The Big Dig: geological and other outcomes of the 2008–2009 Freshwater Brook sewer replacement project, Halifax, Nova Scotia, Canada
DOI:
https://doi.org/10.4138/atlgeo.2025.004Abstract
In 2008 Halifax Regional Municipality undertook a major construction project to replace the underground sewer system that carries Freshwater Brook from the Halifax Commons to its outlet at the southeastern end of the Halifax Peninsula. The project was necessary because the existing system did not meet modern standards and the old pipes ran under city blocks and were therefore inaccessible in many places for maintenance and repair. The first part of the project (2008-09) involved installing a modern dual pipe system along a route that crossed the predicted locations of the boundary between the Cunard and Bluestone Quarry formations of the Halifax Group, and the biotite-in and andalusite-in isograds of the contact aureole of the South Mountain Batholith. Bedrock was exposed along much of the excavated trench, which was nearly 10 m deep in many places. Outcrop observations and samples from the trench revealed that the Cunard-Bluestone Quarry contact runs under the Sobeys parking lot, between Fenwick and Queen streets. The andalusite-in isograd in the Cunard Formation can be traced as far as the west end of Fenwick Street. The cordierite-in isograd lies east of the study area, and the biotite-in isograd to the west. The lithology and isograd map for south end Halifax has been updated based on these results. Problems including uncertain subsurface location of the old pipes, contaminated soil, and carbon monoxide migration into residential buildings contributed to significant delays and cost overruns; some of these might have been mitigated with better knowledge of the subsurface geology.
References
Barr, S.M., Kuiper, Y., van Rooyen, D., and White, C.E. 2022. Geological comparisons and correlations among crustal blocks in eastern North America, northwest Africa, and western Europe. Field trip part of the International Geoscience Programme (IGCP) project 683 (https://igcp683.org/), held during GAC-MAC-IAH-CNC-CSPG Joint Meeting, May 15–18, Halifax Nova Scotia.
Bickerton, L., Kontak, D.J., Murphy, J.B., Kellett, D.A., Samson, I.M., Marsh, J.H., Dunning, G.R., and Stern, R. 2022. The age and origin of the South Mountain Batholith (Nova Scotia, Canada) as constrained by zircon U–Pb geochronology, geochemistry, and O–Hf isotopes. Canadian Journal of Earth Sciences, 59, pp. 418–454. https://doi.org/10.1139/cjes-2021-0097
CBC Archives. 2009. Blasting halted in Halifax neighbourhood. URL <https://www.cbc.ca/news/canada/nova-scotia/blasting-halted-in-halifax-neighbourhood-1.789461>, January 2010 and December 2024.
CBC Archives. 2011. Troubled south-end sewer project continues. URL <https://www.cbc.ca/news/canada/nova-scotia/troubled-south-end-sewer-project-continues-1.1067502>, 27 October 2024.
Halifax Public Libraries. 2022. Whatever happened to Freshwater Brook? – A brief and not at all definitive history. Halifax Local History. URL <https://www.halifaxpubliclibraries.ca/blogs/post/whatever-happened-to-freshwater-brook-a-brief-and-not-at-all-definitive-history/?>, 10 October 2024.
Halifax Regional Council. 2006a. Canada Strategic Infrastructure Fund – Update. Information Report by D. English (Chief Administrative Officer) to Halifax Regional Council, 13 June, 2006. URL <https://legacycontent.halifax.ca/council/agendasc/documents/info13.pdf, 27> October 2024.
Halifax Regional Council, 2006b. Policy on Daylighting Rivers. Report by D. English (Chief Administrative Officer) to Halifax Regional Council, 7 February 2006. URL <https://legacycontent.halifax.ca/council/agendasc/documents/PolicyforDaylightingRivers.pdf>, 27 October 2024.
Halifax Water, 2008a. Twelfth Annual Report, 31 March 2008, to Halifax Regional Council. URL <https://legacycontent.halifax.ca/council/agendasc/documents/100309cai07.pdf>, 27 October 2024.
Halifax Water, 2008b. Freshwater Brook Combined Sewer Rehabilitation. Report by D. Ellis to Halifax Regional Water Commission, 23 May 2007, considered by Board in May 2008; accessed through Freedom of Information request, 24 December 2024.
Halifax Water, 2009. Thirteenth Annual Report, 31 March 2009, to Halifax Regional Council; accessed through Freedom of Information request, 24 December 2024.
Halifax Water, 2010. Freshwater Brook Combined Sewer Rehabilitation. Report by C. Yates to Utility and Review Board, 8 June 2010; accessed through Freedom of Information request, 24 December 2024.
Health Canada, 2024. Residential indoor air quality guideline for carbon monoxide. URL , 10 December 2024.
Hicks, R.J., Jamieson, R.A., and Reynolds, P.H. 1999. Detrital and metamorphic 40Ar/39Ar ages from muscovite and whole-rock samples, Meguma Supergroup, southern Nova Scotia. Canadian Journal of Earth Sciences, 36, pp. 23–32. https://doi.org/10.1139/e98-081
Hilchie, L.J. and Jamieson, R.A. 2014. Graphite thermometry in a low-pressure contact aureole, Halifax, Nova Scotia. Lithos, 208-209, pp. 21–33. https://doi.org/10.1016/j.lithos.2014.08.015
Hopkins, H.W. 1878. City Atlas of Halifax, Nova Scotia, from Actual Surveys and Records by and under the supervision of H.W. Hopkins, civil engineer. Provincial Survey and Pub. Co. G. B. Vandervoort, Manager. URL <https://archives.novascotia.ca/Archives Library O/S G 1129 H3 H67 1878>, 28 April 2023.
