Water is our most precious resource

December 23, 2018

A recent article published in The New Mexican (“Clean water rules could be sullied,” Dec. 11) reported on a Trump administration proposal to reduce protections for the nation’s surface water quality.

The proposal would change the U.S. Environmental Protection Agency’s definition of “waters of the United States,” or “WOTUS,” to limit longstanding Clean Water Act protections for many watercourses, streams and wetlands. Nationally, these reductions pose grave concerns for surface waters relied on for drinking water, recreation, wildlife habitat and other important uses. In New Mexico in particular, these rollbacks would create gaps in water-quality protection for a large percentage of the state’s surface waters. The EPA will take comment on the proposal for 60 days after publication in the Federal Register. For more information, see www.epa.gov/wotus-rule/rulemaking-process.

One of the biggest concerns of the proposed rollbacks is the elimination of water-quality protections for “ephemeral” waters. Ephemeral waters, typically called arroyos in New Mexico, are tributary streams that flow in response to rain events.

Most of the year, they are dry, but during monsoons and other storms, arroyos carry a significant amount of flow throughout watersheds. According to the New Mexico Environment Department, 88,810 miles of our state’s waters flow only in response to rain (ephemeral waters) or seasonally due to factors such as snow melt (intermittent waters). In contrast, only 6,362 miles of our nontribal watercourses flow year-round (perennial waters). The proposed rule, if finalized, could jeopardize protection for a significant percentage of the state’s surface water.

Loss of protection for ephemeral streams is not only an issue in those waters; federal rollbacks could also impact water quality in the state’s major rivers. Pollutants in arroyos are carried downstream during storm events into receiving waters such as the Rio Grande.

In 2015, the EPA published a scientific report regarding the impact that tributary ephemeral waters have on downstream rivers. The report concluded that ephemeral streams can have substantial consequences for the integrity of downstream waters. The report also concludes that although a single pollutant discharge into an ephemeral stream might be negligible, the cumulative effect of multiple discharges could degrade the integrity of receiving waters. Stated another way, impacts to ephemeral streams can affect water quality in important downstream rivers such as the Rio Grande.

The rule, if finalized, will have significant consequences for New Mexico unless we take action to protect our surface water resources. New Mexico is one of three states in the U.S., and the only state in the West, that does not have its own authority to implement the primary Clean Water Act program that protects surface water quality, the National Pollutant Discharge Elimination System permitting program. All states except New Mexico, New Hampshire and Massachusetts have adopted laws and regulations that require state permits to control pollutant discharges into surface waters. State programs can customize the national pollution discharge elimination program to address state-specific concerns rather than relying on the EPA, as we do in New Mexico.

This means that even if the EPA loses its authority to comprehensively protect surface water quality, most states have their own authority to fill that gap. In New Mexico, the Legislature and Water Quality Control Commission have not adopted laws and regulations needed for the state to assume control over surface water quality.

The incoming Michelle Lujan Grisham administration should make state National Pollutant Discharge Elimination System authority a priority, especially in light of proposed federal rollbacks that could jeopardize our state’s surface water quality. Water is our most precious resource, and now is the time for the state to take full control to protect that resource.

Marcy Leavitt worked for 24 years in the New Mexico Environment Department on water-quality issues.

Update hourly