UPDATE: Waste Management officials say the lab has been reopened, while a state review has found the lab to be in compliance with rules and regulations. The U.S. EPA investigation continues, however.
The U.S. Environmental Protection Agency is investigating Waste Management's Kettleman Hills Facility laboratory.
The lab plays a crucial role in ensuring environmental safety at the toxic landfill.
According to a letter dated in May of 2010, U.S. EPA regulators are concerned about the lab's environmental test results. In the letter, EPA officials claim the lab has a history of "poor quality control."
The letter goes on to say that unreliable test results could lead the company to violate state hazardous waste requirements. EPA began looking at the facility after test results provided by Chemical Waste, a subsidiary of Waste Management, did not match the EPA's findings.
A Waste Management spokeswoman declined to give recorded comment, instead issuing an email statement. Waste Management's Jennifer Andrews says the company is fully cooperating with investigators.
The EPA strongly suggested in the letter the company should halt lab testing until the investigation is complete. Waste Management has not used the facility since then. Currently a third part vendor is doing the lab work.
"We have confidence in our lab and await the ok to resume using it," Andrews writes.
Greenaction's Bradley Angel is a critic of Waste Management. Angel questions the company's claims that it works closely with regulators to comply with environmental rules.
"Because, if you look at the big picture, there's an investigation about their lab results. How does that jive with the fact that Chem Waste has a long and well documented history of enforcement actions by the EPA against them?," Bradley asks.
"People should be concerned," he adds.
On Thursday, Waste Management released a study showing PCBs and other dioxin like substances from the facility pose little risk to human health.
The EPA stressed the investigation into the lab is in no way connected to that study.
In 2010, the EPA fined Waste Management over $300,000 for mishandling PCBs at the facility.
For more information about the facility, and the toxicity concerns in Kettleman City, click here for CPR's Toxic Town series.