Reality and opportunity – nova scotia future energy requirements, the role of shale gas development
Naturally Occurring Radioactive Materials - “NORMS”
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- Navigate this page:
- Water Chemistry and Discharge History
- Pond Leaking
- Missing Wastewater/Windsor Treatment and Disposal
- Frozen Wastewater Melted On Site
- Conclusions
Naturally Occurring Radioactive Materials - “NORMS”Much is made in the NOFRAC report of the lack of NORM measurement from 2008-11, and of the readings taken since October 2011 resulting in special treatment before disposal. Let us be clear….there is no threat to the population in any shape or form from the NORM levels recorded from the ponds. Radioactivity levels have to be placed in context, and not left as statements saying that the pond waters contain “elements having long half-lives and known health risks.” This is misleading and scaremongering. Radioactivity is a complex, natural phenomenon occurring in most ancient rocks, and typically found across Nova Scotia. We live with it every day and are surrounded by it from buildings, concrete and everyday objects. For example, sea water has an average naturally occurring radioactivity of 13 Becquerel per Liter (Bq/L), while pond radioactivity at the Kennetcook site ranged from 2 to 35 Bq/L. A human adult has an average radioactivity of 100 Bq/kg and bananas, 130 Bq/kg. Becquerel’s are the unit for radioactivity intensity measurement where one Becquerel is one radioactive decay per second. Health Canada (HC) puts out a series of conservative guidelines for NORM to safeguard the public from any excessive exposure. HC identified guideline limits for material to be released to the environment without further control is based on an appropriate dose value. This dose is calculated from the total effect of differing types of radiation on different parts of the body giving an additional total exposure of 0.3 milli Sieverts (mSv) or less per year. It is noted that the background average for Canadians is approximately 2.0 mSv per year with a range from 1.2 to 3.2 mSv per year. Where this exposure is not exceeded, the NORM is unrestricted, i.e., does not constitute a risk or hazard to humans and requires no further action for control. These guideline limits are identified as Unconditional Derived Release Limits (UDRL) by HC. The HC dose guidelines (UDRL limits) are more stringent for waters (aqueous solutions) assuming drinking water ingestion, as this is the most sensitive pathway for humans. The standards adopted by Environment for the Kennetcook pond water were for the most stringent HC UDRL guideline’s for human exposure, even though no drinking water pathway was present. The radioactivity measured in the Kennetcook ponds is contained in the total dissolved/suspended solids in the brines that were drawn from the rock formations following the testing of the Kennetcook wells. The pond water has stratified (less saline water floats on top of more saline water) as the surface has been diluted with rainfall while more saline/dense water remains at the bottom. The samples tested in the upper section of the ponds were below UDRL limits for NORM and thus suitable for unconditional release based on HC guidelines for natural radioactivity. It was only in the deeper samples that had slight exceedances of UDRL guideline limits for aqueous solutions with potential for the water to enter a drinking water supply with less than 10 fold dilution. Regardless of the treatment destination for the pond water, no discharge to drinking water sources was ever contemplated, permitted or undertaken. Given that the pond brines are not going near drinking water pathways and are to be treated before ultimate discharge to the marine environment, there is no risk of unacceptable ingestion. Radium 226, the key identified radionuclide in the pond water predominantly emits 96% alpha radiation that fail to penetrate skin or air. So to fall into any unacceptable exposure scenario, a person would need to drink a huge amount of the brine pond constantly over a long period of time (years) to expose themselves to any unacceptable level of radioactivity. However, in an abundance of caution, the Department of Environment currently requires us to meet the HC aqueous UDRLs prior to discharge of any waters. Triangle devised filter methods by which the NORM could be removed, and the resultant filtered waters were retested to ensure the NORM’s were reduced to below UDRL levels. This we have done to the satisfaction of independent and certified laboratories and the Department of Environment. The levels of NORM identified for the pond waters pose no unacceptable exposure to humans. However we are happy to work with the Department of the Environment and deliver standards at the more stringent HC aqueous level. On approval from the Department of Environment using the proven treatment process we propose to complete the treatment of the current pond waters and discharge water meeting limits set to protect humans and the environment at an approved location on agreement with the municipal authorities. In summary, NORMs were sampled at the request of Department of Environment and we now have incorporated the process into our protocols for any future drilling or discharge. The results of testing have shown NORM to be minor in amount. The pond waters are being discharged through a treatment facility, in the same fashion as wastes from sinks and toilets. Litres per day of untreated wastewater would need to be ingested by individuals continuously over years to cause any concern related to additional radiation exposure.
