Wastewater from an abandoned gold mine continues to drain into a Colorado river, causing it to turn to a mustard-yellow hue.
According to the U.S. Environmental Protection Agency, the wastewater contaminated with heavy metals such as cadmium, arsenic, copper, lead and zinc is leaking into the river at a rate of more than 2,000 liters per minute.
EPA workers were conducting a cleanup of Colorado's Gold King Mine when they accidentally breached a debris dam Wednesday, causing nearly 4 million liters of wastewater to spill.
The spill from the mine flowed from the Animas River, which leads to the San Juan River in New Mexico and Utah, later joining the Colorado River near Lake Powell, located in southern Utah and northern Arizona.
Near the mine, the EPA said the water registered at a pH level of 3.74, similar to the acidity of tomato juice, but further downstream pH levels measured at 4.8, which is closer to the acidity of black coffee.
The EPA said it has built two retention ponds to begin trapping and screening out the yellow contaminants.
The amount of time needed for cleanup efforts is unknown.
Local officials in affected areas have shut down the river's access to water treatment plants. While the EPA has warned people to stay out of the river and to keep domestic animals from drinking it.