6. Which Split Alternative to Adopt?

NANPA, based on industry consensus, presented split alternatives one and four to the public. Split alternative one is the previously adopted split from D.99-07-017 (July 8, 1999). It keeps the cities and communities on both sides of the split line intact. The eastern boundary of the split area follows the Imperial County line. Consequently, all of Imperial County is part of Area A. The majority of telephone lines in the 760 area code¹³ are located in Area A, which has a projected life of 14 years. Area B (the south-west or San Diego County portion) has a projected life of 22 years. Of the public comments supporting a split, 79% favored alternative one.

NANPA and the industry representatives developed split alternative four, which is their preferred split alternative. Like alternative one, alternative four keeps northern San Diego County and Imperial Valley together and keeps the cities and communities on both sides of the split line intact. Alternative four differs from alternative one in that the eastern boundary follows a LATA line, which bisects Imperial County. Area A has a projected life of 18 years and Area B, 16 years. The primary advantage of alternative four is that the dividing line follows a LATA line such that the new area code, 442, is fully located within LATA 732 (San Diego). The inclusion of more than one LATA within an area code results in unusual billing requirements because calls between LATAs are billed as long distance, but could be within the same area code.

While NANPA and the industry representatives presented sound technical reasons for their proposed improvements to the split line we adopted in D.99-07-017, Imperial County residents and government officials objected to the hardships caused by dividing the county. We note that several area code borders bisect LATA lines and the carriers have successfully addressed the billing anomalies. We find, therefore, that the alternative one split line, which keeps Imperial County in one area code and is the line we adopted in 1999, is the best split alternative.

Accordingly, we will authorize the implementation of a two-way geographic split of the 760 area code following the dividing line set out in alternative one. Area A, the north-east portion, has substantially more working telephone numbers so it will retain the 760 area code to minimize customer inconvenience.

¹³ There are approximately 1.9 million working telephone numbers in Area A, which will retain the 760, and about 1.6 million working telephone lines in Area B, which will change to 442.