diff --git a/examples/2pinfiltration/README.md b/examples/2pinfiltration/README.md
index 8c96a3244b799e804e2f366fc95486c44d85dce1..635b58dcf1ec4212258665eb12e239aef19078fa 100644
--- a/examples/2pinfiltration/README.md
+++ b/examples/2pinfiltration/README.md
@@ -10,8 +10,25 @@ Soil contamination problem where DNAPL infiltrates a fully water saturated mediu
 
 
 ## Infiltration (point source)
+### problem.hh
+The point sources are specified in the problem.hh file by the addPointSources method, in which you can add an arbitrary number of point sources to the vector of point sources.
+To instantiate a point source the position and the infiltration values are needed.
+For the definition of the PointSource class see dumux/common/pointsource.hh
+```C++
+void addPointSources(std::vector<PointSource>& pointSources) const
+{
+    // inject 0.1 kg/s of non-wetting phase at position (0.502, 3.02);
+    pointSources.push_back(PointSource({0.502, 3.02}, {0, 0.1}));
+}
+```
 
-
+### main.cc
+In the main.cc file the computePointSourceMap method deals with the point sources. It must be called during the initialisation (l. 97) and after each refinement of the mesh (ll. 135, 151 and 205).
+```C++
+problem->computePointSourceMap();
+```
+The computePointSourceMap method is inherited from the fvproblem and therefore specified in the dumux/common/fvproblem.hh.
+It calls the addPointSource method specified in the problem.hh file.
 
 ## Adaptive grid
 ### main.cc
diff --git a/examples/2pinfiltration/problem.hh b/examples/2pinfiltration/problem.hh
index 73d7c64ce02469efc05fb15a3eebb880063ca8fc..96a3ef7c748684c0cd5fae5010ddcc559d1b8c71 100644
--- a/examples/2pinfiltration/problem.hh
+++ b/examples/2pinfiltration/problem.hh
@@ -265,7 +265,7 @@ public:
      */
     void addPointSources(std::vector<PointSource>& pointSources) const
     {
-        // inject 2 kg/s of non-wetting phase at position (1, 1);
+        // inject 0.1 kg/s of non-wetting phase at position (0.502, 3.02);
         pointSources.push_back(PointSource({0.502, 3.02}, {0, 0.1}));
     }