A faint plume of smoke against a clear August sky signaled the ominous beginning of a wildfire in New Mexico’s Sangre de Cristo Mountains. The blaze ignited near the village of Cundiyó, rapidly consuming drought-stricken canyons surrounding the Río Frijoles. This delicate ecosystem, vital to the region’s agricultural heritage, now faces the dual threats of fire and potential contamination.

The Río Frijoles, a thirteen-mile stream, along with the Río en Medio, originates in the Sangre de Cristo range and flows into Santa Cruz Lake. This reservoir serves as a critical water source, releasing its contents into the Santa Cruz River, which is further augmented by the Río Quemado. For centuries, this water has sustained the small family farms of historic communities through a network of approximately thirty hand-dug channels known as acequias. These ancient irrigation systems, collectively owned by some 3,000 parciantes (members), predate the Santa Cruz Dam by many generations and are recognized as political subdivisions of New Mexico, overseen by commissions and individual mayordomos responsible for distribution and maintenance.

The Frijoles Fire, however, placed more than half of the Río Frijoles directly in its path, jeopardizing the health of the entire watershed and the future of the area’s irrigation. Ron Gallegos, chair of the Santa Cruz Irrigation District, described the tense wait for news as the fire spread. "Once it started, I was just waiting for a call, a text, a message from somebody to see if they could pump water from the lake," he recalled, referencing the crucial role the reservoir played in firefighting efforts.

Within days, U.S. Forest Service aircraft began drawing water from Santa Cruz Lake to combat the flames, employing aerial drops of water and fire retardant. Gallegos’s district entered into a contract with the agency, receiving a nominal payment of one cent per gallon of water used. While the compensation, totaling around $8,500 for approximately 850,000 gallons, was modest, the paramount concern was safeguarding the watershed that supports the livelihoods of some 3,000 people.

As of early October, nearly two months after the Frijoles Fire ignited, containment efforts had reached about 90%. Initial assessments indicated that much of the fire burned at low intensity, a factor that could potentially mitigate long-term ecological damage. Nevertheless, concerns persist regarding post-fire flooding and its impact on water quality. Increased sediment runoff could cloud Santa Cruz Lake, and local communities are apprehensive about the potential effects of this sediment and the fire retardant chemicals on the water they rely upon for survival.

Even before the Frijoles Fire, the region’s irrigation systems had been under immense strain due to the increasing volatility of weather patterns. Recent years have witnessed extreme shifts between prolonged drought and torrential downpours, making water management precarious. This year, a combination of minimal snowpack and persistently high temperatures severely curtailed natural runoff. Hydrogeologist and geochemist Steve Finch described the situation as potentially "the worst on record," noting that a U.S. Geological Survey gauge near the lake registered a mere four cubic feet per second throughout the summer, a stark contrast to the usual twenty to thirty cubic feet per second.

The low water levels, coupled with warmer temperatures, contributed to an unusually early and potent algae bloom that transformed the lake into a murky green expanse, emitting a strong, unpleasant odor. Joel Esquibel, who maintains the Santa Cruz Dam much like his father before him, meticulously monitors the lake’s water levels. He expressed growing unease as the fire encroached, observing that the water level had not been this low since the reservoir was dredged in the late 1980s. However, by the end of September, a moisture plume from Hurricane Polo brought a welcome fifteen-foot rise in the lake’s elevation.

Yet, the threat of excessive water also looms large. In 2025, a historic flood inundated acequia infrastructure, halting irrigation for months as communities grappled with rebuilding headgates and clearing debris and silt, a process that incurred significant costs and time. This past September, heavy rains, reminiscent of the 2025 flood, washed fire debris and sediment into the lake. Finch voiced concerns that this influx will diminish the reservoir’s storage capacity. He estimates that Santa Cruz Lake has accumulated approximately 1,000 acre-feet of silt over the past century, representing about a quarter of its original capacity. The exact amount of silt deposited by the recent post-fire rains remains undetermined, but Finch anticipates that the reservoir will eventually require dredging to restore its storage capabilities.

The immediate aftermath of the fire’s ignition on August 4th saw a proactive move by New Mexico Representative Teresa Leger Fernández. She formally requested the Government Accountability Office, a federal watchdog agency, to investigate the prevalence and potential environmental impacts of toxic metals present in fire retardants used by the Forest Service and the Department of the Interior. The letter, co-signed by eight other members of Congress, acknowledged the "essential, lifesaving support" provided by aerial firefighting operations while highlighting recent concerns regarding the safety of commonly deployed retardants.

A spokesperson for the Forest Service stated that all fire retardants used by the agency fall under the Environmental Protection Agency’s "practically non-toxic" classification for mammals and aquatic species. The Forest Service also maintains a policy prohibiting retardant drops within waterways and sensitive environmental or cultural resource areas. While fire retardants primarily consist of phosphate compounds, widely used in fertilizers, independent investigations in California have detected arsenic, cadmium, chromium, and lead in samples collected after several major wildfires.

These findings echo concerns raised in New Mexico following the devastating Hermit’s Peak/Calf Canyon Fire. Independent analyses conducted three years after that blaze revealed the presence of heavy metals in private well water, with a subsequent report attributing these findings to a combination of natural ore deposits, burnt structures, and fire suppression agents. The Forest Service reported that approximately 453,000 gallons of retardant were deployed on the Frijoles Fire, a fraction of the 1,600,000 gallons used on the much larger Hermit’s Peak/Calf Canyon Fire, which encompassed over 340,000 acres. The Frijoles Fire, by comparison, burned approximately 16,000 acres.

When questioned about the presence of heavy metals in the retardant used on the Frijoles Fire at a public meeting, a deputy district ranger for the Santa Fe National Forest directed inquiries to the manufacturer. The president of the Americas Retardants business at Perimeter Solutions, the manufacturer of PHOS-CHEK, clarified that no heavy metals are intentionally added to their formulations, and any trace amounts are naturally occurring within the raw materials. He further stated that the phosphate undergoes extensive processing to reduce heavy metal levels below fertilizer grade.

PHOS-CHEK, a brand of firefighting foam developed by Monsanto in the late 1960s, has been a key component in wildfire suppression. While most of its ingredients are publicly available in safety data sheets, a small percentage remain undisclosed as trade secrets. This opacity prompted a research team from the University of Southern California to investigate the presence of heavy metals in retardants, analyzing data from fires between 2009 and 2021. Their 2024 findings indicated that one particular product, PHOS-CHEK LC95W, used for ground applications and phased out in 2024, contained heavy metal levels significantly exceeding EPA drinking water standards. The agency confirmed the use of a formulation from the same PHOS-CHEK line, albeit with red coloring and aerial application, on the Hermit’s Peak/Calf Canyon blaze.

PHOS-CHEK MVP-Fx, another retardant employed on the Hermit’s Peak/Calf Canyon fire and confirmed by the manufacturer to have been used to help contain the Frijoles Fire, was also utilized in recent major California fires. Subsequent analysis by the USC team identified toxic heavy metals in this formulation as well. The lead researcher noted that a second retardant used on the Frijoles Fire, PHOS-CHEK 259-Fx, was not analyzed due to a lack of access to manufacturer samples.

On the ground, the acequia parciantes remain in a state of anxious anticipation. The entire lake has taken on a dark, ashen hue, and the uncertainty surrounding water quality persists. With no further water releases scheduled for the remainder of the year, any debris and silt that has entered the lake will have the opportunity to settle over the winter months. This natural sedimentation process means that the immediate distribution of these contaminants into the acequias is unlikely this year, offering a temporary reprieve from one immediate threat, but underscoring the long-term challenges facing this vital water system.