A Wonder Down Under : Beneath the Valley, civilization’s conduits form a maze of sewers, pipelines and enough telephone wire to wrap the Equator 334 times.

When crude oil began hemorrhaging to the surface of Ventura Boulevard in September, it was the first time that most Encino residents knew they were living above an oil pipeline.

In fact, it had been there for 50 years, intertwining with a maze of other pipes and conduits, one part of an increasingly congested subterranean traffic jam.

Statistics for the underground can be mind-numbing: 15,000 miles of natural gas lines, 8 million miles of telephone wires, 3,000 miles of sewers, hundreds of miles of storm drains and more than 50,000 manholes. But there is much more, including nine oil company pipelines, water lines large enough to accommodate a car and a cavernous natural gas storage facility that holds tens of billions of cubic feet of fuel.

It took one visit and five subsequent telephone calls before someone from the Department of Public Works could answer the question: “Who do I speak with to learn what is under the San Fernando Valley?” And in the case of an emergency response to a man-made or natural disaster, representatives from the state fire marshal’s office, which keeps tabs on underground hazardous materials, said that until a new state law went into effect Jan. 1, not every pipeline had to be reported to their office, making it difficult to know exactly where everything really is.

The largest part of this invisible empire belongs to the Metropolitan Water District and the Los Angeles Department of Water and Power. Both companies have control facilities in Granada Hills and, like the tentacles of an octopus, major water lines radiate from there in all directions.

“We have 75% of L.A.’s water supply coming through the Valley, with the primary purpose of the major transmission lines being not only to get the water there, but into the rest of Los Angeles as well,” said DWP engineer Jerry Gewe.

The largest is the Metropolitan Water District’s Sepulveda Feeder, a 12 1/2-foot-diameter pipe that roughly parallels the San Diego Freeway before tunneling through the Sepulveda Pass on its way south. According to Assistant Area Supt. Frank Bellisle, if a major catastrophe ruptured the line, hundreds of acre-feet of water would be released before it could be shut down. (One acre-foot is 326,000 gallons.) “If a contractor punched a hole, even a relatively small one, you’d probably see water shooting 300-and-something feet in the air.”

Three other water transmission lines weave under the Simi Valley Freeway west from Granada Hills, and a single line heads east. Other major lines go under Roscoe Boulevard, Topanga Canyon Boulevard, San Fernando Road and Coldwater Canyon Avenue.

Everybody from AT&T; to Western Union has something under the Valley, with Pacific Telephone taking top communication honors. If the wire underneath the Valley were stretched out, Pacific Telephone engineers estimated that it would wrap the Equator more than 334 times.

AT&T;, on the other hand, controls most of the long-distance trunk lines, the oldest being the 4-inch-thick Los Angeles-to-Santa Barbara cable that burrows under Cahuenga Pass and follows the Ventura Freeway out of town.

Other lines include cables from Sherman Oaks north up the San Diego Freeway; a pair that work their way down San Fernando Road from Newhall, one going to Los Angeles, the other to San Bernardino, and a new fiber-optic line from Los Angeles to Santa Barbara that, when finished, will follow the Southern Pacific railroad tracks west before heading to Simi Valley.

All sewers in the Valley can be traced to the original North Outfall Sewer line constructed parallel to the Los Angeles River in 1929. Today, there are 3,000 miles of lines from homes and businesses that dump into 300 miles of larger sewage transmission pipes. Two other working lines are older, the DWP’s 1913 Owens Valley Aqueduct and an Arco oil pipeline dating from 1925.

Major sewer pipes average 3 1/2 feet in diameter, but are up to 8 feet wide in the vicinity of the Donald C. Tillman water purification plant in Van Nuys, which is capable of recycling 40 million gallons of water daily.

If something is lost in the sewer system, it will reappear at such places as Tillman. In addition to a never-ending stream of softballs, workers have found everything from jewelry and money to a complete motorcycle. The sewer system is also the Valley’s manhole champion, with about 45,000. Pacific Telephone comes in a distant second with 6,000.

“Storm drains usually follow the street pattern,” said George Groves of the Los Angeles Bureau of Engineering. “Where the street goes, so go the drains.”

Besides sewers, most major north-south streets have some form of storm drain system about 10 feet below, with major arteries ranging anywhere from 5- to 9-foot-wide pipes.

The largest of the storm drains, measuring 17 feet wide by 10 feet high, runs along Topanga Canyon Boulevard from underneath Topanga Plaza south to Calabasas Street and Mulholland Drive.