Horne, R. and Culshaw, N. 2001. Flexural-slip folding in the Meguma Group, Nova Scotia, Canada. Journal of Structural Geology, 23, pp. 1631–1652. https://doi.org/10.1016/S0191-8141(01)00017-7
Jacques Whitford, 2008a. Freshwater Brook Sewer Project, Phase 2 Tender - Queen Street to Inglis Street Handling of Excavated Material. Report by M. Bochmanm to G. Rice, Halifax Regional Water Commission, 18 February 2008; accessed through Freedom of Information request, 24 December 2024.
Jacques Whitford, 2008b. Soil stockpile sampling - Freshwater Brook Phase 1, Seaview stockpiling area, Halifax. Report by E. Bostwick and D. Carey to I. Bishop, Terrain Group, 18 December 2008; accessed through Freedom of Information request, 24 December 2024.
Jamieson, R.A. 2010. The big dig: lithologies, isograds, and other outcomes of the Freshwater Brook sewer replacement project. Atlantic Geology, 46, p. 54.
Jamieson, R.A., Hart, G.G., Chapman, G.G., and Tobey, N.W. 2012. The contact aureole of the South Mountain Batholith in Halifax, Nova Scotia: Geology, mineral assemblages, and isograds. Canadian Journal of Earth Sciences, 49, pp. 1280–1296. https://doi.org/10.1139/e2012-058
MacDonald, M.A. 2001. Geology of the South Mountain Batholith, southwestern Nova Scotia. Nova Scotia Department of Natural Resources, Open File Report ME2001-2, 281 p.
MacDonald, M.A. and Horne, R.J. 1988. Petrology of the zoned, peraluminous Halifax Pluton, south-central Nova Scotia. Atlantic Geology, 24, pp. 33–45. https://doi.org/10.4138/1638
Martel, R., Trepanier, L., Levesque, B., Sanfaçon, G., Brosseau, P., Lavigne, M-A., Boutin, L-C., Auger, P., Gauvin, D. and Galarneau, L. 2004a. Carbon monoxide poisoning associated with blasting operations close to underground enclosed spaces. Part 1. CO production and migration mechanisms. Canadian Geotechnical Journal, 41, pp. 371–382. https://doi.org/10.1139/t04-001
Martel, R., Trepanier, L., Lavigne, M-A., Levesque, B., Sanfaçon, G., Brosseau, P., Auger, P. 2004b. Carbon monoxide poisoning associated with blasting operations close to underground enclosed spaces. Part 2. Special working procedures to minimize CO migration. Canadian Geotechnical Journal, 41, pp. 383–391. https://doi.org/10.1139/t04-002
McKenzie, C. and Clarke, D.B. 1975. Petrology of the South Mountain Batholith, Nova Scotia. Canadian Journal of Earth Sciences, 12, pp. 1209–1218. https://doi.org/10.1139/e75-110
Reid, M. 2012. Better planning from better understanding: Incorporating historically derived data into modern coastal management planning on the Halifax Peninsula. Unpublished Master’s of Marine Management thesis, Dalhousie University, 79 p.
Waldron, J.W.F., Jamieson, R.A., Pothier, H. and White, C.E. 2015. Sedimentary and tectonic setting of a mass-transport slope deposit in the Halifax Group, Halifax Peninsula, Nova Scotia. Atlantic Geology, 51, pp. 84–104. https://doi.org/10.4138/atlgeol.2015.004
White, C.E. and Barr, S.M. 2012. Meguma Terrane revisited: stratigraphy, metamorphism, paleontology, and provenance. Geoscience Canada, 39, pp. 8–12.
White, C.E. and Goodwin, T.A. 2011. Lithogeochemistry, petrology, and the acid-generating potential of the Goldenville and Halifax groups and associated granitoid rocks in metropolitan Halifax Regional Municipality, Nova Scotia, Canada. Atlantic Geology, 47, pp. 158–184. https://doi.org/10.4138/atlgeol.2011.008
White, C.E. and Nickerson, S.J. 2021. Working towards a new bedrock geology map of the Meguma terrane, Eastern Shore of Nova Scotia: building a stratigraphy. In Geoscience and Mines Branch, Report of Activities 2020-2021. Edited by D.R. MacDonald and E.W. MacDonald. Nova Scotia Department of Natural Resources and Renewables, Report ME 2021-002, pp. 73–78.
White, C.E., Bell, J.A., McLeish, D.F., MacDonald, M.A., Goodwin, T.A. and MacNeil, J.D. 2008. Geology of the Halifax Regional Municipality, central Nova Scotia. Mineral Resources Branch, Report of Activities 2007. Nova Scotia Department of Natural Resources, Report ME 2008-1, pp. 125–139.
White, C.E., MacDonald, M.A., and Horne, R.J. 2014. Bedrock geology map of the Halifax area, NTS 11D/12, Halifax County, Nova Scotia. Nova Scotia Department of Natural Resources, Minerals Resource Branch, Open File Map ME 2014-010, scale 1:50 000.
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