Month: July 2017

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eNews July 2017

Notes from the 2nd Annual Conference on Environmental Conditions of the Animas and San Juan Watersheds with Emphasis on Gold King Mine and Other Mine Waste Issues (continued)

Between 1871 and 1935, an estimated 8.6 million short tons of mine tailings were deposited directly into the Animas River. Decades of industrial and mining impacts brought myriad environmental regulations, but none that required mining companies to reclaim the disturbed land and tailing piles. In the Animas Watershed, an estimated 5,397 mine shafts, adits, and tunnels created new pathways for increased water flow through the rocks and reduced weathering process time to years. Many of the tailing piles remain in the same location for decades, slowly eroding into the watershed. Thus, acid mine drainage has been chronic in the Animas Watershed for more than a century.

On August 5, 2015 while assessing the feasibility for mine remediation, the U.S. Environmental Protection Agency (EPA) accidentally triggered the release of mine-impacted water from the Gold King Mine in Silverton, Colorado. Over a seven-hour period approximately three million gallons of acid mine waste flowed from Cement Creek into the Animas and then San Juan Rivers and ultimately ended up in Lake Powell in Utah. Numerous federal, state, and mainly, local agencies responded.

The Gold King Mine release created a spike in dissolved heavy metals in the waterway, most coming from the rapid erosion of the adjacent mine tailing piles. According to an EPA report, mines in the Upper Animas Watershed discharge an average of 5.4 million gallons per day. The volume of the release was equivalent to four days of current acid mine drainage (EPA, 2016).

Monitoring started immediately following the spill and is still ongoing. Several agencies and universities analyzed soil and water samples to understand the fate of the metals from the Gold King spill. Water and soil samples were collected at 310 locations between the Gold King Mine and Lake Powell. The results of the continued monitoring suggest that metals from the Gold King Mine spill were flushed from the rivers and delivered to Lake Powell by the end of May 2016.

Members of the community are concerned with the negative attention the event brought to the area, particularly the impact on agriculture. Researchers assured the audience that in fact, there appears to be no negative impacts on agricultural products from the area from the Gold King Mine release. However, researchers are still concerned about the social and economic fall-out from the spill. During the final conference panel discussion, those involved in the response to the Gold King Spill provided their perspective on what would help make the community whole again. Community members in attendance were encouraged to direct concerns and questions to the panel. The State of New Mexico continues to seek compensation from the EPA for those who have been damaged. Preparedness was a common theme in the discussion, in particular, the ability of the EPA to coordinate response efforts more effectively in situations where watersheds cross multiple EPA regional jurisdictions (three for the Gold King Mine). Navajo agriculturalists have concerns with water quality and the emotional impacts from the spill. Outreach efforts are underway by extension agents and citizens’ advisory committees to ease concerns over water quality.

The problem of acid mine drainage is this region is well known, and the spill brought heightened awareness to communities and researchers. Emergency response to potential future releases is being improved. The EPA designated the Gold King Mine a Superfund site, and it now operates a treatment facility to manage water from the Gold King Mine. Further work needs to be done to address the hundreds of other mines that are actively discharging acid mine drainage into the Animas Watershed.

A third conference will be held in the summer of 2018.

For links to the presentations click here.

Environmental Protection Agency (EPA). 2016. One Year After the Gold King Mine Incident: A Retrospective of EPA’s Efforts to Restore and Protect Impacted Communities. August 1, 2016. https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=530074

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eNews July 2017

Final Report on Debris Flow Potential Following Wildfires in Watershed Near Santa Fe Now Available (continued)

Previous studies have established models based on statistical data from past forest basin burn events that estimate the debris-flow probability and intensity as a function of areal burn extent, soil properties, basin morphology, and rainfall from different types of short-duration storms. Models of this kind have been adapted for use in this study by making reasonable assumptions and estimates regarding these significant physical properties. In particular, a series of GIS-produced maps and accompanying data have been produced that show the estimated probability and volume of post-fire debris flows for SFMW, given a 2-, 5-, and 10-year, 30-minute rainfall event following a moderate to high severity wildfire. For their study, they have also hypothesized that watershed basins with slopes greater than 30% are to be identified as the potential debris flow zones.

As expected, this study confirms that increases in storm intensity increases yield in potential debris flow volumes. The highest values are located in the main stream channels, most notably the Santa Fe River. As side tributaries converge and gather further debris, the main channel could carry tens of thousands of cubic meters of debris into the McClure Reservoir, which supplies water for Santa Fe. For a 10-year recurrence storm, the sum of all sub-basin sediment volumes was estimated to be in excess of 100,000 cubic meters. As a result, the authors are confident that if a severe wildfire were to occur in the SFMW, debris flows would have a high probability of occurrence pending a large storm event. The negative impact on the freshwater supply for the city would be significant, and would also entail a considerable expense for the subsequent required dredging of the McClure Reservoir. The results of this study may help provide city and forest managers with an opportunity to prepare for and mitigate potential issues associated with debris flows.

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eNews July 2017

NM WRRI Receives Funding from USDA to Address Critical Agricultural Water Resources Issues (continued)

Dr. Zohrab Samani from NMSU’s Civil Engineering Department will conduct field experiments where multiple levels of water and salinity stress are imposed on a select group of crops that comprise more than 90% of the irrigated agriculture in the area. These crops are subject to various soil textures and properties including salinity. After identifying factors that affect crop stress, farmers and water managers will receive training to identify problems, and to maintain, repair, and manage systems for optimum water use efficiency and economic return.

Dr. April Ulery of NMSU’s Plant & Environmental Sciences Department will conduct field studies at the US Bureau of Reclamation’s Brackish Groundwater National Desalination Research Facility in Alamogordo, NM. She will be evaluating potential bioenergy crops such as canola, blade sorghum, and switchgrass in a saline environment using drip irrigation. Drs. John Idowu and Robert Flynn from NMSU’s Department of Plant Extension Sciences will also take part in the project and provide extension outreach to local farmers interested in improving crop yields using salt tolerant crops and alternative water sources.

NMSU’s Physical Science Laboratory’s Flight Test Site will support the flight sensor acquisition, installation, operation, and data collection from flights over the New Mexico field sites. The Site’s personnel will develop and fly the overflight missions to ensure the desired data and images are collected and assist in the processing of the raw sensor data for mapping the geospatial data acquired.

Since 2014, NIFA has awarded nearly $42 million through the Water for Agriculture Challenge Area. Project details on all the NIFA project can be found at the NIFA website: www.nifa.usda.gov.

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eNews July 2017

UNM Student Studies Effects of Las Conchas Fire on Soil Chemistry

UNM Student Studies Effects of Las Conchas Fire on Soil Chemistry

The 2011 Las Conchas fire in the Jemez Mountains of New Mexico has had lingering effects on nearby surface water and waterways, primarily due to the leaching of burnt soils. Such effects of wildfires are typically exacerbated by the fact that the monsoon season follows after the wildfire season. Amanda Otieno, an NM WRRI 2017 student grant recipient who is completing her master’s degree studies in Water Resource Management at UNM, has just published her final report on a field and laboratory study of the chemistry of soils exposed in varying degree to the wildfire. Her faculty advisor for this research is Professor Rebecca Bixby, of the UNM Biology Department. Additional assistance has come from UNM Professor Ali of the Earth and Planetary Science Department and Professor Cerrato of the Civil Engineering Department.

For this study, thirty-two soil samples were collected from the Sierra de los Valles dome within the Valles Caldera National Preserve (VCNP) in Jemez, New Mexico. Eight samples were collected from each of four different areas classified in terms of burn severity, labeled respectively as high, moderate, low, and unburned areas. The top three inches of soil were collected, and the soil texture type was found to be mostly loamy, containing roughly equal proportions of sand, clay, and silt, although six sandy loam samples, containing less clay, were collected from the unburned area. Equal numbers of samples were taken in winter and spring to capture some seasonal influences.

Soil samples were analyzed chemically by first partially dissolving them in strong acids to produce positively charged molecular fragments in solution (metal cations), and negatively charged counterparts (anions). Dissolved metal concentrations were then determined by inductively coupled plasma optical emission spectrometry. In this technique, small samples are sprayed into an extremely hot plasma flame, which produces highly energized metal ions which, in turn, emit light with a spectrum of wavelengths that is different for each element and can, therefore, serve as a means of identification. Since anions are often small molecular groups that would be destroyed by intense heat, a different approach, called ion chromatography, was used to determine their concentration. Chromatography involves the migration of charged molecules in a controlled chemical environment.

The research shows that the Las Conchas fire has had long lasting impacts on the chemical composition of soil in the VCNP. Twenty-two metals were analyzed and sixteen were found to be significantly different among the burn severity categories. The majority of differences were between the high/moderate and low/unburned groups for elements: Al, As, Ba, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Si, Sr, and V. Cobalt and vanadium were the only two metals showing a significant mean difference among sites for both December and April samples. Lead was one of the few elements to show differences between the high and moderate burns. Concentrations of magnesium and nickel in the low burn severity sites differed from those in the remaining three categories. The presence of heavy metals in particular is of concern for their influence on plant and animal life in these environments. Wildfires simultaneously mobilize heavy metals in the soil that are typically inert and restrained, and introduce metals from the overlying vegetation as ash deposits. Burn severity influenced the mean concentrations of metals but there was no trend indicating higher or lower mean concentrations by burn severity, whereas mean anion concentrations appeared to vary collectively with burn severity. The overall distribution of anions was higher in high/moderate burn areas; however, statistical tests showed that this outcome may have been due to chance. The only anions having a significant difference among the four burn categories were bromine in December and nitrite in April.

Soil is a medium for metals and anions to collect, but may also be a transporter of these substances when a disturbance is introduced into a system. A wildfire will disrupt the aggregate capacity of soils, making them more susceptible to erosion during precipitation events. Thus, burnt soils have a high potential for entering and affecting waterways in areas like the VCNP. Continuous inputs of these constituents may possibly affect the aquatic and/or terrestrial environment. It is therefore important to understand the distribution of metals and anions in surface soils of different burn severities, as well as their interaction with nearby surface water. This study helps to describe some of the long-term changes expected for soils exposed to wildfire, which may therefore provide additional insight into achieving better management practices. The New Mexico Environment Department, the Valles Caldera National Preserve, and the Forest Service are examples of agencies that may benefit from such analyses.

The final report for the project entitled: Characterization of Metals in Soil Contributions to Runoff Events Following Wildfires, contains many tables and graphical displays of metal and anion concentrations for the different circumstances considered in the study. These results can be viewed online by clicking here.

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