diff --git a/ebos/eclgenericthresholdpressure.hh b/ebos/eclgenericthresholdpressure.hh
index f5a64482c..4451ac74e 100644
--- a/ebos/eclgenericthresholdpressure.hh
+++ b/ebos/eclgenericthresholdpressure.hh
@@ -29,17 +29,23 @@
 #define EWOMS_ECL_GENERIC_THRESHOLD_PRESSURE_HH
 
 #include <opm/grid/common/CartesianIndexMapper.hpp>
+#include <opm/grid/LookUpData.hh>
+
 
 #include <vector>
 
 namespace Opm {
 
 class EclipseState;
+template<typename Grid, typename GridView> class LookUpData;
+template<typename Grid, typename GridView> class LookUpCartesianData;
 
 template<class Grid, class GridView, class ElementMapper, class Scalar>
 class EclGenericThresholdPressure {
 public:
     using CartesianIndexMapper = Dune::CartesianIndexMapper<Grid>;
+    using LookUpData = Opm::LookUpData<Grid,GridView>;
+    using LookUpCartesianData = Opm::LookUpCartesianData<Grid,GridView>;
 
     EclGenericThresholdPressure(const CartesianIndexMapper& cartMapper,
                                 const GridView& gridView,
@@ -93,6 +99,8 @@ protected:
     const CartesianIndexMapper& cartMapper_;
     const GridView& gridView_;
     const ElementMapper& elementMapper_;
+    const LookUpData lookUpData_;
+    const LookUpCartesianData lookUpCartesianData_;
     const EclipseState& eclState_;
     std::vector<Scalar> thpresDefault_;
     std::vector<Scalar> thpres_;
diff --git a/ebos/eclgenericthresholdpressure_impl.hh b/ebos/eclgenericthresholdpressure_impl.hh
index 16afaea1c..33d5d6d6f 100644
--- a/ebos/eclgenericthresholdpressure_impl.hh
+++ b/ebos/eclgenericthresholdpressure_impl.hh
@@ -55,6 +55,8 @@ EclGenericThresholdPressure(const CartesianIndexMapper& cartMapper,
     : cartMapper_(cartMapper)
     , gridView_(gridView)
     , elementMapper_(elementMapper)
+    , lookUpData_(gridView)
+    , lookUpCartesianData_(gridView, cartMapper_)
     , eclState_(eclState)
 {
 }
@@ -68,14 +70,10 @@ thresholdPressure(int elem1Idx, int elem2Idx) const
 
     // threshold pressure accross faults
     if (!thpresftValues_.empty()) {
-        int cartElem1Idx = cartMapper_.cartesianIndex(elem1Idx);
-        int cartElem2Idx = cartMapper_.cartesianIndex(elem2Idx);
 
-        assert(0 <= cartElem1Idx && static_cast<int>(cartElemFaultIdx_.size()) > cartElem1Idx);
-        assert(0 <= cartElem2Idx && static_cast<int>(cartElemFaultIdx_.size()) > cartElem2Idx);
+        int fault1Idx = lookUpCartesianData_(elem1Idx, cartElemFaultIdx_);
+        int fault2Idx = lookUpCartesianData_(elem2Idx, cartElemFaultIdx_);
 
-        int fault1Idx = cartElemFaultIdx_[cartElem1Idx];
-        int fault2Idx = cartElemFaultIdx_[cartElem2Idx];
         if (fault1Idx != -1 && fault1Idx == fault2Idx)
             // inside a fault there's no threshold pressure, even accross EQUIL
             // regions.
@@ -173,11 +171,9 @@ applyExplicitThresholdPressures_()
             const auto& inside = intersection.inside();
             const auto& outside = intersection.outside();
 
-            unsigned insideElemIdx = elementMapper_.index(inside);
-            unsigned outsideElemIdx = elementMapper_.index(outside);
+            auto equilRegionInside = lookUpData_(inside, elemEquilRegion_);
+            auto equilRegionOutside = lookUpData_(outside, elemEquilRegion_);
 
-            auto equilRegionInside = elemEquilRegion_[insideElemIdx];
-            auto equilRegionOutside = elemEquilRegion_[outsideElemIdx];
             if (thpres.hasRegionBarrier(equilRegionInside + 1, equilRegionOutside + 1)) {
                 Scalar pth = 0.0;
                 if (thpres.hasThresholdPressure(equilRegionInside + 1, equilRegionOutside + 1)) {