The gas does not pose a risk to health or safety, but city officials decided to close the park so its source could be determined, The Los Angeles Times reported.
City officials and representatives from Plains Exploration & Production and California's Division of Oil, Gas and Geothermal Resources have investigated an unexplained water seep and low levels of methane gas but have not determined its cause.
In a statement, city officials said, "preliminary air samples indicated a very low level of methane gas is present."
Officials decided to keep the dog park closed to make it easier for Plains Exploration & Production to make any necessary repairs, the report said.
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