Background & Analysis: Total Volume Of Mt Polley TSF Failure Significantly Higher
RevIsed Estimate Puts Toxic Sediments at 60% of Total Spill Volume
(10/2/2014This table presumably now shows corrected table. B.C. MOM issued this errata on 9/27http://www.env.gov.bc.ca/eemp/incidents/2014/mount-polley/pdf/20140929/Memo-QuesnelSedimentQualityCorrection-Sept24.pdf W have not had an opportunity yet to see whether any of the analysis below is affected. The errata is sonly for mercury 2010-2014)
Mt Polley was already the largest TSF failure in recorded history. (http://www.wise-uranium.org/mdaf.html) Canadian press now reports that the release was not 14.8 million M3 but 24.8 million M3. The difference, significantly, is in the revised estimate of highly toxic sediments from an initial estimate of 4.6 million M3 to 14.8 million M3 (and the addition of 0.6 million M3 of construction waste). This represents a 300% initial under reporting/underestimating of sediment release.
Whether it is significant or just a number remains to be seen but that also means that sediments were 60% of the total release not 29%. Just intuitively that seems to suggest the possibility that the pressures on the face of the 112’ man made wall and resulting breach originated in/ or through the sediment layer.
Resident Of Likely With Sediment Clouded Water From Quesnel Lake
Sediments were the major issue raised by Brian Olding Associates in its 2009 review for Imperial and First Nations of the permit application for annual discharge 1.4 million cubic meters of waste water per year. http://s3.documentcloud.org/documents/1262983/final-report-mpmc-master-ta-review-jun21-2011.pdf . The TSF had been doing double duty as a temporary holding pond for mine and drainage waters, a common practice. The Olding Associates report concluded that the risk of contamination of receiving waters was too high without a “polishing pond” for sediments prior to discharge. “Sediment or associated contaminants could enter Hazeltine Creek unless there is an effective sedimentation pond between the Tailings Storage Facility (TSF) and Hazeltine Creek. (T)he sedimentation/polishing pond that is mentioned in the TA Report should be a condition of the discharge permit. “
Olding Associates also found that the data presented in the discharge permit application tended to under assess and/or not accurately measure the risk to receiving waters and habitats of the requested 1.4 million M3 annual discharge.“Throughout the TA Report, predicted chemical concentrations in Hazeltine Creek are based on annual or monthly mean values of effluent discharge to Hazeltine Creek. This approach can mask the potential for short-lived high concentrations of potentially harmful chemicals to exceed water-quality guidelines and potentially be harmful to the aquatic life of Hazeltine Creek. To correct this in a precautionary way, maximum concentrations of chemical parameters such as Sulphate, Selenium, Copper and Cadmium need to be calculated for minimum ( emphasis added) flow rates in Hazeltine Creek”
The B.C. Government was slow to release raw data on sediments. Recently released, the raw data , a combination of post failure grab samples and averages from a sampling program of TSF sediments 2010-2014 shows that sediments which are presently laying in the immediate vicinity of the spill have a contaminant profile consistent with the pre breach average profile of sediments within the TSF. Post failure grab samples reported in this raw data do not show those characteristics at other sample sites but do show some exceedances which could be pre-failure or could have resulted from operations and not be related to the failure.
Before the raw data was released, the provincial government had released this August 15th analysis of sediments and visual inspections.http://www.env.gov.bc.ca/eemp/incidents/2014/pdf/aug16/Memo-Quesnel-Lk-Sediment-Quality-Aug-10-revised.pdf
“Quesnel Lake near mouth of Hazeltine Creek in water 1 and 2.5 m deep. The lake bottom appeared to be covered in tailings and no aquatic plants were visible”.
It is not clear whether the two grab sample columns labled “Outside Tailings Dam Breach” are this observed “dead zone” at Quesnel Lake. These two columns show exceedances as follows as compared with the “Impoundment Average 2010-2014” and “Outside At the Breach” ( all measurements in ug/g dw)
Sample Sites Inside AVG At Breach.
Arsenic 12 12.4 12.32 11.7
Copper 646 723 931 918
Manganese 757 705 652 525
Selenium 1.2 1.1 1.04 1.4
Sulfur 3410 3320 ——– 2750
Vanadium 161 162 180.54 145
No further studies or results on sediment impacts are listed at the provincial government website as completed or in progress. No footnotes or commentary are offered on the consistent pattern of lower measurements “At the breach” as compared with the two sample sites.
