Our View
By Margaret and Larry McQuade

The following My View is written in response to the "Voices Away From the Bluff" with Catherine Stover, published in the Oct. 24 The Nantucket Independent.

We read with interest Mrs. Stover's comments and appreciate her expressions of sympathy to those of us on the Bluff in danger of losing our houses. Two clarifying points: one, we do not have a place to which to move our house (common misconception) and two, we believe it is important to save the land of the North Bluff whether or not it has houses on it.

While we intend to specifically address the technical issues Mrs. Stover raises, there is an overall thread which runs through her letter which is puzzling and worthy of comment. Mrs. Stover seems unable to acknowledge any potential benefits of the SBPF project, even when they are backed by science. Yet she proffers great and sweeping certainty about the dire consequences of the project based on conjecture and emotion. In so doing, she disseminates misinformation and does a grave disservice to all concerned.

1) Beach nourishment has been successful in high energy environments.

We agree with Mrs. Stover that 'Sconset experiences intense ocean forces. Knowing this, our project engineers designed the beach expecting that just over half would erode over approximately 5 years, while the remaining portion would still be sufficient to provide protection to the bluff during a major (50-year) storm. During storms, the beach nourishment will erode just as the natural beach would erode because we are placing almost identical sediment on the beach. While we reviewed decades of actual wind and wave data to determine a range of conditions we may encounter over time, we agree with Mrs. Stover that no one can predict when the next colossal storm will hit Nantucket. Nonetheless, we can say that, with the project in place, the impact to the bluff, if any, will be drastically reduced. We'll be monitoring the beach regularly to ensure it is performing as we expect.

Finally, we note that beach nourishment has been undertaken successfully in high energy environments. Beach nourishment projects in multiple locations on Fire Island in New York have performed well even with similar high energy to 'Sconset.

2) Long-term impacts from beach nourishment will be minimal.

Our assessment of the beach nourishment project's impact on the environment is based on past experience with similar projects combined with site-specific analysis at Siasconset. Beach nourishment projects are conducted all over the world without long-term detrimental impacts on the environment. Over time, these projects have adopted additional safeguards including turtle excluder devices and time-of-year restrictions to minimize environmental impacts. The US Army Corps of Engineers conducted a seven-year monitoring program of its Manasquan Inlet to Asbury Park beach nourishment project, which was almost ten times larger than that proposed for Siasconset. The Corps concluded that the impacts from this beach nourishment project were "minor and short-term." What we know about the environment off of Siasconset supports the prediction that the impacts of the beach nourishment project will be minimal. The high energy environment that is eroding the Siasconset Bluffs is removing great amounts of sand, disturbing habitats, and causing sedimentation. The fish species and other organisms that inhabit this hostile environment have evolved to accommodate it. The level of disturbance caused by this project is small in comparison to that exacted by the Atlantic Ocean. Once the project is constructed, the sea will re-work these areas, restore habitat, and organisms will recolonize.

Therefore we do not expect any long-term negative effects, but again we are committed to an intensive follow-up monitoring process to measure and record any project impacts.

3) Turbidity will be similar to or less than natural conditions.

In light of concerns about turbidity similar to those expressed by Mrs. Stover, we recently expanded our turbidity studies. Taking into account this new information, we expect that turbidity impacts will be minimal for multiple reasons. First, the borrow site sediment is only one percent silt (Silt is the primary contributing factor to turbidity.) In comparison, the eroding bluff has a silt content that is three times higher. Second, the contractor will be required to use turbidityreducing measures. The sediment will be slurried within the hopper dredge and then pumped onto the beach landward of a sediment dike. By using this dike, a considerable portion of the suspended sediment will settle out of the slurry before backwash returns to the ocean, thereby reducing turbidity. Third, predicted turbidity values from the project are not expected to exceed natural turbidity levels. Project engineers performed stateof the-art modeling with an extremely conservative assumption of 10percent silt (ten times higher than actual); this modeling indicated maximum projectinduced turbidity of only 31 NTU. The predicted turbidity values are less than turbidity values measured during storms and are within or near the range of turbidity values measured during average conditions. Finally, we will monitor turbidity during construction and will suspend dredging or discharge activities if turbidity exceeds regulatory criteria. Over the long-term, the project will likely decrease turbidity by reducing the contribution of silt from the eroding bluff (which has triple the silt content of the borrow site sediment).

4) The borrow site was chosen after a thorough review of other alternatives.

