrying other pollutants such as animal and pet urine and feces.

I strongly request that the Tisbury planning board establish an immediate moratorium against any further multi-family year-round developments in the Tashmoo watershed, at least and until the Tisbury conservation commission reviews the plans and the related environmental impact on Lake Tashmoo. All applicable environmental studies relating to Lake Tashmoo need to be examined before any additional special permits to change and relax present restrictions relating to zoning in the Tashmoo watershed should be considered.

From my review of published studies on Lake Tashmoo, denying the environmental impact of multi-family development in the Tashmoo watershed is like denying climate change.

Connie Alexander

Vineyard Haven