The Los Angeles County waterway has frequently had visible oil and grease in the water for years. One source of the problem that hadn’t been recognized was the La Brea Tar Pits.
This frequently-visited site, it turns out, has been spilling oily waste water into the creek in times of heavy rain, making it even more polluted. The pits attract about 350,000 visitors annually. The runoff from the the pits has been gettin into the storm drain system, on into the creek and eventually into the ocean.
The pits are the result of oil seeping up through the ground. Since the last ice age they have trapped thousands of animals, including woolly mammoths and saber tooth tigers.
The Los Angeles County supervisors voted recently to spend $2 million to build a new system that will clean the water before it is deposited into the sewers.