We spent several months locating a sand source with the required volume and grain size. Mrs. Stover is correct that we've previously used sand from a Nantucket gravel pit for terraces; however, sand of the correct grain size is not available in sufficient quantity. We've also previously used off-island sand and gravel pits; however, the logistics of transporting the much larger volume of sand needed for beach nourishment - either to Nantucket Harbor or directly to the beach - were daunting. If sand were brought to Nantucket Harbor, 3,250 barge trips and over 130,000 truck trips on our roads would be required. If sand were brought directly to the beach, we would either have to attempt the risky maneuver of "beaching" the barges (i.e., running them ashore at low tide), or we would have to pump the material to the beach from offshore barges. Either way, we would have to simultaneously use two ports (Port of Providence and Port of New Bedford) at their maximum daily load capacity for months, have consistently ideal weather to allow round-the-clock trips of 4-5 connected barges, and procure scarce equipment -- and it would still take over 2.5 times longer than the proposed June-November construction.

Given the impossible nature of these options, we then looked at offshore sand sources. We evaluated 8 sites and excluded all but the preferred borrow site based on grain size incompatibility and heavy charter and/or commercial fishing use. Detailed investigations have shown that the borrow site provides ideal grain size and impacts will be minimal. Federal and state regulatory agencies concluded that the evaluation of alternatives was satisfactory.

5) The nourished beach will require periodic maintenance, similar to our gardens, homes, or automobiles.

Many worthwhile endeavors require maintenance. For example, we plant our gardens annually and subsequently weed and water them; we maintain our homes against the weather and repair our roofs; and we periodically change our oil or replace our tires. Our beaches can similarly be viewed as worthwhile resources that need maintenance (in the form of periodic renourishment). We plan to continue funding renourishment as needed (initially every 5 years; the renourishment interval typically increases with time). In the event SBPF could no longer fund renourishment, the beach would return to the existing conditions we experience today, with no public cost or action needed.

6) Moving houses is not a viable long-term option and does not address the threat of ongoing erosion. Nantucketers can choose to address erosion, just as we have chosen to address other important issues in the past.

We've pursued moving houses over the past 15 years, such that many homes have been moved as far landward as possible on their existing lots and most of the nearby lots are full. Moving houses is no longer a workable option. Further, simply moving houses does not address the threat of ongoing erosion, which will ultimately claim 'Sconset Village, the sewer beds, and even the airport if left unchecked.

While we agree with Mrs. Stover that the island has a history of erosion, our history also includes lack of electricity, siltation of the Harbor; and lack of easy access - all of which we've chosen to address. For example, we altered our environment to bring electricity along the ocean bottom from the Cape to Nantucket; we periodically maintain the channels and jetties so that Nantucket Harbor can function; and we embrace the high speed ferry. We can likewise choose to address the threat of ongoing erosion. We believe we should protect our shoreline and historic properties when we have an environmentally-responsible means available. Our project is about maintaining the beauty of what already exists; we are not seeking any new development.

7) We will provide public access to the nourished beach.

Unlike many coastal communities where the landowner's property includes the beach, 'Sconset Beach is primarily owned by the Town of Nantucket (as Mrs. Stover states), as well as by private individuals and organizations. SBPF is requesting permission from each property owner; in return, SBPF is committed to providing public access to the beach.

8) The Project will not result in erosion of adjacent shorelines or destabilization of the shoals.

Mrs. Stover relates that armoring at Brant Point is exacerbating erosion on the north side; the potential for negative impacts from armoring is precisely why we have chosen beach nourishment. Unlike other options that can interfere with natural sand transport patterns, beach nourishment simply adds more sand to the system without causing increased erosion on adjacent beaches or changing the existing sediment transport patterns.

The additional sand from the beach nourishment project will work its way down to Sesachacha Pond, Squam, Quidnet and Wauwinet. Rather than having a narrower beach, the beach will remain the same or potentially increase in width slightly. Indeed, adjacent beaches may receive additional storm protection through modest increases in beach width. At Sesachacha Pond, which directly abuts the beach nourishment project and thus will have greater increased beach width than more distant areas, the SBPF has promised to pay to cut across the additional 40 feet of beach to open Sesachacha Pond.

While we expect that the beaches along the shoreline will widen due to the project, concern has been raised about the removal of sand from the borrow area opening a gap in the shoal. However, the borrow area is not located on the shoal. The average depth in the borrow area is 41-feet, ranging up to 60-feet. The modeling shows that any changes to the waves are restricted to a radius of 1.5 miles from the borrow area with any wave imactremaining more than one mile offshore. There will be no changes to nearshore sediment transportation, wave patterns, or currents.

Recognizing the importance of the concerns expressed by Mrs. Stover, residents of 'Sconset have been working with world-class professionals to design the Project so it will mitigate the rate of erosion of the Bluff in a way consistent with the interests of our fishermen, of adjacent communities and of the entire Island.

Sincerely,

- Margaret and Larry McQuade