PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Problem Set # 4Remediation of a Leaking Landfill Site• 3 layers• MODFLOW’s River Package• transient flow• remediation designrivermunicipal water supply wellIn layer 3Objectives1. Determine the impacts of contamination from the leaking landfill (shown in light blue) at the river and the municipal well.2. Design a strategy to mitigate the effects of the contamination.Head Dependent Boundariesin MODFLOW• River Package• Drain Package• General Head Boundary (GHB) Package• ET PackageQ = C hReview from Geology 724River PackageQ = C (hR – hijk)where C = (Kv/m) L whR = head in the riverhijk is the head at thenode below the riverRiver PackageQ = C (hR – hijk)where C = (Kv/m) L whR = head in the riverhijk is the head at thenode below the riverTypically thewidth of theriver is smallerthan the widthof the grid cell.Length of the riverwithin each cellalso may vary.Areal view of the riverRBOTGaining River CellQ = C (hR – hijk)hijkwmRBOTLosing River CellQ = C (hR – hijk)RBOTLosing River CellQ = C (hR – hijk)RBOTPercolating River CellQ = C (hR – RBOT)DefinitionsRiverbed Conductance = (Kv/m) wLLeakance = Kv/mResistance = m/KvKv = vertical hydraulic conductivity of riverbed sedimentsm = thickness of riverbed sedimentsw = width of the riverL = length of the river within the cellRiver with sandy bottom = 1 daySmall stream with silty bottom = 1- 10 daysStream/lake in till = 100 daysResistanceIn PS4, we consider the alternative to “do nothing”as a remediation strategy. This is called “natural attenuation”.Recommended groundwater monitoring network fordemonstrating natural attenuation. Source: EPA circularInitialconditionsZheng &BennettIn Part 3A of PS4,We will use I.C.of the typeshown in Figure a.This is done in theinitial concentrationswindow of