Some underground water supplies in Livermore show signs of contamination, according to a newly released report ordered by Alameda County. The findings come in the wake of a hazardous chemical leak at an oil field owned by E&B Natural Resources.

Eight months ago, county inspectors learned dangerous chemicals seeped out of an oil tank, which contaminated the soil below. Now, the groundwater tests are in and have been released in a 961-page report.

The results from of a groundwater sample show “a low concentration of residual crude oil, very low detections of semi-volatile hydrocarbons, and elevated concentrations of metals.” The report also says, “The laboratory did not filter the sample prior to analysis,” which means the water samples could have contaminated soil in it.

In a statement, the Alameda Department of Environmental Health said since the soil contamination did not go below 15 feet and the depth of the groundwater is 47 feet, “there is little to no risk of residents being exposed to contamination, as the oil has now been excavated and removed from the site.”

The cleanup effort and all groundwater and soil testing have been paid for by E&B as part of a voluntary agreement it struck with Alameda County's Department of Environmental Health.

Earlier this month, the Investigative Unit uncovered emails between the county and E&B which showed the oil company opted to pay $4,351 in additional fines in order to avoid making a "formal" acknowledgement of its failure to report the hazardous chemical leak to state and local regulators.

E&B would not comment on the most recent groundwater findings, but cited a preliminary report issued last month, which found the leak did not pose a threat to "water supply wells or groundwater resources in the area." A spokesperson for E&B said the company will also pay for additional water sampling. The results of that testing are due in February.

The Center for Biological Diversity, an environmental advocacy group based in Oakland, said the latest developments concerning the Livermore leak are a reminder of the risks of oil production. The group has also raised concerns about the response effort mounted by Alameda county.

"In an emergency like this, county officials should be moving quickly to contain the damage and broaden the testing," Hollin Kretzmann, a staff attorney with the group, said in a statement. "Instead, they’re still dragging their feet.”