Tracing the Problem
The algal bloom in Edgartown Great Pond has prompted much well-justified discussion and concern.The following is intended to provide a little additional detail on prospective solutions to improve the health of the pond.
• The Massachusetts Estuaries Project report calls for reducing nitrogen entering the Pond by 30 per cent to save it from eutrophication (enrichment), or worse, dystrophication (anoxic degradation). The recent algal bloom clearly indicates that nitrogen levels in the pond are too high and that eutrophication is increasing. The Great Pond Foundation has been researching the feasibility of harvesting the algae to remove nitrogen from the pond and prevent smothering of oyster beds with the decaying detritus accumulating on the bottom as the algae dies. Now that Bill Wilcox of the Martha’s Vineyard Commission has gotten a positive identification of the algae species, we can pursue management solutions for this particular species. If we do find a means of controlling the plant, it will be a long and expensive process.
About 27 per cent of the nitrogen in the pond comes from acid rain deposits. There is little we can do about that but to celebrate the fact that Midwest coal-fired power plants responsible for it have finally been ordered to install effective equipment to curtail this source of nitrogen from polluting the ponds of the Northeast. Nor can we stop the high nitrogen content in the old groundwater plume between the Edgartown wastewater treatment facility and the pond, which moves about a foot per day. This old plume resulted from the original wastewater facility lacking the technology to remove nitrogen from the waste. The foundation will continue to monitor the plume to give us some sense of its movement and longevity.
A very positive long range step in reducing nitrogen in the pond is being planned by the Edgartown wastewater commission. Voters this fall will be asked to support a proposal for sewering Island Grove, thereby removing a significant source of nitrogen from the groundwater entering the pond. Voter approval will be a major first action by the town in implementing the estuaries project recommendations for the pond. Additional hook-ups of major subdivisions in the Edgartown Great Pond watershed in coming years will be critical to further reductions in nitrogen entering the pond.
The limitations of Title V (state mandated) on-site septic technology are a major obstacle to nitrogen reduction in all of our Island ponds. Several innovative alternative technologies for nitrogen removal are in use in Edgartown. However, the systems in use to date are expensive and require regular maintenance and inspection. A major technical and bureaucratic breakthrough was recently approved by Department of Environmental Protection, allowing the use of septic effluent for the irrigation of lawns. Instead of effluent going into a leach field, where the nitrogen flows directly into the water table, the irrigation system allows the roots of lawns, trees and shrubs to benefit from nitrogen distributed just below the ground surface. This is an enormous breakthrough and one which could benefit both landowner and the environment. The Great Pond Foundation and the Martha’s Vineyard Water Alliance support this kind of innovation, which could have very positive long-range benefits for the health of our ponds. We will continue to monitor this and other promising technologies as they appear.
The drastic reduction or complete elimination of nitrogen fertilizer use on lawns and golf courses is supported by the Great Pond Foundation and the water alliance. The use of inorganic quick-release nitrogen fertilizers is a contributing threat to our coastal ponds. This brings us back to the algae. Imagine the use of the algae as a source of slow-release nitrogen for agricultural and horticultural uses. Marine algae has been used for food, fertilizer, and medicines for centuries. We need to look at the possibility of the algae as a possible resource of value, not just as a threat to our ponds.
The town management plan for the pond calls for four openings per year to provide as much release of nitrogen to the sea as possible, and sufficient inflow of salt water to sustain a healthy estuarine ecosystem. A midsummer opening is especially desirable because it is ideally timed for maximum release of nitrogen from the pond. This is not easy to achieve because of low summer water levels in the pond due to lack of rain and prevailing southwesterly winds which often close the pond prematurely. Thanks to the determination of shellfish constable Paul Bagnall and contractor Steve Handy, a high pond, and favorable wind direction, a good opening was achieved in August for the first time in several years.
Part and parcel of a successful opening is managing the large delta which forms in the pond adjacent to the opening. This results because with each opening, more sand flows into the pond than leaves the pond. The purchase by the foundation of a small, powerful, readily portable dredge that will be used to manage the delta is a major step toward more effective openings and, we hope, the removal of significantly more nitrogen from the system. When not engaged with the delta, the dredge can also be used elsewhere in the pond to improve circulation, and available Island-wide for work on other ponds. It is scheduled to arrive in spring of 2009.
The Edgartown Great Pond oyster restoration project, initiated by the Martha’s Vineyard Shellfish Group this summer, is another major step toward better management of the pond. Rick Karney and staff spawned some three million oysters, carefully nurtured by veteran Edgartown shellfisherman William (Boo) Bassett and his staff of three foundation interns: Ryan Daly, Carl Spielvogel and Alex Huth. Not only is this good for the future of the shellfishermen, it is good for the health of the pond, since oysters are unparalled in removing nitrogen from the system by converting it to protein. The bumper sticker might read: Save the Great Pond!— Eat more Great Pond Oysters! The project, funded through 2009, is a demonstration of what good science and hard work can do for the pond. The foundation will work to be certain that the project continues, if and when needed, to restore a depleted resource of inestimable importance to the health of the pond.
This summer, under the direction of our resident foundation hydrologist Craig Saunders and our interns, we continued the important work of Bill Wilcox over the past two decades, monitoring water quality in the pond. This data is essential to give us an understanding of whether sustainable levels of oxygen, salinity, nitrogen, and other parameters are being maintained for the pond to function properly. Managing coastal ponds is a tricky business. Originally primarily fresh water environments, these systems have a delicate balance that must be maintained with the sea and the land. Whenever man attempts to manage natural systems he is in for some surprises. We are gradually learning what roles humans can and cannot play in our attempt to nurture our environment. The most elemental is for us to simply stop polluting it. (Picture the Wampanoags living on the shores of these ponds for the past several thousand years in close harmony with the resources which sustained them.) Achieving the goal of saving our threatened coastal ponds means changes in our lifestyles, especially in handling our wastes. Just as certain as the fact that we are the cause of the degradation of our environment is the certainty that we can restore these priceless resources to their original pristine state.
Reclaiming the Pond
Editors, Vineyard Gazette:
The Edgartown Great Pond algae bloom is the predictable result of ignoring the impacts of a wastewater treatment facility on a pond and instead using less harmful impacts as a decoy for preventing the real problems from being solved.
For the Vineyard Gazette to publish the idea that this pond needs another study is disheartening. What follows are the steps necessary to protect the Great Pond as a district of critical planning concern which to date have been ignored by everyone:
• We need to hire independent, outside experts with no affiliation with the Department of Environmental Protection, local experts or the Martha’s Vineyard Commission.
• Draw up and implement a nitrogen management plan that deals with pollution coming into the Great Pond from outside its watershed.
• Stop the 12-year practice of abandoning operable Title V systems outside the watershed and hooking up to the wastewater treatment facility.
• Promote water conservation by converting sewer billing from the current antiquated system of “the number of outlets to drain” to metered billing.
• Stop the practice of accepting septage from all over the Island whose array of contaminants enter the pond via the wastewater treatment facility plume.
• Continue the plume study that, against expert recommendations, was curtailed.
Just like when you are sick, there are steps you can take now, and you don’t need an expert to tell you what to do. Ignoring these problems and failing to initiate the cure as we have done this last decade will only make reclamation more expensive.
Jay A. Guest