Groundwater in the Great Lakes Basin

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Table 3. Washtenaw County, Michigan, Time of Sale – Historical Comparisons. Year Number of Evaluations Percent Failure 2003 807 18 2002 881 20 Overall 3,451 17 Table 4. Wayne County, Michigan, Transfer Evaluation Summary, February 2000 - December 2003. Year Number of Evaluations Number of Failures 2000 108 22 20.37 2001 100 32 32.0 2002 121 31 25.6 2003 112 31 22.67 Total 441 116 26.30 Percent Failure Washtenaw County, Michigan, time-of-sale records reveal that of the 3,451 evaluations since 2000 17% of septic systems had failures of some type (Table 3). A Wayne County, Michigan, transfer evaluation summary from February 2000 to December 2003 shows that of 441 evaluations there were 116 failures (Table 4). The number of failures is increasing as the number of U.S. systems older than their 30-year life span continues to increase (Gorman, personal communication). Considering the large number of septic systems in the Great Lakes region, the potential for widespread groundwater contamination is immense. In some communities authorities are offering grants to upgrade septic systems. For example, the Essex Region Conservation Authority (ERCA) is offering grants of up to $5,000 (ERCA, 2008; “ERCA offers,” 2008). There are an estimated 12,000 faulty septic systems in the Essex County, Ontario, region (“Clean water,” 2006). In the nearby community of Lakeshore faulty septic tanks from 400 homes in the community are believed to be the main cause of water pollution contaminating Lake St. Clair (Rennie, 2006). Other undertakings include a $400,000 supplemental environmental project by Fort Wayne, Indiana, to eliminate failing septic systems (USEPA, 2007). FAILURE PREVENTION – REGULAR MAINTENANCE AND BACKWASH FLUSHING Careful landscaping of the soil absorption bed, awareness of inputs (e.g., wastes disposed in sinks, garbage disposals and toilets should be easy to break down) and regular pumping, maintenance and upgrades will prolong septic tank life (Septic Tanks, 2004; Veritec Consulting, 2004; Manitoba Conservation, 2006). A typical family will discharge enough material fibers or lint down the drain to carpet a living room every year. These fibers are a major cause of clogged pipes or plugged absorption bed soil, causing septic systems to fail (Septic Tanks, 2004). Garbage disposal systems are also extremely hard on septic systems (Rafter, 2005). To prevent failures, septic tank pumping frequency should be based on tank capacity and household size (Table 5). A study by Veritec Consulting (2004), commissioned by Manitoba Conservation (2006), was designed to provide information to assist homeowners installing septic fields to more appropriately size their absorption fields and to identify options to reduce wastewater load. Veritec concluded that reducing the flow of wastewater through the septic tank by installing water conserving fixtures (e.g., low-flush toilets and dual-flush technology, front-loading clothes washers and low-flow shower heads), spacing out water use throughout the day of week (i.e., avoid doing all laundry on one day) and keeping fixtures in good repair can help prolong septic life. See http://www.gov.mb.ca/ conservation/envprograms/wastewater/maintenance/ index.html. The reduction allowed time for solids to 61
Table 5. Septic Tank Pumping Frequency Based on Tank and Household Size. Source: The Groundwater Foundation, 2006. 62 settle out and lessened the chance of solid particles being carried over to the drain field. Less water in the drain field meant better aeration for the soil microbes at work in the system. Appropriate design, building, installation and maintenance are important to avoid system failure and vary depending on amount and characteristic of wastewater. For example, the wastewater generated by a restaurant has a typical biological oxygen demand (BOD) of 1,000 and a content of fats, oils and greases of 200 milligrams per liter. Comparatively, a typical household has a BOD of 200 and 20 milligrams per liter of fats, oils and greases (Vere, 2007). Predicting wastewater flow quantity also is extremely important. A number of studies have been conducted to help provide more accurate estimates (Stephens, 2007). Regular inspection and maintenance are essential to ensure a properly functioning system. It has been recommended that all systems be maintained by professional operators (Ip, Jowett and Laidman, 2004). Water softener backwash increases the amount of sodium relative to the amount of magnesium and calcium, or the sodium absorption ratio (SAR). Previous studies found that soils that are 15% clay swell and become less permeable when SAR exceeds 10. A study from the Canada Mortgage and Housing Corporation (CMHC) reports that even effluent with a SAR not greater than 10 can cause “hydraulic failure” due to the incapacity of the absorption bed to drain properly (CMHC, 2006). Clay content and age of the system were listed as the primary reasons for septic failure (CHMC, 2006). The impact of flushing water softener backwash on weeping tiles is also a concern (Crabbe, 2007). Although one study on the effect of water softener backwash discharge on tank performance indicated that it had no significant effect upon the biological or physical functioning of the septic tank, elevated chloride concentrations could accelerate corrosion of tanks (Kinsley, Crolla and Joy, 2005). Seventeen states have banned such flushing. All states in the Great Lakes Basin except Michigan have enacted such a ban. Another concern regarding water softener brine is that it may cause septic tanks to discharge greater amounts of solids, grease and oil into the dispersal field. This can result in plugging of the drainfield (Gross and Bounds, 2007). ON-SITE SYSTEM REGULATION A wave of OWTS codes was created in the 1970s by the Great Lakes jurisdictions (Gorman and Halvorsen, 2006). These permit systems were established to verify proper installation. In creating these codes, the regulatory authorities falsely assumed use of conventional septic systems, that the owners would take responsibility for pumping and maintaining their systems and
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AReportoftheGreatLakesScienceAdviso
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Citation: Great Lakes Science Advis
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Commissioners’ Preface The Great
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2 required to monitor basin groundw
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4 Systems have a 30-year lifespan d
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6 Groundwater quality is routinely
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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 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
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112 Desalinization Potential water
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Gray, J. (2004, January). Brine Spr
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INTRODUCTION 116 In 2003 there were
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118 feed has increased to upwards o
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References and Bibliography 120 Arn
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APPENDIX J Threats to Groundwater Q
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for recreational purposes and destr
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126 errors (human or mechanical), p
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Apparent Losses Old meters are like
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Figure 6. Examples of Windsor, Onta
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REFERENCES AND BIBLIOGRAPHY 132 Ada
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134 Levy, S. (2004, November 16). T
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APPENDIX K The Châteauguay Transbo
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138 the clay sediments of the St. L
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REFERENCES AND BIBLIOGRAPHY Bureau
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INTRODUCTION 142 Groundwater law ac
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144 • Water withdrawn be returned
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146 found to be failing. Now, with
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Part 373: Third Stage Treatment Lag
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150 Chapter 1501:15 Soil and Water
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152 Title 29 - Water Resources Mana
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APPENDIX M List of Acronyms ADHD -
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Groundwater in the Great Lakes Basin

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