Received a private e-mail:
“I also know that there is some type of oil pipeline that runs under either Cobb or Gehrig Streets. We had a seepage there back in the 80’s (oil coming up out of the asphalt) but we could not determine who’s it was or where it was going or coming from. There was probably an old oil field in the area before the homes were built.”
See also Historic Oil Wells In Placentia.