Groundwater in the Great Lakes Basin

More documents

Recommendations

Info

In 1980, part of the non-pumpable wastes remaining in the lagoons was excavated and stored in a containment cell located on the nearby Champlain Sea clays. However, some of the organic wastes remained in place and was neither excavated nor incinerated. An estimated volume of 90,000 m³ of liquid organic chemical compounds (BAPE, 1994) remained in the Mercier Esker under the lagoons and in the underlying bedrock. In July 1982, the Quebec government enacted a regulation respecting the protection of ground water in the region of the town of Mercier (Q-2, r.18.1), in order to provide a framework for groundwater exploitation in the region. As a consequence, the town of Mercier abandoned a project to extract groundwater from the esker; and the municipality of Sainte-Martine, located to the south, had to stop pumping its wells and connect to a regional water line supplied by the wells of Chateauguay. In 1984, the Ministry of Environment (MENV) built three wells and a groundwater treatment plant. At that time, it was believed that the lagoons did not constitute a source of contamination and that a pump-and-treat system would allow full decontamination over a period of five years. In 1991, several years after the implementation of the pump-and-treat system, the levels of contaminants remained elevated and an investigation at the site of the former lagoons conducted by MENV led to the excavation of hundreds of barrels and several transformers, many still containing organic and chemical compounds. In 1992, MENV informed the Laidlaw Company that it would have to: (1) excavate all the contaminated soils and the contaminated residues located in the area of the former lagoons and (2) eliminate or treat in an authorized site or store in a safe place all the excavated contaminated soils and contaminated residues. However, MENV was not successful in persuading Laidlaw to decontaminate the site. Laidlaw still maintains today that the excavation of contaminated soils is useless because complete decontamination is impossible, due to the presence of heavy oils which have contaminated the deeper fractured aquifer. In 1993, a group of international experts (The Mercier Remediation Panel) mandated by Laidlaw, filed a report that concluded that it would be too risky to excavate the site where the lagoons were located. They proposed rather to confine them and ensure the maintenance of the hydraulic trap. One of the recommendations was to examine the feasibility of emplacing lateral containment walls. In 1994, another international expert committee mandated by MENV filed its own report and proposed to confine the lagoons (lateral walls and capping) as well as to carry out the research and development necessary to decontaminate in situ the site in order to minimize the concentrations of the current contamination. In 1994, MENV created a commission on the restoration of the Mercier contaminated site to study the proposed solutions and to hold public hearings on the question. In its report, the commission recognized the health risks related to excavation at the site, accepted the proposed solution by the expert committee of MENV and recommended the construction of containment walls and an impermeable covering as well as the immediate excavation of the uppermost part of the contaminated soils. It is now known that several organic chemical compounds in immiscible phase have migrated through the esker sands and gravels and reached the fractured aquifer through a window where the till is absent at the base of the esker. Elsewhere, the silts and compact till play the role of an aquiclude that has prevented these same compounds from percolating farther down. The compounds are DNAPLs and are very difficult to flush out of the fractures; furthermore they tend to degrade slowly into soluble and carcinogenic compounds that can then migrate with the groundwater flow. The distribution of contamination at the site of the old lagoons appears as follows: • The lagoons contain an unknown volume of organic chemical compounds in immiscible phase (heavy oils) which remain an important active source of contamination for the groundwater circulating in the sand and gravel aquifer. • Immiscible phase compounds also are present in the rock, at depth, and they constitute another active source of contamination for the groundwater that circulates in the rock aquifer which is used regionally. • Contaminated plumes of dissolved phase compounds resulting from the contact of groundwater with the active sources are present both in the esker and in the bedrock aquifer. Presently, the hydraulic containment system operated by the Ministère du Développement durable, de l'Environnement st des Pares provides efficient control of the contamination and prevents its migration. A publishing ban covers the technical documents surrounding this case since, on the legal side, the lawsuit between the government and the owner of the site is still not settled. 139
