From Palo Alto Wiki
An eruv, for observers of Orthodox Judaism, extends the private domain from individual homes to all land within its boundaries. Under religious law, Orthodox Jews on the Sabbath are forbidden from engaging in 39 forms of "creative labor." That includes carrying things from the home, or private domain, to the busy outside world, or public domain. During the Sabbath they are not allowed to carry small children to parks, push strollers or wheelchairs, or even bring prayer books to services. An eruv would extend the private domain, enabling observers from sundown on Friday night to sundown on Saturday night to carry things from their homes to synagogue or to friends' houses.
 Eruvs in Palo Alto
The eruv effort began in Palo Alto in 1999. Religious leaders asked the city to recognize the city's perimeter -- about 80 percent of it already demarcated by creeks and freeway walls -- as an eruv. They also wanted to get the city's permission to fill in the gaps in the "wall" by stringing twine between poles that would span streets and bridges in 25 locations.
Debate erupted over whether the eruv would breach the U.S. Constitution's required separation between church and state. Rabbi Yitzchok Feldman, of Congregation Emek Beracha, spearheaded the Palo Alto eruv effort. One of the city's complaints was that having the eruv made of twine wind around city utility poles would be dangerous.
Feldman, along with the Palo Alto Community Eruv, Inc. (PACE) submitted a new plan in 2004 that would not need to use city utility poles for twine to be linked around Palo Alto. It took nearly three more years for the group to satisfy Palo Alto's remaining conditions for the project, including providing a 24-hour, seven-day-a-week contact for an eruv maintenance contractor and insurance for the eruv. In addition to obtaining an encroachment permit from the City of Palo Alto, proponents secured permission from Stanford University, Caltrans, Santa Clara Valley Water District, Santa Clara County and the Peninsula Joint Powers Board for the eruv to cross their lands, according to the city attorney report. Feldman said that PACE would pay for and maintain the eruv.
June 18, 2007 City Attorney Gary Baum stated that Palo Alto is "legally compelled" to allow the eruv. The eruv will encompasse where people live in Stanford and Palo Alto. A 13-mile-long eruv, a border that would allow Orthodox Jews to carry objects from home to their synagogue on the Sabbath, was to be constructed around Palo Alto.
- Palo Alto eruv approved -- after eight years: Orthodox Jewish boundary will be strung around Palo Alto Palo Alto Online, June 19, 2007