The completion that took place was a simple, two stage slickwater fracture stimulation, over very restricted 5-10 m intervals below 1300 m depth and used the following:
The surfactant and friction reducers (sophisticated detergents) are used to improve injection into the rock formation and were minor in amount, less than 0.001% of the total fluids. The chemicals used were made available to Departments of Energy and Environment. Proprietary (i.e., non-disclosed) fracking chemicals were not used. Less than 5% of the volume of chemicals inferred by the NOFRAC Report was used. Further, it is a distortion and misinterpretation to imply human contact and consumption of the fracking chemicals and so define them as carcinogens and mutagens. These same materials are in your yard (sand), under your kitchen sink and used for daily in-house cleaning. Many of the chemical hazards associated with the chemicals are misrepresented as the dry powered form of any chemical represents an inhalation hazard or potential eye irritant. The pond waters are not in powder form for human ingestion, and will be treated meeting environmental and human health limits and discharged with no contact to drinking water. The fresh water was pumped into the lined ponds from the nearby rivers, each pond with a total capacity of 10 million litres. The fracture stimulations were completed and no gas returned to surface. To stimulate the rock to potentially free gas, pumping was applied and formation water flowed to surface in both the Kennetcook wells, but the N14A well was abandoned with no flow and remaining waters returned to Kennetcook #2. The hope was that in time the water production would be replaced by gas, but this did not happen and the Kennetcook tests were terminated. Approval was granted by the Department of Environment to use the lined fresh water ponds to contain the produced formation water/returned flow-back water. It is not known exactly how much formation water was produced, or how much slickwater was returned, but both ponds were each roughly half full, so 5 to 6,000 cubic metres (cuM) in each is a reasonable estimate. The formation water chemistry has been analyzed consistently and repeatedly over the years and it is shown to predominantly contain high levels of chlorides (salts) that are being gradually diluted by rainwater. At 25-40,000 mg/L chlorides currently at the base of the ponds, this is corresponds to a salinity range approximately double the salinity of ocean salt water. The following table shows additional chloride results to that provided by NOFRAC. KC-1. Comparison of Chloride Concentrations (mg/L)
KC-2. Comparison of Chloride Concentrations (mg/L)
During this time, chemical sampling and analysis has taken place and continues to occur on a regular basis. Pond water sampling included an extensive suite of chemical analyses - general parameters, metals parameters, hydrocarbons, Polycyclic-aromatic hydrocarbons (PAHs) and Volatile Organic Carbon parameters (VOC)s. This analysis was conducted by a certified laboratory and part of the laboratory protocol is notification of the presence of detectable unknown chemicals not specifically targeted in analysis – the analysis did not identify any chemical spikes or presence of unidentifiable chemicals. The organic additives used in the fracking are readily naturally degradable and although PAHs and some light end petroleum hydrocarbon compounds were detected at low levels (below guidelines for humans or aquatic life) in 2008, sampling of pond waters from 2011 to present has not detected these constituents. Recent chemical analyses has not identified any significant concentrations of potential contaminants with guideline limits other than chloride and minor exceedances of the UDRL guideline limits for select NORM isotopes. Pond LeakingRainwater/snow/ice has added to the ponds since 2008. The brines have been diluted and over time stratified such that the surface waters, as shown by chemical analysis are nearly fresh water. The pond lining has retained its integrity although what could have been a small liner leak in the upper portion of the liner was identified at Kennetcook #1 in May 2011. On agreement with the Department of Environment, the pond level was lowered to below the level of the leak and has been maintained at that low level prior to freeze-up. The ponds are inspected regularly and safe freeboard water levels maintained to prevent over-spillage. Soil samples have been tested from around the pond for NORM both by the Department of the Environment and Triangle and were below UDRL with levels consistent with typical soil ranges (i.e., no indication of any form of contamination). Missing Wastewater/Windsor Treatment and DisposalRainwater/snow/ice is estimated to have added 1 m/year to the ponds and this works out at some 3 million litres per year/pond. Triangle has worked with the Department of Environment to maintain freeboard (i.e., keeping the water level below spillway height). Since 2008, the ponds have remained and brines have been repeatedly