In the meantime, there are some aspects that warrant further reference. First, pipeline spills in the province of Alberta have been improving dramatically over the past 10+ yrs. Average spill rate has decreased from 2.5/1000km (2000) to 2.1/1000km (2008) to 1.5/1000km (2011). Continuous improvement is a mantra in the energy business period. This improvement will continue. Will they get to zero? No. Will they continue to improve? Yes.
Second, there have been a couple of references that cite the spill must have been going for a long time to cover 42 sq. km and thus likely originated sometime under the cover of winter. With the pictures below reposted by Twitter feeds from @JacobBarkerCBC and @HillaryBirdCBC, there is new spring growth evident which would suggest that the growth occurred when conditions were favorable - i.e., after the retreat of snow, and the onset of spring. With the apparent toxicity of the spilled contents, I would not have expected that to occur.
Third, and finally, the appearance in these photos does not look very much like a 'produced water' spill. "Produced water" is a mixture of dispersed oil, dissolved or soluble organics, treatment chemicals, produced solids, scales, bacteria, metals, sulfates, and naturally occuring radioactive material. The target formations, the drilling technology, and the selected treatment options all affect what a 'produced water' pipeline might be transporting. The produced water in these pictures appears to have a high dispersed oil component.
While it will still take some time for an ERCB Incident Report, I am eager to learn more about what, how, and why this pipeline leak occurred. Whether it is an ExxonMobil, or Plains Midstream, or Enbridge, or anyone with the responsibility of transporting product by pipeline, whatever the product is, the public safety of the line and the potentially affected parties/environs is paramount. The energy business is a critical element of a strong foundation to economic development and quality of life ~ in Canada and around the globe.