STATEPHOTOS: Fire at petrochemicals facility near HoustonEmergency crews continue to douse what's left of the now-extinguished petrochemical tank fire at Intercontinental Terminals Company on Wednesday, March 20, 2019, in Deer Park. Fire crews extinguished the blaze at ITC about 3 a.m., Wednesday, almost four days after it started, which caused a plume of black smoke to linger over the Houston area. ITC officials said the cause of the fire is still unknown. EPA on-site coordinator Adam Adams said they have been in Deer Park since Sunday, conducting air monitoring at ground level and in the plume. Biggest concerns are "volatile organic chemicals" and particulates, Adams said. He added that no hazardous levels have been detected. (Brett Coomer/Houston Chronicle via AP)Austin American-StatesmanHarris County Judge Lina Hidalgo talks about the air quality in east Harris County during a press conference at TranStar Thursday, March 21, 2019, in Houston. National Guard troops have been called in and residents were told to stay inside after elevated levels of benzene were detected early Thursday near a Houston-area petrochemicals storage facility that caught fire this week. ( Godofredo A. Vasquez/Houston Chronicle via AP)Austin American-StatesmanBruce Bechtel, 64, stands next to his 2008 Harley-Davidson Ultra as he watches the plume of smoke caused by the petrochemical fire at the Intercontinental Terminals Company during his lunch break Monday, March 18, 2019, in Deer Park, Texas. The large fire at a Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines.(Godofredo A. Vasquez/Houston Chronicle via AP)Austin American-StatesmanPeople gather to watch as firefighters continue to battle the petrochemical fire at Intercontinental Terminals Company, which grew in size due to a lack of water pressure last night, Tuesday, March 19, 2019, in Deer Park, Texas. (Godofredo A. Vasquez/Houston Chronicle via AP)Austin American-StatesmanEmergency crews continue to douse what's left of the now-extinguished petrochemical tank fire at Intercontinental Terminals Company on Wednesday, March 20, 2019, in Deer Park. Fire crews extinguished the blaze at ITC about 3 a.m., Wednesday, almost four days after it started, which caused a plume of black smoke to linger over the Houston area. ITC officials said the cause of the fire is still unknown. EPA on-site coordinator Adam Adams said they have been in Deer Park since Sunday, conducting air monitoring at ground level and in the plume. Biggest concerns are "volatile organic chemicals" and particulates, Adams said. He added that no hazardous levels have been detected. (Brett Coomer/Houston Chronicle via AP)Austin American-StatesmanFirefighters battle a petrochemical fire at the Intercontinental Terminals Company Monday, March 18, 2019, in Deer Park, Texas. The large fire at a Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines. (Godofredo A. Vasquez/Houston Chronicle via AP)Austin American-StatesmanFirefighters battle a petrochemical fire at the Intercontinental Terminals Company Monday, March 18, 2019, in Deer Park, Texas. The large fire at a Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines. (AP Photo/David J. Phillip)Austin American-StatesmanA plume of smoke from a petrochemical fire at the Intercontinental Terminals Company is shown over downtown Houston Monday, March 18, 2019. The large fire at the Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines. (AP Photo/David J. Phillip)Austin American-StatesmanA plume of smoke from a petrochemical fire at the Intercontinental Terminals Company is shown over downtown Houston Monday, March 18, 2019. The large fire at the Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines. (AP Photo/David J. Phillip)Austin American-StatesmanA plume of smoke rises from a petrochemical fire at the Intercontinental Terminals Company Monday, March 18, 2019, in Deer Park, Texas. The large fire at the Houston-area petrochemicals terminal will likely burn for another two days, authorities said Monday, noting that air quality around the facility was testing within normal guidelines. (AP Photo/David J. Phillip)Austin American-StatesmanFirefighters continue to battle the petrochemical fire at Intercontinental Terminals Company, which grew in size due to a lack of water pressure last night Tuesday, March 19, 2019, in Deer Park, Texas. (Godofredo A. Vasquez/Houston Chronicle via AP)Austin American-StatesmanGolfers practice at the Battleground Golf Course driving range as a chemical fire at Intercontinental Terminals Company continues to send dark smoke over Deer Park, Texas, Tuesday, March 19, 2019. (Melissa Phillip/Houston Chronicle via AP)Austin American-Statesman