Oklahoma Department of Environmental Quality

University of Oklahoma professor Bob Nairn stands on a bridge overlooking Tar Creek, which is contaminated with arsenic, cadmium, iron, lead and zinc from decades of mining.
Joe Wertz / StateImpact Oklahoma

The Tri-State Mining District in northeastern Oklahoma’s Ottawa County was once the world’s largest source of lead and zinc. The mines had closed by the 1970s, butpernicious pollution still plagues what is now known as the Tar Creek superfund site.

Hugo Lake Dam following recording-breaking rainfall in May 2015.

The company that runs Hugo’s water treatment plant is contesting the $3.17 million fine the Oklahoma Department of Environmental Quality levied against it for — as the Journal Record‘s Sarah Terry-Cobo reported in August — not using “enough chlorine for more than 300 days over the course of two years.”

Algae grow on the floor of the pipe room in the Hugo water plant because water leaks constantly, as shown in this late July photo.
Sarah Terry-Cobo / The Journal Record

About 7,000 residents in Hugo lived for months with unsafe drinking water because a private company improperly disinfected municipal water supplies and misreported data to local and state officials.

water well
Kashif Mardani / Flickr

The Oklahoma Department of Environmental Quality is offering free bacterial testing of private well water due to statewide flooding.

The agency announced Tuesday that the testing will be available until August 15.

The National Weather Service issued multiple tornado warnings Monday as a storm system spawned twisters and high winds across much of central and eastern Oklahoma.

Ozone is a major contributor to smog, seen here blanketing Los Angeles.
Pieter Edelman / Flickr

The U.S. Environmental Protection Agency’s proposal for stricter ozone standards has been praised by environmentalists as a step in the right direction and derided by industry groups, which argue the rules will cost jobs and lead to higher prices for electricity and natural gas.

Traffic moves along I-44 just west of a syrup spill that shut down one lane of the highway Wednesday morning.
Oklahoma Dept. of Transportation

Oklahoma is in compliance with the National Ambient Air Quality Standard for ozone as the 2014 ozone season draws to a close.

Compliance is determined by an average at each ozone monitoring site in the state. Drought and high temperatures in 2011 and 2012 resulted in the state exceeding the standard at monitors across the state. The 2013 and 2014 ozone seasons have been dramatically better.

While the control of emissions contributed to the lower ozone readings, other factors including weather, fewer wildfires and less demand for electricity also played a role.

Mass. Dept. of Energy / Flickr.com

The Environmental Protection Agency and Oklahoma Department of Environmental Quality will meet next week to discuss cleanup plans for the Tulsa Fuel and Manufacturing Superfund Site in Collinsville.

The Sept. 11 meeting will be held at Collinsville City Hall.

The site is an abandoned 60-acre zinc smelter, and cleanup of the site includes the consolidation and capping of waste, contaminated soil and sediments.

Source: Oklahoma Hazardous Materials Emergency Response Commission

Trains carrying 1 million more gallons of crude oil from the Bakken formation are expected to cross 20 Oklahoma counties each week, data from the Oklahoma Hazardous Materials Emergency Response Commission show.

Explosive, deadly derailments and fiery accidents have raised safety concerns about rail transport of North Dakota Bakken crude oil, which tests suggest might be more explosive than other types of crude oil.

car exhaust
Simone Ramella / Flickr Creative Commons

The Oklahoma Department of Environmental Quality says Thursday will have conditions favorable to the formation of ground-level ozone air pollution, and declared an Ozone Alert Day for July 24.

Sam Beebe / Flickr Creative Commons

In the wake of deadly derailments, fiery explosions and dangerous spills, the federal government in May ordered railroads to share with state authorities more information about some crude oil shipments.