Unfortunately no geographic coordinates were provided with the raw data which would have facilitated spatial analysis. This Mount Polley Mine Corporation (MPMC) map of sample sites appears at the Ministry of Environment (MOE) website but does not clearly correlate with the raw data on grab samples released a few weeks ago http://www.env.gov.bc.ca/eemp/incidents/2014/mount-polley/pdf/20140903/621717-006_SEDLocPlan_140829.pdf It does,however show the location of these MOPC sediment sampling results reported to MOE , http://www.env.gov.bc.ca/eemp/incidents/2014/mount-polley/pdf/20140903/QusnelLake_SEDMaster_20140826.pdf
“Environment Canada’s data on Imperial Metal’s mine tailings show mercury compounds, a neurotoxin that can cause degenerative disease, ramped up from 435 kilograms in 2012 to 3,114 kg last year – a seven-fold increase in one year.”http://commonground.ca/2014/09/the-mount-polley-mine-disaster/ (No exceedances of mercury are shown in the raw data either in the area immediately next to the breach or in any grab sample sites.)
Vanadium is not regarded as a serious (human) health hazard, is found in most soils and common in foods including olive oil, eggs, apples and soya beans . It does strongly bio accumulate in mussels and crabs causing inhibitions to certain enzymes.(http://www.lenntech.com/periodic/elements/v.htm#Health%20effects%20of%20vanadium )
Large metallic mineral deposits have natural releases of toxic metals which are established in background water quality studies pre-mining. Different parts of a deposit can have a very different profile of metals and very varying levels of environmental risk. Mining operations and advanced explorations can create new pathways. Exceedances shown in the raw data need further explanation and analysis to assess what is attributable to the failure beyond what is immediately at the breach.
The day after the failure, Brian Olding, the consultant to Imperial & First Nations on the 2009 re analysis of Imperials permit application to discharge 1.4 million M3 per year said “More water was coming in over the year than they could deal with…They just kept building the walls up higher and higher every year and it got to the point where that was untenable.” http://www.theprovince.com/news/Polley+Mine+tailings+pond+growing+unsustainable+rate+says/10091105/story.html
Olding & Associates had also urged a structural reassessment which Imperial did not agree to. “I requested a structural engineering company be involved, and that was nixed. They did not want to deal with that problem at that time.”( op.cit Province.com/news)
Today (September9) a non compliance directive on continued unauthorized discharges was issued to Imperial/Mt.Polley
At an inspection on Sep 4 it was discovered that Mont Polley Mining Corporation (MPMC) was discharging effluent into Hazeltine Creek.Order 107461 directed the installation of passive and or active sediment control systems designed to a 1 in 10 year 24 hr rainfall event.
Interflow & Salmon Spawning Impacts
Scientist Carl Walters is keeping a close eye on the “interflow” which has suspended the sediments released in TSF failure in a layer under the top warm layer of water and above the deeper cold waters. http://www.macleans.ca/news/canada/new-information-gives-salmon-expert-pause-on-mine-leak-impact/
This situation, Walters said, can worsen for the coming sockeye run given three possible conditions:
- It is common for a strong west wind to blow through the area for a day or two every few weeks this time of year, and if this happens the warm surface water will be pushed east away from the lake outlet where it can be carried out of the system, and the polluted water may surface and run downstream past Likely.
- Samples of the polluted water have shown that it has copper levels that are “close” to levels that can impair the salmon’s directional sense of smell, which the sockeye may need to move up Quesnel Lake and find their primary spawning areas in the Horsefly and Mitchell Rivers. As they move into the lake, they may seek deeper, cooler water and so will encounter the polluted, colder, dense water of the interflow layer cake. “This is especially worrisome for the Mitchell River fish that need to make a left turn about 20 km up the lake into the lake’s north arm and travel 60 km up that arm,” he said.
- About 20 km up the lake from the outlet, there is a shallow area called a sill, across which the lake water usually flows westward. That flow concentrates small plankton that feeds young salmon, but the polluted water has spread eastward enough to reach the sill, which could affect both the young fish and its food supply.
“I still don’t think it will be a serious problem, but I just can’t say for sure,” said Walters. “But at this point all we can do is to keep our fingers crossed that the polluted layer will be diluted enough by the time the main body of fish arrives so as not to be a major problem for them.”
October 10,2014 Sediment Plume deep in Quesnel Lake http://www.vancouversun.com/Sediment+from+Mount+Polley+mine+collapse+found+deep+Quesnel+Lake/10274733/story.html