A second chemical was mixed in with the previously identified MCHM crude that leaked from a storage tank at Freedom Industries chemical company earlier this month and tainted drinking water in a large swath of West Virginia, a spokeswoman for Gov. Earl Ray Tomblin told Al Jazeera Tuesday evening.

State authorities said that earlier Tuesday they had received a document from Freedom Industries indicating the presence of the second substance, a modified form of a chemical called PPH. The chemical appears to be less toxic than MCHM, government authorities said, but further study will be required.

State regulators sharply criticized Freedom Industries for failing to report the presence of a second chemical earlier and ordered the company to disclose everything that leaked into the Elk River from their storage tank by 4 p.m. Wednesday.

"Having to order them to provide such obvious information is indicative of the continued decline of their credibility," said Randy Huffman, secretary of the state's Department of Environmental Protection.

Freedom Industries replied to the DEP order in a letter late Wednesday night saying that no other chemicals were present in the tank.

"PPH is added to the Crude MCHM to act as an "extender," in that the Crude MCHM is available in limited, sporadic quantities," the letter said.

The chemical spill into the Elk River prompted authorities to impose a Jan. 9 ban on drinking, bathing or even touching water from taps. The ban was lifted Jan. 19, but residents this week were still reporting symptoms such as rashes or nausea after coming into contact with the water. Some also complained of a strange, licorice-like odor emanating from taps and toilets.

On Wednesday afternoon, the West Virginia American Water Company (WVAW), the company responsible for the region's water supply, released a statement announcing that ongoing water sampling and testing had found "non-detectable" or "extremely low" levels of MCHM, a material used in the processing of coal, throughout the affected Kanawha Valley area.

“Data points collected by our interagency team over the past few days indicate decreasing levels of MCHM,” said the company's president, Jeff McIntyre. “The majority of samples are reading Non-Detectable. In areas where sample results show levels above the non-detectable limit, they are still extremely low and only a fraction of the CDC-established 1 ppm health-protective limit.”

The West Virginia governor’s office had strong words for the chemical company in the wake of the second chemical revelations.

"It was Freedom's responsibility to let people know there was another chemical in the tank and they did not," Amy Goodwin, the director of communications for Gov. Tomblin, told Al Jazeera.

"At this point there is very limited trust in any of the information that is being provided by Freedom, but the second we found out about it, the Department of Environmental Protection, the Department of Health and Human Resources, the National Guard and the Office of Homeland Security went out and did testing within the system," she said.

The Environmental Protection Agency (EPA) told Al Jazeera in an email statement that there was likely no cause for alarm.

"Given the small percentage of PPH in the tank and information suggesting similar water solubility as MCHM, it is likely that any amount of PPH currently in the water system would be extremely low."

"However, the water system has not been tested for this material," the statement added.

In its initial assessment of the chemical spill, the CDC also said it is unlikely that the chemical poses any new threat to people's safety.

"An initial review of the currently available toxicologic information does not suggest any new health concerns associated with the release of PPH," a CDC statement read.

Members of the West Virginia National Guard conducted about 20 tests on Tuesday using samples collected from Jan. 9. Their preliminary results also indicated the levels were nondetectable.

Goodwin said the second chemical was a "stripped form" of the chemical PPH, meaning it has certain elements removed from its pure form.

About 300 gallons of the chemical were in the tank, making up about 5 percent of the tank's total capacity, Goodwin said.

The Freedom Industries letter Wednesday, however, stated that 7.3 percent of the tank's capacity was made up of PPH.

During the height of the tainted water crisis last weekend, officials said they were waiting for tests to show that MCHM had dropped to around 1 part per million, which authorities had deemed a safe threshold.

Some residents are still refusing to drink the water, and authorities have warned pregnant women against drinking it until levels of MCHM are undetectable.

According to the local Charleston Gazette newspaper, Gary Southern, president of Freedom Industries, told West Virginia environmental regulator Mike Dorsey about the presence of the second chemical about 10 a.m. Tuesday.

Al Jazeera. David Douglas and Jonathan Martin contributed to this report.