diff --git a/src/pks/transport/constitutive_relations/sources/qc_relation_field_evaluator.cc b/src/pks/transport/constitutive_relations/sources/qc_relation_field_evaluator.cc
index 3c4785510..a738c31ed 100644
--- a/src/pks/transport/constitutive_relations/sources/qc_relation_field_evaluator.cc
+++ b/src/pks/transport/constitutive_relations/sources/qc_relation_field_evaluator.cc
@@ -76,7 +76,7 @@ QCRelationFieldEvaluator::Evaluate_(const State& S, const std::vector<CompositeV
 
       // return solute mass rate by multiplying with discharge (molC/s)
       // Here we assume the molar mass is 1. TODO: add molar mass to the function.
-      surf_src[0][c] = source_mass * field_flow * molar_den[0][c] / cv[0][c];
+      surf_src[0][c] = source_mass * field_flow / cv[0][c];
     }
   }
 }
diff --git a/src/pks/transport/constitutive_relations/sources/qc_relation_overland_evaluator.cc b/src/pks/transport/constitutive_relations/sources/qc_relation_overland_evaluator.cc
index a19176fc6..f86a5a4a6 100644
--- a/src/pks/transport/constitutive_relations/sources/qc_relation_overland_evaluator.cc
+++ b/src/pks/transport/constitutive_relations/sources/qc_relation_overland_evaluator.cc
@@ -85,7 +85,7 @@ QCRelationOverlandEvaluator::Evaluate_(const State& S, const std::vector<Composi
 
       // transport source (mass) as a function of discharge (e.g. overland)
       double source_transport = (*QC_curve_)(std::vector<double>{ total_flux_meter });
-      surf_src[0][c] = source_transport * total_flux_meter * molar_den[0][c] / cv[0][c];
+      surf_src[0][c] = source_transport * total_flux_meter / cv[0][c];
     }
   }
 }