The council plan to consider the company's appeal Sept. 22.
The Planning Commission decision "violates federal law and in particular the Telecommunications Act of 1996," said T-Mobile attorney Paul Albritton of the San Francisco firm Mackenzie & Albritton in an Aug. 5 letter to the council.
The commission's decision is not supported by substantial evidence, is unreasonably discriminatory, and has the effect of prohibiting T-Mobile from providing personal wireless services in Portola Valley, Mr. Albritton said.
In denying the permit in a 4-1 vote, the majority on the Planning Commission said the tower failed on aesthetic grounds, reasoning that the courts have yet to address a cell phone company's discretion in a small, semi-rural town like Portola Valley.
The commissioners also questioned the validity of competing maps — one from the company and another from an independent technical firm hired by the town to cross check T-Mobile's claim of gaps in phone coverage.
Nate McKitterick, a member of the Planning Commission, said T-Mobile has not demonstrated a significant gap in service. He said the tower would impose "an undue visual impact contrary to the spirit and natural beauty of Portola Valley."
The tower could be hidden inside a faux pine tree, referred to as a monopine, that would be a few feet taller than the tower.
Chip McIntosh, the sole member of the Planning Commission who favored granting the permit, said the streets are already studded with poles, that other cell phone companies may apply for antenna space, and that the proposed site, owned by the California Water Service Co., is "a good place to do it."