As with the sewer system, everything imaginable is found by city workers in the storm drains, especially mattresses. Skateboarders have been known to ride some of the steeper sewers, something the city learned only after homeowners complained of hearing squeals of delight coming from the catch basins. “Today,” said Groves, “we have to put speed bumps in some of the open basins to keep kids from skating.”

Witnesses to a gas main rupturing say it has all the fury of standing next to a jet engine. Two years ago at Burbank Boulevard and Lindley Avenue, a pipe broke during a repaving project, the pressure physically raising the street as the gas moved underground. It did not ignite.

Southern California Gas Co.’s main line enters the Valley through Newhall, journeying to an underground storage facility in Aliso Canyon just above Northridge. The porous sandstone below Aliso Canyon, a depleted oil field, allows the gas company to pump the gas, up to 70 billion cubic feet of it, into the ground, where it is stored for future use.

The gas company’s 125 miles of transmission mains, 2,600 miles of distribution lines and the miles of individual hookups to homes and businesses raise the total gas pipeline figure to about 15,000 miles, company officials estimate.

Radiating from Aliso are two major lines that supply the Valley as well as move the gas to other parts of Los Angeles. One shoots down Wilbur Avenue to the south end of the Valley, another travels below most of Reseda Boulevard, two are buried beneath most of Burbank and Ventura boulevards. Other major lines can be found beneath Woodley Avenue, Balboa Boulevard and White Oak Avenue.

Spokesmen from almost every company with underground facilities say 80% of their puncture problems come from somebody operating a backhoe. But that was not the case on Sept. 10 with the Mobil Oil line in Encino.

According to Mobil, corrosion created by contact with a nearby water line caused a break in the oil line, which parallels Woodley Avenue through the Valley. Then on Sept. 26, during a routine pressure test, the system sprang a leak in the same area. “It wasn’t a rupture. It was kind of like a self-inflicted gunshot wound,” said Tim Selles of Mobil Oil. Whatever they were, the problems have prompted state Sen. Herschel Rosenthal (D-Los Angeles) to propose legislation requiring more rigorous testing of underground pipelines.

Mobil is one of six oil companies operating nine pipelines that crisscross the Valley.

The oldest belongs to the Four Corners Pipeline Co., a subsidiary of Arco. Laid in 1925, it parallels San Fernando Road from Sylmar down through the city of Burbank. The second Arco line follows the Hollywood Freeway south before heading up and over Laurel Canyon.

Two pipelines, one owned by Shell, the other by Unocal, follow the Ventura Freeway through Calabasas. Both roughly parallel each other up Mulholland Highway and follow the mountain crest before turning south into Mandeville Canyon. A second Shell line enters the Valley through Santa Susana Pass in Chatsworth, makes its way along Roscoe Boulevard to Sepulveda and heads south.

Chevron operates one of the only lines specifically designed to serve the Valley rather than just travel under it. A single line runs north through the Sepulveda Pass and ends at a storage terminal at Sepulveda Boulevard and Oxnard Avenue. The company also operates the shortest pipeline, a four-block operation in Pacoima on Paxton Street that connects with an Arco line. Finally, there is a four-mile Texaco line operating from Aliso Canyon east to San Fernando Road.

It falls to the state fire marshal to monitor and inspect all hazardous underground material. Until this year, pipelines operating below a certain pressure did not have to be reported. So when an aviation fuel line was ruptured by a backhoe at San Francisco International Airport last year, the fire marshal had no knowledge of its existence.

“Before Jan. 1, nobody would have had to tell you unless something happened,” said Arnold Moodie, supervising engineer of the state fire marshal’s office. “If this accident hadn’t happened, we still wouldn’t have known it was there.”

Locally, Underground Service Alert of Southern California helps prevent contractors--even after they have secured their digging permits--from inadvertently putting a backhoe through a pipeline or telephone cable. “Before digging, state law requires you must call and find out if there is anything down there,” said Ron Olitsky, president of Underground Service Alert.

A call two days in advance of digging enables the nonprofit corporation to check its maps and call any subscriber showing an interest in that sector. Anyone who has underground facilities must belong to USA; their membership pays for the service.

“We then get the information of where, what, when and who, transmitting it to those owners who have underground lines in that area and alert them that an excavation is going to take place,” Olitsky said. “They then go out and mark and locate those lines where there may be a conflict.

“We don’t have the maps, the blueprints or anything that delineates where or what it is,” Olitsky said. “What we are is the communications link between the excavators in Southern California and the owners of underground lines.”