diff --git a/dune/mmdg/problems/mmdgproblem1.hh b/dune/mmdg/problems/mmdgproblem1.hh
index f35a61ff999ac3eb073e87408dc67cf92c07a1b1..e1caa9b773a8869f508b410b0286097b6235eee2 100644
--- a/dune/mmdg/problems/mmdgproblem1.hh
+++ b/dune/mmdg/problems/mmdgproblem1.hh
@@ -37,14 +37,52 @@ public:
   //aperture d of the fracture at position pos
   Scalar aperture (const Coordinate& pos) const
   {
+    return d_ * (pos[1] + 0.01);
     return d_;
   }
 
+  //interface source term at position pos
+  Scalar qInterface (const Coordinate& pos) const
+  {
+    const Scalar de = aperture(pos);
+    const Scalar dPrime2 = gradAperture(pos) * gradAperture(pos);
+    const Scalar dPrimePrime = 0.0;
+
+    return (-de * dPrimePrime - dPrime2) * de;
+
+    return Scalar(0.0);
+  }
+
+  //tangential gradient of the aperture d of the fracture at position pos
+  Coordinate gradAperture (const Coordinate& pos) const
+  {
+   Coordinate gradD(0.0);
+   gradD[1] = d_;
+   return gradD;
+
+   return Coordinate(0.0);
+  }
+
+  //tangential permeability per aperture tensor of the interface at position pos
+  Matrix Kparallel (const Coordinate& pos) const
+  {
+    Matrix permeability(0.0);
+
+    for (int i = 0; i < dim; i++)
+    {
+      permeability[i][i] = 1.0 * aperture(pos);
+    }
+
+    //return identity matrix
+    return permeability;
+  }
+
+
   //returns the recommended quadrature order to compute an integral
   //over x * boundary(x)
   int quadratureOrderBoundary () const
   {
-    return 2;
+    return 10;//2;
   }
 
 private: