Does the Passport Potash, Inc. Holbrook Basin Project Hold Water?
In 2009, I first visited the Cane Creek Facility, operated by Intrepid Potash – Moab, LLC. The main features of the “facility” include a hydraulic (in-situ) mining operation, large settling ponds, plus a processing building and a loading facility for the finished product. While driving along the public road known as the Shafer Trail, I observed the almost total destruction of the natural environment within the confines of the facility. Contemporary large-scale farming requires potash as a fertilizer. Still, I wondered, when is the environmental cost too high for any particular mine to be developed?
In 2010, environmentalist Kathy Hemenway contacted me regarding my research into potash production near Moab. A consortium of mining companies, she told me, was preparing to mine potash from beneath the Holbrook Basin, near her home in Snowflake, Arizona. Over the next three years, Passport Potash, Inc. became the lead company in the effort to mine potash salts in the Holbrook Basin. After making agreements with various ranchers, other mining interests and the Hopi Tribe, Passport Potash commissioned the German consulting company ERCOSPLAN to create a Preliminary Economic Assessment, or “PEA”. In March 2013, Passport Potash, Inc. published the ERCOSPLAN PEA on their website. (Author's note: By 2015, the ERCOSPLAN PEA was available only as a PDF file)
During 2011, I had researched and written a series of four articles on the Holbrook Basin and the Little Colorado River Basin within which it resides. With over-stressed aquifers and a drying environment, the introduction of a Moab-style, in-situ (solution) mine in the Holbrook Basin would reflect an obvious overuse of a diminishing resource. Initially, when I read the 2013 Passport Potash PEA, I was buoyed by the consultants’ recommendation that Passport Potash conduct conventional, “room and pillar” mining at Holbrook.
When I looked deeper into the report, I discovered potential problems with the Passport Potash conventional mining plan. As they say, “the devil is in the details”. The devil, in this case, is the potential overuse of surface water and groundwater in the Holbrook Basin. Although Passport would build conventional shafts and galleries for their mining operations, large amounts of water would be necessary for ore processing and other uses adjacent to the mine. While much of the Passport Potash PEA looked feasible to me, the lack of a comprehensive hydro-ecological survey raised an immediate red flag.
In Moab, Intrepid Potash needs only to drop a siphon into the adjacent Colorado River to suck up the incredible amounts of water required to flush potash salts from deep underground. To my knowledge, there is no public disclosure of the amounts of water required for the “Big Flush” at Moab. With relatively high purity of desired potash compounds, Intrepid Potash uses sunlight to dry their produced brine. After minimal processing, Intrepid Potash is able to ship its final product by rail or truck.
In the Holbrook Basin, however, there is a “high amount of Carnallite (approx. 8%) and the relatively high amount of insoluble material (nearly 5%) in the mineralized material”. Further, the consultants say, “the reliable processing route to obtain a MOP product (commercial potash) will be a variation of the hot leaching/crystallization route”. Since hot leaching is a water and steam-intensive process, “the total water demand for processing, including process water and make-up water for cooling cycles, is approximately 550 m³/h”. That translates to 145,295 gallons or 2.24 acre-feet per hour.
Put into context, one acre-foot of water will sustain a single U.S. suburban household, or up to four “water wise” households for one year. With a full running time of 6600 hours per year, and water usage of 2.24 acre-feet per 
hour, the annual water usage at the Holbrook Basin Project would be 15,840 acre-feet. In context, that amount of water could support between 15,000 and 60,000 households. Flagstaff, which is the largest city in Northern Arizona, has a population of just over 65,000. With a population of about 5,000, Holbrook is the largest city in the Holbrook Basin. When operational, the Holbrook Basin Project would dwarf the water usage of Holbrook and approach the water needs of Flagstaff. Instantly, the Holbrook Basin Project would become the largest single water user in all of Northern Arizona.
According to the PEA, “A regional aquifer is located within the Coconino Sandstone and locally within the uppermost Supai Formation, which is called the C-aquifer. Furthermore, the Moenkopi and Chinle Formations might (italics mine) contain undefined/unreported aquifers. South of the Project Area, there are extensive areas of sinkholes reaching the land surface, which suggests major salt dissolution that likely contributes to the salinity of the water in the Coconino Sandstone (COX, 1965, /6/)”. The above statement ignores the fact that new sinkholes have developed in the area within the past twenty years. Earth scientists know that as the local water table subsides, sinkholes are often the result.
“The Little Colorado (River), a permanent stream (italics mine), and the Puerco River, an intermittent stream, run through the area (COX, 1965,/6/). These streams merge about three miles east of Holbrook and tend to generally produce fresh water, which is reported to be brackish to saline in the surrounding areas”. The only hydrological study cited in the PEA dates to 1965. Perhaps the Little Colorado was a “permanent stream” in the 1960’s, but it is far from that today. In the current century, that river runs hard and fast for only a brief time each spring. At that time, snowmelt from the Mogollon Plateau runs off toward the Colorado River. Summer thunderstorms may produce brief river flow, as well. Otherwise, most of the flow cited in the PEA is running beneath the surface, if at all.
“The availability of water has been investigated in a preliminary hydrogeological study (MONTGOMERY & ASSOCIATES, 2013, /27/), but further in-depth studies are required. According to the MONTGOMERY & ASSOCIATES study, the required amount of water could be supplied (italics mine) by the Coconino Sandstone aquifer”. The cited study, by MONTGOMERY & ASSOCIATES is not currently available on the internet, so its conclusions are speculative, at best. Without drilling, logging and publication of numerous test-well flow-rates, Passport Potash, Inc. should not base their development decisions on such speculative information.
“Water demand will be met by wells drilled in the vicinity of the preliminary plant site. A pipeline system will be installed to pump the water to the plant site, where it will be stored in several large water storage tanks for use in processing, general usage in the mine, fire suppression and potable water supply”. With a planned twenty-six year production cycle at the Holbrook 
Basin Project, we may now extrapolate how much “mystery water” the Coconino Sandstone aquifer must contain in order to provide an adequate supply for the life of the project. My quick calculations indicate that during its lifetime, the Holbrook Basin Project would require water resources equal to almost twice the carrying capacity of Bartlett Lake, near Phoenix, Arizona. Bartlett Lake is twelve miles long, with a surface area of over two thousand acres and an average depth of one hundred feet. Until I see a professional hydrological study of the Coconino Sandstone aquifer, I would not trust mere reference to an unpublished study commissioned by Passport Potash, Inc.
“A sewer system will be constructed on-site to treat the waste-water from the sanitary facilities at the plant. Afterwards, it will be used as process water”. Before it becomes a saturated brine solution, the processing facility would reuse and recycle water several times during various phases of mineral 
production. Although this recycling effort is admirable, “about 15.4 MTPA (millions of tons per annum) of wet solids and 997,000 m³ (808 acre-feet) of brine per year remain as processing residues, which have to be disposed of”.
The PEA states, “The disposal brine remaining from the production process can be disposed of by deep well injection”. To me, that is a glib statement. Over the life of the project, injecting over 21,000 acre-feet of saturated brine into deep wells could result in unintended consequences. To see what might happen, look no further than the States of Arkansas, Oklahoma and Kansas, where deep rock fracturing (fracking) and process water disposal in deep wells may have caused earthquakes of unprecedented size and scale. The only way to study deep well injection at a particular site is to do it. Could large-scale process-brine injection compromise the rock barrier that separates the injection sites from the Coconino Sandstone aquifer above?
Production Waste Disposal – “The processing of the potential potash ore described in Section 16.2 produces about 400 million metric tons of wet solid tailings and about 25 million m³ MgCl2-rich waste brine over the whole project lifetime. The tailings will be stockpiled on the surface and will remain after the mining operation. Potential emissions from the tailings pile are either salty water (brine), which will be collected and handled like the waste brine, or dust transported by wind”.
“Furthermore, a 1.5 m high dyke should surround the tailings pond and will collect water run-off. The collected water will be pumped into the brine ponds and disposed by deep well injection”. In the summer months, the regional Monsoon can bring heavy downpours to the Holbrook Basin. If a major thunderstorm were to unload its water supply directly on the Holbrook Basin Project, would a five-foot tall berm of earth be sufficient to contain the mountainous, salt-saturated tailings pile? If such a disaster were to occur, 
the resulting flood of brine could enter the Little Colorado River and from there, flow unimpeded toward the Colorado River and the Grand Canyon.
“In total, about 400 million metric tons of wet solid tailings will accumulate during the operation. The wet salt from the plant has to be stockpiled permanently on the surface. Taking into consideration a height of 40 m and a material density of 1.7 t/m³, an area of about 6 km² is necessary to handle the solid disposal from the process”. Converted to U.S. standards, 6 km² is equal to 3.7 square miles of unprotected tailings, standing over one hundred thirty feet high.
Although the PEA passes off “dust transported by wind” in a single sentence, wind borne dust is already a major modifier of weather and stream flow throughout the Colorado Plateau. In recent years, spring dust storms have drastically altered the environment in the Colorado Rocky Mountains and 
other high altitude snow banks throughout the region. As wind borne dust lands on the snow pack, it changes the albedo (light reflectance) of the snow, darkening it and causing early snow melt. Rather than allowing slow release of melt water into the environment, rapid melting of dirty snow creates floods along both the Little Colorado River and throughout the Upper Colorado River Basin.
The Holbrook Basin Project, Phase 1 – “Studies to confirm and verify the assumptions made for the PEA. These studies include detailed hydrogeological investigations to determine the quantity and quality of groundwater available for the project. An initial water study indicates the general suitability of the Coconino Sandstone aquifer as a water source, but no specific investigations have been conducted. Recommendations: Detailed hydrogeological investigations to determine the quantity and quality of groundwater available for the project”.
If the legacy of the Holbrook Basin Project shall be a dried-up or brine-compromised Coconino Sandstone aquifer and a mountainous pile of salt tailings blowing in the wind, Passport Potash, Inc. should abandon the project now. Before the company moves forward with the project, it should publicly address the following issues:
• Are there sufficient water reserves available to support both the mining operation and the Holbrook Basin at large?
• What are the potential environmental effects of injecting brine into deep wells, beneath the Coconino Sandstone aquifer?
• Will the company provide adequate protective covering and drainage for the tailings pile, both during and after the project life-cycle?
Until these basic questions are answered, I remain unconvinced that the ERCOSPLAN/Passport Potash, Inc. Preliminary Economic Assessment (PEA) holds any more water than does the Little Colorado River during its dry season.
