Hurricane harvey: Sewage overflow, toxic chemical spill in Houston

At least 12 sewage overflows and toxic chemical spilling from about 36 industrial facilities were reported in the US city of Houston in the aftermath of the devastating hurricane Harvey that swept through Texas state.

One more container of volatile organic peroxides exploded on Friday afternoon at the Arkema chemical plant, which is about 40 km from downtown Houston, reports Xinhua.

The plant was knocked out of power by floodwaters on Monday. It needs electricity to keep volatile chemicals stored at the facility cool. The first explosion was reported on Thursday.

The chemicals at risk -- organic peroxides -- are stored in nine 18-wheeler box vans, each containing 36,000 pounds. Once they lose refrigeration, they generate heat that causes them to degrade and burn.

Authorities cautioned nearby residents to stay inside, turn off their air conditioning, and close their windows and doors. All employees at the plant were evacuated by late Tuesday, as were residents nearby.

About 36 industrial facilities have reported toxic chemical spills, and 13 of these incidents saw spills into adjacent waterways.

An unknown amount of polychlorinated biphenyls (PCBs) was involved in the spills.

Harvey has set a record for rainfall with almost 1.4 metres in continental US, according to the National Weather Service.

Harvey made landfall as a Category 4 hurricane on August 25, but has since been downgraded to a tropical storm and moved towards east on Tuesday.

So far, 46 people have lost their lives with over 30,000 affected.