REFERENCES AND BIBLIOGRAPHY Bureau d’audience en environnement (BAPE). (1994). Restauration du site conatminé de Mercier. Rapport d’enquête et d’audience publique, Gouvernement du Québec. Prichonnet, G. (1977). La déglaciation de la vallée du Saint- Laurent et l’invasion marine contemporaine. Geographie physique et quaternaire 31, 323-345. Ross, M. (2005). Stratigraphie et architecture des formations quaternaires au nord-ouest de Montréal – applications en géologie régionale. INRS – Eau, Terre et Environnement, Québec. 140
Page 1 and 2:
AReportoftheGreatLakesScienceAdviso
Page 3 and 4:
Citation: Great Lakes Science Advis
Page 6:
Commissioners’ Preface The Great
Page 9 and 10:
2 required to monitor basin groundw
Page 11 and 12:
4 Systems have a 30-year lifespan d
Page 13 and 14:
6 Groundwater quality is routinely
Page 15 and 16:
8 Transmittal Letter Groundwater/An
Page 17 and 18:
10 Acknowledgements, Activities and
Page 19 and 20:
APPENDICES Appendices A through L p
Page 21 and 22:
INTRODUCTION Groundwater, a major n
Page 23 and 24:
16 DESCRIPTION OF NATURAL SYSTEMS M
Page 25 and 26:
that are not substantially affected
Page 27 and 28:
Estimates of the Level and Extent o
Page 29 and 30:
APPENDIX B Threats to Groundwater Q
Page 31 and 32:
24 PATHOGENS Bacteria, viruses and
Page 33 and 34:
Viruses Viral pathogens continue to
Page 35 and 36:
SPECIFIC EPISODES Walkerton In 2000
Page 37 and 38:
30 season. The sampling sites inclu
Page 39 and 40:
32 Curriero, F.C., Patz, J.A., Rose
Page 41 and 42:
Infection of a suitable host specie
Page 44 and 45:
APPENDIX C Threats to Groundwater Q
Page 46 and 47:
Road salt has significant toxic eff
Page 48 and 49:
converted to nitrite in the human s
Page 50 and 51:
Atrazine Atrazine is an extensively
Page 52 and 53:
Wisconsin DNR keeps track of about
Page 54 and 55:
Table 1. Chemical Contaminants in G
Page 56 and 57:
isks for 23 diseases in six contigu
Page 58 and 59:
Figure 1. Number* of waterborne-dis
Page 60 and 61:
Guidelines for Canadian Drinking Wa
Page 62 and 63:
APPENDIX D Threats to Groundwater Q
Page 64 and 65:
Figure 1. Source: General Descripti
Page 66 and 67:
(Gorman and Halvorsen, 2006). Any s
Page 68 and 69:
Table 3. Washtenaw County, Michigan
Page 70 and 71:
that the OWTS would last until it w
Page 72 and 73:
REFERENCES AND BIBLIOGRAPHY Aglie,
Page 74:
Septic Tanks - Septic Tank Articles
Page 77 and 78:
INTRODUCTION Leaking underground st
Page 79 and 80:
sites that were previously closed,
Page 81 and 82:
Table 1. USTs in Great Lakes States
Page 83 and 84:
Estimation of Costs for Remediation
Page 85 and 86:
Table 6. Operational Compliance of
Page 87 and 88:
80 Indiana Government. (2007, Febru
Page 89 and 90:
82 GLOSSARY AST - above ground stor
Page 91 and 92:
INTRODUCTION 84 Hazardous wastes ar
Page 93 and 94:
The town of Kincardine, Ontario, ha
Page 95 and 96: 88 • The monitoring and surveilla
Page 97 and 98: However, the U.S. EPA has been relu
Page 99 and 100: 92 Johnson, B.L. & DeRosa, C.T. (19
Page 101 and 102: PAHs - Polycyclic aromatic hydrocar
Page 103 and 104: INTRODUCTION An abandoned well is d
Page 105 and 106: Figure 6: Leaking oil well Source:
Page 107 and 108: CONTAMINANT SOURCES 100 During any
Page 109 and 110: Nearly 16 million operational water
Page 111 and 112: • Development of a targeted progr
Page 113 and 114: 106 Michigan Department of Environm
Page 115 and 116: APPENDIX H Threats to Groundwater Q
Page 117 and 118: far reaching. Road salt can inhibit
Page 119 and 120: 112 Desalinization Potential water
Page 121 and 122: Gray, J. (2004, January). Brine Spr
Page 123 and 124: INTRODUCTION 116 In 2003 there were
Page 125 and 126: 118 feed has increased to upwards o
Page 127 and 128: References and Bibliography 120 Arn
Page 129 and 130: APPENDIX J Threats to Groundwater Q
Page 131 and 132: for recreational purposes and destr
Page 133 and 134: 126 errors (human or mechanical), p
Page 135 and 136: Apparent Losses Old meters are like
Page 137 and 138: Figure 6. Examples of Windsor, Onta
Page 139 and 140: REFERENCES AND BIBLIOGRAPHY 132 Ada
Page 141 and 142: 134 Levy, S. (2004, November 16). T
Page 143 and 144: APPENDIX K The Châteauguay Transbo
Page 145: 138 the clay sediments of the St. L
Page 149 and 150: INTRODUCTION 142 Groundwater law ac
Page 151 and 152: 144 • Water withdrawn be returned
Page 153 and 154: 146 found to be failing. Now, with
Page 155 and 156: Part 373: Third Stage Treatment Lag
Page 157 and 158: 150 Chapter 1501:15 Soil and Water
Page 159 and 160: 152 Title 29 - Water Resources Mana
Page 161 and 162: APPENDIX M List of Acronyms ADHD -
show all

Groundwater in the Great Lakes Basin

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?