withdrawn with required approvals to ensure no overspill. To date $1.9 million has been spent on brine disposal from the ponds. For NOFRAC to say there is missing wastewater is again scaremongering; all volumes were monitored with full knowledge of benign chemistry and good processing and safe discharge. Atlantic Industrial Services (AIS) have been our service provider for the past five years. AIS is very experienced in appropriate handling, transport, treatment, disposal and discharge of various industrial waste waters and other wastes. Their facilities have a wide variety of treatment capabilities and AIS is one of the most capable waste water treatment companies in Canada with over a dozen different technologies at its facilities. AIS have demonstrated their ability to treat the pond waters to meet environmental quality requirements. There have been no incidents or upsets and AIS and the Municipality of Colchester have full knowledge of all chemicals involved. AIS use several steps to ensure it meets its discharge criteria before release of the final effluent. The ability to treat the Kennetcook pond water has been shown at both lab scale conditions and large scale volumes. Some Kennetcook brines were taken to the Windsor sewerage system with Department of Environment approval. The water chemistry met environmental requirements for provincial discharge. It is incorrect of NOFRAC to say the Windsor or Debert wastewater plants are unable to accept the brine. The brine water was managed in a manner that was protective of wastewater treatment capacity and, as noted in discussing the chemicals and NORM constituents, did not represent a hazard to humans or the environment.
Building a tent over the ponds to keep the rain out and then truck away the brines; Setting up jets in the ponds to cause evaporation; Take the ice from the ponds and melt it on the well-site; Pump the brines away directly to the ocean by temporary pipeline; Use the brines for grit and/snow/ice melt on roads; or Re-inject into the formation whence it came. None of the above was adopted as they were impractical, too costly, or unacceptable to the Department of Environment or Triangle. A formal approval was granted for the freeze thaw proposal; however, that was not implemented as it was thought it would damage the liners and was felt to be not practical or appropriate. ConclusionsThis response seeks to stop the claim/counterclaim approach to any identified issue. The facts should be gathered, reviewed by all and a common approach taken in full context both of the environment and energy future of Nova Scotia, together the development of the provincial economy. NOFRAC has concluded that fracking wastewater is a problem without a solution. We have demonstrated that technologically feasible solutions are in place. A treatment for NORM has been developed, with acceptable discharge criteria. In addition, we believe that the practical solution of reinjection of formation waters to where they originated should be further evaluated. It is best practice in Canada and most all other areas where shale development takes place. The geology is favorable, and the aquifers separated from the gas bearing intervals by over 1000 metres of rock including an impermeable salt section. The well designs have five layers of separation of steel casings and cements from the production casing carrying the gas and/or formation water. This makes any aquifer contamination all but impossible. It is the contention of Triangle that a “proof of concept” program be put together to see if there is any shale gas development potential. The program should be openly discussed and pay special attention to the concerns of the local communities. This way, a phased approach is taken and much can be learned and confidence grown to determine if shale development is sustainable, economic and environmentally acceptable. Triangle is happy to make all data available to any party, so long as they agree to discuss their views and findings in an open minded way seeking to find solutions and progress the growth of Nova Scotia. Respectfully Dr. Peter J. Hill Chairman, Triangle Petroleum Corporation Page Directory: wp-content -> uploads -> 2015 2015 -> Police Militarization 2015 -> 2015 ihbb championships: hs history Bowl Round 4 – Prelims First Quarter 2015 -> Wrtp/big step · 3841 W. Wisconsin Ave., Milwaukee, wi 53208 2015 -> Rao bulletin 1 December 2015 html edition this bulletin contains the following articles 2015 -> Darton College 2015 -> Training Workshop on Planning and Implementation of Multi-Sectoral Development Programme (MsDP) in Bihar Date : 6th 2015 -> Rao bulletin 15 June 2015 html edition this bulletin contains the following articles 2015 -> Rao bulletin 1 September 2015 html edition this bulletin contains the following articles 2015 -> Rao bulletin 1 August 2015 html edition this bulletin contains the following articles 2015 -> Science, and transportation united states senate Download 189.03 Kb. Share with your friends:
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