While controversies about the construction of an eruv tends to create arguments in various towns between recently-arrived Orthodox Jews and longer-resident Jews or non-Jews.
Manhattan’s an interesting exception: no one other than the Orthodox will object to the construction of one, on the basis of its coherence with rabbinic law. This follows, in part, due to various specifics of rabbinic law that have to do with how an island and large thoroughfares are treated. For example, Rabbi Moshe Feinstein pretty much nixed the idea of an eruv in Manhattan at all; many have circumvented that ruling to create local ones in areas of Manhattan such as the Upper West Side and the eastern end of Washington Heights (of course, in the specifics of the debate, the groups that created these may or may not feel that they are reflecting Feinstein’s intent). In some other areas (the western end of Washington Heights comes to mind), there are some Orthodox who want to construct a local eruv, but feel that the larger community in the area would block it. In my community of the Lower East Side, where Feinstein lived and where some of his children remain, people who’d want an eruv don’t even bother discussing it, because the opposing view is so dominant (though there is the common feature of the quite-small courtyard eruv, which will enclose the park space between apartment buildings).
Perhaps the most controversial eruv of all, though, is the “Manhattan Eruv,” an assertion by Rabbi Menachem Kasher in a 1959 pamphlet that the sea walls, piers, and general construction of the perimeter of the island created a legitimate eruv, in and of itself. Various leading area rabbis spoke out in favor of or against Kasher’s idea in the decades since, and it’s certainly the case taht the majority of Orthodox Jews on the island eventually disagreed with him (in part because some asserted that his study of the sea walls in Harlem was flawed).
Rabbi Adam Mintz of Kehilat Rayim Ahuvim (formerly, and controversially, of the Lincoln Square Synagogue), sent out an e-mail that Esther Kustanowitz shares revealing that:
Much has changed on the Island of Manhattan in the past 46 years, including the structural configuration of the sea walls and piers. A survey of Manhattan was recently conducted by the Mechon Le-Horaah, a rabbinical court in Monsey that has built eruvin in many communities around the country. The rabbis of the Mechon determined that due to structural changes in the sea wall and piers, the Manhattan Eruv was no longer halachically acceptable. The rabbis of Manhattan met at Congregation Kehilat Jeshurun on June 29, 2005 to discuss the report of the Mechon. I participated at this meeting that brought together rabbis of different synagogues and organizations in Manhattan. At the conclusion of the meeting, the rabbis decided that it was their responsibility to announce to their congregations that the Manhattan Eruv was no longer halachically acceptable.
At the same time, the rabbis agreed to support the creation of a new Manhattan Eruv that would be built under the auspices of the Mechon Le-Horaah and would utilize strings and poles to encompass as much of Manhattan as is deemed halachically possible. This work has already begun in the past few years as individual shuls have worked with the Mechon to build smaller eruvim within Manhattan.
Much, presumably, to come.
[Note that Kustanowitz is wrong when she writes that “Upper West and Upper East Sides and Central Park still fall within the halachic limits of the eruv.” Those are the individual, smaller ones that Mintz mentions at his conclusion.]
UPDATE: A slightly different explanation from Rabbi Nasanyl Braun of The Lincoln Square Synagogue:
After months of study and discussion, it appears that the Manhattan eruv, which was established almost fifty years ago, can no longer be maintained as a proper eruv. The problem is not halakhic but rather structural. Many changes have taken place over the last decade or two, which make it extremely difficult to maintain the kashrut of the eruv. The necessary improvements to bring the eruv up to the standards that Rabbi Kasher, of blessed memory, established would be very expensive to make and, in any event, the nature of traffic and construction in Manhattan make it virtually impossible to assure the kashrut of the eruv on any given Shabbat.
A group of rabbis met on Wedesday, June 29 and made the painful decision to stop checking the Manhattan eruv and cease to maintain it. At the same time, we agreed to support the Mid-Manhattan eruv, which essentially covers all of Manhattan from the 50’s up to 111th Street on the East Side, and up to 126th Street in parts of the West Side. This includes the former West Side eruv and a major extension to Central Park and the East Side. The boundaries of the eruv can be found on the door of the shul and on our website.
We further agreed to encourage and fund the extension of the Manhattan eruv southward as far as it can be extended. At present, there are already plans developing to extend the eruv into the 20’s on the East Side. We would like to encompass as much of Manhattan below 126th Street as we possibly can in order to include as many Jewish communities as possible.