Today 3 3 14 Introduction to groundwater hydrology Contaminant of the Week 4 Quiz 4 Groundwater Contamination Thursday 3 5 14 Contaminant Transport in Subsurface Contaminant of the Week 5 CEE 330 8 6 textbook and lecture notes Next Tuesday 3 10 14 Bioaccumulation and Remediation Contaminant of the Week 6 1 2 What source does ChampaignUrbana use for drinking water A B C D E Mississippi river Lake Michigan Mahomet aquifer Clinton aquifer None of the above 3 http www mahometaquiferconsortium org 4 How does groundwater move A Groundwater infiltrates through layers of sediments B Groundwater moves from high hydraulic head where recharge area is to low hydraulic head where the discharge area is C Groundwater is NOT connected with surface water D A and B E B and C Introduction to groundwater movie 5 6 1 Confined Unconfined Aquifers http igs indiana edu allenCounty waterTableElevation cfm Hydraulic gradient 7 Darcy s Law 8 Porosity Porosity volume of voids total volume of solids and voids Q KA dh dL Q KA dh dL K dh dL A A K hydraulic conductivity Darcy velocity v Material Darcy velocity v K dh dL actual velocity v Porosity h h 9 Two groundwater wells are located 100 m apart in permeable sand and gravel The water level in Well 1 is 50 m below the surface and in Well 2 the water level is 75 m below the surface The hydraulic conductivity is 1 m day and porosity is 0 6 What is Porosity Specific Yield Clay 45 3 Sand 34 25 Gravel 25 22 Gravel and sand 20 16 Sandstone 15 8 10 dh 75 50 m 0 25 dL 100m Q m m dh Darcy s velocity vDarcy K 1 0 25 0 25 A day day dL Hydraulic gradient 1 The Darcy s velocity A 0 025 m day B 25 m day C 0 25 m day D None of the above 11 12 2 Two groundwater wells are located 100 m apart in permeable sand and gravel The water level in Well 1 is 50 m below the surface and in Well 2 the water level is 75 m below the surface The hydraulic conductivity is 1 m day and porosity is 0 6 What is True velocity vtrue 1 The Darcy s velocity 2 The true velocity vDarcy m m day 0 42 0 6 day 0 25 A 0 042 m day B 42 m day C 0 42 m day D None of the above 13 Two groundwater wells are located 100 m apart in permeable sand and gravel The water level in Well 1 is 50 m below the surface and in Well 2 the water level is 75 m below the surface The hydraulic conductivity is 1 m day and porosity is 0 6 What is 1 The Darcy s velocity 2 The true velocity 3 The time it takes water to travel between two wells A 2 days B 238 days C 38 days D None of the above 14 Time L vtrue 100m 238days m 0 42 day 15 Groundwater level Vermilion County Illinois What is groundwater used for A B C D E 16 Groundwater level Cochise County Arizona Drinking water source Irrigation Bottled water The electronic industry All of the above 17 18 3 Dissolved Plume Introduction to groundwater movie Contamination 19 Light non aqueous phase liquid LNAPL http oceanworld tamu edu resources environment book groundwaterremediation html 20 Camp Lejeune Water Contamination 21 Dense non aqueous phase liquid DNAPL 22 A Civil Action Woburn Massachusetts True story about a hazardous waste site Chemical pollutant is trichloroethylene TCE Long history of chemical manufacturing and leather tanning http oceanworld tamu edu resources environment book groundwaterremediation html 23 24 4 Groundwater Contamination Day 2 CEE 330 8 6 textbook and lecture notes 25 26 Dr Norm Jones at Brigham Young University Why wouldn t we use the Darcy velocity for distance calculations Darcy s Experiments Discharge is Q KA dh dL Area Head difference Q KA dh dL Darcy velocity v K dh dL Darcy didn t do anyA experiments regarding velocity A K hydraulic conductivity actual velocity v Inversely proportional to Length Q z1 h h Q A 1 2 L h2 Sand column Datum plane z2 Q Q KA h2 h1 L Q KA Dh L Besides moving with groundwater what will happen to chemicals in the subsurface Darcy s Velocity Q KA dh dL Q KA dh dL K dh dL A A K hydraulic conductivity But the equation v Q A is only valid for open channel flow so Q velocity KA dh has dL no true Darcy velocity v cannot K dhbe dL this meaning and used to actual velocity v calculate distance orQtime KA dh hdL Porosity h Darcy velocity v K dh dL A for the Adifferences in porous media Area must be adjusted verses open channel K hydraulic conductivity Darcy velocity v A They can be degraded by bacteria B They can be degraded by reacting with other chemicals in the soil C They can sorb to the organic carbon fraction of the soil D All of the above E None of the above Darcy velocity v K dh dL Porosity h h This velocity can be used to calculate distance and time Note that this is the average velocity of the groundwater not the velocity through the pores P2 g v h1 K hydraulic conductivity 27 actual velocity v L Coefficient of proportionality is Darcy velocity v K dh dL Porosity h h hL P1 g A Proportional to Ar ea Look at Darcy s Law Note that the equation is for flow Q 29 30 5 CEE 330 Prizes Soil sorption coefficient Koc Groups with highest exam scores are 3 6 18 Group with best I clicker scores are 14 17 22 Soil carbon Koc water K Ctotalsoil K oc f oc Cw Ctotalsoil K oc f ocCw Cw Ctotalsoil K oc f oc 31 32 Contaminant transport in subsurface Contaminant transport in subsurface groundwater flow groundwater flow Contaminant source monitoring well Contaminant source monitoring well retarded plume sorption causes slower movement non retarded plume moving with groundwater flow 33 How much slower will the contaminant move groundwater flow monitoring well Contaminant source 34 A typical value of subsurface porosity is 0 3 and soil bulk mass density is 2 1g cm3 The subsurface materials fraction of organic carbon is 0 01 foc 0 01 Epiwin gives Koc for CTET 48 64 and Koc for PCE 106 8 Which contaminant moves slower retarded plume sorption causes slower movement Retardation factor R K f Average groundwater velocity v 1 oc oc B Average velocity of the sorbed chemical vs K oc Soil sorption coefficient A CTET B PCE K oc f oc r B h K oc Soil sorption coefficient f oc fraction of organic carbon in soil sediment h porosity r B density of soil sediment f oc fraction of organic carbon in soil sediment porosity B density of soil sediment Retardation factor R 1 35 36 6 A typical value of subsurface porosity is 0 3 and soil bulk mass …