Martin Heinrich is a Democrat representing New Mexico in the U.S. Senate.

Last month, a large plume of bright orange toxic waste spilled into the Animas and San Juan Rivers and polluted the Four Corners region.

When I toured affected areas following the Gold King Mine spill, I visited with impacted residents and joined the San Juan County Fire Department to deliver water to farmers in Aztec. I was also briefed on the coordinated approach from the Environmental Protection Agency and other federal agencies working with state, local, and tribal officials, including Navajo Nation President Russell Begaye.

I share the anger and frustration over this terrible accident and have demanded that the EPA act with urgency to protect the health and safety of our communities and repair the damage inflicted on the watershed. This must be our first and top priority. New Mexicans can count on me to conduct aggressive oversight as this work is completed.

But we must also look over the horizon and take action to clean up the hundreds of thousands of similarly contaminated mines across the West that are leaking toxins into our watersheds.

For decades before the spill last month, the Gold King Mine leeched water laced with heavy metals and sulfuric acid into Cement Creek, a tributary of the Animas River. Over the last 10 years, an average of 200 gallons of highly polluted water per minute — or more than 100 million gallons per year — flowed out of the mine. To this day, the Gold King and other un-reclaimed mines in the San Juan Mountains are still leaking into the watershed.

This widespread problem is all too familiar to some in the region. In 1975, in an even larger accident than the Gold King blowout, a large tailings pile near Silverton spilled 50,000 tons of toxic heavy metal into the Animas watershed. Four years later, a breached dam at a uranium mill tailings disposal pond near Church Rock, New Mexico sent more than 1,000 tons of solid radioactive waste and 93 million gallons of acidic liquid into the Rio Puerco.

There are estimates that 40 percent of Western watersheds have been polluted by toxic mining waste and that reclaiming and cleaning up abandoned mines could cost upwards of $32 to $72 billion.

This latest accident serves as yet another wake-up call to fix our flawed and outdated policies on abandoned mines and hardrock mining.

During the era of Manifest Destiny, the federal government encouraged Americans to settle newly acquired lands in the West by passing laws — like the Timber and Stone Act of 1878 and the Desert Land Act of 1878 — that gave away public lands and resources to private users with no strings and often no price tag attached.

The General Mining Act of 1872 came along in this era of unrestrained Western expansion. It allowed individuals and companies to claim ownership of minerals in the public domain — such as gold, silver, copper, uranium, molybdenum, and others — simply by locating a mineral source, staking a claim, and paying $5 an acre for the land. Miners did not have to consider environmental impacts or make any plans to clean up the waste they left behind, which has created the pollution and contamination we confront today.

This law drew thousands of people to the West — my father and my mother’s father both made their livings working in hardrock mining. But shortsighted policy also left behind a scarred legacy on our lands.

Unlike other 19th century western settlement laws, which have long since been reformed or replaced, the Mining Act of 1872 is still on the books.

While developers of resources like oil, natural gas, and coal pay royalties to return fair value to taxpayers for our public resources, hardrock mining companies can still mine publicly-owned minerals for free, and without a plan to address a century of pollution from abandoned mines.

We need to bring our mining laws into the 21st century. I am working with Sen. Tom Udall, D-N.M., and Rep. Ben Ray Luján, D-N.M., on legislation to require that reasonable royalties and fees from hardrock mining be used to create a dedicated funding stream for cleaning up toxic mine waste. A reclamation program will allow states, tribes, and non-profit organizations to collaborate on projects to restore fish and wildlife habitat affected by past hardrock mining.

We also need to reform the permitting process for new mines. Under this legislation, operators will need to protect water and wildlife resources and provide financial assurance that they can fund reclamation and restoration efforts after their mines close.

Another component of reform that I support is updating the Clean Water Act to allow Good Samaritan organizations — groups willing to conduct mine reclamation and habitat restoration projects — to help Western communities clean up abandoned mines without assuming financial and environmental liability for sites that they did not contaminate.

I appreciate the value of the hardrock mining industry and recognize that the industry continues to provide good-paying jobs throughout the West. Some mining companies are already stepping up to help clean up old mining waste sites. I look forward to working with industry stakeholders to bring our policies up to date.

Passing long overdue reforms to our federal mining laws is critical if we want to prevent future disasters like the Gold King spill and protect the health of our communities, land, and water.